/* * Copyright (c) 2016, Salvatore Sanfilippo * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * * Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * Neither the name of Redis nor the names of its contributors may be used * to endorse or promote products derived from this software without * specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include "server.h" #include "cluster.h" #include #define REDISMODULE_CORE 1 #include "redismodule.h" /* -------------------------------------------------------------------------- * Private data structures used by the modules system. Those are data * structures that are never exposed to Redis Modules, if not as void * pointers that have an API the module can call with them) * -------------------------------------------------------------------------- */ /* This structure represents a module inside the system. */ struct RedisModule { void *handle; /* Module dlopen() handle. */ char *name; /* Module name. */ int ver; /* Module version. We use just progressive integers. */ int apiver; /* Module API version as requested during initialization.*/ list *types; /* Module data types. */ }; typedef struct RedisModule RedisModule; static dict *modules; /* Hash table of modules. SDS -> RedisModule ptr.*/ /* Entries in the context->amqueue array, representing objects to free * when the callback returns. */ struct AutoMemEntry { void *ptr; int type; }; /* AutMemEntry type field values. */ #define REDISMODULE_AM_KEY 0 #define REDISMODULE_AM_STRING 1 #define REDISMODULE_AM_REPLY 2 #define REDISMODULE_AM_FREED 3 /* Explicitly freed by user already. */ /* The pool allocator block. Redis Modules can allocate memory via this special * allocator that will automatically release it all once the callback returns. * This means that it can only be used for ephemeral allocations. However * there are two advantages for modules to use this API: * * 1) The memory is automatically released when the callback returns. * 2) This allocator is faster for many small allocations since whole blocks * are allocated, and small pieces returned to the caller just advancing * the index of the allocation. * * Allocations are always rounded to the size of the void pointer in order * to always return aligned memory chunks. */ #define REDISMODULE_POOL_ALLOC_MIN_SIZE (1024*8) #define REDISMODULE_POOL_ALLOC_ALIGN (sizeof(void*)) typedef struct RedisModulePoolAllocBlock { uint32_t size; uint32_t used; struct RedisModulePoolAllocBlock *next; char memory[]; } RedisModulePoolAllocBlock; /* This structure represents the context in which Redis modules operate. * Most APIs module can access, get a pointer to the context, so that the API * implementation can hold state across calls, or remember what to free after * the call and so forth. * * Note that not all the context structure is always filled with actual values * but only the fields needed in a given context. */ struct RedisModuleBlockedClient; struct RedisModuleCtx { void *getapifuncptr; /* NOTE: Must be the first field. */ struct RedisModule *module; /* Module reference. */ client *client; /* Client calling a command. */ struct RedisModuleBlockedClient *blocked_client; /* Blocked client for thread safe context. */ struct AutoMemEntry *amqueue; /* Auto memory queue of objects to free. */ int amqueue_len; /* Number of slots in amqueue. */ int amqueue_used; /* Number of used slots in amqueue. */ int flags; /* REDISMODULE_CTX_... flags. */ void **postponed_arrays; /* To set with RM_ReplySetArrayLength(). */ int postponed_arrays_count; /* Number of entries in postponed_arrays. */ void *blocked_privdata; /* Privdata set when unblocking a client. */ /* Used if there is the REDISMODULE_CTX_KEYS_POS_REQUEST flag set. */ int *keys_pos; int keys_count; struct RedisModulePoolAllocBlock *pa_head; }; typedef struct RedisModuleCtx RedisModuleCtx; #define REDISMODULE_CTX_INIT {(void*)(unsigned long)&RM_GetApi, NULL, NULL, NULL, NULL, 0, 0, 0, NULL, 0, NULL, NULL, 0, NULL} #define REDISMODULE_CTX_MULTI_EMITTED (1<<0) #define REDISMODULE_CTX_AUTO_MEMORY (1<<1) #define REDISMODULE_CTX_KEYS_POS_REQUEST (1<<2) #define REDISMODULE_CTX_BLOCKED_REPLY (1<<3) #define REDISMODULE_CTX_BLOCKED_TIMEOUT (1<<4) #define REDISMODULE_CTX_THREAD_SAFE (1<<5) #define REDISMODULE_CTX_BLOCKED_DISCONNECTED (1<<6) /* This represents a Redis key opened with RM_OpenKey(). */ struct RedisModuleKey { RedisModuleCtx *ctx; redisDb *db; robj *key; /* Key name object. */ robj *value; /* Value object, or NULL if the key was not found. */ void *iter; /* Iterator. */ int mode; /* Opening mode. */ /* Zset iterator. */ uint32_t ztype; /* REDISMODULE_ZSET_RANGE_* */ zrangespec zrs; /* Score range. */ zlexrangespec zlrs; /* Lex range. */ uint32_t zstart; /* Start pos for positional ranges. */ uint32_t zend; /* End pos for positional ranges. */ void *zcurrent; /* Zset iterator current node. */ int zer; /* Zset iterator end reached flag (true if end was reached). */ }; typedef struct RedisModuleKey RedisModuleKey; /* RedisModuleKey 'ztype' values. */ #define REDISMODULE_ZSET_RANGE_NONE 0 /* This must always be 0. */ #define REDISMODULE_ZSET_RANGE_LEX 1 #define REDISMODULE_ZSET_RANGE_SCORE 2 #define REDISMODULE_ZSET_RANGE_POS 3 /* Function pointer type of a function representing a command inside * a Redis module. */ struct RedisModuleBlockedClient; typedef int (*RedisModuleCmdFunc) (RedisModuleCtx *ctx, void **argv, int argc); typedef void (*RedisModuleDisconnectFunc) (RedisModuleCtx *ctx, struct RedisModuleBlockedClient *bc); /* This struct holds the information about a command registered by a module.*/ struct RedisModuleCommandProxy { struct RedisModule *module; RedisModuleCmdFunc func; struct redisCommand *rediscmd; }; typedef struct RedisModuleCommandProxy RedisModuleCommandProxy; #define REDISMODULE_REPLYFLAG_NONE 0 #define REDISMODULE_REPLYFLAG_TOPARSE (1<<0) /* Protocol must be parsed. */ #define REDISMODULE_REPLYFLAG_NESTED (1<<1) /* Nested reply object. No proto or struct free. */ /* Reply of RM_Call() function. The function is filled in a lazy * way depending on the function called on the reply structure. By default * only the type, proto and protolen are filled. */ typedef struct RedisModuleCallReply { RedisModuleCtx *ctx; int type; /* REDISMODULE_REPLY_... */ int flags; /* REDISMODULE_REPLYFLAG_... */ size_t len; /* Len of strings or num of elements of arrays. */ char *proto; /* Raw reply protocol. An SDS string at top-level object. */ size_t protolen;/* Length of protocol. */ union { const char *str; /* String pointer for string and error replies. This does not need to be freed, always points inside a reply->proto buffer of the reply object or, in case of array elements, of parent reply objects. */ long long ll; /* Reply value for integer reply. */ struct RedisModuleCallReply *array; /* Array of sub-reply elements. */ } val; } RedisModuleCallReply; /* Structure representing a blocked client. We get a pointer to such * an object when blocking from modules. */ typedef struct RedisModuleBlockedClient { client *client; /* Pointer to the blocked client. or NULL if the client was destroyed during the life of this object. */ RedisModule *module; /* Module blocking the client. */ RedisModuleCmdFunc reply_callback; /* Reply callback on normal completion.*/ RedisModuleCmdFunc timeout_callback; /* Reply callback on timeout. */ RedisModuleDisconnectFunc disconnect_callback; /* Called on disconnection.*/ void (*free_privdata)(RedisModuleCtx*,void*);/* privdata cleanup callback.*/ void *privdata; /* Module private data that may be used by the reply or timeout callback. It is set via the RedisModule_UnblockClient() API. */ client *reply_client; /* Fake client used to accumulate replies in thread safe contexts. */ int dbid; /* Database number selected by the original client. */ } RedisModuleBlockedClient; static pthread_mutex_t moduleUnblockedClientsMutex = PTHREAD_MUTEX_INITIALIZER; static list *moduleUnblockedClients; /* We need a mutex that is unlocked / relocked in beforeSleep() in order to * allow thread safe contexts to execute commands at a safe moment. */ static pthread_mutex_t moduleGIL = PTHREAD_MUTEX_INITIALIZER; /* Function pointer type for keyspace event notification subscriptions from modules. */ typedef int (*RedisModuleNotificationFunc) (RedisModuleCtx *ctx, int type, const char *event, RedisModuleString *key); /* Keyspace notification subscriber information. * See RM_SubscribeToKeyspaceEvents() for more information. */ typedef struct RedisModuleKeyspaceSubscriber { /* The module subscribed to the event */ RedisModule *module; /* Notification callback in the module*/ RedisModuleNotificationFunc notify_callback; /* A bit mask of the events the module is interested in */ int event_mask; /* Active flag set on entry, to avoid reentrant subscribers * calling themselves */ int active; } RedisModuleKeyspaceSubscriber; /* The module keyspace notification subscribers list */ static list *moduleKeyspaceSubscribers; /* Static client recycled for all notification clients, to avoid allocating * per round. */ static client *moduleKeyspaceSubscribersClient; /* -------------------------------------------------------------------------- * Prototypes * -------------------------------------------------------------------------- */ void RM_FreeCallReply(RedisModuleCallReply *reply); void RM_CloseKey(RedisModuleKey *key); void autoMemoryCollect(RedisModuleCtx *ctx); robj **moduleCreateArgvFromUserFormat(const char *cmdname, const char *fmt, int *argcp, int *flags, va_list ap); void moduleReplicateMultiIfNeeded(RedisModuleCtx *ctx); void RM_ZsetRangeStop(RedisModuleKey *kp); static void zsetKeyReset(RedisModuleKey *key); /* -------------------------------------------------------------------------- * Heap allocation raw functions * -------------------------------------------------------------------------- */ /* Use like malloc(). Memory allocated with this function is reported in * Redis INFO memory, used for keys eviction according to maxmemory settings * and in general is taken into account as memory allocated by Redis. * You should avoid using malloc(). */ void *RM_Alloc(size_t bytes) { return zmalloc(bytes); } /* Use like calloc(). Memory allocated with this function is reported in * Redis INFO memory, used for keys eviction according to maxmemory settings * and in general is taken into account as memory allocated by Redis. * You should avoid using calloc() directly. */ void *RM_Calloc(size_t nmemb, size_t size) { return zcalloc(nmemb*size); } /* Use like realloc() for memory obtained with RedisModule_Alloc(). */ void* RM_Realloc(void *ptr, size_t bytes) { return zrealloc(ptr,bytes); } /* Use like free() for memory obtained by RedisModule_Alloc() and * RedisModule_Realloc(). However you should never try to free with * RedisModule_Free() memory allocated with malloc() inside your module. */ void RM_Free(void *ptr) { zfree(ptr); } /* Like strdup() but returns memory allocated with RedisModule_Alloc(). */ char *RM_Strdup(const char *str) { return zstrdup(str); } /* -------------------------------------------------------------------------- * Pool allocator * -------------------------------------------------------------------------- */ /* Release the chain of blocks used for pool allocations. */ void poolAllocRelease(RedisModuleCtx *ctx) { RedisModulePoolAllocBlock *head = ctx->pa_head, *next; while(head != NULL) { next = head->next; zfree(head); head = next; } ctx->pa_head = NULL; } /* Return heap allocated memory that will be freed automatically when the * module callback function returns. Mostly suitable for small allocations * that are short living and must be released when the callback returns * anyway. The returned memory is aligned to the architecture word size * if at least word size bytes are requested, otherwise it is just * aligned to the next power of two, so for example a 3 bytes request is * 4 bytes aligned while a 2 bytes request is 2 bytes aligned. * * There is no realloc style function since when this is needed to use the * pool allocator is not a good idea. * * The function returns NULL if `bytes` is 0. */ void *RM_PoolAlloc(RedisModuleCtx *ctx, size_t bytes) { if (bytes == 0) return NULL; RedisModulePoolAllocBlock *b = ctx->pa_head; size_t left = b ? b->size - b->used : 0; /* Fix alignment. */ if (left >= bytes) { size_t alignment = REDISMODULE_POOL_ALLOC_ALIGN; while (bytes < alignment && alignment/2 >= bytes) alignment /= 2; if (b->used % alignment) b->used += alignment - (b->used % alignment); left = (b->used > b->size) ? 0 : b->size - b->used; } /* Create a new block if needed. */ if (left < bytes) { size_t blocksize = REDISMODULE_POOL_ALLOC_MIN_SIZE; if (blocksize < bytes) blocksize = bytes; b = zmalloc(sizeof(*b) + blocksize); b->size = blocksize; b->used = 0; b->next = ctx->pa_head; ctx->pa_head = b; } char *retval = b->memory + b->used; b->used += bytes; return retval; } /* -------------------------------------------------------------------------- * Helpers for modules API implementation * -------------------------------------------------------------------------- */ /* Create an empty key of the specified type. 'kp' must point to a key object * opened for writing where the .value member is set to NULL because the * key was found to be non existing. * * On success REDISMODULE_OK is returned and the key is populated with * the value of the specified type. The function fails and returns * REDISMODULE_ERR if: * * 1) The key is not open for writing. * 2) The key is not empty. * 3) The specified type is unknown. */ int moduleCreateEmptyKey(RedisModuleKey *key, int type) { robj *obj; /* The key must be open for writing and non existing to proceed. */ if (!(key->mode & REDISMODULE_WRITE) || key->value) return REDISMODULE_ERR; switch(type) { case REDISMODULE_KEYTYPE_LIST: obj = createQuicklistObject(); quicklistSetOptions(obj->ptr, server.list_max_ziplist_size, server.list_compress_depth); break; case REDISMODULE_KEYTYPE_ZSET: obj = createZsetZiplistObject(); break; case REDISMODULE_KEYTYPE_HASH: obj = createHashObject(); break; default: return REDISMODULE_ERR; } dbAdd(key->db,key->key,obj); key->value = obj; return REDISMODULE_OK; } /* This function is called in low-level API implementation functions in order * to check if the value associated with the key remained empty after an * operation that removed elements from an aggregate data type. * * If this happens, the key is deleted from the DB and the key object state * is set to the right one in order to be targeted again by write operations * possibly recreating the key if needed. * * The function returns 1 if the key value object is found empty and is * deleted, otherwise 0 is returned. */ int moduleDelKeyIfEmpty(RedisModuleKey *key) { if (!(key->mode & REDISMODULE_WRITE) || key->value == NULL) return 0; int isempty; robj *o = key->value; switch(o->type) { case OBJ_LIST: isempty = listTypeLength(o) == 0; break; case OBJ_SET: isempty = setTypeSize(o) == 0; break; case OBJ_ZSET: isempty = zsetLength(o) == 0; break; case OBJ_HASH : isempty = hashTypeLength(o) == 0; break; default: isempty = 0; } if (isempty) { dbDelete(key->db,key->key); key->value = NULL; return 1; } else { return 0; } } /* -------------------------------------------------------------------------- * Service API exported to modules * * Note that all the exported APIs are called RM_ in the core * and RedisModule_ in the module side (defined as function * pointers in redismodule.h). In this way the dynamic linker does not * mess with our global function pointers, overriding it with the symbols * defined in the main executable having the same names. * -------------------------------------------------------------------------- */ /* Lookup the requested module API and store the function pointer into the * target pointer. The function returns REDISMODULE_ERR if there is no such * named API, otherwise REDISMODULE_OK. * * This function is not meant to be used by modules developer, it is only * used implicitly by including redismodule.h. */ int RM_GetApi(const char *funcname, void **targetPtrPtr) { dictEntry *he = dictFind(server.moduleapi, funcname); if (!he) return REDISMODULE_ERR; *targetPtrPtr = dictGetVal(he); return REDISMODULE_OK; } /* Free the context after the user function was called. */ void moduleFreeContext(RedisModuleCtx *ctx) { autoMemoryCollect(ctx); poolAllocRelease(ctx); if (ctx->postponed_arrays) { zfree(ctx->postponed_arrays); ctx->postponed_arrays_count = 0; serverLog(LL_WARNING, "API misuse detected in module %s: " "RedisModule_ReplyWithArray(REDISMODULE_POSTPONED_ARRAY_LEN) " "not matched by the same number of RedisModule_SetReplyArrayLen() " "calls.", ctx->module->name); } if (ctx->flags & REDISMODULE_CTX_THREAD_SAFE) freeClient(ctx->client); } /* Helper function for when a command callback is called, in order to handle * details needed to correctly replicate commands. */ void moduleHandlePropagationAfterCommandCallback(RedisModuleCtx *ctx) { client *c = ctx->client; if (c->flags & CLIENT_LUA) return; /* Handle the replication of the final EXEC, since whatever a command * emits is always wrappered around MULTI/EXEC. */ if (ctx->flags & REDISMODULE_CTX_MULTI_EMITTED) { robj *propargv[1]; propargv[0] = createStringObject("EXEC",4); alsoPropagate(server.execCommand,c->db->id,propargv,1, PROPAGATE_AOF|PROPAGATE_REPL); decrRefCount(propargv[0]); } } /* This Redis command binds the normal Redis command invocation with commands * exported by modules. */ void RedisModuleCommandDispatcher(client *c) { RedisModuleCommandProxy *cp = (void*)(unsigned long)c->cmd->getkeys_proc; RedisModuleCtx ctx = REDISMODULE_CTX_INIT; ctx.module = cp->module; ctx.client = c; cp->func(&ctx,(void**)c->argv,c->argc); moduleHandlePropagationAfterCommandCallback(&ctx); moduleFreeContext(&ctx); } /* This function returns the list of keys, with the same interface as the * 'getkeys' function of the native commands, for module commands that exported * the "getkeys-api" flag during the registration. This is done when the * list of keys are not at fixed positions, so that first/last/step cannot * be used. * * In order to accomplish its work, the module command is called, flagging * the context in a way that the command can recognize this is a special * "get keys" call by calling RedisModule_IsKeysPositionRequest(ctx). */ int *moduleGetCommandKeysViaAPI(struct redisCommand *cmd, robj **argv, int argc, int *numkeys) { RedisModuleCommandProxy *cp = (void*)(unsigned long)cmd->getkeys_proc; RedisModuleCtx ctx = REDISMODULE_CTX_INIT; ctx.module = cp->module; ctx.client = NULL; ctx.flags |= REDISMODULE_CTX_KEYS_POS_REQUEST; cp->func(&ctx,(void**)argv,argc); int *res = ctx.keys_pos; if (numkeys) *numkeys = ctx.keys_count; moduleFreeContext(&ctx); return res; } /* Return non-zero if a module command, that was declared with the * flag "getkeys-api", is called in a special way to get the keys positions * and not to get executed. Otherwise zero is returned. */ int RM_IsKeysPositionRequest(RedisModuleCtx *ctx) { return (ctx->flags & REDISMODULE_CTX_KEYS_POS_REQUEST) != 0; } /* When a module command is called in order to obtain the position of * keys, since it was flagged as "getkeys-api" during the registration, * the command implementation checks for this special call using the * RedisModule_IsKeysPositionRequest() API and uses this function in * order to report keys, like in the following example: * * if (RedisModule_IsKeysPositionRequest(ctx)) { * RedisModule_KeyAtPos(ctx,1); * RedisModule_KeyAtPos(ctx,2); * } * * Note: in the example below the get keys API would not be needed since * keys are at fixed positions. This interface is only used for commands * with a more complex structure. */ void RM_KeyAtPos(RedisModuleCtx *ctx, int pos) { if (!(ctx->flags & REDISMODULE_CTX_KEYS_POS_REQUEST)) return; if (pos <= 0) return; ctx->keys_pos = zrealloc(ctx->keys_pos,sizeof(int)*(ctx->keys_count+1)); ctx->keys_pos[ctx->keys_count++] = pos; } /* Helper for RM_CreateCommand(). Truns a string representing command * flags into the command flags used by the Redis core. * * It returns the set of flags, or -1 if unknown flags are found. */ int commandFlagsFromString(char *s) { int count, j; int flags = 0; sds *tokens = sdssplitlen(s,strlen(s)," ",1,&count); for (j = 0; j < count; j++) { char *t = tokens[j]; if (!strcasecmp(t,"write")) flags |= CMD_WRITE; else if (!strcasecmp(t,"readonly")) flags |= CMD_READONLY; else if (!strcasecmp(t,"admin")) flags |= CMD_ADMIN; else if (!strcasecmp(t,"deny-oom")) flags |= CMD_DENYOOM; else if (!strcasecmp(t,"deny-script")) flags |= CMD_NOSCRIPT; else if (!strcasecmp(t,"allow-loading")) flags |= CMD_LOADING; else if (!strcasecmp(t,"pubsub")) flags |= CMD_PUBSUB; else if (!strcasecmp(t,"random")) flags |= CMD_RANDOM; else if (!strcasecmp(t,"allow-stale")) flags |= CMD_STALE; else if (!strcasecmp(t,"no-monitor")) flags |= CMD_SKIP_MONITOR; else if (!strcasecmp(t,"fast")) flags |= CMD_FAST; else if (!strcasecmp(t,"getkeys-api")) flags |= CMD_MODULE_GETKEYS; else if (!strcasecmp(t,"no-cluster")) flags |= CMD_MODULE_NO_CLUSTER; else break; } sdsfreesplitres(tokens,count); if (j != count) return -1; /* Some token not processed correctly. */ return flags; } /* Register a new command in the Redis server, that will be handled by * calling the function pointer 'func' using the RedisModule calling * convention. The function returns REDISMODULE_ERR if the specified command * name is already busy or a set of invalid flags were passed, otherwise * REDISMODULE_OK is returned and the new command is registered. * * This function must be called during the initialization of the module * inside the RedisModule_OnLoad() function. Calling this function outside * of the initialization function is not defined. * * The command function type is the following: * * int MyCommand_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc); * * And is supposed to always return REDISMODULE_OK. * * The set of flags 'strflags' specify the behavior of the command, and should * be passed as a C string compoesd of space separated words, like for * example "write deny-oom". The set of flags are: * * * **"write"**: The command may modify the data set (it may also read * from it). * * **"readonly"**: The command returns data from keys but never writes. * * **"admin"**: The command is an administrative command (may change * replication or perform similar tasks). * * **"deny-oom"**: The command may use additional memory and should be * denied during out of memory conditions. * * **"deny-script"**: Don't allow this command in Lua scripts. * * **"allow-loading"**: Allow this command while the server is loading data. * Only commands not interacting with the data set * should be allowed to run in this mode. If not sure * don't use this flag. * * **"pubsub"**: The command publishes things on Pub/Sub channels. * * **"random"**: The command may have different outputs even starting * from the same input arguments and key values. * * **"allow-stale"**: The command is allowed to run on slaves that don't * serve stale data. Don't use if you don't know what * this means. * * **"no-monitor"**: Don't propoagate the command on monitor. Use this if * the command has sensible data among the arguments. * * **"fast"**: The command time complexity is not greater * than O(log(N)) where N is the size of the collection or * anything else representing the normal scalability * issue with the command. * * **"getkeys-api"**: The command implements the interface to return * the arguments that are keys. Used when start/stop/step * is not enough because of the command syntax. * * **"no-cluster"**: The command should not register in Redis Cluster * since is not designed to work with it because, for * example, is unable to report the position of the * keys, programmatically creates key names, or any * other reason. */ int RM_CreateCommand(RedisModuleCtx *ctx, const char *name, RedisModuleCmdFunc cmdfunc, const char *strflags, int firstkey, int lastkey, int keystep) { int flags = strflags ? commandFlagsFromString((char*)strflags) : 0; if (flags == -1) return REDISMODULE_ERR; if ((flags & CMD_MODULE_NO_CLUSTER) && server.cluster_enabled) return REDISMODULE_ERR; struct redisCommand *rediscmd; RedisModuleCommandProxy *cp; sds cmdname = sdsnew(name); /* Check if the command name is busy. */ if (lookupCommand(cmdname) != NULL) { sdsfree(cmdname); return REDISMODULE_ERR; } /* Create a command "proxy", which is a structure that is referenced * in the command table, so that the generic command that works as * binding between modules and Redis, can know what function to call * and what the module is. * * Note that we use the Redis command table 'getkeys_proc' in order to * pass a reference to the command proxy structure. */ cp = zmalloc(sizeof(*cp)); cp->module = ctx->module; cp->func = cmdfunc; cp->rediscmd = zmalloc(sizeof(*rediscmd)); cp->rediscmd->name = cmdname; cp->rediscmd->proc = RedisModuleCommandDispatcher; cp->rediscmd->arity = -1; cp->rediscmd->flags = flags | CMD_MODULE; cp->rediscmd->getkeys_proc = (redisGetKeysProc*)(unsigned long)cp; cp->rediscmd->firstkey = firstkey; cp->rediscmd->lastkey = lastkey; cp->rediscmd->keystep = keystep; cp->rediscmd->microseconds = 0; cp->rediscmd->calls = 0; dictAdd(server.commands,sdsdup(cmdname),cp->rediscmd); dictAdd(server.orig_commands,sdsdup(cmdname),cp->rediscmd); return REDISMODULE_OK; } /* Called by RM_Init() to setup the `ctx->module` structure. * * This is an internal function, Redis modules developers don't need * to use it. */ void RM_SetModuleAttribs(RedisModuleCtx *ctx, const char *name, int ver, int apiver) { RedisModule *module; if (ctx->module != NULL) return; module = zmalloc(sizeof(*module)); module->name = sdsnew((char*)name); module->ver = ver; module->apiver = apiver; module->types = listCreate(); ctx->module = module; } /* Return non-zero if the module name is busy. * Otherwise zero is returned. */ int RM_IsModuleNameBusy(const char *name) { sds modulename = sdsnew(name); dictEntry *de = dictFind(modules,modulename); sdsfree(modulename); return de != NULL; } /* Return the current UNIX time in milliseconds. */ long long RM_Milliseconds(void) { return mstime(); } /* -------------------------------------------------------------------------- * Automatic memory management for modules * -------------------------------------------------------------------------- */ /* Enable automatic memory management. See API.md for more information. * * The function must be called as the first function of a command implementation * that wants to use automatic memory. */ void RM_AutoMemory(RedisModuleCtx *ctx) { ctx->flags |= REDISMODULE_CTX_AUTO_MEMORY; } /* Add a new object to release automatically when the callback returns. */ void autoMemoryAdd(RedisModuleCtx *ctx, int type, void *ptr) { if (!(ctx->flags & REDISMODULE_CTX_AUTO_MEMORY)) return; if (ctx->amqueue_used == ctx->amqueue_len) { ctx->amqueue_len *= 2; if (ctx->amqueue_len < 16) ctx->amqueue_len = 16; ctx->amqueue = zrealloc(ctx->amqueue,sizeof(struct AutoMemEntry)*ctx->amqueue_len); } ctx->amqueue[ctx->amqueue_used].type = type; ctx->amqueue[ctx->amqueue_used].ptr = ptr; ctx->amqueue_used++; } /* Mark an object as freed in the auto release queue, so that users can still * free things manually if they want. * * The function returns 1 if the object was actually found in the auto memory * pool, otherwise 0 is returned. */ int autoMemoryFreed(RedisModuleCtx *ctx, int type, void *ptr) { if (!(ctx->flags & REDISMODULE_CTX_AUTO_MEMORY)) return 0; int count = (ctx->amqueue_used+1)/2; for (int j = 0; j < count; j++) { for (int side = 0; side < 2; side++) { /* For side = 0 check right side of the array, for * side = 1 check the left side instead (zig-zag scanning). */ int i = (side == 0) ? (ctx->amqueue_used - 1 - j) : j; if (ctx->amqueue[i].type == type && ctx->amqueue[i].ptr == ptr) { ctx->amqueue[i].type = REDISMODULE_AM_FREED; /* Switch the freed element and the last element, to avoid growing * the queue unnecessarily if we allocate/free in a loop */ if (i != ctx->amqueue_used-1) { ctx->amqueue[i] = ctx->amqueue[ctx->amqueue_used-1]; } /* Reduce the size of the queue because we either moved the top * element elsewhere or freed it */ ctx->amqueue_used--; return 1; } } } return 0; } /* Release all the objects in queue. */ void autoMemoryCollect(RedisModuleCtx *ctx) { if (!(ctx->flags & REDISMODULE_CTX_AUTO_MEMORY)) return; /* Clear the AUTO_MEMORY flag from the context, otherwise the functions * we call to free the resources, will try to scan the auto release * queue to mark the entries as freed. */ ctx->flags &= ~REDISMODULE_CTX_AUTO_MEMORY; int j; for (j = 0; j < ctx->amqueue_used; j++) { void *ptr = ctx->amqueue[j].ptr; switch(ctx->amqueue[j].type) { case REDISMODULE_AM_STRING: decrRefCount(ptr); break; case REDISMODULE_AM_REPLY: RM_FreeCallReply(ptr); break; case REDISMODULE_AM_KEY: RM_CloseKey(ptr); break; } } ctx->flags |= REDISMODULE_CTX_AUTO_MEMORY; zfree(ctx->amqueue); ctx->amqueue = NULL; ctx->amqueue_len = 0; ctx->amqueue_used = 0; } /* -------------------------------------------------------------------------- * String objects APIs * -------------------------------------------------------------------------- */ /* Create a new module string object. The returned string must be freed * with RedisModule_FreeString(), unless automatic memory is enabled. * * The string is created by copying the `len` bytes starting * at `ptr`. No reference is retained to the passed buffer. */ RedisModuleString *RM_CreateString(RedisModuleCtx *ctx, const char *ptr, size_t len) { RedisModuleString *o = createStringObject(ptr,len); autoMemoryAdd(ctx,REDISMODULE_AM_STRING,o); return o; } /* Create a new module string object from a printf format and arguments. * The returned string must be freed with RedisModule_FreeString(), unless * automatic memory is enabled. * * The string is created using the sds formatter function sdscatvprintf(). */ RedisModuleString *RM_CreateStringPrintf(RedisModuleCtx *ctx, const char *fmt, ...) { sds s = sdsempty(); va_list ap; va_start(ap, fmt); s = sdscatvprintf(s, fmt, ap); va_end(ap); RedisModuleString *o = createObject(OBJ_STRING, s); autoMemoryAdd(ctx,REDISMODULE_AM_STRING,o); return o; } /* Like RedisModule_CreatString(), but creates a string starting from a long long * integer instead of taking a buffer and its length. * * The returned string must be released with RedisModule_FreeString() or by * enabling automatic memory management. */ RedisModuleString *RM_CreateStringFromLongLong(RedisModuleCtx *ctx, long long ll) { char buf[LONG_STR_SIZE]; size_t len = ll2string(buf,sizeof(buf),ll); return RM_CreateString(ctx,buf,len); } /* Like RedisModule_CreatString(), but creates a string starting from another * RedisModuleString. * * The returned string must be released with RedisModule_FreeString() or by * enabling automatic memory management. */ RedisModuleString *RM_CreateStringFromString(RedisModuleCtx *ctx, const RedisModuleString *str) { RedisModuleString *o = dupStringObject(str); autoMemoryAdd(ctx,REDISMODULE_AM_STRING,o); return o; } /* Free a module string object obtained with one of the Redis modules API calls * that return new string objects. * * It is possible to call this function even when automatic memory management * is enabled. In that case the string will be released ASAP and removed * from the pool of string to release at the end. */ void RM_FreeString(RedisModuleCtx *ctx, RedisModuleString *str) { decrRefCount(str); autoMemoryFreed(ctx,REDISMODULE_AM_STRING,str); } /* Every call to this function, will make the string 'str' requiring * an additional call to RedisModule_FreeString() in order to really * free the string. Note that the automatic freeing of the string obtained * enabling modules automatic memory management counts for one * RedisModule_FreeString() call (it is just executed automatically). * * Normally you want to call this function when, at the same time * the following conditions are true: * * 1) You have automatic memory management enabled. * 2) You want to create string objects. * 3) Those string objects you create need to live *after* the callback * function(for example a command implementation) creating them returns. * * Usually you want this in order to store the created string object * into your own data structure, for example when implementing a new data * type. * * Note that when memory management is turned off, you don't need * any call to RetainString() since creating a string will always result * into a string that lives after the callback function returns, if * no FreeString() call is performed. */ void RM_RetainString(RedisModuleCtx *ctx, RedisModuleString *str) { if (!autoMemoryFreed(ctx,REDISMODULE_AM_STRING,str)) { /* Increment the string reference counting only if we can't * just remove the object from the list of objects that should * be reclaimed. Why we do that, instead of just incrementing * the refcount in any case, and let the automatic FreeString() * call at the end to bring the refcount back at the desired * value? Because this way we ensure that the object refcount * value is 1 (instead of going to 2 to be dropped later to 1) * after the call to this function. This is needed for functions * like RedisModule_StringAppendBuffer() to work. */ incrRefCount(str); } } /* Given a string module object, this function returns the string pointer * and length of the string. The returned pointer and length should only * be used for read only accesses and never modified. */ const char *RM_StringPtrLen(const RedisModuleString *str, size_t *len) { if (str == NULL) { const char *errmsg = "(NULL string reply referenced in module)"; if (len) *len = strlen(errmsg); return errmsg; } if (len) *len = sdslen(str->ptr); return str->ptr; } /* -------------------------------------------------------------------------- * Higher level string operations * ------------------------------------------------------------------------- */ /* Convert the string into a long long integer, storing it at `*ll`. * Returns REDISMODULE_OK on success. If the string can't be parsed * as a valid, strict long long (no spaces before/after), REDISMODULE_ERR * is returned. */ int RM_StringToLongLong(const RedisModuleString *str, long long *ll) { return string2ll(str->ptr,sdslen(str->ptr),ll) ? REDISMODULE_OK : REDISMODULE_ERR; } /* Convert the string into a double, storing it at `*d`. * Returns REDISMODULE_OK on success or REDISMODULE_ERR if the string is * not a valid string representation of a double value. */ int RM_StringToDouble(const RedisModuleString *str, double *d) { int retval = getDoubleFromObject(str,d); return (retval == C_OK) ? REDISMODULE_OK : REDISMODULE_ERR; } /* Compare two string objects, returning -1, 0 or 1 respectively if * a < b, a == b, a > b. Strings are compared byte by byte as two * binary blobs without any encoding care / collation attempt. */ int RM_StringCompare(RedisModuleString *a, RedisModuleString *b) { return compareStringObjects(a,b); } /* Return the (possibly modified in encoding) input 'str' object if * the string is unshared, otherwise NULL is returned. */ RedisModuleString *moduleAssertUnsharedString(RedisModuleString *str) { if (str->refcount != 1) { serverLog(LL_WARNING, "Module attempted to use an in-place string modify operation " "with a string referenced multiple times. Please check the code " "for API usage correctness."); return NULL; } if (str->encoding == OBJ_ENCODING_EMBSTR) { /* Note: here we "leak" the additional allocation that was * used in order to store the embedded string in the object. */ str->ptr = sdsnewlen(str->ptr,sdslen(str->ptr)); str->encoding = OBJ_ENCODING_RAW; } else if (str->encoding == OBJ_ENCODING_INT) { /* Convert the string from integer to raw encoding. */ str->ptr = sdsfromlonglong((long)str->ptr); str->encoding = OBJ_ENCODING_RAW; } return str; } /* Append the specified buffere to the string 'str'. The string must be a * string created by the user that is referenced only a single time, otherwise * REDISMODULE_ERR is returend and the operation is not performed. */ int RM_StringAppendBuffer(RedisModuleCtx *ctx, RedisModuleString *str, const char *buf, size_t len) { UNUSED(ctx); str = moduleAssertUnsharedString(str); if (str == NULL) return REDISMODULE_ERR; str->ptr = sdscatlen(str->ptr,buf,len); return REDISMODULE_OK; } /* -------------------------------------------------------------------------- * Reply APIs * * Most functions always return REDISMODULE_OK so you can use it with * 'return' in order to return from the command implementation with: * * if (... some condition ...) * return RM_ReplyWithLongLong(ctx,mycount); * -------------------------------------------------------------------------- */ /* Send an error about the number of arguments given to the command, * citing the command name in the error message. * * Example: * * if (argc != 3) return RedisModule_WrongArity(ctx); */ int RM_WrongArity(RedisModuleCtx *ctx) { addReplyErrorFormat(ctx->client, "wrong number of arguments for '%s' command", (char*)ctx->client->argv[0]->ptr); return REDISMODULE_OK; } /* Return the client object the `RM_Reply*` functions should target. * Normally this is just `ctx->client`, that is the client that called * the module command, however in the case of thread safe contexts there * is no directly associated client (since it would not be safe to access * the client from a thread), so instead the blocked client object referenced * in the thread safe context, has a fake client that we just use to accumulate * the replies. Later, when the client is unblocked, the accumulated replies * are appended to the actual client. * * The function returns the client pointer depending on the context, or * NULL if there is no potential client. This happens when we are in the * context of a thread safe context that was not initialized with a blocked * client object. Other contexts without associated clients are the ones * initialized to run the timers callbacks. */ client *moduleGetReplyClient(RedisModuleCtx *ctx) { if (ctx->flags & REDISMODULE_CTX_THREAD_SAFE) { if (ctx->blocked_client) return ctx->blocked_client->reply_client; else return NULL; } else { /* If this is a non thread safe context, just return the client * that is running the command if any. This may be NULL as well * in the case of contexts that are not executed with associated * clients, like timer contexts. */ return ctx->client; } } /* Send an integer reply to the client, with the specified long long value. * The function always returns REDISMODULE_OK. */ int RM_ReplyWithLongLong(RedisModuleCtx *ctx, long long ll) { client *c = moduleGetReplyClient(ctx); if (c == NULL) return REDISMODULE_OK; addReplyLongLong(c,ll); return REDISMODULE_OK; } /* Reply with an error or simple string (status message). Used to implement * ReplyWithSimpleString() and ReplyWithError(). * The function always returns REDISMODULE_OK. */ int replyWithStatus(RedisModuleCtx *ctx, const char *msg, char *prefix) { client *c = moduleGetReplyClient(ctx); if (c == NULL) return REDISMODULE_OK; sds strmsg = sdsnewlen(prefix,1); strmsg = sdscat(strmsg,msg); strmsg = sdscatlen(strmsg,"\r\n",2); addReplySds(c,strmsg); return REDISMODULE_OK; } /* Reply with the error 'err'. * * Note that 'err' must contain all the error, including * the initial error code. The function only provides the initial "-", so * the usage is, for example: * * RedisModule_ReplyWithError(ctx,"ERR Wrong Type"); * * and not just: * * RedisModule_ReplyWithError(ctx,"Wrong Type"); * * The function always returns REDISMODULE_OK. */ int RM_ReplyWithError(RedisModuleCtx *ctx, const char *err) { return replyWithStatus(ctx,err,"-"); } /* Reply with a simple string (+... \r\n in RESP protocol). This replies * are suitable only when sending a small non-binary string with small * overhead, like "OK" or similar replies. * * The function always returns REDISMODULE_OK. */ int RM_ReplyWithSimpleString(RedisModuleCtx *ctx, const char *msg) { return replyWithStatus(ctx,msg,"+"); } /* Reply with an array type of 'len' elements. However 'len' other calls * to `ReplyWith*` style functions must follow in order to emit the elements * of the array. * * When producing arrays with a number of element that is not known beforehand * the function can be called with the special count * REDISMODULE_POSTPONED_ARRAY_LEN, and the actual number of elements can be * later set with RedisModule_ReplySetArrayLength() (which will set the * latest "open" count if there are multiple ones). * * The function always returns REDISMODULE_OK. */ int RM_ReplyWithArray(RedisModuleCtx *ctx, long len) { client *c = moduleGetReplyClient(ctx); if (c == NULL) return REDISMODULE_OK; if (len == REDISMODULE_POSTPONED_ARRAY_LEN) { ctx->postponed_arrays = zrealloc(ctx->postponed_arrays,sizeof(void*)* (ctx->postponed_arrays_count+1)); ctx->postponed_arrays[ctx->postponed_arrays_count] = addDeferredMultiBulkLength(c); ctx->postponed_arrays_count++; } else { addReplyMultiBulkLen(c,len); } return REDISMODULE_OK; } /* When RedisModule_ReplyWithArray() is used with the argument * REDISMODULE_POSTPONED_ARRAY_LEN, because we don't know beforehand the number * of items we are going to output as elements of the array, this function * will take care to set the array length. * * Since it is possible to have multiple array replies pending with unknown * length, this function guarantees to always set the latest array length * that was created in a postponed way. * * For example in order to output an array like [1,[10,20,30]] we * could write: * * RedisModule_ReplyWithArray(ctx,REDISMODULE_POSTPONED_ARRAY_LEN); * RedisModule_ReplyWithLongLong(ctx,1); * RedisModule_ReplyWithArray(ctx,REDISMODULE_POSTPONED_ARRAY_LEN); * RedisModule_ReplyWithLongLong(ctx,10); * RedisModule_ReplyWithLongLong(ctx,20); * RedisModule_ReplyWithLongLong(ctx,30); * RedisModule_ReplySetArrayLength(ctx,3); // Set len of 10,20,30 array. * RedisModule_ReplySetArrayLength(ctx,2); // Set len of top array * * Note that in the above example there is no reason to postpone the array * length, since we produce a fixed number of elements, but in the practice * the code may use an interator or other ways of creating the output so * that is not easy to calculate in advance the number of elements. */ void RM_ReplySetArrayLength(RedisModuleCtx *ctx, long len) { client *c = moduleGetReplyClient(ctx); if (c == NULL) return; if (ctx->postponed_arrays_count == 0) { serverLog(LL_WARNING, "API misuse detected in module %s: " "RedisModule_ReplySetArrayLength() called without previous " "RedisModule_ReplyWithArray(ctx,REDISMODULE_POSTPONED_ARRAY_LEN) " "call.", ctx->module->name); return; } ctx->postponed_arrays_count--; setDeferredMultiBulkLength(c, ctx->postponed_arrays[ctx->postponed_arrays_count], len); if (ctx->postponed_arrays_count == 0) { zfree(ctx->postponed_arrays); ctx->postponed_arrays = NULL; } } /* Reply with a bulk string, taking in input a C buffer pointer and length. * * The function always returns REDISMODULE_OK. */ int RM_ReplyWithStringBuffer(RedisModuleCtx *ctx, const char *buf, size_t len) { client *c = moduleGetReplyClient(ctx); if (c == NULL) return REDISMODULE_OK; addReplyBulkCBuffer(c,(char*)buf,len); return REDISMODULE_OK; } /* Reply with a bulk string, taking in input a RedisModuleString object. * * The function always returns REDISMODULE_OK. */ int RM_ReplyWithString(RedisModuleCtx *ctx, RedisModuleString *str) { client *c = moduleGetReplyClient(ctx); if (c == NULL) return REDISMODULE_OK; addReplyBulk(c,str); return REDISMODULE_OK; } /* Reply to the client with a NULL. In the RESP protocol a NULL is encoded * as the string "$-1\r\n". * * The function always returns REDISMODULE_OK. */ int RM_ReplyWithNull(RedisModuleCtx *ctx) { client *c = moduleGetReplyClient(ctx); if (c == NULL) return REDISMODULE_OK; addReply(c,shared.nullbulk); return REDISMODULE_OK; } /* Reply exactly what a Redis command returned us with RedisModule_Call(). * This function is useful when we use RedisModule_Call() in order to * execute some command, as we want to reply to the client exactly the * same reply we obtained by the command. * * The function always returns REDISMODULE_OK. */ int RM_ReplyWithCallReply(RedisModuleCtx *ctx, RedisModuleCallReply *reply) { client *c = moduleGetReplyClient(ctx); if (c == NULL) return REDISMODULE_OK; sds proto = sdsnewlen(reply->proto, reply->protolen); addReplySds(c,proto); return REDISMODULE_OK; } /* Send a string reply obtained converting the double 'd' into a bulk string. * This function is basically equivalent to converting a double into * a string into a C buffer, and then calling the function * RedisModule_ReplyWithStringBuffer() with the buffer and length. * * The function always returns REDISMODULE_OK. */ int RM_ReplyWithDouble(RedisModuleCtx *ctx, double d) { client *c = moduleGetReplyClient(ctx); if (c == NULL) return REDISMODULE_OK; addReplyDouble(c,d); return REDISMODULE_OK; } /* -------------------------------------------------------------------------- * Commands replication API * -------------------------------------------------------------------------- */ /* Helper function to replicate MULTI the first time we replicate something * in the context of a command execution. EXEC will be handled by the * RedisModuleCommandDispatcher() function. */ void moduleReplicateMultiIfNeeded(RedisModuleCtx *ctx) { /* Skip this if client explicitly wrap the command with MULTI, or if * the module command was called by a script. */ if (ctx->client->flags & (CLIENT_MULTI|CLIENT_LUA)) return; /* If we already emitted MULTI return ASAP. */ if (ctx->flags & REDISMODULE_CTX_MULTI_EMITTED) return; /* If this is a thread safe context, we do not want to wrap commands * executed into MUTLI/EXEC, they are executed as single commands * from an external client in essence. */ if (ctx->flags & REDISMODULE_CTX_THREAD_SAFE) return; execCommandPropagateMulti(ctx->client); ctx->flags |= REDISMODULE_CTX_MULTI_EMITTED; } /* Replicate the specified command and arguments to slaves and AOF, as effect * of execution of the calling command implementation. * * The replicated commands are always wrapped into the MULTI/EXEC that * contains all the commands replicated in a given module command * execution. However the commands replicated with RedisModule_Call() * are the first items, the ones replicated with RedisModule_Replicate() * will all follow before the EXEC. * * Modules should try to use one interface or the other. * * This command follows exactly the same interface of RedisModule_Call(), * so a set of format specifiers must be passed, followed by arguments * matching the provided format specifiers. * * Please refer to RedisModule_Call() for more information. * * The command returns REDISMODULE_ERR if the format specifiers are invalid * or the command name does not belong to a known command. */ int RM_Replicate(RedisModuleCtx *ctx, const char *cmdname, const char *fmt, ...) { struct redisCommand *cmd; robj **argv = NULL; int argc = 0, flags = 0, j; va_list ap; cmd = lookupCommandByCString((char*)cmdname); if (!cmd) return REDISMODULE_ERR; /* Create the client and dispatch the command. */ va_start(ap, fmt); argv = moduleCreateArgvFromUserFormat(cmdname,fmt,&argc,&flags,ap); va_end(ap); if (argv == NULL) return REDISMODULE_ERR; /* Replicate! */ moduleReplicateMultiIfNeeded(ctx); alsoPropagate(cmd,ctx->client->db->id,argv,argc, PROPAGATE_AOF|PROPAGATE_REPL); /* Release the argv. */ for (j = 0; j < argc; j++) decrRefCount(argv[j]); zfree(argv); server.dirty++; return REDISMODULE_OK; } /* This function will replicate the command exactly as it was invoked * by the client. Note that this function will not wrap the command into * a MULTI/EXEC stanza, so it should not be mixed with other replication * commands. * * Basically this form of replication is useful when you want to propagate * the command to the slaves and AOF file exactly as it was called, since * the command can just be re-executed to deterministically re-create the * new state starting from the old one. * * The function always returns REDISMODULE_OK. */ int RM_ReplicateVerbatim(RedisModuleCtx *ctx) { alsoPropagate(ctx->client->cmd,ctx->client->db->id, ctx->client->argv,ctx->client->argc, PROPAGATE_AOF|PROPAGATE_REPL); server.dirty++; return REDISMODULE_OK; } /* -------------------------------------------------------------------------- * DB and Key APIs -- Generic API * -------------------------------------------------------------------------- */ /* Return the ID of the current client calling the currently active module * command. The returned ID has a few guarantees: * * 1. The ID is different for each different client, so if the same client * executes a module command multiple times, it can be recognized as * having the same ID, otherwise the ID will be different. * 2. The ID increases monotonically. Clients connecting to the server later * are guaranteed to get IDs greater than any past ID previously seen. * * Valid IDs are from 1 to 2^64-1. If 0 is returned it means there is no way * to fetch the ID in the context the function was currently called. */ unsigned long long RM_GetClientId(RedisModuleCtx *ctx) { if (ctx->client == NULL) return 0; return ctx->client->id; } /* Return the currently selected DB. */ int RM_GetSelectedDb(RedisModuleCtx *ctx) { return ctx->client->db->id; } /* Return the current context's flags. The flags provide information on the * current request context (whether the client is a Lua script or in a MULTI), * and about the Redis instance in general, i.e replication and persistence. * * The available flags are: * * * REDISMODULE_CTX_FLAGS_LUA: The command is running in a Lua script * * * REDISMODULE_CTX_FLAGS_MULTI: The command is running inside a transaction * * * REDISMODULE_CTX_FLAGS_MASTER: The Redis instance is a master * * * REDISMODULE_CTX_FLAGS_SLAVE: The Redis instance is a slave * * * REDISMODULE_CTX_FLAGS_READONLY: The Redis instance is read-only * * * REDISMODULE_CTX_FLAGS_CLUSTER: The Redis instance is in cluster mode * * * REDISMODULE_CTX_FLAGS_AOF: The Redis instance has AOF enabled * * * REDISMODULE_CTX_FLAGS_RDB: The instance has RDB enabled * * * REDISMODULE_CTX_FLAGS_MAXMEMORY: The instance has Maxmemory set * * * REDISMODULE_CTX_FLAGS_EVICT: Maxmemory is set and has an eviction * policy that may delete keys * * * REDISMODULE_CTX_FLAGS_OOM: Redis is out of memory according to the * maxmemory setting. * * * REDISMODULE_CTX_FLAGS_OOM_WARNING: Less than 25% of memory remains before * reaching the maxmemory level. */ int RM_GetContextFlags(RedisModuleCtx *ctx) { int flags = 0; /* Client specific flags */ if (ctx->client) { if (ctx->client->flags & CLIENT_LUA) flags |= REDISMODULE_CTX_FLAGS_LUA; if (ctx->client->flags & CLIENT_MULTI) flags |= REDISMODULE_CTX_FLAGS_MULTI; } if (server.cluster_enabled) flags |= REDISMODULE_CTX_FLAGS_CLUSTER; /* Maxmemory and eviction policy */ if (server.maxmemory > 0) { flags |= REDISMODULE_CTX_FLAGS_MAXMEMORY; if (server.maxmemory_policy != MAXMEMORY_NO_EVICTION) flags |= REDISMODULE_CTX_FLAGS_EVICT; } /* Persistence flags */ if (server.aof_state != AOF_OFF) flags |= REDISMODULE_CTX_FLAGS_AOF; if (server.saveparamslen > 0) flags |= REDISMODULE_CTX_FLAGS_RDB; /* Replication flags */ if (server.masterhost == NULL) { flags |= REDISMODULE_CTX_FLAGS_MASTER; } else { flags |= REDISMODULE_CTX_FLAGS_SLAVE; if (server.repl_slave_ro) flags |= REDISMODULE_CTX_FLAGS_READONLY; } /* OOM flag. */ float level; int retval = getMaxmemoryState(NULL,NULL,NULL,&level); if (retval == C_ERR) flags |= REDISMODULE_CTX_FLAGS_OOM; if (level > 0.75) flags |= REDISMODULE_CTX_FLAGS_OOM_WARNING; return flags; } /* Change the currently selected DB. Returns an error if the id * is out of range. * * Note that the client will retain the currently selected DB even after * the Redis command implemented by the module calling this function * returns. * * If the module command wishes to change something in a different DB and * returns back to the original one, it should call RedisModule_GetSelectedDb() * before in order to restore the old DB number before returning. */ int RM_SelectDb(RedisModuleCtx *ctx, int newid) { int retval = selectDb(ctx->client,newid); return (retval == C_OK) ? REDISMODULE_OK : REDISMODULE_ERR; } /* Return an handle representing a Redis key, so that it is possible * to call other APIs with the key handle as argument to perform * operations on the key. * * The return value is the handle repesenting the key, that must be * closed with RM_CloseKey(). * * If the key does not exist and WRITE mode is requested, the handle * is still returned, since it is possible to perform operations on * a yet not existing key (that will be created, for example, after * a list push operation). If the mode is just READ instead, and the * key does not exist, NULL is returned. However it is still safe to * call RedisModule_CloseKey() and RedisModule_KeyType() on a NULL * value. */ void *RM_OpenKey(RedisModuleCtx *ctx, robj *keyname, int mode) { RedisModuleKey *kp; robj *value; if (mode & REDISMODULE_WRITE) { value = lookupKeyWrite(ctx->client->db,keyname); } else { value = lookupKeyRead(ctx->client->db,keyname); if (value == NULL) { return NULL; } } /* Setup the key handle. */ kp = zmalloc(sizeof(*kp)); kp->ctx = ctx; kp->db = ctx->client->db; kp->key = keyname; incrRefCount(keyname); kp->value = value; kp->iter = NULL; kp->mode = mode; zsetKeyReset(kp); autoMemoryAdd(ctx,REDISMODULE_AM_KEY,kp); return (void*)kp; } /* Close a key handle. */ void RM_CloseKey(RedisModuleKey *key) { if (key == NULL) return; if (key->mode & REDISMODULE_WRITE) signalModifiedKey(key->db,key->key); /* TODO: if (key->iter) RM_KeyIteratorStop(kp); */ RM_ZsetRangeStop(key); decrRefCount(key->key); autoMemoryFreed(key->ctx,REDISMODULE_AM_KEY,key); zfree(key); } /* Return the type of the key. If the key pointer is NULL then * REDISMODULE_KEYTYPE_EMPTY is returned. */ int RM_KeyType(RedisModuleKey *key) { if (key == NULL || key->value == NULL) return REDISMODULE_KEYTYPE_EMPTY; /* We map between defines so that we are free to change the internal * defines as desired. */ switch(key->value->type) { case OBJ_STRING: return REDISMODULE_KEYTYPE_STRING; case OBJ_LIST: return REDISMODULE_KEYTYPE_LIST; case OBJ_SET: return REDISMODULE_KEYTYPE_SET; case OBJ_ZSET: return REDISMODULE_KEYTYPE_ZSET; case OBJ_HASH: return REDISMODULE_KEYTYPE_HASH; case OBJ_MODULE: return REDISMODULE_KEYTYPE_MODULE; default: return 0; } } /* Return the length of the value associated with the key. * For strings this is the length of the string. For all the other types * is the number of elements (just counting keys for hashes). * * If the key pointer is NULL or the key is empty, zero is returned. */ size_t RM_ValueLength(RedisModuleKey *key) { if (key == NULL || key->value == NULL) return 0; switch(key->value->type) { case OBJ_STRING: return stringObjectLen(key->value); case OBJ_LIST: return listTypeLength(key->value); case OBJ_SET: return setTypeSize(key->value); case OBJ_ZSET: return zsetLength(key->value); case OBJ_HASH: return hashTypeLength(key->value); default: return 0; } } /* If the key is open for writing, remove it, and setup the key to * accept new writes as an empty key (that will be created on demand). * On success REDISMODULE_OK is returned. If the key is not open for * writing REDISMODULE_ERR is returned. */ int RM_DeleteKey(RedisModuleKey *key) { if (!(key->mode & REDISMODULE_WRITE)) return REDISMODULE_ERR; if (key->value) { dbDelete(key->db,key->key); key->value = NULL; } return REDISMODULE_OK; } /* If the key is open for writing, unlink it (that is delete it in a * non-blocking way, not reclaiming memory immediately) and setup the key to * accept new writes as an empty key (that will be created on demand). * On success REDISMODULE_OK is returned. If the key is not open for * writing REDISMODULE_ERR is returned. */ int RM_UnlinkKey(RedisModuleKey *key) { if (!(key->mode & REDISMODULE_WRITE)) return REDISMODULE_ERR; if (key->value) { dbAsyncDelete(key->db,key->key); key->value = NULL; } return REDISMODULE_OK; } /* Return the key expire value, as milliseconds of remaining TTL. * If no TTL is associated with the key or if the key is empty, * REDISMODULE_NO_EXPIRE is returned. */ mstime_t RM_GetExpire(RedisModuleKey *key) { mstime_t expire = getExpire(key->db,key->key); if (expire == -1 || key->value == NULL) return -1; expire -= mstime(); return expire >= 0 ? expire : 0; } /* Set a new expire for the key. If the special expire * REDISMODULE_NO_EXPIRE is set, the expire is cancelled if there was * one (the same as the PERSIST command). * * Note that the expire must be provided as a positive integer representing * the number of milliseconds of TTL the key should have. * * The function returns REDISMODULE_OK on success or REDISMODULE_ERR if * the key was not open for writing or is an empty key. */ int RM_SetExpire(RedisModuleKey *key, mstime_t expire) { if (!(key->mode & REDISMODULE_WRITE) || key->value == NULL) return REDISMODULE_ERR; if (expire != REDISMODULE_NO_EXPIRE) { expire += mstime(); setExpire(key->ctx->client,key->db,key->key,expire); } else { removeExpire(key->db,key->key); } return REDISMODULE_OK; } /* -------------------------------------------------------------------------- * Key API for String type * -------------------------------------------------------------------------- */ /* If the key is open for writing, set the specified string 'str' as the * value of the key, deleting the old value if any. * On success REDISMODULE_OK is returned. If the key is not open for * writing or there is an active iterator, REDISMODULE_ERR is returned. */ int RM_StringSet(RedisModuleKey *key, RedisModuleString *str) { if (!(key->mode & REDISMODULE_WRITE) || key->iter) return REDISMODULE_ERR; RM_DeleteKey(key); setKey(key->db,key->key,str); key->value = str; return REDISMODULE_OK; } /* Prepare the key associated string value for DMA access, and returns * a pointer and size (by reference), that the user can use to read or * modify the string in-place accessing it directly via pointer. * * The 'mode' is composed by bitwise OR-ing the following flags: * * REDISMODULE_READ -- Read access * REDISMODULE_WRITE -- Write access * * If the DMA is not requested for writing, the pointer returned should * only be accessed in a read-only fashion. * * On error (wrong type) NULL is returned. * * DMA access rules: * * 1. No other key writing function should be called since the moment * the pointer is obtained, for all the time we want to use DMA access * to read or modify the string. * * 2. Each time RM_StringTruncate() is called, to continue with the DMA * access, RM_StringDMA() should be called again to re-obtain * a new pointer and length. * * 3. If the returned pointer is not NULL, but the length is zero, no * byte can be touched (the string is empty, or the key itself is empty) * so a RM_StringTruncate() call should be used if there is to enlarge * the string, and later call StringDMA() again to get the pointer. */ char *RM_StringDMA(RedisModuleKey *key, size_t *len, int mode) { /* We need to return *some* pointer for empty keys, we just return * a string literal pointer, that is the advantage to be mapped into * a read only memory page, so the module will segfault if a write * attempt is performed. */ char *emptystring = ""; if (key->value == NULL) { *len = 0; return emptystring; } if (key->value->type != OBJ_STRING) return NULL; /* For write access, and even for read access if the object is encoded, * we unshare the string (that has the side effect of decoding it). */ if ((mode & REDISMODULE_WRITE) || key->value->encoding != OBJ_ENCODING_RAW) key->value = dbUnshareStringValue(key->db, key->key, key->value); *len = sdslen(key->value->ptr); return key->value->ptr; } /* If the string is open for writing and is of string type, resize it, padding * with zero bytes if the new length is greater than the old one. * * After this call, RM_StringDMA() must be called again to continue * DMA access with the new pointer. * * The function returns REDISMODULE_OK on success, and REDISMODULE_ERR on * error, that is, the key is not open for writing, is not a string * or resizing for more than 512 MB is requested. * * If the key is empty, a string key is created with the new string value * unless the new length value requested is zero. */ int RM_StringTruncate(RedisModuleKey *key, size_t newlen) { if (!(key->mode & REDISMODULE_WRITE)) return REDISMODULE_ERR; if (key->value && key->value->type != OBJ_STRING) return REDISMODULE_ERR; if (newlen > 512*1024*1024) return REDISMODULE_ERR; /* Empty key and new len set to 0. Just return REDISMODULE_OK without * doing anything. */ if (key->value == NULL && newlen == 0) return REDISMODULE_OK; if (key->value == NULL) { /* Empty key: create it with the new size. */ robj *o = createObject(OBJ_STRING,sdsnewlen(NULL, newlen)); setKey(key->db,key->key,o); key->value = o; decrRefCount(o); } else { /* Unshare and resize. */ key->value = dbUnshareStringValue(key->db, key->key, key->value); size_t curlen = sdslen(key->value->ptr); if (newlen > curlen) { key->value->ptr = sdsgrowzero(key->value->ptr,newlen); } else if (newlen < curlen) { sdsrange(key->value->ptr,0,newlen-1); /* If the string is too wasteful, reallocate it. */ if (sdslen(key->value->ptr) < sdsavail(key->value->ptr)) key->value->ptr = sdsRemoveFreeSpace(key->value->ptr); } } return REDISMODULE_OK; } /* -------------------------------------------------------------------------- * Key API for List type * -------------------------------------------------------------------------- */ /* Push an element into a list, on head or tail depending on 'where' argumnet. * If the key pointer is about an empty key opened for writing, the key * is created. On error (key opened for read-only operations or of the wrong * type) REDISMODULE_ERR is returned, otherwise REDISMODULE_OK is returned. */ int RM_ListPush(RedisModuleKey *key, int where, RedisModuleString *ele) { if (!(key->mode & REDISMODULE_WRITE)) return REDISMODULE_ERR; if (key->value && key->value->type != OBJ_LIST) return REDISMODULE_ERR; if (key->value == NULL) moduleCreateEmptyKey(key,REDISMODULE_KEYTYPE_LIST); listTypePush(key->value, ele, (where == REDISMODULE_LIST_HEAD) ? QUICKLIST_HEAD : QUICKLIST_TAIL); return REDISMODULE_OK; } /* Pop an element from the list, and returns it as a module string object * that the user should be free with RM_FreeString() or by enabling * automatic memory. 'where' specifies if the element should be popped from * head or tail. The command returns NULL if: * 1) The list is empty. * 2) The key was not open for writing. * 3) The key is not a list. */ RedisModuleString *RM_ListPop(RedisModuleKey *key, int where) { if (!(key->mode & REDISMODULE_WRITE) || key->value == NULL || key->value->type != OBJ_LIST) return NULL; robj *ele = listTypePop(key->value, (where == REDISMODULE_LIST_HEAD) ? QUICKLIST_HEAD : QUICKLIST_TAIL); robj *decoded = getDecodedObject(ele); decrRefCount(ele); moduleDelKeyIfEmpty(key); autoMemoryAdd(key->ctx,REDISMODULE_AM_STRING,decoded); return decoded; } /* -------------------------------------------------------------------------- * Key API for Sorted Set type * -------------------------------------------------------------------------- */ /* Conversion from/to public flags of the Modules API and our private flags, * so that we have everything decoupled. */ int RM_ZsetAddFlagsToCoreFlags(int flags) { int retflags = 0; if (flags & REDISMODULE_ZADD_XX) retflags |= ZADD_XX; if (flags & REDISMODULE_ZADD_NX) retflags |= ZADD_NX; return retflags; } /* See previous function comment. */ int RM_ZsetAddFlagsFromCoreFlags(int flags) { int retflags = 0; if (flags & ZADD_ADDED) retflags |= REDISMODULE_ZADD_ADDED; if (flags & ZADD_UPDATED) retflags |= REDISMODULE_ZADD_UPDATED; if (flags & ZADD_NOP) retflags |= REDISMODULE_ZADD_NOP; return retflags; } /* Add a new element into a sorted set, with the specified 'score'. * If the element already exists, the score is updated. * * A new sorted set is created at value if the key is an empty open key * setup for writing. * * Additional flags can be passed to the function via a pointer, the flags * are both used to receive input and to communicate state when the function * returns. 'flagsptr' can be NULL if no special flags are used. * * The input flags are: * * REDISMODULE_ZADD_XX: Element must already exist. Do nothing otherwise. * REDISMODULE_ZADD_NX: Element must not exist. Do nothing otherwise. * * The output flags are: * * REDISMODULE_ZADD_ADDED: The new element was added to the sorted set. * REDISMODULE_ZADD_UPDATED: The score of the element was updated. * REDISMODULE_ZADD_NOP: No operation was performed because XX or NX flags. * * On success the function returns REDISMODULE_OK. On the following errors * REDISMODULE_ERR is returned: * * * The key was not opened for writing. * * The key is of the wrong type. * * 'score' double value is not a number (NaN). */ int RM_ZsetAdd(RedisModuleKey *key, double score, RedisModuleString *ele, int *flagsptr) { int flags = 0; if (!(key->mode & REDISMODULE_WRITE)) return REDISMODULE_ERR; if (key->value && key->value->type != OBJ_ZSET) return REDISMODULE_ERR; if (key->value == NULL) moduleCreateEmptyKey(key,REDISMODULE_KEYTYPE_ZSET); if (flagsptr) flags = RM_ZsetAddFlagsToCoreFlags(*flagsptr); if (zsetAdd(key->value,score,ele->ptr,&flags,NULL) == 0) { if (flagsptr) *flagsptr = 0; return REDISMODULE_ERR; } if (flagsptr) *flagsptr = RM_ZsetAddFlagsFromCoreFlags(flags); return REDISMODULE_OK; } /* This function works exactly like RM_ZsetAdd(), but instead of setting * a new score, the score of the existing element is incremented, or if the * element does not already exist, it is added assuming the old score was * zero. * * The input and output flags, and the return value, have the same exact * meaning, with the only difference that this function will return * REDISMODULE_ERR even when 'score' is a valid double number, but adding it * to the existing score resuts into a NaN (not a number) condition. * * This function has an additional field 'newscore', if not NULL is filled * with the new score of the element after the increment, if no error * is returned. */ int RM_ZsetIncrby(RedisModuleKey *key, double score, RedisModuleString *ele, int *flagsptr, double *newscore) { int flags = 0; if (!(key->mode & REDISMODULE_WRITE)) return REDISMODULE_ERR; if (key->value && key->value->type != OBJ_ZSET) return REDISMODULE_ERR; if (key->value == NULL) moduleCreateEmptyKey(key,REDISMODULE_KEYTYPE_ZSET); if (flagsptr) flags = RM_ZsetAddFlagsToCoreFlags(*flagsptr); flags |= ZADD_INCR; if (zsetAdd(key->value,score,ele->ptr,&flags,newscore) == 0) { if (flagsptr) *flagsptr = 0; return REDISMODULE_ERR; } /* zsetAdd() may signal back that the resulting score is not a number. */ if (flagsptr && (*flagsptr & ZADD_NAN)) { *flagsptr = 0; return REDISMODULE_ERR; } if (flagsptr) *flagsptr = RM_ZsetAddFlagsFromCoreFlags(flags); return REDISMODULE_OK; } /* Remove the specified element from the sorted set. * The function returns REDISMODULE_OK on success, and REDISMODULE_ERR * on one of the following conditions: * * * The key was not opened for writing. * * The key is of the wrong type. * * The return value does NOT indicate the fact the element was really * removed (since it existed) or not, just if the function was executed * with success. * * In order to know if the element was removed, the additional argument * 'deleted' must be passed, that populates the integer by reference * setting it to 1 or 0 depending on the outcome of the operation. * The 'deleted' argument can be NULL if the caller is not interested * to know if the element was really removed. * * Empty keys will be handled correctly by doing nothing. */ int RM_ZsetRem(RedisModuleKey *key, RedisModuleString *ele, int *deleted) { if (!(key->mode & REDISMODULE_WRITE)) return REDISMODULE_ERR; if (key->value && key->value->type != OBJ_ZSET) return REDISMODULE_ERR; if (key->value != NULL && zsetDel(key->value,ele->ptr)) { if (deleted) *deleted = 1; } else { if (deleted) *deleted = 0; } return REDISMODULE_OK; } /* On success retrieve the double score associated at the sorted set element * 'ele' and returns REDISMODULE_OK. Otherwise REDISMODULE_ERR is returned * to signal one of the following conditions: * * * There is no such element 'ele' in the sorted set. * * The key is not a sorted set. * * The key is an open empty key. */ int RM_ZsetScore(RedisModuleKey *key, RedisModuleString *ele, double *score) { if (key->value == NULL) return REDISMODULE_ERR; if (key->value->type != OBJ_ZSET) return REDISMODULE_ERR; if (zsetScore(key->value,ele->ptr,score) == C_ERR) return REDISMODULE_ERR; return REDISMODULE_OK; } /* -------------------------------------------------------------------------- * Key API for Sorted Set iterator * -------------------------------------------------------------------------- */ void zsetKeyReset(RedisModuleKey *key) { key->ztype = REDISMODULE_ZSET_RANGE_NONE; key->zcurrent = NULL; key->zer = 1; } /* Stop a sorted set iteration. */ void RM_ZsetRangeStop(RedisModuleKey *key) { /* Free resources if needed. */ if (key->ztype == REDISMODULE_ZSET_RANGE_LEX) zslFreeLexRange(&key->zlrs); /* Setup sensible values so that misused iteration API calls when an * iterator is not active will result into something more sensible * than crashing. */ zsetKeyReset(key); } /* Return the "End of range" flag value to signal the end of the iteration. */ int RM_ZsetRangeEndReached(RedisModuleKey *key) { return key->zer; } /* Helper function for RM_ZsetFirstInScoreRange() and RM_ZsetLastInScoreRange(). * Setup the sorted set iteration according to the specified score range * (see the functions calling it for more info). If 'first' is true the * first element in the range is used as a starting point for the iterator * otherwise the last. Return REDISMODULE_OK on success otherwise * REDISMODULE_ERR. */ int zsetInitScoreRange(RedisModuleKey *key, double min, double max, int minex, int maxex, int first) { if (!key->value || key->value->type != OBJ_ZSET) return REDISMODULE_ERR; RM_ZsetRangeStop(key); key->ztype = REDISMODULE_ZSET_RANGE_SCORE; key->zer = 0; /* Setup the range structure used by the sorted set core implementation * in order to seek at the specified element. */ zrangespec *zrs = &key->zrs; zrs->min = min; zrs->max = max; zrs->minex = minex; zrs->maxex = maxex; if (key->value->encoding == OBJ_ENCODING_ZIPLIST) { key->zcurrent = first ? zzlFirstInRange(key->value->ptr,zrs) : zzlLastInRange(key->value->ptr,zrs); } else if (key->value->encoding == OBJ_ENCODING_SKIPLIST) { zset *zs = key->value->ptr; zskiplist *zsl = zs->zsl; key->zcurrent = first ? zslFirstInRange(zsl,zrs) : zslLastInRange(zsl,zrs); } else { serverPanic("Unsupported zset encoding"); } if (key->zcurrent == NULL) key->zer = 1; return REDISMODULE_OK; } /* Setup a sorted set iterator seeking the first element in the specified * range. Returns REDISMODULE_OK if the iterator was correctly initialized * otherwise REDISMODULE_ERR is returned in the following conditions: * * 1. The value stored at key is not a sorted set or the key is empty. * * The range is specified according to the two double values 'min' and 'max'. * Both can be infinite using the following two macros: * * REDISMODULE_POSITIVE_INFINITE for positive infinite value * REDISMODULE_NEGATIVE_INFINITE for negative infinite value * * 'minex' and 'maxex' parameters, if true, respectively setup a range * where the min and max value are exclusive (not included) instead of * inclusive. */ int RM_ZsetFirstInScoreRange(RedisModuleKey *key, double min, double max, int minex, int maxex) { return zsetInitScoreRange(key,min,max,minex,maxex,1); } /* Exactly like RedisModule_ZsetFirstInScoreRange() but the last element of * the range is selected for the start of the iteration instead. */ int RM_ZsetLastInScoreRange(RedisModuleKey *key, double min, double max, int minex, int maxex) { return zsetInitScoreRange(key,min,max,minex,maxex,0); } /* Helper function for RM_ZsetFirstInLexRange() and RM_ZsetLastInLexRange(). * Setup the sorted set iteration according to the specified lexicographical * range (see the functions calling it for more info). If 'first' is true the * first element in the range is used as a starting point for the iterator * otherwise the last. Return REDISMODULE_OK on success otherwise * REDISMODULE_ERR. * * Note that this function takes 'min' and 'max' in the same form of the * Redis ZRANGEBYLEX command. */ int zsetInitLexRange(RedisModuleKey *key, RedisModuleString *min, RedisModuleString *max, int first) { if (!key->value || key->value->type != OBJ_ZSET) return REDISMODULE_ERR; RM_ZsetRangeStop(key); key->zer = 0; /* Setup the range structure used by the sorted set core implementation * in order to seek at the specified element. */ zlexrangespec *zlrs = &key->zlrs; if (zslParseLexRange(min, max, zlrs) == C_ERR) return REDISMODULE_ERR; /* Set the range type to lex only after successfully parsing the range, * otherwise we don't want the zlexrangespec to be freed. */ key->ztype = REDISMODULE_ZSET_RANGE_LEX; if (key->value->encoding == OBJ_ENCODING_ZIPLIST) { key->zcurrent = first ? zzlFirstInLexRange(key->value->ptr,zlrs) : zzlLastInLexRange(key->value->ptr,zlrs); } else if (key->value->encoding == OBJ_ENCODING_SKIPLIST) { zset *zs = key->value->ptr; zskiplist *zsl = zs->zsl; key->zcurrent = first ? zslFirstInLexRange(zsl,zlrs) : zslLastInLexRange(zsl,zlrs); } else { serverPanic("Unsupported zset encoding"); } if (key->zcurrent == NULL) key->zer = 1; return REDISMODULE_OK; } /* Setup a sorted set iterator seeking the first element in the specified * lexicographical range. Returns REDISMODULE_OK if the iterator was correctly * initialized otherwise REDISMODULE_ERR is returned in the * following conditions: * * 1. The value stored at key is not a sorted set or the key is empty. * 2. The lexicographical range 'min' and 'max' format is invalid. * * 'min' and 'max' should be provided as two RedisModuleString objects * in the same format as the parameters passed to the ZRANGEBYLEX command. * The function does not take ownership of the objects, so they can be released * ASAP after the iterator is setup. */ int RM_ZsetFirstInLexRange(RedisModuleKey *key, RedisModuleString *min, RedisModuleString *max) { return zsetInitLexRange(key,min,max,1); } /* Exactly like RedisModule_ZsetFirstInLexRange() but the last element of * the range is selected for the start of the iteration instead. */ int RM_ZsetLastInLexRange(RedisModuleKey *key, RedisModuleString *min, RedisModuleString *max) { return zsetInitLexRange(key,min,max,0); } /* Return the current sorted set element of an active sorted set iterator * or NULL if the range specified in the iterator does not include any * element. */ RedisModuleString *RM_ZsetRangeCurrentElement(RedisModuleKey *key, double *score) { RedisModuleString *str; if (key->zcurrent == NULL) return NULL; if (key->value->encoding == OBJ_ENCODING_ZIPLIST) { unsigned char *eptr, *sptr; eptr = key->zcurrent; sds ele = ziplistGetObject(eptr); if (score) { sptr = ziplistNext(key->value->ptr,eptr); *score = zzlGetScore(sptr); } str = createObject(OBJ_STRING,ele); } else if (key->value->encoding == OBJ_ENCODING_SKIPLIST) { zskiplistNode *ln = key->zcurrent; if (score) *score = ln->score; str = createStringObject(ln->ele,sdslen(ln->ele)); } else { serverPanic("Unsupported zset encoding"); } autoMemoryAdd(key->ctx,REDISMODULE_AM_STRING,str); return str; } /* Go to the next element of the sorted set iterator. Returns 1 if there was * a next element, 0 if we are already at the latest element or the range * does not include any item at all. */ int RM_ZsetRangeNext(RedisModuleKey *key) { if (!key->ztype || !key->zcurrent) return 0; /* No active iterator. */ if (key->value->encoding == OBJ_ENCODING_ZIPLIST) { unsigned char *zl = key->value->ptr; unsigned char *eptr = key->zcurrent; unsigned char *next; next = ziplistNext(zl,eptr); /* Skip element. */ if (next) next = ziplistNext(zl,next); /* Skip score. */ if (next == NULL) { key->zer = 1; return 0; } else { /* Are we still within the range? */ if (key->ztype == REDISMODULE_ZSET_RANGE_SCORE) { /* Fetch the next element score for the * range check. */ unsigned char *saved_next = next; next = ziplistNext(zl,next); /* Skip next element. */ double score = zzlGetScore(next); /* Obtain the next score. */ if (!zslValueLteMax(score,&key->zrs)) { key->zer = 1; return 0; } next = saved_next; } else if (key->ztype == REDISMODULE_ZSET_RANGE_LEX) { if (!zzlLexValueLteMax(next,&key->zlrs)) { key->zer = 1; return 0; } } key->zcurrent = next; return 1; } } else if (key->value->encoding == OBJ_ENCODING_SKIPLIST) { zskiplistNode *ln = key->zcurrent, *next = ln->level[0].forward; if (next == NULL) { key->zer = 1; return 0; } else { /* Are we still within the range? */ if (key->ztype == REDISMODULE_ZSET_RANGE_SCORE && !zslValueLteMax(next->score,&key->zrs)) { key->zer = 1; return 0; } else if (key->ztype == REDISMODULE_ZSET_RANGE_LEX) { if (!zslLexValueLteMax(next->ele,&key->zlrs)) { key->zer = 1; return 0; } } key->zcurrent = next; return 1; } } else { serverPanic("Unsupported zset encoding"); } } /* Go to the previous element of the sorted set iterator. Returns 1 if there was * a previous element, 0 if we are already at the first element or the range * does not include any item at all. */ int RM_ZsetRangePrev(RedisModuleKey *key) { if (!key->ztype || !key->zcurrent) return 0; /* No active iterator. */ if (key->value->encoding == OBJ_ENCODING_ZIPLIST) { unsigned char *zl = key->value->ptr; unsigned char *eptr = key->zcurrent; unsigned char *prev; prev = ziplistPrev(zl,eptr); /* Go back to previous score. */ if (prev) prev = ziplistPrev(zl,prev); /* Back to previous ele. */ if (prev == NULL) { key->zer = 1; return 0; } else { /* Are we still within the range? */ if (key->ztype == REDISMODULE_ZSET_RANGE_SCORE) { /* Fetch the previous element score for the * range check. */ unsigned char *saved_prev = prev; prev = ziplistNext(zl,prev); /* Skip element to get the score.*/ double score = zzlGetScore(prev); /* Obtain the prev score. */ if (!zslValueGteMin(score,&key->zrs)) { key->zer = 1; return 0; } prev = saved_prev; } else if (key->ztype == REDISMODULE_ZSET_RANGE_LEX) { if (!zzlLexValueGteMin(prev,&key->zlrs)) { key->zer = 1; return 0; } } key->zcurrent = prev; return 1; } } else if (key->value->encoding == OBJ_ENCODING_SKIPLIST) { zskiplistNode *ln = key->zcurrent, *prev = ln->backward; if (prev == NULL) { key->zer = 1; return 0; } else { /* Are we still within the range? */ if (key->ztype == REDISMODULE_ZSET_RANGE_SCORE && !zslValueGteMin(prev->score,&key->zrs)) { key->zer = 1; return 0; } else if (key->ztype == REDISMODULE_ZSET_RANGE_LEX) { if (!zslLexValueGteMin(prev->ele,&key->zlrs)) { key->zer = 1; return 0; } } key->zcurrent = prev; return 1; } } else { serverPanic("Unsupported zset encoding"); } } /* -------------------------------------------------------------------------- * Key API for Hash type * -------------------------------------------------------------------------- */ /* Set the field of the specified hash field to the specified value. * If the key is an empty key open for writing, it is created with an empty * hash value, in order to set the specified field. * * The function is variadic and the user must specify pairs of field * names and values, both as RedisModuleString pointers (unless the * CFIELD option is set, see later). * * Example to set the hash argv[1] to the value argv[2]: * * RedisModule_HashSet(key,REDISMODULE_HASH_NONE,argv[1],argv[2],NULL); * * The function can also be used in order to delete fields (if they exist) * by setting them to the specified value of REDISMODULE_HASH_DELETE: * * RedisModule_HashSet(key,REDISMODULE_HASH_NONE,argv[1], * REDISMODULE_HASH_DELETE,NULL); * * The behavior of the command changes with the specified flags, that can be * set to REDISMODULE_HASH_NONE if no special behavior is needed. * * REDISMODULE_HASH_NX: The operation is performed only if the field was not * already existing in the hash. * REDISMODULE_HASH_XX: The operation is performed only if the field was * already existing, so that a new value could be * associated to an existing filed, but no new fields * are created. * REDISMODULE_HASH_CFIELDS: The field names passed are null terminated C * strings instead of RedisModuleString objects. * * Unless NX is specified, the command overwrites the old field value with * the new one. * * When using REDISMODULE_HASH_CFIELDS, field names are reported using * normal C strings, so for example to delete the field "foo" the following * code can be used: * * RedisModule_HashSet(key,REDISMODULE_HASH_CFIELDS,"foo", * REDISMODULE_HASH_DELETE,NULL); * * Return value: * * The number of fields updated (that may be less than the number of fields * specified because of the XX or NX options). * * In the following case the return value is always zero: * * * The key was not open for writing. * * The key was associated with a non Hash value. */ int RM_HashSet(RedisModuleKey *key, int flags, ...) { va_list ap; if (!(key->mode & REDISMODULE_WRITE)) return 0; if (key->value && key->value->type != OBJ_HASH) return 0; if (key->value == NULL) moduleCreateEmptyKey(key,REDISMODULE_KEYTYPE_HASH); int updated = 0; va_start(ap, flags); while(1) { RedisModuleString *field, *value; /* Get the field and value objects. */ if (flags & REDISMODULE_HASH_CFIELDS) { char *cfield = va_arg(ap,char*); if (cfield == NULL) break; field = createRawStringObject(cfield,strlen(cfield)); } else { field = va_arg(ap,RedisModuleString*); if (field == NULL) break; } value = va_arg(ap,RedisModuleString*); /* Handle XX and NX */ if (flags & (REDISMODULE_HASH_XX|REDISMODULE_HASH_NX)) { int exists = hashTypeExists(key->value, field->ptr); if (((flags & REDISMODULE_HASH_XX) && !exists) || ((flags & REDISMODULE_HASH_NX) && exists)) { if (flags & REDISMODULE_HASH_CFIELDS) decrRefCount(field); continue; } } /* Handle deletion if value is REDISMODULE_HASH_DELETE. */ if (value == REDISMODULE_HASH_DELETE) { updated += hashTypeDelete(key->value, field->ptr); if (flags & REDISMODULE_HASH_CFIELDS) decrRefCount(field); continue; } int low_flags = HASH_SET_COPY; /* If CFIELDS is active, we can pass the ownership of the * SDS object to the low level function that sets the field * to avoid a useless copy. */ if (flags & REDISMODULE_HASH_CFIELDS) low_flags |= HASH_SET_TAKE_FIELD; updated += hashTypeSet(key->value, field->ptr, value->ptr, low_flags); /* If CFIELDS is active, SDS string ownership is now of hashTypeSet(), * however we still have to release the 'field' object shell. */ if (flags & REDISMODULE_HASH_CFIELDS) { field->ptr = NULL; /* Prevent the SDS string from being freed. */ decrRefCount(field); } } va_end(ap); moduleDelKeyIfEmpty(key); return updated; } /* Get fields from an hash value. This function is called using a variable * number of arguments, alternating a field name (as a StringRedisModule * pointer) with a pointer to a StringRedisModule pointer, that is set to the * value of the field if the field exist, or NULL if the field did not exist. * At the end of the field/value-ptr pairs, NULL must be specified as last * argument to signal the end of the arguments in the variadic function. * * This is an example usage: * * RedisModuleString *first, *second; * RedisModule_HashGet(mykey,REDISMODULE_HASH_NONE,argv[1],&first, * argv[2],&second,NULL); * * As with RedisModule_HashSet() the behavior of the command can be specified * passing flags different than REDISMODULE_HASH_NONE: * * REDISMODULE_HASH_CFIELD: field names as null terminated C strings. * * REDISMODULE_HASH_EXISTS: instead of setting the value of the field * expecting a RedisModuleString pointer to pointer, the function just * reports if the field esists or not and expects an integer pointer * as the second element of each pair. * * Example of REDISMODULE_HASH_CFIELD: * * RedisModuleString *username, *hashedpass; * RedisModule_HashGet(mykey,"username",&username,"hp",&hashedpass, NULL); * * Example of REDISMODULE_HASH_EXISTS: * * int exists; * RedisModule_HashGet(mykey,argv[1],&exists,NULL); * * The function returns REDISMODULE_OK on success and REDISMODULE_ERR if * the key is not an hash value. * * Memory management: * * The returned RedisModuleString objects should be released with * RedisModule_FreeString(), or by enabling automatic memory management. */ int RM_HashGet(RedisModuleKey *key, int flags, ...) { va_list ap; if (key->value && key->value->type != OBJ_HASH) return REDISMODULE_ERR; va_start(ap, flags); while(1) { RedisModuleString *field, **valueptr; int *existsptr; /* Get the field object and the value pointer to pointer. */ if (flags & REDISMODULE_HASH_CFIELDS) { char *cfield = va_arg(ap,char*); if (cfield == NULL) break; field = createRawStringObject(cfield,strlen(cfield)); } else { field = va_arg(ap,RedisModuleString*); if (field == NULL) break; } /* Query the hash for existence or value object. */ if (flags & REDISMODULE_HASH_EXISTS) { existsptr = va_arg(ap,int*); if (key->value) *existsptr = hashTypeExists(key->value,field->ptr); else *existsptr = 0; } else { valueptr = va_arg(ap,RedisModuleString**); if (key->value) { *valueptr = hashTypeGetValueObject(key->value,field->ptr); if (*valueptr) { robj *decoded = getDecodedObject(*valueptr); decrRefCount(*valueptr); *valueptr = decoded; } if (*valueptr) autoMemoryAdd(key->ctx,REDISMODULE_AM_STRING,*valueptr); } else { *valueptr = NULL; } } /* Cleanup */ if (flags & REDISMODULE_HASH_CFIELDS) decrRefCount(field); } va_end(ap); return REDISMODULE_OK; } /* -------------------------------------------------------------------------- * Redis <-> Modules generic Call() API * -------------------------------------------------------------------------- */ /* Create a new RedisModuleCallReply object. The processing of the reply * is lazy, the object is just populated with the raw protocol and later * is processed as needed. Initially we just make sure to set the right * reply type, which is extremely cheap to do. */ RedisModuleCallReply *moduleCreateCallReplyFromProto(RedisModuleCtx *ctx, sds proto) { RedisModuleCallReply *reply = zmalloc(sizeof(*reply)); reply->ctx = ctx; reply->proto = proto; reply->protolen = sdslen(proto); reply->flags = REDISMODULE_REPLYFLAG_TOPARSE; /* Lazy parsing. */ switch(proto[0]) { case '$': case '+': reply->type = REDISMODULE_REPLY_STRING; break; case '-': reply->type = REDISMODULE_REPLY_ERROR; break; case ':': reply->type = REDISMODULE_REPLY_INTEGER; break; case '*': reply->type = REDISMODULE_REPLY_ARRAY; break; default: reply->type = REDISMODULE_REPLY_UNKNOWN; break; } if ((proto[0] == '*' || proto[0] == '$') && proto[1] == '-') reply->type = REDISMODULE_REPLY_NULL; return reply; } void moduleParseCallReply_Int(RedisModuleCallReply *reply); void moduleParseCallReply_BulkString(RedisModuleCallReply *reply); void moduleParseCallReply_SimpleString(RedisModuleCallReply *reply); void moduleParseCallReply_Array(RedisModuleCallReply *reply); /* Do nothing if REDISMODULE_REPLYFLAG_TOPARSE is false, otherwise * use the protcol of the reply in reply->proto in order to fill the * reply with parsed data according to the reply type. */ void moduleParseCallReply(RedisModuleCallReply *reply) { if (!(reply->flags & REDISMODULE_REPLYFLAG_TOPARSE)) return; reply->flags &= ~REDISMODULE_REPLYFLAG_TOPARSE; switch(reply->proto[0]) { case ':': moduleParseCallReply_Int(reply); break; case '$': moduleParseCallReply_BulkString(reply); break; case '-': /* handled by next item. */ case '+': moduleParseCallReply_SimpleString(reply); break; case '*': moduleParseCallReply_Array(reply); break; } } void moduleParseCallReply_Int(RedisModuleCallReply *reply) { char *proto = reply->proto; char *p = strchr(proto+1,'\r'); string2ll(proto+1,p-proto-1,&reply->val.ll); reply->protolen = p-proto+2; reply->type = REDISMODULE_REPLY_INTEGER; } void moduleParseCallReply_BulkString(RedisModuleCallReply *reply) { char *proto = reply->proto; char *p = strchr(proto+1,'\r'); long long bulklen; string2ll(proto+1,p-proto-1,&bulklen); if (bulklen == -1) { reply->protolen = p-proto+2; reply->type = REDISMODULE_REPLY_NULL; } else { reply->val.str = p+2; reply->len = bulklen; reply->protolen = p-proto+2+bulklen+2; reply->type = REDISMODULE_REPLY_STRING; } } void moduleParseCallReply_SimpleString(RedisModuleCallReply *reply) { char *proto = reply->proto; char *p = strchr(proto+1,'\r'); reply->val.str = proto+1; reply->len = p-proto-1; reply->protolen = p-proto+2; reply->type = proto[0] == '+' ? REDISMODULE_REPLY_STRING : REDISMODULE_REPLY_ERROR; } void moduleParseCallReply_Array(RedisModuleCallReply *reply) { char *proto = reply->proto; char *p = strchr(proto+1,'\r'); long long arraylen, j; string2ll(proto+1,p-proto-1,&arraylen); p += 2; if (arraylen == -1) { reply->protolen = p-proto; reply->type = REDISMODULE_REPLY_NULL; return; } reply->val.array = zmalloc(sizeof(RedisModuleCallReply)*arraylen); reply->len = arraylen; for (j = 0; j < arraylen; j++) { RedisModuleCallReply *ele = reply->val.array+j; ele->flags = REDISMODULE_REPLYFLAG_NESTED | REDISMODULE_REPLYFLAG_TOPARSE; ele->proto = p; ele->ctx = reply->ctx; moduleParseCallReply(ele); p += ele->protolen; } reply->protolen = p-proto; reply->type = REDISMODULE_REPLY_ARRAY; } /* Free a Call reply and all the nested replies it contains if it's an * array. */ void RM_FreeCallReply_Rec(RedisModuleCallReply *reply, int freenested){ /* Don't free nested replies by default: the user must always free the * toplevel reply. However be gentle and don't crash if the module * misuses the API. */ if (!freenested && reply->flags & REDISMODULE_REPLYFLAG_NESTED) return; if (!(reply->flags & REDISMODULE_REPLYFLAG_TOPARSE)) { if (reply->type == REDISMODULE_REPLY_ARRAY) { size_t j; for (j = 0; j < reply->len; j++) RM_FreeCallReply_Rec(reply->val.array+j,1); zfree(reply->val.array); } } /* For nested replies, we don't free reply->proto (which if not NULL * references the parent reply->proto buffer), nor the structure * itself which is allocated as an array of structures, and is freed * when the array value is released. */ if (!(reply->flags & REDISMODULE_REPLYFLAG_NESTED)) { if (reply->proto) sdsfree(reply->proto); zfree(reply); } } /* Wrapper for the recursive free reply function. This is needed in order * to have the first level function to return on nested replies, but only * if called by the module API. */ void RM_FreeCallReply(RedisModuleCallReply *reply) { RedisModuleCtx *ctx = reply->ctx; RM_FreeCallReply_Rec(reply,0); autoMemoryFreed(ctx,REDISMODULE_AM_REPLY,reply); } /* Return the reply type. */ int RM_CallReplyType(RedisModuleCallReply *reply) { if (!reply) return REDISMODULE_REPLY_UNKNOWN; return reply->type; } /* Return the reply type length, where applicable. */ size_t RM_CallReplyLength(RedisModuleCallReply *reply) { moduleParseCallReply(reply); switch(reply->type) { case REDISMODULE_REPLY_STRING: case REDISMODULE_REPLY_ERROR: case REDISMODULE_REPLY_ARRAY: return reply->len; default: return 0; } } /* Return the 'idx'-th nested call reply element of an array reply, or NULL * if the reply type is wrong or the index is out of range. */ RedisModuleCallReply *RM_CallReplyArrayElement(RedisModuleCallReply *reply, size_t idx) { moduleParseCallReply(reply); if (reply->type != REDISMODULE_REPLY_ARRAY) return NULL; if (idx >= reply->len) return NULL; return reply->val.array+idx; } /* Return the long long of an integer reply. */ long long RM_CallReplyInteger(RedisModuleCallReply *reply) { moduleParseCallReply(reply); if (reply->type != REDISMODULE_REPLY_INTEGER) return LLONG_MIN; return reply->val.ll; } /* Return the pointer and length of a string or error reply. */ const char *RM_CallReplyStringPtr(RedisModuleCallReply *reply, size_t *len) { moduleParseCallReply(reply); if (reply->type != REDISMODULE_REPLY_STRING && reply->type != REDISMODULE_REPLY_ERROR) return NULL; if (len) *len = reply->len; return reply->val.str; } /* Return a new string object from a call reply of type string, error or * integer. Otherwise (wrong reply type) return NULL. */ RedisModuleString *RM_CreateStringFromCallReply(RedisModuleCallReply *reply) { moduleParseCallReply(reply); switch(reply->type) { case REDISMODULE_REPLY_STRING: case REDISMODULE_REPLY_ERROR: return RM_CreateString(reply->ctx,reply->val.str,reply->len); case REDISMODULE_REPLY_INTEGER: { char buf[64]; int len = ll2string(buf,sizeof(buf),reply->val.ll); return RM_CreateString(reply->ctx,buf,len); } default: return NULL; } } /* Returns an array of robj pointers, and populates *argc with the number * of items, by parsing the format specifier "fmt" as described for * the RM_Call(), RM_Replicate() and other module APIs. * * The integer pointed by 'flags' is populated with flags according * to special modifiers in "fmt". For now only one exists: * * "!" -> REDISMODULE_ARGV_REPLICATE * * On error (format specifier error) NULL is returned and nothing is * allocated. On success the argument vector is returned. */ #define REDISMODULE_ARGV_REPLICATE (1<<0) robj **moduleCreateArgvFromUserFormat(const char *cmdname, const char *fmt, int *argcp, int *flags, va_list ap) { int argc = 0, argv_size, j; robj **argv = NULL; /* As a first guess to avoid useless reallocations, size argv to * hold one argument for each char specifier in 'fmt'. */ argv_size = strlen(fmt)+1; /* +1 because of the command name. */ argv = zrealloc(argv,sizeof(robj*)*argv_size); /* Build the arguments vector based on the format specifier. */ argv[0] = createStringObject(cmdname,strlen(cmdname)); argc++; /* Create the client and dispatch the command. */ const char *p = fmt; while(*p) { if (*p == 'c') { char *cstr = va_arg(ap,char*); argv[argc++] = createStringObject(cstr,strlen(cstr)); } else if (*p == 's') { robj *obj = va_arg(ap,void*); argv[argc++] = obj; incrRefCount(obj); } else if (*p == 'b') { char *buf = va_arg(ap,char*); size_t len = va_arg(ap,size_t); argv[argc++] = createStringObject(buf,len); } else if (*p == 'l') { long ll = va_arg(ap,long long); argv[argc++] = createObject(OBJ_STRING,sdsfromlonglong(ll)); } else if (*p == 'v') { /* A vector of strings */ robj **v = va_arg(ap, void*); size_t vlen = va_arg(ap, size_t); /* We need to grow argv to hold the vector's elements. * We resize by vector_len-1 elements, because we held * one element in argv for the vector already */ argv_size += vlen-1; argv = zrealloc(argv,sizeof(robj*)*argv_size); size_t i = 0; for (i = 0; i < vlen; i++) { incrRefCount(v[i]); argv[argc++] = v[i]; } } else if (*p == '!') { if (flags) (*flags) |= REDISMODULE_ARGV_REPLICATE; } else { goto fmterr; } p++; } *argcp = argc; return argv; fmterr: for (j = 0; j < argc; j++) decrRefCount(argv[j]); zfree(argv); return NULL; } /* Exported API to call any Redis command from modules. * On success a RedisModuleCallReply object is returned, otherwise * NULL is returned and errno is set to the following values: * * EINVAL: command non existing, wrong arity, wrong format specifier. * EPERM: operation in Cluster instance with key in non local slot. */ RedisModuleCallReply *RM_Call(RedisModuleCtx *ctx, const char *cmdname, const char *fmt, ...) { struct redisCommand *cmd; client *c = NULL; robj **argv = NULL; int argc = 0, flags = 0; va_list ap; RedisModuleCallReply *reply = NULL; int replicate = 0; /* Replicate this command? */ cmd = lookupCommandByCString((char*)cmdname); if (!cmd) { errno = EINVAL; return NULL; } /* Create the client and dispatch the command. */ va_start(ap, fmt); c = createClient(-1); argv = moduleCreateArgvFromUserFormat(cmdname,fmt,&argc,&flags,ap); replicate = flags & REDISMODULE_ARGV_REPLICATE; va_end(ap); /* Setup our fake client for command execution. */ c->flags |= CLIENT_MODULE; c->db = ctx->client->db; c->argv = argv; c->argc = argc; c->cmd = c->lastcmd = cmd; /* We handle the above format error only when the client is setup so that * we can free it normally. */ if (argv == NULL) goto cleanup; /* Basic arity checks. */ if ((cmd->arity > 0 && cmd->arity != argc) || (argc < -cmd->arity)) { errno = EINVAL; goto cleanup; } /* If this is a Redis Cluster node, we need to make sure the module is not * trying to access non-local keys, with the exception of commands * received from our master. */ if (server.cluster_enabled && !(ctx->client->flags & CLIENT_MASTER)) { /* Duplicate relevant flags in the module client. */ c->flags &= ~(CLIENT_READONLY|CLIENT_ASKING); c->flags |= ctx->client->flags & (CLIENT_READONLY|CLIENT_ASKING); if (getNodeByQuery(c,c->cmd,c->argv,c->argc,NULL,NULL) != server.cluster->myself) { errno = EPERM; goto cleanup; } } /* If we are using single commands replication, we need to wrap what * we propagate into a MULTI/EXEC block, so that it will be atomic like * a Lua script in the context of AOF and slaves. */ if (replicate) moduleReplicateMultiIfNeeded(ctx); /* Run the command */ int call_flags = CMD_CALL_SLOWLOG | CMD_CALL_STATS; if (replicate) { call_flags |= CMD_CALL_PROPAGATE_AOF; call_flags |= CMD_CALL_PROPAGATE_REPL; } call(c,call_flags); /* Convert the result of the Redis command into a suitable Lua type. * The first thing we need is to create a single string from the client * output buffers. */ sds proto = sdsnewlen(c->buf,c->bufpos); c->bufpos = 0; while(listLength(c->reply)) { sds o = listNodeValue(listFirst(c->reply)); proto = sdscatsds(proto,o); listDelNode(c->reply,listFirst(c->reply)); } reply = moduleCreateCallReplyFromProto(ctx,proto); autoMemoryAdd(ctx,REDISMODULE_AM_REPLY,reply); cleanup: freeClient(c); return reply; } /* Return a pointer, and a length, to the protocol returned by the command * that returned the reply object. */ const char *RM_CallReplyProto(RedisModuleCallReply *reply, size_t *len) { if (reply->proto) *len = sdslen(reply->proto); return reply->proto; } /* -------------------------------------------------------------------------- * Modules data types * * When String DMA or using existing data structures is not enough, it is * possible to create new data types from scratch and export them to * Redis. The module must provide a set of callbacks for handling the * new values exported (for example in order to provide RDB saving/loading, * AOF rewrite, and so forth). In this section we define this API. * -------------------------------------------------------------------------- */ /* Turn a 9 chars name in the specified charset and a 10 bit encver into * a single 64 bit unsigned integer that represents this exact module name * and version. This final number is called a "type ID" and is used when * writing module exported values to RDB files, in order to re-associate the * value to the right module to load them during RDB loading. * * If the string is not of the right length or the charset is wrong, or * if encver is outside the unsigned 10 bit integer range, 0 is returned, * otherwise the function returns the right type ID. * * The resulting 64 bit integer is composed as follows: * * (high order bits) 6|6|6|6|6|6|6|6|6|10 (low order bits) * * The first 6 bits value is the first character, name[0], while the last * 6 bits value, immediately before the 10 bits integer, is name[8]. * The last 10 bits are the encoding version. * * Note that a name and encver combo of "AAAAAAAAA" and 0, will produce * zero as return value, that is the same we use to signal errors, thus * this combination is invalid, and also useless since type names should * try to be vary to avoid collisions. */ const char *ModuleTypeNameCharSet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" "abcdefghijklmnopqrstuvwxyz" "0123456789-_"; uint64_t moduleTypeEncodeId(const char *name, int encver) { /* We use 64 symbols so that we can map each character into 6 bits * of the final output. */ const char *cset = ModuleTypeNameCharSet; if (strlen(name) != 9) return 0; if (encver < 0 || encver > 1023) return 0; uint64_t id = 0; for (int j = 0; j < 9; j++) { char *p = strchr(cset,name[j]); if (!p) return 0; unsigned long pos = p-cset; id = (id << 6) | pos; } id = (id << 10) | encver; return id; } /* Search, in the list of exported data types of all the modules registered, * a type with the same name as the one given. Returns the moduleType * structure pointer if such a module is found, or NULL otherwise. */ moduleType *moduleTypeLookupModuleByName(const char *name) { dictIterator *di = dictGetIterator(modules); dictEntry *de; while ((de = dictNext(di)) != NULL) { struct RedisModule *module = dictGetVal(de); listIter li; listNode *ln; listRewind(module->types,&li); while((ln = listNext(&li))) { moduleType *mt = ln->value; if (memcmp(name,mt->name,sizeof(mt->name)) == 0) { dictReleaseIterator(di); return mt; } } } dictReleaseIterator(di); return NULL; } /* Lookup a module by ID, with caching. This function is used during RDB * loading. Modules exporting data types should never be able to unload, so * our cache does not need to expire. */ #define MODULE_LOOKUP_CACHE_SIZE 3 moduleType *moduleTypeLookupModuleByID(uint64_t id) { static struct { uint64_t id; moduleType *mt; } cache[MODULE_LOOKUP_CACHE_SIZE]; /* Search in cache to start. */ int j; for (j = 0; j < MODULE_LOOKUP_CACHE_SIZE && cache[j].mt != NULL; j++) if (cache[j].id == id) return cache[j].mt; /* Slow module by module lookup. */ moduleType *mt = NULL; dictIterator *di = dictGetIterator(modules); dictEntry *de; while ((de = dictNext(di)) != NULL && mt == NULL) { struct RedisModule *module = dictGetVal(de); listIter li; listNode *ln; listRewind(module->types,&li); while((ln = listNext(&li))) { moduleType *this_mt = ln->value; /* Compare only the 54 bit module identifier and not the * encoding version. */ if (this_mt->id >> 10 == id >> 10) { mt = this_mt; break; } } } dictReleaseIterator(di); /* Add to cache if possible. */ if (mt && j < MODULE_LOOKUP_CACHE_SIZE) { cache[j].id = id; cache[j].mt = mt; } return mt; } /* Turn an (unresolved) module ID into a type name, to show the user an * error when RDB files contain module data we can't load. * The buffer pointed by 'name' must be 10 bytes at least. The function will * fill it with a null terminated module name. */ void moduleTypeNameByID(char *name, uint64_t moduleid) { const char *cset = ModuleTypeNameCharSet; name[9] = '\0'; char *p = name+8; moduleid >>= 10; for (int j = 0; j < 9; j++) { *p-- = cset[moduleid & 63]; moduleid >>= 6; } } /* Register a new data type exported by the module. The parameters are the * following. Please for in depth documentation check the modules API * documentation, especially the TYPES.md file. * * * **name**: A 9 characters data type name that MUST be unique in the Redis * Modules ecosystem. Be creative... and there will be no collisions. Use * the charset A-Z a-z 9-0, plus the two "-_" characters. A good * idea is to use, for example `-`. For example * "tree-AntZ" may mean "Tree data structure by @antirez". To use both * lower case and upper case letters helps in order to prevent collisions. * * **encver**: Encoding version, which is, the version of the serialization * that a module used in order to persist data. As long as the "name" * matches, the RDB loading will be dispatched to the type callbacks * whatever 'encver' is used, however the module can understand if * the encoding it must load are of an older version of the module. * For example the module "tree-AntZ" initially used encver=0. Later * after an upgrade, it started to serialize data in a different format * and to register the type with encver=1. However this module may * still load old data produced by an older version if the rdb_load * callback is able to check the encver value and act accordingly. * The encver must be a positive value between 0 and 1023. * * **typemethods_ptr** is a pointer to a RedisModuleTypeMethods structure * that should be populated with the methods callbacks and structure * version, like in the following example: * * RedisModuleTypeMethods tm = { * .version = REDISMODULE_TYPE_METHOD_VERSION, * .rdb_load = myType_RDBLoadCallBack, * .rdb_save = myType_RDBSaveCallBack, * .aof_rewrite = myType_AOFRewriteCallBack, * .free = myType_FreeCallBack, * * // Optional fields * .digest = myType_DigestCallBack, * .mem_usage = myType_MemUsageCallBack, * } * * * **rdb_load**: A callback function pointer that loads data from RDB files. * * **rdb_save**: A callback function pointer that saves data to RDB files. * * **aof_rewrite**: A callback function pointer that rewrites data as commands. * * **digest**: A callback function pointer that is used for `DEBUG DIGEST`. * * **free**: A callback function pointer that can free a type value. * * The **digest* and **mem_usage** methods should currently be omitted since * they are not yet implemented inside the Redis modules core. * * Note: the module name "AAAAAAAAA" is reserved and produces an error, it * happens to be pretty lame as well. * * If there is already a module registering a type with the same name, * and if the module name or encver is invalid, NULL is returned. * Otherwise the new type is registered into Redis, and a reference of * type RedisModuleType is returned: the caller of the function should store * this reference into a gobal variable to make future use of it in the * modules type API, since a single module may register multiple types. * Example code fragment: * * static RedisModuleType *BalancedTreeType; * * int RedisModule_OnLoad(RedisModuleCtx *ctx) { * // some code here ... * BalancedTreeType = RM_CreateDataType(...); * } */ moduleType *RM_CreateDataType(RedisModuleCtx *ctx, const char *name, int encver, void *typemethods_ptr) { uint64_t id = moduleTypeEncodeId(name,encver); if (id == 0) return NULL; if (moduleTypeLookupModuleByName(name) != NULL) return NULL; long typemethods_version = ((long*)typemethods_ptr)[0]; if (typemethods_version == 0) return NULL; struct typemethods { uint64_t version; moduleTypeLoadFunc rdb_load; moduleTypeSaveFunc rdb_save; moduleTypeRewriteFunc aof_rewrite; moduleTypeMemUsageFunc mem_usage; moduleTypeDigestFunc digest; moduleTypeFreeFunc free; } *tms = (struct typemethods*) typemethods_ptr; moduleType *mt = zcalloc(sizeof(*mt)); mt->id = id; mt->module = ctx->module; mt->rdb_load = tms->rdb_load; mt->rdb_save = tms->rdb_save; mt->aof_rewrite = tms->aof_rewrite; mt->mem_usage = tms->mem_usage; mt->digest = tms->digest; mt->free = tms->free; memcpy(mt->name,name,sizeof(mt->name)); listAddNodeTail(ctx->module->types,mt); return mt; } /* If the key is open for writing, set the specified module type object * as the value of the key, deleting the old value if any. * On success REDISMODULE_OK is returned. If the key is not open for * writing or there is an active iterator, REDISMODULE_ERR is returned. */ int RM_ModuleTypeSetValue(RedisModuleKey *key, moduleType *mt, void *value) { if (!(key->mode & REDISMODULE_WRITE) || key->iter) return REDISMODULE_ERR; RM_DeleteKey(key); robj *o = createModuleObject(mt,value); setKey(key->db,key->key,o); decrRefCount(o); key->value = o; return REDISMODULE_OK; } /* Assuming RedisModule_KeyType() returned REDISMODULE_KEYTYPE_MODULE on * the key, returns the moduel type pointer of the value stored at key. * * If the key is NULL, is not associated with a module type, or is empty, * then NULL is returned instead. */ moduleType *RM_ModuleTypeGetType(RedisModuleKey *key) { if (key == NULL || key->value == NULL || RM_KeyType(key) != REDISMODULE_KEYTYPE_MODULE) return NULL; moduleValue *mv = key->value->ptr; return mv->type; } /* Assuming RedisModule_KeyType() returned REDISMODULE_KEYTYPE_MODULE on * the key, returns the module type low-level value stored at key, as * it was set by the user via RedisModule_ModuleTypeSet(). * * If the key is NULL, is not associated with a module type, or is empty, * then NULL is returned instead. */ void *RM_ModuleTypeGetValue(RedisModuleKey *key) { if (key == NULL || key->value == NULL || RM_KeyType(key) != REDISMODULE_KEYTYPE_MODULE) return NULL; moduleValue *mv = key->value->ptr; return mv->value; } /* -------------------------------------------------------------------------- * RDB loading and saving functions * -------------------------------------------------------------------------- */ /* Called when there is a load error in the context of a module. This cannot * be recovered like for the built-in types. */ void moduleRDBLoadError(RedisModuleIO *io) { serverLog(LL_WARNING, "Error loading data from RDB (short read or EOF). " "Read performed by module '%s' about type '%s' " "after reading '%llu' bytes of a value.", io->type->module->name, io->type->name, (unsigned long long)io->bytes); exit(1); } /* Save an unsigned 64 bit value into the RDB file. This function should only * be called in the context of the rdb_save method of modules implementing new * data types. */ void RM_SaveUnsigned(RedisModuleIO *io, uint64_t value) { if (io->error) return; /* Save opcode. */ int retval = rdbSaveLen(io->rio, RDB_MODULE_OPCODE_UINT); if (retval == -1) goto saveerr; io->bytes += retval; /* Save value. */ retval = rdbSaveLen(io->rio, value); if (retval == -1) goto saveerr; io->bytes += retval; return; saveerr: io->error = 1; } /* Load an unsigned 64 bit value from the RDB file. This function should only * be called in the context of the rdb_load method of modules implementing * new data types. */ uint64_t RM_LoadUnsigned(RedisModuleIO *io) { if (io->ver == 2) { uint64_t opcode = rdbLoadLen(io->rio,NULL); if (opcode != RDB_MODULE_OPCODE_UINT) goto loaderr; } uint64_t value; int retval = rdbLoadLenByRef(io->rio, NULL, &value); if (retval == -1) goto loaderr; return value; loaderr: moduleRDBLoadError(io); return 0; /* Never reached. */ } /* Like RedisModule_SaveUnsigned() but for signed 64 bit values. */ void RM_SaveSigned(RedisModuleIO *io, int64_t value) { union {uint64_t u; int64_t i;} conv; conv.i = value; RM_SaveUnsigned(io,conv.u); } /* Like RedisModule_LoadUnsigned() but for signed 64 bit values. */ int64_t RM_LoadSigned(RedisModuleIO *io) { union {uint64_t u; int64_t i;} conv; conv.u = RM_LoadUnsigned(io); return conv.i; } /* In the context of the rdb_save method of a module type, saves a * string into the RDB file taking as input a RedisModuleString. * * The string can be later loaded with RedisModule_LoadString() or * other Load family functions expecting a serialized string inside * the RDB file. */ void RM_SaveString(RedisModuleIO *io, RedisModuleString *s) { if (io->error) return; /* Save opcode. */ ssize_t retval = rdbSaveLen(io->rio, RDB_MODULE_OPCODE_STRING); if (retval == -1) goto saveerr; io->bytes += retval; /* Save value. */ retval = rdbSaveStringObject(io->rio, s); if (retval == -1) goto saveerr; io->bytes += retval; return; saveerr: io->error = 1; } /* Like RedisModule_SaveString() but takes a raw C pointer and length * as input. */ void RM_SaveStringBuffer(RedisModuleIO *io, const char *str, size_t len) { if (io->error) return; /* Save opcode. */ ssize_t retval = rdbSaveLen(io->rio, RDB_MODULE_OPCODE_STRING); if (retval == -1) goto saveerr; io->bytes += retval; /* Save value. */ retval = rdbSaveRawString(io->rio, (unsigned char*)str,len); if (retval == -1) goto saveerr; io->bytes += retval; return; saveerr: io->error = 1; } /* Implements RM_LoadString() and RM_LoadStringBuffer() */ void *moduleLoadString(RedisModuleIO *io, int plain, size_t *lenptr) { if (io->ver == 2) { uint64_t opcode = rdbLoadLen(io->rio,NULL); if (opcode != RDB_MODULE_OPCODE_STRING) goto loaderr; } void *s = rdbGenericLoadStringObject(io->rio, plain ? RDB_LOAD_PLAIN : RDB_LOAD_NONE, lenptr); if (s == NULL) goto loaderr; return s; loaderr: moduleRDBLoadError(io); return NULL; /* Never reached. */ } /* In the context of the rdb_load method of a module data type, loads a string * from the RDB file, that was previously saved with RedisModule_SaveString() * functions family. * * The returned string is a newly allocated RedisModuleString object, and * the user should at some point free it with a call to RedisModule_FreeString(). * * If the data structure does not store strings as RedisModuleString objects, * the similar function RedisModule_LoadStringBuffer() could be used instead. */ RedisModuleString *RM_LoadString(RedisModuleIO *io) { return moduleLoadString(io,0,NULL); } /* Like RedisModule_LoadString() but returns an heap allocated string that * was allocated with RedisModule_Alloc(), and can be resized or freed with * RedisModule_Realloc() or RedisModule_Free(). * * The size of the string is stored at '*lenptr' if not NULL. * The returned string is not automatically NULL termianted, it is loaded * exactly as it was stored inisde the RDB file. */ char *RM_LoadStringBuffer(RedisModuleIO *io, size_t *lenptr) { return moduleLoadString(io,1,lenptr); } /* In the context of the rdb_save method of a module data type, saves a double * value to the RDB file. The double can be a valid number, a NaN or infinity. * It is possible to load back the value with RedisModule_LoadDouble(). */ void RM_SaveDouble(RedisModuleIO *io, double value) { if (io->error) return; /* Save opcode. */ int retval = rdbSaveLen(io->rio, RDB_MODULE_OPCODE_DOUBLE); if (retval == -1) goto saveerr; io->bytes += retval; /* Save value. */ retval = rdbSaveBinaryDoubleValue(io->rio, value); if (retval == -1) goto saveerr; io->bytes += retval; return; saveerr: io->error = 1; } /* In the context of the rdb_save method of a module data type, loads back the * double value saved by RedisModule_SaveDouble(). */ double RM_LoadDouble(RedisModuleIO *io) { if (io->ver == 2) { uint64_t opcode = rdbLoadLen(io->rio,NULL); if (opcode != RDB_MODULE_OPCODE_DOUBLE) goto loaderr; } double value; int retval = rdbLoadBinaryDoubleValue(io->rio, &value); if (retval == -1) goto loaderr; return value; loaderr: moduleRDBLoadError(io); return 0; /* Never reached. */ } /* In the context of the rdb_save method of a module data type, saves a float * value to the RDB file. The float can be a valid number, a NaN or infinity. * It is possible to load back the value with RedisModule_LoadFloat(). */ void RM_SaveFloat(RedisModuleIO *io, float value) { if (io->error) return; /* Save opcode. */ int retval = rdbSaveLen(io->rio, RDB_MODULE_OPCODE_FLOAT); if (retval == -1) goto saveerr; io->bytes += retval; /* Save value. */ retval = rdbSaveBinaryFloatValue(io->rio, value); if (retval == -1) goto saveerr; io->bytes += retval; return; saveerr: io->error = 1; } /* In the context of the rdb_save method of a module data type, loads back the * float value saved by RedisModule_SaveFloat(). */ float RM_LoadFloat(RedisModuleIO *io) { if (io->ver == 2) { uint64_t opcode = rdbLoadLen(io->rio,NULL); if (opcode != RDB_MODULE_OPCODE_FLOAT) goto loaderr; } float value; int retval = rdbLoadBinaryFloatValue(io->rio, &value); if (retval == -1) goto loaderr; return value; loaderr: moduleRDBLoadError(io); return 0; /* Never reached. */ } /* -------------------------------------------------------------------------- * Key digest API (DEBUG DIGEST interface for modules types) * -------------------------------------------------------------------------- */ /* Add a new element to the digest. This function can be called multiple times * one element after the other, for all the elements that constitute a given * data structure. The function call must be followed by the call to * `RedisModule_DigestEndSequence` eventually, when all the elements that are * always in a given order are added. See the Redis Modules data types * documentation for more info. However this is a quick example that uses Redis * data types as an example. * * To add a sequence of unordered elements (for example in the case of a Redis * Set), the pattern to use is: * * foreach element { * AddElement(element); * EndSequence(); * } * * Because Sets are not ordered, so every element added has a position that * does not depend from the other. However if instead our elements are * ordered in pairs, like field-value pairs of an Hash, then one should * use: * * foreach key,value { * AddElement(key); * AddElement(value); * EndSquence(); * } * * Because the key and value will be always in the above order, while instead * the single key-value pairs, can appear in any position into a Redis hash. * * A list of ordered elements would be implemented with: * * foreach element { * AddElement(element); * } * EndSequence(); * */ void RM_DigestAddStringBuffer(RedisModuleDigest *md, unsigned char *ele, size_t len) { mixDigest(md->o,ele,len); } /* Like `RedisModule_DigestAddStringBuffer()` but takes a long long as input * that gets converted into a string before adding it to the digest. */ void RM_DigestAddLongLong(RedisModuleDigest *md, long long ll) { char buf[LONG_STR_SIZE]; size_t len = ll2string(buf,sizeof(buf),ll); mixDigest(md->o,buf,len); } /* See the doucmnetation for `RedisModule_DigestAddElement()`. */ void RM_DigestEndSequence(RedisModuleDigest *md) { xorDigest(md->x,md->o,sizeof(md->o)); memset(md->o,0,sizeof(md->o)); } /* -------------------------------------------------------------------------- * AOF API for modules data types * -------------------------------------------------------------------------- */ /* Emits a command into the AOF during the AOF rewriting process. This function * is only called in the context of the aof_rewrite method of data types exported * by a module. The command works exactly like RedisModule_Call() in the way * the parameters are passed, but it does not return anything as the error * handling is performed by Redis itself. */ void RM_EmitAOF(RedisModuleIO *io, const char *cmdname, const char *fmt, ...) { if (io->error) return; struct redisCommand *cmd; robj **argv = NULL; int argc = 0, flags = 0, j; va_list ap; cmd = lookupCommandByCString((char*)cmdname); if (!cmd) { serverLog(LL_WARNING, "Fatal: AOF method for module data type '%s' tried to " "emit unknown command '%s'", io->type->name, cmdname); io->error = 1; errno = EINVAL; return; } /* Emit the arguments into the AOF in Redis protocol format. */ va_start(ap, fmt); argv = moduleCreateArgvFromUserFormat(cmdname,fmt,&argc,&flags,ap); va_end(ap); if (argv == NULL) { serverLog(LL_WARNING, "Fatal: AOF method for module data type '%s' tried to " "call RedisModule_EmitAOF() with wrong format specifiers '%s'", io->type->name, fmt); io->error = 1; errno = EINVAL; return; } /* Bulk count. */ if (!io->error && rioWriteBulkCount(io->rio,'*',argc) == 0) io->error = 1; /* Arguments. */ for (j = 0; j < argc; j++) { if (!io->error && rioWriteBulkObject(io->rio,argv[j]) == 0) io->error = 1; decrRefCount(argv[j]); } zfree(argv); return; } /* -------------------------------------------------------------------------- * IO context handling * -------------------------------------------------------------------------- */ RedisModuleCtx *RM_GetContextFromIO(RedisModuleIO *io) { if (io->ctx) return io->ctx; /* Can't have more than one... */ RedisModuleCtx ctxtemplate = REDISMODULE_CTX_INIT; io->ctx = zmalloc(sizeof(RedisModuleCtx)); *(io->ctx) = ctxtemplate; io->ctx->module = io->type->module; io->ctx->client = NULL; return io->ctx; } /* -------------------------------------------------------------------------- * Logging * -------------------------------------------------------------------------- */ /* This is the low level function implementing both: * * RM_Log() * RM_LogIOError() * */ void RM_LogRaw(RedisModule *module, const char *levelstr, const char *fmt, va_list ap) { char msg[LOG_MAX_LEN]; size_t name_len; int level; if (!strcasecmp(levelstr,"debug")) level = LL_DEBUG; else if (!strcasecmp(levelstr,"verbose")) level = LL_VERBOSE; else if (!strcasecmp(levelstr,"notice")) level = LL_NOTICE; else if (!strcasecmp(levelstr,"warning")) level = LL_WARNING; else level = LL_VERBOSE; /* Default. */ name_len = snprintf(msg, sizeof(msg),"<%s> ", module->name); vsnprintf(msg + name_len, sizeof(msg) - name_len, fmt, ap); serverLogRaw(level,msg); } /* Produces a log message to the standard Redis log, the format accepts * printf-alike specifiers, while level is a string describing the log * level to use when emitting the log, and must be one of the following: * * * "debug" * * "verbose" * * "notice" * * "warning" * * If the specified log level is invalid, verbose is used by default. * There is a fixed limit to the length of the log line this function is able * to emit, this limti is not specified but is guaranteed to be more than * a few lines of text. */ void RM_Log(RedisModuleCtx *ctx, const char *levelstr, const char *fmt, ...) { if (!ctx->module) return; /* Can only log if module is initialized */ va_list ap; va_start(ap, fmt); RM_LogRaw(ctx->module,levelstr,fmt,ap); va_end(ap); } /* Log errors from RDB / AOF serialization callbacks. * * This function should be used when a callback is returning a critical * error to the caller since cannot load or save the data for some * critical reason. */ void RM_LogIOError(RedisModuleIO *io, const char *levelstr, const char *fmt, ...) { va_list ap; va_start(ap, fmt); RM_LogRaw(io->type->module,levelstr,fmt,ap); va_end(ap); } /* -------------------------------------------------------------------------- * Blocking clients from modules * -------------------------------------------------------------------------- */ /* Readable handler for the awake pipe. We do nothing here, the awake bytes * will be actually read in a more appropriate place in the * moduleHandleBlockedClients() function that is where clients are actually * served. */ void moduleBlockedClientPipeReadable(aeEventLoop *el, int fd, void *privdata, int mask) { UNUSED(el); UNUSED(fd); UNUSED(mask); UNUSED(privdata); } /* This is called from blocked.c in order to unblock a client: may be called * for multiple reasons while the client is in the middle of being blocked * because the client is terminated, but is also called for cleanup when a * client is unblocked in a clean way after replaying. * * What we do here is just to set the client to NULL in the redis module * blocked client handle. This way if the client is terminated while there * is a pending threaded operation involving the blocked client, we'll know * that the client no longer exists and no reply callback should be called. * * The structure RedisModuleBlockedClient will be always deallocated when * running the list of clients blocked by a module that need to be unblocked. */ void unblockClientFromModule(client *c) { RedisModuleBlockedClient *bc = c->bpop.module_blocked_handle; /* Call the disconnection callback if any. */ if (bc->disconnect_callback) { RedisModuleCtx ctx = REDISMODULE_CTX_INIT; ctx.blocked_privdata = bc->privdata; ctx.module = bc->module; ctx.client = bc->client; bc->disconnect_callback(&ctx,bc); moduleFreeContext(&ctx); } bc->client = NULL; /* Reset the client for a new query since, for blocking commands implemented * into modules, we do not it immediately after the command returns (and * the client blocks) in order to be still able to access the argument * vector from callbacks. */ resetClient(c); } /* Block a client in the context of a blocking command, returning an handle * which will be used, later, in order to unblock the client with a call to * RedisModule_UnblockClient(). The arguments specify callback functions * and a timeout after which the client is unblocked. * * The callbacks are called in the following contexts: * * reply_callback: called after a successful RedisModule_UnblockClient() * call in order to reply to the client and unblock it. * * reply_timeout: called when the timeout is reached in order to send an * error to the client. * * free_privdata: called in order to free the privata data that is passed * by RedisModule_UnblockClient() call. */ RedisModuleBlockedClient *RM_BlockClient(RedisModuleCtx *ctx, RedisModuleCmdFunc reply_callback, RedisModuleCmdFunc timeout_callback, void (*free_privdata)(RedisModuleCtx*,void*), long long timeout_ms) { client *c = ctx->client; int islua = c->flags & CLIENT_LUA; int ismulti = c->flags & CLIENT_MULTI; c->bpop.module_blocked_handle = zmalloc(sizeof(RedisModuleBlockedClient)); RedisModuleBlockedClient *bc = c->bpop.module_blocked_handle; /* We need to handle the invalid operation of calling modules blocking * commands from Lua or MULTI. We actually create an already aborted * (client set to NULL) blocked client handle, and actually reply with * an error. */ bc->client = (islua || ismulti) ? NULL : c; bc->module = ctx->module; bc->reply_callback = reply_callback; bc->timeout_callback = timeout_callback; bc->disconnect_callback = NULL; /* Set by RM_SetDisconnectCallback() */ bc->free_privdata = free_privdata; bc->privdata = NULL; bc->reply_client = createClient(-1); bc->reply_client->flags |= CLIENT_MODULE; bc->dbid = c->db->id; c->bpop.timeout = timeout_ms ? (mstime()+timeout_ms) : 0; if (islua || ismulti) { c->bpop.module_blocked_handle = NULL; addReplyError(c, islua ? "Blocking module command called from Lua script" : "Blocking module command called from transaction"); } else { blockClient(c,BLOCKED_MODULE); } return bc; } /* Unblock a client blocked by `RedisModule_BlockedClient`. This will trigger * the reply callbacks to be called in order to reply to the client. * The 'privdata' argument will be accessible by the reply callback, so * the caller of this function can pass any value that is needed in order to * actually reply to the client. * * A common usage for 'privdata' is a thread that computes something that * needs to be passed to the client, included but not limited some slow * to compute reply or some reply obtained via networking. * * Note: this function can be called from threads spawned by the module. */ int RM_UnblockClient(RedisModuleBlockedClient *bc, void *privdata) { pthread_mutex_lock(&moduleUnblockedClientsMutex); bc->privdata = privdata; listAddNodeTail(moduleUnblockedClients,bc); if (write(server.module_blocked_pipe[1],"A",1) != 1) { /* Ignore the error, this is best-effort. */ } pthread_mutex_unlock(&moduleUnblockedClientsMutex); return REDISMODULE_OK; } /* Abort a blocked client blocking operation: the client will be unblocked * without firing any callback. */ int RM_AbortBlock(RedisModuleBlockedClient *bc) { bc->reply_callback = NULL; bc->disconnect_callback = NULL; return RM_UnblockClient(bc,NULL); } /* Set a callback that will be called if a blocked client disconnects * before the module has a chance to call RedisModule_UnblockClient() * * Usually what you want to do there, is to cleanup your module state * so that you can call RedisModule_UnblockClient() safely, otherwise * the client will remain blocked forever if the timeout is large. * * Notes: * * 1. It is not safe to call Reply* family functions here, it is also * useless since the client is gone. * * 2. This callback is not called if the client disconnects because of * a timeout. In such a case, the client is unblocked automatically * and the timeout callback is called. */ void RM_SetDisconnectCallback(RedisModuleBlockedClient *bc, RedisModuleDisconnectFunc callback) { bc->disconnect_callback = callback; } /* This function will check the moduleUnblockedClients queue in order to * call the reply callback and really unblock the client. * * Clients end into this list because of calls to RM_UnblockClient(), * however it is possible that while the module was doing work for the * blocked client, it was terminated by Redis (for timeout or other reasons). * When this happens the RedisModuleBlockedClient structure in the queue * will have the 'client' field set to NULL. */ void moduleHandleBlockedClients(void) { listNode *ln; RedisModuleBlockedClient *bc; pthread_mutex_lock(&moduleUnblockedClientsMutex); /* Here we unblock all the pending clients blocked in modules operations * so we can read every pending "awake byte" in the pipe. */ char buf[1]; while (read(server.module_blocked_pipe[0],buf,1) == 1); while (listLength(moduleUnblockedClients)) { ln = listFirst(moduleUnblockedClients); bc = ln->value; client *c = bc->client; listDelNode(moduleUnblockedClients,ln); pthread_mutex_unlock(&moduleUnblockedClientsMutex); /* Release the lock during the loop, as long as we don't * touch the shared list. */ /* Call the reply callback if the client is valid and we have * any callback. */ if (c && bc->reply_callback) { RedisModuleCtx ctx = REDISMODULE_CTX_INIT; ctx.flags |= REDISMODULE_CTX_BLOCKED_REPLY; ctx.blocked_privdata = bc->privdata; ctx.module = bc->module; ctx.client = bc->client; ctx.blocked_client = bc; bc->reply_callback(&ctx,(void**)c->argv,c->argc); moduleHandlePropagationAfterCommandCallback(&ctx); moduleFreeContext(&ctx); } /* Free privdata if any. */ if (bc->privdata && bc->free_privdata) { RedisModuleCtx ctx = REDISMODULE_CTX_INIT; if (c == NULL) ctx.flags |= REDISMODULE_CTX_BLOCKED_DISCONNECTED; ctx.blocked_privdata = bc->privdata; ctx.module = bc->module; ctx.client = bc->client; bc->free_privdata(&ctx,bc->privdata); moduleFreeContext(&ctx); } /* It is possible that this blocked client object accumulated * replies to send to the client in a thread safe context. * We need to glue such replies to the client output buffer and * free the temporary client we just used for the replies. */ if (c) { if (bc->reply_client->bufpos) addReplyString(c,bc->reply_client->buf, bc->reply_client->bufpos); if (listLength(bc->reply_client->reply)) listJoin(c->reply,bc->reply_client->reply); c->reply_bytes += bc->reply_client->reply_bytes; } freeClient(bc->reply_client); if (c != NULL) { /* Before unblocking the client, set the disconnect callback * to NULL, because if we reached this point, the client was * properly unblocked by the module. */ bc->disconnect_callback = NULL; unblockClient(c); /* Put the client in the list of clients that need to write * if there are pending replies here. This is needed since * during a non blocking command the client may receive output. */ if (clientHasPendingReplies(c) && !(c->flags & CLIENT_PENDING_WRITE)) { c->flags |= CLIENT_PENDING_WRITE; listAddNodeHead(server.clients_pending_write,c); } } /* Free 'bc' only after unblocking the client, since it is * referenced in the client blocking context, and must be valid * when calling unblockClient(). */ zfree(bc); /* Lock again before to iterate the loop. */ pthread_mutex_lock(&moduleUnblockedClientsMutex); } pthread_mutex_unlock(&moduleUnblockedClientsMutex); } /* Called when our client timed out. After this function unblockClient() * is called, and it will invalidate the blocked client. So this function * does not need to do any cleanup. Eventually the module will call the * API to unblock the client and the memory will be released. */ void moduleBlockedClientTimedOut(client *c) { RedisModuleBlockedClient *bc = c->bpop.module_blocked_handle; RedisModuleCtx ctx = REDISMODULE_CTX_INIT; ctx.flags |= REDISMODULE_CTX_BLOCKED_TIMEOUT; ctx.module = bc->module; ctx.client = bc->client; ctx.blocked_client = bc; bc->timeout_callback(&ctx,(void**)c->argv,c->argc); moduleFreeContext(&ctx); /* For timeout events, we do not want to call the disconnect callback, * because the blocekd client will be automatically disconnected in * this case, and the user can still hook using the timeout callback. */ bc->disconnect_callback = NULL; } /* Return non-zero if a module command was called in order to fill the * reply for a blocked client. */ int RM_IsBlockedReplyRequest(RedisModuleCtx *ctx) { return (ctx->flags & REDISMODULE_CTX_BLOCKED_REPLY) != 0; } /* Return non-zero if a module command was called in order to fill the * reply for a blocked client that timed out. */ int RM_IsBlockedTimeoutRequest(RedisModuleCtx *ctx) { return (ctx->flags & REDISMODULE_CTX_BLOCKED_TIMEOUT) != 0; } /* Get the privata data set by RedisModule_UnblockClient() */ void *RM_GetBlockedClientPrivateData(RedisModuleCtx *ctx) { return ctx->blocked_privdata; } /* Get the blocked client associated with a given context. * This is useful in the reply and timeout callbacks of blocked clients, * before sometimes the module has the blocked client handle references * around, and wants to cleanup it. */ RedisModuleBlockedClient *RM_GetBlockedClientHandle(RedisModuleCtx *ctx) { return ctx->blocked_client; } /* Return true if when the free callback of a blocked client is called, * the reason for the client to be unblocked is that it disconnected * while it was blocked. */ int RM_BlockedClientDisconnected(RedisModuleCtx *ctx) { return (ctx->flags & REDISMODULE_CTX_BLOCKED_DISCONNECTED) != 0; } /* -------------------------------------------------------------------------- * Thread Safe Contexts * -------------------------------------------------------------------------- */ /* Return a context which can be used inside threads to make Redis context * calls with certain modules APIs. If 'bc' is not NULL then the module will * be bound to a blocked client, and it will be possible to use the * `RedisModule_Reply*` family of functions to accumulate a reply for when the * client will be unblocked. Otherwise the thread safe context will be * detached by a specific client. * * To call non-reply APIs, the thread safe context must be prepared with: * * RedisModule_ThreadSafeCallStart(ctx); * ... make your call here ... * RedisModule_ThreadSafeCallStop(ctx); * * This is not needed when using `RedisModule_Reply*` functions, assuming * that a blocked client was used when the context was created, otherwise * no RedisModule_Reply* call should be made at all. * * TODO: thread safe contexts do not inherit the blocked client * selected database. */ RedisModuleCtx *RM_GetThreadSafeContext(RedisModuleBlockedClient *bc) { RedisModuleCtx *ctx = zmalloc(sizeof(*ctx)); RedisModuleCtx empty = REDISMODULE_CTX_INIT; memcpy(ctx,&empty,sizeof(empty)); if (bc) { ctx->blocked_client = bc; ctx->module = bc->module; } ctx->flags |= REDISMODULE_CTX_THREAD_SAFE; /* Even when the context is associated with a blocked client, we can't * access it safely from another thread, so we create a fake client here * in order to keep things like the currently selected database and similar * things. */ ctx->client = createClient(-1); if (bc) selectDb(ctx->client,bc->dbid); return ctx; } /* Release a thread safe context. */ void RM_FreeThreadSafeContext(RedisModuleCtx *ctx) { moduleFreeContext(ctx); zfree(ctx); } /* Acquire the server lock before executing a thread safe API call. * This is not needed for `RedisModule_Reply*` calls when there is * a blocked client connected to the thread safe context. */ void RM_ThreadSafeContextLock(RedisModuleCtx *ctx) { UNUSED(ctx); moduleAcquireGIL(); } /* Release the server lock after a thread safe API call was executed. */ void RM_ThreadSafeContextUnlock(RedisModuleCtx *ctx) { UNUSED(ctx); moduleReleaseGIL(); } void moduleAcquireGIL(void) { pthread_mutex_lock(&moduleGIL); } void moduleReleaseGIL(void) { pthread_mutex_unlock(&moduleGIL); } /* -------------------------------------------------------------------------- * Module Keyspace Notifications API * -------------------------------------------------------------------------- */ /* Subscribe to keyspace notifications. This is a low-level version of the * keyspace-notifications API. A module cand register callbacks to be notified * when keyspce events occur. * * Notification events are filtered by their type (string events, set events, * etc), and the subsriber callback receives only events that match a specific * mask of event types. * * When subscribing to notifications with RedisModule_SubscribeToKeyspaceEvents * the module must provide an event type-mask, denoting the events the subscriber * is interested in. This can be an ORed mask of any of the following flags: * * - REDISMODULE_NOTIFY_GENERIC: Generic commands like DEL, EXPIRE, RENAME * - REDISMODULE_NOTIFY_STRING: String events * - REDISMODULE_NOTIFY_LIST: List events * - REDISMODULE_NOTIFY_SET: Set events * - REDISMODULE_NOTIFY_HASH: Hash events * - REDISMODULE_NOTIFY_ZSET: Sorted Set events * - REDISMODULE_NOTIFY_EXPIRED: Expiration events * - REDISMODULE_NOTIFY_EVICTED: Eviction events * - REDISMODULE_NOTIFY_STREAM: Stream events * - REDISMODULE_NOTIFY_ALL: All events * * We do not distinguish between key events and keyspace events, and it is up * to the module to filter the actions taken based on the key. * * The subscriber signature is: * * int (*RedisModuleNotificationFunc) (RedisModuleCtx *ctx, int type, * const char *event, * RedisModuleString *key); * * `type` is the event type bit, that must match the mask given at registration * time. The event string is the actual command being executed, and key is the * relevant Redis key. * * Notification callback gets executed with a redis context that can not be * used to send anything to the client, and has the db number where the event * occured as its selected db number. * * Notice that it is not necessary to enable norifications in redis.conf for * module notifications to work. * * Warning: the notification callbacks are performed in a synchronous manner, * so notification callbacks must to be fast, or they would slow Redis down. * If you need to take long actions, use threads to offload them. * * See https://redis.io/topics/notifications for more information. */ int RM_SubscribeToKeyspaceEvents(RedisModuleCtx *ctx, int types, RedisModuleNotificationFunc callback) { RedisModuleKeyspaceSubscriber *sub = zmalloc(sizeof(*sub)); sub->module = ctx->module; sub->event_mask = types; sub->notify_callback = callback; sub->active = 0; listAddNodeTail(moduleKeyspaceSubscribers, sub); return REDISMODULE_OK; } /* Dispatcher for keyspace notifications to module subscriber functions. * This gets called only if at least one module requested to be notified on * keyspace notifications */ void moduleNotifyKeyspaceEvent(int type, const char *event, robj *key, int dbid) { /* Don't do anything if there aren't any subscribers */ if (listLength(moduleKeyspaceSubscribers) == 0) return; listIter li; listNode *ln; listRewind(moduleKeyspaceSubscribers,&li); /* Remove irrelevant flags from the type mask */ type &= ~(NOTIFY_KEYEVENT | NOTIFY_KEYSPACE); while((ln = listNext(&li))) { RedisModuleKeyspaceSubscriber *sub = ln->value; /* Only notify subscribers on events matching they registration, * and avoid subscribers triggering themselves */ if ((sub->event_mask & type) && sub->active == 0) { RedisModuleCtx ctx = REDISMODULE_CTX_INIT; ctx.module = sub->module; ctx.client = moduleKeyspaceSubscribersClient; selectDb(ctx.client, dbid); /* mark the handler as activer to avoid reentrant loops. * If the subscriber performs an action triggering itself, * it will not be notified about it. */ sub->active = 1; sub->notify_callback(&ctx, type, event, key); sub->active = 0; moduleFreeContext(&ctx); } } } /* Unsubscribe any notification subscirbers this module has upon unloading */ void moduleUnsubscribeNotifications(RedisModule *module) { listIter li; listNode *ln; listRewind(moduleKeyspaceSubscribers,&li); while((ln = listNext(&li))) { RedisModuleKeyspaceSubscriber *sub = ln->value; if (sub->module == module) { listDelNode(moduleKeyspaceSubscribers, ln); zfree(sub); } } } /* -------------------------------------------------------------------------- * Modules Cluster API * -------------------------------------------------------------------------- */ /* The Cluster message callback function pointer type. */ typedef void (*RedisModuleClusterMessageReceiver)(RedisModuleCtx *ctx, const char *sender_id, uint8_t type, const unsigned char *payload, uint32_t len); /* This structure identifies a registered caller: it must match a given module * ID, for a given message type. The callback function is just the function * that was registered as receiver. */ typedef struct moduleClusterReceiver { uint64_t module_id; RedisModuleClusterMessageReceiver callback; struct RedisModule *module; struct moduleClusterReceiver *next; } moduleClusterReceiver; typedef struct moduleClusterNodeInfo { int flags; char ip[NET_IP_STR_LEN]; int port; char master_id[40]; /* Only if flags & REDISMODULE_NODE_MASTER is true. */ } mdouleClusterNodeInfo; /* We have an array of message types: each bucket is a linked list of * configured receivers. */ static moduleClusterReceiver *clusterReceivers[UINT8_MAX]; /* Dispatch the message to the right module receiver. */ void moduleCallClusterReceivers(const char *sender_id, uint64_t module_id, uint8_t type, const unsigned char *payload, uint32_t len) { moduleClusterReceiver *r = clusterReceivers[type]; while(r) { if (r->module_id == module_id) { RedisModuleCtx ctx = REDISMODULE_CTX_INIT; ctx.module = r->module; r->callback(&ctx,sender_id,type,payload,len); moduleFreeContext(&ctx); return; } r = r->next; } } /* Register a callback receiver for cluster messages of type 'type'. If there * was already a registered callback, this will replace the callback function * with the one provided, otherwise if the callback is set to NULL and there * is already a callback for this function, the callback is unregistered * (so this API call is also used in order to delete the receiver). */ void RM_RegisterClusterMessageReceiver(RedisModuleCtx *ctx, uint8_t type, RedisModuleClusterMessageReceiver callback) { if (!server.cluster_enabled) return; uint64_t module_id = moduleTypeEncodeId(ctx->module->name,0); moduleClusterReceiver *r = clusterReceivers[type], *prev = NULL; while(r) { if (r->module_id == module_id) { /* Found! Set or delete. */ if (callback) { r->callback = callback; } else { /* Delete the receiver entry if the user is setting * it to NULL. Just unlink the receiver node from the * linked list. */ if (prev) prev->next = r->next; else clusterReceivers[type]->next = r->next; zfree(r); } return; } prev = r; r = r->next; } /* Not found, let's add it. */ if (callback) { r = zmalloc(sizeof(*r)); r->module_id = module_id; r->module = ctx->module; r->callback = callback; r->next = clusterReceivers[type]; clusterReceivers[type] = r; } } /* Send a message to all the nodes in the cluster if `target` is NULL, otherwise * at the specified target, which is a REDISMODULE_NODE_ID_LEN bytes node ID, as * returned by the receiver callback or by the nodes iteration functions. * * The function returns REDISMODULE_OK if the message was successfully sent, * otherwise if the node is not connected or such node ID does not map to any * known cluster node, REDISMODULE_ERR is returned. */ int RM_SendClusterMessage(RedisModuleCtx *ctx, char *target_id, uint8_t type, unsigned char *msg, uint32_t len) { if (!server.cluster_enabled) return REDISMODULE_ERR; uint64_t module_id = moduleTypeEncodeId(ctx->module->name,0); if (clusterSendModuleMessageToTarget(target_id,module_id,type,msg,len) == C_OK) return REDISMODULE_OK; else return REDISMODULE_ERR; } /* Return an array of string pointers, each string pointer points to a cluster * node ID of exactly REDISMODULE_NODE_ID_SIZE bytes (without any null term). * The number of returned node IDs is stored into `*numnodes`. * However if this function is called by a module not running an a Redis * instance with Redis Cluster enabled, NULL is returned instead. * * The IDs returned can be used with RedisModule_GetClusterNodeInfo() in order * to get more information about single nodes. * * The array returned by this function must be freed using the function * RedisModule_FreeClusterNodesList(). * * Example: * * size_t count, j; * char **ids = RedisModule_GetClusterNodesList(ctx,&count); * for (j = 0; j < count; j++) { * RedisModule_Log("notice","Node %.*s", * REDISMODULE_NODE_ID_LEN,ids[j]); * } * RedisModule_FreeClusterNodesList(ids); */ char **RM_GetClusterNodesList(RedisModuleCtx *ctx, size_t *numnodes) { UNUSED(ctx); if (!server.cluster_enabled) return NULL; size_t count = dictSize(server.cluster->nodes); char **ids = zmalloc((count+1)*REDISMODULE_NODE_ID_LEN); dictIterator *di = dictGetIterator(server.cluster->nodes); dictEntry *de; int j = 0; while((de = dictNext(di)) != NULL) { clusterNode *node = dictGetVal(de); if (node->flags & (CLUSTER_NODE_NOADDR|CLUSTER_NODE_HANDSHAKE)) continue; ids[j] = zmalloc(REDISMODULE_NODE_ID_LEN); memcpy(ids[j],node->name,REDISMODULE_NODE_ID_LEN); j++; } *numnodes = j; ids[j] = NULL; /* Null term so that FreeClusterNodesList does not need * to also get the count argument. */ dictReleaseIterator(di); return ids; } /* Free the node list obtained with RedisModule_GetClusterNodesList. */ void RM_FreeClusterNodesList(char **ids) { if (ids == NULL) return; for (int j = 0; ids[j]; j++) zfree(ids[j]); zfree(ids); } /* Return this node ID (REDISMODULE_CLUSTER_ID_LEN bytes) or NULL if the cluster * is disabled. */ const char *RM_GetMyClusterID(void) { if (!server.cluster_enabled) return NULL; return server.cluster->myself->name; } /* Return the number of nodes in the cluster, regardless of their state * (handshake, noaddress, ...) so that the number of active nodes may actually * be smaller, but not greater than this number. If the instance is not in * cluster mode, zero is returned. */ size_t RM_GetClusterSize(void) { if (!server.cluster_enabled) return 0; return dictSize(server.cluster->nodes); } /* Populate the specified info for the node having as ID the specified 'id', * then returns REDISMODULE_OK. Otherwise if the node ID does not exist from * the POV of this local node, REDISMODULE_ERR is returned. * * The arguments ip, master_id, port and flags can be NULL in case we don't * need to populate back certain info. If an ip and master_id (only populated * if the instance is a slave) are specified, they point to buffers holding * at least REDISMODULE_NODE_ID_LEN bytes. The strings written back as ip * and master_id are not null terminated. * * The list of flags reported is the following: * * * REDISMODULE_NODE_MYSELF This node * * REDISMODULE_NODE_MASTER The node is a master * * REDISMODULE_NODE_SLAVE The ndoe is a slave * * REDISMODULE_NODE_PFAIL We see the node as failing * * REDISMODULE_NODE_FAIL The cluster agrees the node is failing * * REDISMODULE_NODE_NOFAILOVER The slave is configured to never failover */ clusterNode *clusterLookupNode(const char *name); /* We need access to internals */ int RM_GetClusterNodeInfo(RedisModuleCtx *ctx, const char *id, char *ip, char *master_id, int *port, int *flags) { UNUSED(ctx); clusterNode *node = clusterLookupNode(id); if (node->flags & (CLUSTER_NODE_NOADDR|CLUSTER_NODE_HANDSHAKE)) return REDISMODULE_ERR; if (ip) memcpy(ip,node->name,REDISMODULE_NODE_ID_LEN); if (master_id) { /* If the information is not available, the function will set the * field to zero bytes, so that when the field can't be populated the * function kinda remains predictable. */ if (node->flags & CLUSTER_NODE_MASTER && node->slaveof) memcpy(master_id,node->slaveof->name,REDISMODULE_NODE_ID_LEN); else memset(master_id,0,REDISMODULE_NODE_ID_LEN); } if (port) *port = node->port; /* As usually we have to remap flags for modules, in order to ensure * we can provide binary compatibility. */ if (flags) { *flags = 0; if (node->flags & CLUSTER_NODE_MYSELF) *flags |= REDISMODULE_NODE_MYSELF; if (node->flags & CLUSTER_NODE_MASTER) *flags |= REDISMODULE_NODE_MASTER; if (node->flags & CLUSTER_NODE_SLAVE) *flags |= REDISMODULE_NODE_SLAVE; if (node->flags & CLUSTER_NODE_PFAIL) *flags |= REDISMODULE_NODE_PFAIL; if (node->flags & CLUSTER_NODE_FAIL) *flags |= REDISMODULE_NODE_FAIL; if (node->flags & CLUSTER_NODE_NOFAILOVER) *flags |= REDISMODULE_NODE_NOFAILOVER; } return REDISMODULE_OK; } /* -------------------------------------------------------------------------- * Modules Timers API * * Module timers are an high precision "green timers" abstraction where * every module can register even millions of timers without problems, even if * the actual event loop will just have a single timer that is used to awake the * module timers subsystem in order to process the next event. * * All the timers are stored into a radix tree, ordered by expire time, when * the main Redis event loop timer callback is called, we try to process all * the timers already expired one after the other. Then we re-enter the event * loop registering a timer that will expire when the next to process module * timer will expire. * * Every time the list of active timers drops to zero, we unregister the * main event loop timer, so that there is no overhead when such feature is * not used. * -------------------------------------------------------------------------- */ static rax *Timers; /* The radix tree of all the timers sorted by expire. */ long long aeTimer = -1; /* Main event loop (ae.c) timer identifier. */ typedef void (*RedisModuleTimerProc)(RedisModuleCtx *ctx, void *data); /* The timer descriptor, stored as value in the radix tree. */ typedef struct RedisModuleTimer { RedisModule *module; /* Module reference. */ RedisModuleTimerProc callback; /* The callback to invoke on expire. */ void *data; /* Private data for the callback. */ } RedisModuleTimer; /* This is the timer handler that is called by the main event loop. We schedule * this timer to be called when the nearest of our module timers will expire. */ int moduleTimerHandler(struct aeEventLoop *eventLoop, long long id, void *clientData) { UNUSED(eventLoop); UNUSED(id); UNUSED(clientData); /* To start let's try to fire all the timers already expired. */ raxIterator ri; raxStart(&ri,Timers); uint64_t now = ustime(); long long next_period = 0; while(1) { raxSeek(&ri,"^",NULL,0); if (!raxNext(&ri)) break; uint64_t expiretime; memcpy(&expiretime,ri.key,sizeof(expiretime)); expiretime = ntohu64(expiretime); if (now >= expiretime) { RedisModuleTimer *timer = ri.data; RedisModuleCtx ctx = REDISMODULE_CTX_INIT; ctx.module = timer->module; timer->callback(&ctx,timer->data); moduleFreeContext(&ctx); raxRemove(Timers,(unsigned char*)ri.key,ri.key_len,NULL); zfree(timer); } else { next_period = (expiretime-now)/1000; /* Scale to milliseconds. */ break; } } raxStop(&ri); /* Reschedule the next timer or cancel it. */ if (next_period <= 0) next_period = 1; return (raxSize(Timers) > 0) ? next_period : AE_NOMORE; } /* Create a new timer that will fire after `period` milliseconds, and will call * the specified function using `data` as argument. The returned timer ID can be * used to get information from the timer or to stop it before it fires. */ RedisModuleTimerID RM_CreateTimer(RedisModuleCtx *ctx, mstime_t period, RedisModuleTimerProc callback, void *data) { RedisModuleTimer *timer = zmalloc(sizeof(*timer)); timer->module = ctx->module; timer->callback = callback; timer->data = data; uint64_t expiretime = ustime()+period*1000; uint64_t key; while(1) { key = htonu64(expiretime); if (raxFind(Timers, (unsigned char*)&key,sizeof(key)) == raxNotFound) { raxInsert(Timers,(unsigned char*)&key,sizeof(key),timer,NULL); break; } else { expiretime++; } } /* We need to install the main event loop timer if it's not already * installed, or we may need to refresh its period if we just installed * a timer that will expire sooner than any other else. */ if (aeTimer != -1) { raxIterator ri; raxStart(&ri,Timers); raxSeek(&ri,"^",NULL,0); raxNext(&ri); if (memcmp(ri.key,&key,sizeof(key)) == 0) { /* This is the first key, we need to re-install the timer according * to the just added event. */ aeDeleteTimeEvent(server.el,aeTimer); aeTimer = -1; } raxStop(&ri); } /* If we have no main timer (the old one was invalidated, or this is the * first module timer we have), install one. */ if (aeTimer == -1) aeTimer = aeCreateTimeEvent(server.el,period,moduleTimerHandler,NULL,NULL); return key; } /* Stop a timer, returns REDISMODULE_OK if the timer was found, belonged to the * calling module, and was stoped, otherwise REDISMODULE_ERR is returned. * If not NULL, the data pointer is set to the value of the data argument when * the timer was created. */ int RM_StopTimer(RedisModuleCtx *ctx, RedisModuleTimerID id, void **data) { RedisModuleTimer *timer = raxFind(Timers,(unsigned char*)&id,sizeof(id)); if (timer == raxNotFound || timer->module != ctx->module) return REDISMODULE_ERR; if (data) *data = timer->data; raxRemove(Timers,(unsigned char*)&id,sizeof(id),NULL); zfree(timer); return REDISMODULE_OK; } /* Obtain information about a timer: its remaining time before firing * (in milliseconds), and the private data pointer associated with the timer. * If the timer specified does not exist or belongs to a different module * no information is returned and the function returns REDISMODULE_ERR, otherwise * REDISMODULE_OK is returned. The argumnets remaining or data can be NULL if * the caller does not need certain information. */ int RM_GetTimerInfo(RedisModuleCtx *ctx, RedisModuleTimerID id, uint64_t *remaining, void **data) { RedisModuleTimer *timer = raxFind(Timers,(unsigned char*)&id,sizeof(id)); if (timer == raxNotFound || timer->module != ctx->module) return REDISMODULE_ERR; if (remaining) { int64_t rem = ntohu64(id)-ustime(); if (rem < 0) rem = 0; *remaining = rem/1000; /* Scale to milliseconds. */ } if (data) *data = timer->data; return REDISMODULE_OK; } /* -------------------------------------------------------------------------- * Modules utility APIs * -------------------------------------------------------------------------- */ /* Return random bytes using SHA1 in counter mode with a /dev/urandom * initialized seed. This function is fast so can be used to generate * many bytes without any effect on the operating system entropy pool. * Currently this function is not thread safe. */ void RM_GetRandomBytes(unsigned char *dst, size_t len) { getRandomBytes(dst,len); } /* Like RedisModule_GetRandomBytes() but instead of setting the string to * random bytes the string is set to random characters in the in the * hex charset [0-9a-f]. */ void RM_GetRandomHexChars(char *dst, size_t len) { getRandomHexChars(dst,len); } /* -------------------------------------------------------------------------- * Modules API internals * -------------------------------------------------------------------------- */ /* server.moduleapi dictionary type. Only uses plain C strings since * this gets queries from modules. */ uint64_t dictCStringKeyHash(const void *key) { return dictGenHashFunction((unsigned char*)key, strlen((char*)key)); } int dictCStringKeyCompare(void *privdata, const void *key1, const void *key2) { UNUSED(privdata); return strcmp(key1,key2) == 0; } dictType moduleAPIDictType = { dictCStringKeyHash, /* hash function */ NULL, /* key dup */ NULL, /* val dup */ dictCStringKeyCompare, /* key compare */ NULL, /* key destructor */ NULL /* val destructor */ }; int moduleRegisterApi(const char *funcname, void *funcptr) { return dictAdd(server.moduleapi, (char*)funcname, funcptr); } #define REGISTER_API(name) \ moduleRegisterApi("RedisModule_" #name, (void *)(unsigned long)RM_ ## name) /* Global initialization at Redis startup. */ void moduleRegisterCoreAPI(void); void moduleInitModulesSystem(void) { moduleUnblockedClients = listCreate(); server.loadmodule_queue = listCreate(); modules = dictCreate(&modulesDictType,NULL); /* Set up the keyspace notification susbscriber list and static client */ moduleKeyspaceSubscribers = listCreate(); moduleKeyspaceSubscribersClient = createClient(-1); moduleKeyspaceSubscribersClient->flags |= CLIENT_MODULE; moduleRegisterCoreAPI(); if (pipe(server.module_blocked_pipe) == -1) { serverLog(LL_WARNING, "Can't create the pipe for module blocking commands: %s", strerror(errno)); exit(1); } /* Make the pipe non blocking. This is just a best effort aware mechanism * and we do not want to block not in the read nor in the write half. */ anetNonBlock(NULL,server.module_blocked_pipe[0]); anetNonBlock(NULL,server.module_blocked_pipe[1]); /* Create the timers radix tree. */ Timers = raxNew(); /* Our thread-safe contexts GIL must start with already locked: * it is just unlocked when it's safe. */ pthread_mutex_lock(&moduleGIL); } /* Load all the modules in the server.loadmodule_queue list, which is * populated by `loadmodule` directives in the configuration file. * We can't load modules directly when processing the configuration file * because the server must be fully initialized before loading modules. * * The function aborts the server on errors, since to start with missing * modules is not considered sane: clients may rely on the existance of * given commands, loading AOF also may need some modules to exist, and * if this instance is a slave, it must understand commands from master. */ void moduleLoadFromQueue(void) { listIter li; listNode *ln; listRewind(server.loadmodule_queue,&li); while((ln = listNext(&li))) { struct moduleLoadQueueEntry *loadmod = ln->value; if (moduleLoad(loadmod->path,(void **)loadmod->argv,loadmod->argc) == C_ERR) { serverLog(LL_WARNING, "Can't load module from %s: server aborting", loadmod->path); exit(1); } } } void moduleFreeModuleStructure(struct RedisModule *module) { listRelease(module->types); sdsfree(module->name); zfree(module); } void moduleUnregisterCommands(struct RedisModule *module) { /* Unregister all the commands registered by this module. */ dictIterator *di = dictGetSafeIterator(server.commands); dictEntry *de; while ((de = dictNext(di)) != NULL) { struct redisCommand *cmd = dictGetVal(de); if (cmd->proc == RedisModuleCommandDispatcher) { RedisModuleCommandProxy *cp = (void*)(unsigned long)cmd->getkeys_proc; sds cmdname = cp->rediscmd->name; if (cp->module == module) { dictDelete(server.commands,cmdname); dictDelete(server.orig_commands,cmdname); sdsfree(cmdname); zfree(cp->rediscmd); zfree(cp); } } } dictReleaseIterator(di); } /* Load a module and initialize it. On success C_OK is returned, otherwise * C_ERR is returned. */ int moduleLoad(const char *path, void **module_argv, int module_argc) { int (*onload)(void *, void **, int); void *handle; RedisModuleCtx ctx = REDISMODULE_CTX_INIT; handle = dlopen(path,RTLD_NOW|RTLD_LOCAL); if (handle == NULL) { serverLog(LL_WARNING, "Module %s failed to load: %s", path, dlerror()); return C_ERR; } onload = (int (*)(void *, void **, int))(unsigned long) dlsym(handle,"RedisModule_OnLoad"); if (onload == NULL) { dlclose(handle); serverLog(LL_WARNING, "Module %s does not export RedisModule_OnLoad() " "symbol. Module not loaded.",path); return C_ERR; } if (onload((void*)&ctx,module_argv,module_argc) == REDISMODULE_ERR) { if (ctx.module) { moduleUnregisterCommands(ctx.module); moduleFreeModuleStructure(ctx.module); } dlclose(handle); serverLog(LL_WARNING, "Module %s initialization failed. Module not loaded",path); return C_ERR; } /* Redis module loaded! Register it. */ dictAdd(modules,ctx.module->name,ctx.module); ctx.module->handle = handle; serverLog(LL_NOTICE,"Module '%s' loaded from %s",ctx.module->name,path); moduleFreeContext(&ctx); return C_OK; } /* Unload the module registered with the specified name. On success * C_OK is returned, otherwise C_ERR is returned and errno is set * to the following values depending on the type of error: * * * ENONET: No such module having the specified name. * * EBUSY: The module exports a new data type and can only be reloaded. */ int moduleUnload(sds name) { struct RedisModule *module = dictFetchValue(modules,name); if (module == NULL) { errno = ENOENT; return REDISMODULE_ERR; } if (listLength(module->types)) { errno = EBUSY; return REDISMODULE_ERR; } moduleUnregisterCommands(module); /* Remvoe any noification subscribers this module might have */ moduleUnsubscribeNotifications(module); /* Unregister all the hooks. TODO: Yet no hooks support here. */ /* Unload the dynamic library. */ if (dlclose(module->handle) == -1) { char *error = dlerror(); if (error == NULL) error = "Unknown error"; serverLog(LL_WARNING,"Error when trying to close the %s module: %s", module->name, error); } /* Remove from list of modules. */ serverLog(LL_NOTICE,"Module %s unloaded",module->name); dictDelete(modules,module->name); module->name = NULL; /* The name was already freed by dictDelete(). */ moduleFreeModuleStructure(module); return REDISMODULE_OK; } /* Redis MODULE command. * * MODULE LOAD [args...] */ void moduleCommand(client *c) { char *subcmd = c->argv[1]->ptr; if (!strcasecmp(subcmd,"load") && c->argc >= 3) { robj **argv = NULL; int argc = 0; if (c->argc > 3) { argc = c->argc - 3; argv = &c->argv[3]; } if (moduleLoad(c->argv[2]->ptr,(void **)argv,argc) == C_OK) addReply(c,shared.ok); else addReplyError(c, "Error loading the extension. Please check the server logs."); } else if (!strcasecmp(subcmd,"unload") && c->argc == 3) { if (moduleUnload(c->argv[2]->ptr) == C_OK) addReply(c,shared.ok); else { char *errmsg; switch(errno) { case ENOENT: errmsg = "no such module with that name"; break; case EBUSY: errmsg = "the module exports one or more module-side data types, can't unload"; break; default: errmsg = "operation not possible."; break; } addReplyErrorFormat(c,"Error unloading module: %s",errmsg); } } else if (!strcasecmp(subcmd,"list") && c->argc == 2) { dictIterator *di = dictGetIterator(modules); dictEntry *de; addReplyMultiBulkLen(c,dictSize(modules)); while ((de = dictNext(di)) != NULL) { sds name = dictGetKey(de); struct RedisModule *module = dictGetVal(de); addReplyMultiBulkLen(c,4); addReplyBulkCString(c,"name"); addReplyBulkCBuffer(c,name,sdslen(name)); addReplyBulkCString(c,"ver"); addReplyLongLong(c,module->ver); } dictReleaseIterator(di); } else { addReply(c,shared.syntaxerr); } } /* Return the number of registered modules. */ size_t moduleCount(void) { return dictSize(modules); } /* Register all the APIs we export. Keep this function at the end of the * file so that's easy to seek it to add new entries. */ void moduleRegisterCoreAPI(void) { server.moduleapi = dictCreate(&moduleAPIDictType,NULL); REGISTER_API(Alloc); REGISTER_API(Calloc); REGISTER_API(Realloc); REGISTER_API(Free); REGISTER_API(Strdup); REGISTER_API(CreateCommand); REGISTER_API(SetModuleAttribs); REGISTER_API(IsModuleNameBusy); REGISTER_API(WrongArity); REGISTER_API(ReplyWithLongLong); REGISTER_API(ReplyWithError); REGISTER_API(ReplyWithSimpleString); REGISTER_API(ReplyWithArray); REGISTER_API(ReplySetArrayLength); REGISTER_API(ReplyWithString); REGISTER_API(ReplyWithStringBuffer); REGISTER_API(ReplyWithNull); REGISTER_API(ReplyWithCallReply); REGISTER_API(ReplyWithDouble); REGISTER_API(GetSelectedDb); REGISTER_API(SelectDb); REGISTER_API(OpenKey); REGISTER_API(CloseKey); REGISTER_API(KeyType); REGISTER_API(ValueLength); REGISTER_API(ListPush); REGISTER_API(ListPop); REGISTER_API(StringToLongLong); REGISTER_API(StringToDouble); REGISTER_API(Call); REGISTER_API(CallReplyProto); REGISTER_API(FreeCallReply); REGISTER_API(CallReplyInteger); REGISTER_API(CallReplyType); REGISTER_API(CallReplyLength); REGISTER_API(CallReplyArrayElement); REGISTER_API(CallReplyStringPtr); REGISTER_API(CreateStringFromCallReply); REGISTER_API(CreateString); REGISTER_API(CreateStringFromLongLong); REGISTER_API(CreateStringFromString); REGISTER_API(CreateStringPrintf); REGISTER_API(FreeString); REGISTER_API(StringPtrLen); REGISTER_API(AutoMemory); REGISTER_API(Replicate); REGISTER_API(ReplicateVerbatim); REGISTER_API(DeleteKey); REGISTER_API(UnlinkKey); REGISTER_API(StringSet); REGISTER_API(StringDMA); REGISTER_API(StringTruncate); REGISTER_API(SetExpire); REGISTER_API(GetExpire); REGISTER_API(ZsetAdd); REGISTER_API(ZsetIncrby); REGISTER_API(ZsetScore); REGISTER_API(ZsetRem); REGISTER_API(ZsetRangeStop); REGISTER_API(ZsetFirstInScoreRange); REGISTER_API(ZsetLastInScoreRange); REGISTER_API(ZsetFirstInLexRange); REGISTER_API(ZsetLastInLexRange); REGISTER_API(ZsetRangeCurrentElement); REGISTER_API(ZsetRangeNext); REGISTER_API(ZsetRangePrev); REGISTER_API(ZsetRangeEndReached); REGISTER_API(HashSet); REGISTER_API(HashGet); REGISTER_API(IsKeysPositionRequest); REGISTER_API(KeyAtPos); REGISTER_API(GetClientId); REGISTER_API(GetContextFlags); REGISTER_API(PoolAlloc); REGISTER_API(CreateDataType); REGISTER_API(ModuleTypeSetValue); REGISTER_API(ModuleTypeGetType); REGISTER_API(ModuleTypeGetValue); REGISTER_API(SaveUnsigned); REGISTER_API(LoadUnsigned); REGISTER_API(SaveSigned); REGISTER_API(LoadSigned); REGISTER_API(SaveString); REGISTER_API(SaveStringBuffer); REGISTER_API(LoadString); REGISTER_API(LoadStringBuffer); REGISTER_API(SaveDouble); REGISTER_API(LoadDouble); REGISTER_API(SaveFloat); REGISTER_API(LoadFloat); REGISTER_API(EmitAOF); REGISTER_API(Log); REGISTER_API(LogIOError); REGISTER_API(StringAppendBuffer); REGISTER_API(RetainString); REGISTER_API(StringCompare); REGISTER_API(GetContextFromIO); REGISTER_API(BlockClient); REGISTER_API(UnblockClient); REGISTER_API(IsBlockedReplyRequest); REGISTER_API(IsBlockedTimeoutRequest); REGISTER_API(GetBlockedClientPrivateData); REGISTER_API(AbortBlock); REGISTER_API(Milliseconds); REGISTER_API(GetThreadSafeContext); REGISTER_API(FreeThreadSafeContext); REGISTER_API(ThreadSafeContextLock); REGISTER_API(ThreadSafeContextUnlock); REGISTER_API(DigestAddStringBuffer); REGISTER_API(DigestAddLongLong); REGISTER_API(DigestEndSequence); REGISTER_API(SubscribeToKeyspaceEvents); REGISTER_API(RegisterClusterMessageReceiver); REGISTER_API(SendClusterMessage); REGISTER_API(GetClusterNodeInfo); REGISTER_API(GetClusterNodesList); REGISTER_API(FreeClusterNodesList); REGISTER_API(CreateTimer); REGISTER_API(StopTimer); REGISTER_API(GetTimerInfo); REGISTER_API(GetMyClusterID); REGISTER_API(GetClusterSize); REGISTER_API(GetRandomBytes); REGISTER_API(GetRandomHexChars); REGISTER_API(BlockedClientDisconnected); REGISTER_API(SetDisconnectCallback); REGISTER_API(GetBlockedClientHandle); }