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Diffstat (limited to 'extra/libevent/evrpc.h')
| -rw-r--r-- | extra/libevent/evrpc.h | 477 |
1 files changed, 0 insertions, 477 deletions
diff --git a/extra/libevent/evrpc.h b/extra/libevent/evrpc.h deleted file mode 100644 index 45f684ac5ac..00000000000 --- a/extra/libevent/evrpc.h +++ /dev/null @@ -1,477 +0,0 @@ -/* - * Copyright (c) 2006 Niels Provos <provos@citi.umich.edu> - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. 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. - * 3. The name of the author may not be used to endorse or promote products - * derived from this software without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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. - */ -#ifndef _EVRPC_H_ -#define _EVRPC_H_ - -#ifdef __cplusplus -extern "C" { -#endif - -/** @file evrpc.h - * - * This header files provides basic support for an RPC server and client. - * - * To support RPCs in a server, every supported RPC command needs to be - * defined and registered. - * - * EVRPC_HEADER(SendCommand, Request, Reply); - * - * SendCommand is the name of the RPC command. - * Request is the name of a structure generated by event_rpcgen.py. - * It contains all parameters relating to the SendCommand RPC. The - * server needs to fill in the Reply structure. - * Reply is the name of a structure generated by event_rpcgen.py. It - * contains the answer to the RPC. - * - * To register an RPC with an HTTP server, you need to first create an RPC - * base with: - * - * struct evrpc_base *base = evrpc_init(http); - * - * A specific RPC can then be registered with - * - * EVRPC_REGISTER(base, SendCommand, Request, Reply, FunctionCB, arg); - * - * when the server receives an appropriately formatted RPC, the user callback - * is invokved. The callback needs to fill in the reply structure. - * - * void FunctionCB(EVRPC_STRUCT(SendCommand)* rpc, void *arg); - * - * To send the reply, call EVRPC_REQUEST_DONE(rpc); - * - * See the regression test for an example. - */ - -struct evbuffer; -struct event_base; -struct evrpc_req_generic; - -/* Encapsulates a request */ -struct evrpc { - TAILQ_ENTRY(evrpc) next; - - /* the URI at which the request handler lives */ - const char* uri; - - /* creates a new request structure */ - void *(*request_new)(void); - - /* frees the request structure */ - void (*request_free)(void *); - - /* unmarshals the buffer into the proper request structure */ - int (*request_unmarshal)(void *, struct evbuffer *); - - /* creates a new reply structure */ - void *(*reply_new)(void); - - /* creates a new reply structure */ - void (*reply_free)(void *); - - /* verifies that the reply is valid */ - int (*reply_complete)(void *); - - /* marshals the reply into a buffer */ - void (*reply_marshal)(struct evbuffer*, void *); - - /* the callback invoked for each received rpc */ - void (*cb)(struct evrpc_req_generic *, void *); - void *cb_arg; - - /* reference for further configuration */ - struct evrpc_base *base; -}; - -/** The type of a specific RPC Message - * - * @param rpcname the name of the RPC message - */ -#define EVRPC_STRUCT(rpcname) struct evrpc_req__##rpcname - -struct evhttp_request; -struct evrpc_status; - -/* We alias the RPC specific structs to this voided one */ -struct evrpc_req_generic { - /* the unmarshaled request object */ - void *request; - - /* the empty reply object that needs to be filled in */ - void *reply; - - /* - * the static structure for this rpc; that can be used to - * automatically unmarshal and marshal the http buffers. - */ - struct evrpc *rpc; - - /* - * the http request structure on which we need to answer. - */ - struct evhttp_request* http_req; - - /* - * callback to reply and finish answering this rpc - */ - void (*done)(struct evrpc_req_generic* rpc); -}; - -/** Creates the definitions and prototypes for an RPC - * - * You need to use EVRPC_HEADER to create structures and function prototypes - * needed by the server and client implementation. The structures have to be - * defined in an .rpc file and converted to source code via event_rpcgen.py - * - * @param rpcname the name of the RPC - * @param reqstruct the name of the RPC request structure - * @param replystruct the name of the RPC reply structure - * @see EVRPC_GENERATE() - */ -#define EVRPC_HEADER(rpcname, reqstruct, rplystruct) \ -EVRPC_STRUCT(rpcname) { \ - struct reqstruct* request; \ - struct rplystruct* reply; \ - struct evrpc* rpc; \ - struct evhttp_request* http_req; \ - void (*done)(struct evrpc_status *, \ - struct evrpc* rpc, void *request, void *reply); \ -}; \ -int evrpc_send_request_##rpcname(struct evrpc_pool *, \ - struct reqstruct *, struct rplystruct *, \ - void (*)(struct evrpc_status *, \ - struct reqstruct *, struct rplystruct *, void *cbarg), \ - void *); - -/** Generates the code for receiving and sending an RPC message - * - * EVRPC_GENERATE is used to create the code corresponding to sending - * and receiving a particular RPC message - * - * @param rpcname the name of the RPC - * @param reqstruct the name of the RPC request structure - * @param replystruct the name of the RPC reply structure - * @see EVRPC_HEADER() - */ -#define EVRPC_GENERATE(rpcname, reqstruct, rplystruct) \ -int evrpc_send_request_##rpcname(struct evrpc_pool *pool, \ - struct reqstruct *request, struct rplystruct *reply, \ - void (*cb)(struct evrpc_status *, \ - struct reqstruct *, struct rplystruct *, void *cbarg), \ - void *cbarg) { \ - struct evrpc_status status; \ - struct evrpc_request_wrapper *ctx; \ - ctx = (struct evrpc_request_wrapper *) \ - malloc(sizeof(struct evrpc_request_wrapper)); \ - if (ctx == NULL) \ - goto error; \ - ctx->pool = pool; \ - ctx->evcon = NULL; \ - ctx->name = strdup(#rpcname); \ - if (ctx->name == NULL) { \ - free(ctx); \ - goto error; \ - } \ - ctx->cb = (void (*)(struct evrpc_status *, \ - void *, void *, void *))cb; \ - ctx->cb_arg = cbarg; \ - ctx->request = (void *)request; \ - ctx->reply = (void *)reply; \ - ctx->request_marshal = (void (*)(struct evbuffer *, void *))reqstruct##_marshal; \ - ctx->reply_clear = (void (*)(void *))rplystruct##_clear; \ - ctx->reply_unmarshal = (int (*)(void *, struct evbuffer *))rplystruct##_unmarshal; \ - return (evrpc_make_request(ctx)); \ -error: \ - memset(&status, 0, sizeof(status)); \ - status.error = EVRPC_STATUS_ERR_UNSTARTED; \ - (*(cb))(&status, request, reply, cbarg); \ - return (-1); \ -} - -/** Provides access to the HTTP request object underlying an RPC - * - * Access to the underlying http object; can be used to look at headers or - * for getting the remote ip address - * - * @param rpc_req the rpc request structure provided to the server callback - * @return an struct evhttp_request object that can be inspected for - * HTTP headers or sender information. - */ -#define EVRPC_REQUEST_HTTP(rpc_req) (rpc_req)->http_req - -/** Creates the reply to an RPC request - * - * EVRPC_REQUEST_DONE is used to answer a request; the reply is expected - * to have been filled in. The request and reply pointers become invalid - * after this call has finished. - * - * @param rpc_req the rpc request structure provided to the server callback - */ -#define EVRPC_REQUEST_DONE(rpc_req) do { \ - struct evrpc_req_generic *_req = (struct evrpc_req_generic *)(rpc_req); \ - _req->done(_req); \ -} while (0) - - -/* Takes a request object and fills it in with the right magic */ -#define EVRPC_REGISTER_OBJECT(rpc, name, request, reply) \ - do { \ - (rpc)->uri = strdup(#name); \ - if ((rpc)->uri == NULL) { \ - fprintf(stderr, "failed to register object\n"); \ - exit(1); \ - } \ - (rpc)->request_new = (void *(*)(void))request##_new; \ - (rpc)->request_free = (void (*)(void *))request##_free; \ - (rpc)->request_unmarshal = (int (*)(void *, struct evbuffer *))request##_unmarshal; \ - (rpc)->reply_new = (void *(*)(void))reply##_new; \ - (rpc)->reply_free = (void (*)(void *))reply##_free; \ - (rpc)->reply_complete = (int (*)(void *))reply##_complete; \ - (rpc)->reply_marshal = (void (*)(struct evbuffer*, void *))reply##_marshal; \ - } while (0) - -struct evrpc_base; -struct evhttp; - -/* functions to start up the rpc system */ - -/** Creates a new rpc base from which RPC requests can be received - * - * @param server a pointer to an existing HTTP server - * @return a newly allocated evrpc_base struct - * @see evrpc_free() - */ -struct evrpc_base *evrpc_init(struct evhttp *server); - -/** - * Frees the evrpc base - * - * For now, you are responsible for making sure that no rpcs are ongoing. - * - * @param base the evrpc_base object to be freed - * @see evrpc_init - */ -void evrpc_free(struct evrpc_base *base); - -/** register RPCs with the HTTP Server - * - * registers a new RPC with the HTTP server, each RPC needs to have - * a unique name under which it can be identified. - * - * @param base the evrpc_base structure in which the RPC should be - * registered. - * @param name the name of the RPC - * @param request the name of the RPC request structure - * @param reply the name of the RPC reply structure - * @param callback the callback that should be invoked when the RPC - * is received. The callback has the following prototype - * void (*callback)(EVRPC_STRUCT(Message)* rpc, void *arg) - * @param cbarg an additional parameter that can be passed to the callback. - * The parameter can be used to carry around state. - */ -#define EVRPC_REGISTER(base, name, request, reply, callback, cbarg) \ - do { \ - struct evrpc* rpc = (struct evrpc *)calloc(1, sizeof(struct evrpc)); \ - EVRPC_REGISTER_OBJECT(rpc, name, request, reply); \ - evrpc_register_rpc(base, rpc, \ - (void (*)(struct evrpc_req_generic*, void *))callback, cbarg); \ - } while (0) - -int evrpc_register_rpc(struct evrpc_base *, struct evrpc *, - void (*)(struct evrpc_req_generic*, void *), void *); - -/** - * Unregisters an already registered RPC - * - * @param base the evrpc_base object from which to unregister an RPC - * @param name the name of the rpc to unregister - * @return -1 on error or 0 when successful. - * @see EVRPC_REGISTER() - */ -#define EVRPC_UNREGISTER(base, name) evrpc_unregister_rpc(base, #name) - -int evrpc_unregister_rpc(struct evrpc_base *base, const char *name); - -/* - * Client-side RPC support - */ - -struct evrpc_pool; -struct evhttp_connection; - -/** - * provides information about the completed RPC request. - */ -struct evrpc_status { -#define EVRPC_STATUS_ERR_NONE 0 -#define EVRPC_STATUS_ERR_TIMEOUT 1 -#define EVRPC_STATUS_ERR_BADPAYLOAD 2 -#define EVRPC_STATUS_ERR_UNSTARTED 3 -#define EVRPC_STATUS_ERR_HOOKABORTED 4 - int error; - - /* for looking at headers or other information */ - struct evhttp_request *http_req; -}; - -struct evrpc_request_wrapper { - TAILQ_ENTRY(evrpc_request_wrapper) next; - - /* pool on which this rpc request is being made */ - struct evrpc_pool *pool; - - /* connection on which the request is being sent */ - struct evhttp_connection *evcon; - - /* event for implementing request timeouts */ - struct event ev_timeout; - - /* the name of the rpc */ - char *name; - - /* callback */ - void (*cb)(struct evrpc_status*, void *request, void *reply, void *arg); - void *cb_arg; - - void *request; - void *reply; - - /* unmarshals the buffer into the proper request structure */ - void (*request_marshal)(struct evbuffer *, void *); - - /* removes all stored state in the reply */ - void (*reply_clear)(void *); - - /* marshals the reply into a buffer */ - int (*reply_unmarshal)(void *, struct evbuffer*); -}; - -/** launches an RPC and sends it to the server - * - * EVRPC_MAKE_REQUEST() is used by the client to send an RPC to the server. - * - * @param name the name of the RPC - * @param pool the evrpc_pool that contains the connection objects over which - * the request should be sent. - * @param request a pointer to the RPC request structure - it contains the - * data to be sent to the server. - * @param reply a pointer to the RPC reply structure. It is going to be filled - * if the request was answered successfully - * @param cb the callback to invoke when the RPC request has been answered - * @param cbarg an additional argument to be passed to the client - * @return 0 on success, -1 on failure - */ -#define EVRPC_MAKE_REQUEST(name, pool, request, reply, cb, cbarg) \ - evrpc_send_request_##name(pool, request, reply, cb, cbarg) - -int evrpc_make_request(struct evrpc_request_wrapper *); - -/** creates an rpc connection pool - * - * a pool has a number of connections associated with it. - * rpc requests are always made via a pool. - * - * @param base a pointer to an struct event_based object; can be left NULL - * in singled-threaded applications - * @return a newly allocated struct evrpc_pool object - * @see evrpc_pool_free() - */ -struct evrpc_pool *evrpc_pool_new(struct event_base *base); -/** frees an rpc connection pool - * - * @param pool a pointer to an evrpc_pool allocated via evrpc_pool_new() - * @see evrpc_pool_new() - */ -void evrpc_pool_free(struct evrpc_pool *pool); -/* - * adds a connection over which rpc can be dispatched. the connection - * object must have been newly created. - */ -void evrpc_pool_add_connection(struct evrpc_pool *, - struct evhttp_connection *); - -/** - * Sets the timeout in secs after which a request has to complete. The - * RPC is completely aborted if it does not complete by then. Setting - * the timeout to 0 means that it never timeouts and can be used to - * implement callback type RPCs. - * - * Any connection already in the pool will be updated with the new - * timeout. Connections added to the pool after set_timeout has be - * called receive the pool timeout only if no timeout has been set - * for the connection itself. - * - * @param pool a pointer to a struct evrpc_pool object - * @param timeout_in_secs the number of seconds after which a request should - * timeout and a failure be returned to the callback. - */ -void evrpc_pool_set_timeout(struct evrpc_pool *pool, int timeout_in_secs); - -/** - * Hooks for changing the input and output of RPCs; this can be used to - * implement compression, authentication, encryption, ... - */ - -enum EVRPC_HOOK_TYPE { - INPUT, /**< apply the function to an input hook */ - OUTPUT /**< apply the function to an output hook */ -}; - -/** adds a processing hook to either an rpc base or rpc pool - * - * If a hook returns -1, the processing is aborted. - * - * The add functions return handles that can be used for removing hooks. - * - * @param vbase a pointer to either struct evrpc_base or struct evrpc_pool - * @param hook_type either INPUT or OUTPUT - * @param cb the callback to call when the hook is activated - * @param cb_arg an additional argument for the callback - * @return a handle to the hook so it can be removed later - * @see evrpc_remove_hook() - */ -void *evrpc_add_hook(void *vbase, - enum EVRPC_HOOK_TYPE hook_type, - int (*cb)(struct evhttp_request *, struct evbuffer *, void *), - void *cb_arg); - -/** removes a previously added hook - * - * @param vbase a pointer to either struct evrpc_base or struct evrpc_pool - * @param hook_type either INPUT or OUTPUT - * @param handle a handle returned by evrpc_add_hook() - * @return 1 on success or 0 on failure - * @see evrpc_add_hook() - */ -int evrpc_remove_hook(void *vbase, - enum EVRPC_HOOK_TYPE hook_type, - void *handle); - -#ifdef __cplusplus -} -#endif - -#endif /* _EVRPC_H_ */ |