Add RM_ScanKey to scan hash, set, zset, changes to RM_Scan API

- Adding RM_ScanKey
- Adding tests for RM_ScanKey
- Refactoring RM_Scan API

Changes in RM_Scan
- cleanup in docs and coding convention
- Moving out of experimantal Api
- Adding ctx to scan callback
- Dont use cursor of -1 as an indication of done (can be a valid cursor)
- Set errno when returning 0 for various reasons
- Rename Cursor to ScanCursor
- Test filters key that are not strings, and opens a key if NULL

2 files changed, 114 insertions, 38 deletions

diff --git a/tests/modules/scan.c b/tests/modules/scan.c
index 21071720a..afede244b 100644
--- a/tests/modules/scan.c
+++ b/tests/modules/scan.c
@@ -1,62 +1,109 @@
-#define REDISMODULE_EXPERIMENTAL_API
 #include "redismodule.h"
 
 #include <string.h>
 #include <assert.h>
 #include <unistd.h>
 
-#define UNUSED(V) ((void) V)
+typedef struct {
+    size_t nkeys;
+} scan_strings_pd;
 
-typedef struct scan_pd{
-        size_t nkeys;
-        RedisModuleCtx *ctx;
-} scan_pd;
-
-void scan_callback(void *privdata, RedisModuleString* keyname, RedisModuleKey* key){
-    scan_pd* pd = privdata;
-    RedisModule_ReplyWithArray(pd->ctx, 2);
+void scan_strings_callback(RedisModuleCtx *ctx, RedisModuleString* keyname, RedisModuleKey* key, void *privdata) {
+    scan_strings_pd* pd = privdata;
+    int was_opened = 0;
+    if (!key) {
+        key = RedisModule_OpenKey(ctx, keyname, REDISMODULE_READ);
+        was_opened = 1;
+    }
 
-    RedisModule_ReplyWithString(pd->ctx, keyname);
-    if(key && RedisModule_KeyType(key) == REDISMODULE_KEYTYPE_STRING){
+    if (RedisModule_KeyType(key) == REDISMODULE_KEYTYPE_STRING) {
         size_t len;
         char * data = RedisModule_StringDMA(key, &len, REDISMODULE_READ);
-        RedisModule_ReplyWithStringBuffer(pd->ctx, data, len);
-    }else{
-        RedisModule_ReplyWithNull(pd->ctx);
+        RedisModule_ReplyWithArray(ctx, 2);
+        RedisModule_ReplyWithString(ctx, keyname);
+        RedisModule_ReplyWithStringBuffer(ctx, data, len);
+        pd->nkeys++;
     }
-    pd->nkeys++;
+    if (was_opened)
+        RedisModule_CloseKey(key);
 }
 
-int scan_keys_values(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
+int scan_strings(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
 {
-    scan_pd pd = {
-            .nkeys = 0,
-            .ctx = ctx,
+    REDISMODULE_NOT_USED(argv);
+    REDISMODULE_NOT_USED(argc);
+    scan_strings_pd pd = {
+        .nkeys = 0,
     };
 
     RedisModule_ReplyWithArray(ctx, REDISMODULE_POSTPONED_ARRAY_LEN);
 
-    RedisModuleCursor* cursor = RedisModule_CursorCreate();
-    while(RedisModule_Scan(ctx, cursor, scan_callback, &pd));
-    RedisModule_CursorDestroy(cursor);
+    RedisModuleScanCursor* cursor = RedisModule_ScanCursorCreate();
+    while(RedisModule_Scan(ctx, cursor, scan_strings_callback, &pd));
+    RedisModule_ScanCursorDestroy(cursor);
 
     RedisModule_ReplySetArrayLength(ctx, pd.nkeys);
-    return 0;
+    return REDISMODULE_OK;
+}
+
+typedef struct {
+    RedisModuleCtx *ctx;
+    size_t nreplies;
+} scan_key_pd;
+
+void scan_key_callback(RedisModuleKey *key, RedisModuleString* field, RedisModuleString* value, void *privdata) {
+    REDISMODULE_NOT_USED(key);
+    scan_key_pd* pd = privdata;
+    RedisModule_ReplyWithArray(pd->ctx, 2);
+    RedisModule_ReplyWithString(pd->ctx, field);
+    if (value)
+        RedisModule_ReplyWithString(pd->ctx, value);
+    else
+        RedisModule_ReplyWithNull(pd->ctx);
+    pd->nreplies++;
+}
+
+int scan_key(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
+{
+    if (argc != 2) {
+        RedisModule_WrongArity(ctx);
+        return REDISMODULE_OK;
+    }
+    scan_key_pd pd = {
+        .ctx = ctx,
+        .nreplies = 0,
+    };
+
+    RedisModuleKey *key = RedisModule_OpenKey(ctx, argv[1], REDISMODULE_READ);
+    if (!key) {
+        RedisModule_ReplyWithError(ctx, "not found");
+        return REDISMODULE_OK;
+    }
+
+    RedisModule_ReplyWithArray(ctx, REDISMODULE_POSTPONED_ARRAY_LEN);
+
+    RedisModuleScanCursor* cursor = RedisModule_ScanCursorCreate();
+    while(RedisModule_ScanKey(key, cursor, scan_key_callback, &pd));
+    RedisModule_ScanCursorDestroy(cursor);
+
+    RedisModule_ReplySetArrayLength(ctx, pd.nreplies);
+    RedisModule_CloseKey(key);
+    return REDISMODULE_OK;
 }
 
 int RedisModule_OnLoad(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
-    UNUSED(argv);
-    UNUSED(argc);
+    REDISMODULE_NOT_USED(argv);
+    REDISMODULE_NOT_USED(argc);
     if (RedisModule_Init(ctx, "scan", 1, REDISMODULE_APIVER_1)== REDISMODULE_ERR)
         return REDISMODULE_ERR;
 
-    if (RedisModule_CreateCommand(ctx, "scan.scankeysvalues", scan_keys_values, "", 0, 0, 0) == REDISMODULE_ERR)
+    if (RedisModule_CreateCommand(ctx, "scan.scan_strings", scan_strings, "", 0, 0, 0) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx, "scan.scan_key", scan_key, "", 0, 0, 0) == REDISMODULE_ERR)
         return REDISMODULE_ERR;
 
     return REDISMODULE_OK;
 }
 
 
-
-
-
diff --git a/tests/unit/moduleapi/scan.tcl b/tests/unit/moduleapi/scan.tcl
index 5a77e8195..de1672e0a 100644
--- a/tests/unit/moduleapi/scan.tcl
+++ b/tests/unit/moduleapi/scan.tcl
@@ -1,18 +1,47 @@
 set testmodule [file normalize tests/modules/scan.so]
 
-proc count_log_message {pattern} {
-    set result [exec grep -c $pattern < [srv 0 stdout]]
-}
-
 start_server {tags {"modules"}} {
     r module load $testmodule
 
-    test {Module scan} {
-        # the module create a scan command which also return values
+    test {Module scan keyspace} {
+        # the module create a scan command with filtering which also return values
         r set x 1
         r set y 2
         r set z 3
-        lsort [r scan.scankeysvalues]
+        r hset h f v
+        lsort [r scan.scan_strings]
     } {{x 1} {y 2} {z 3}}
 
-}
\ No newline at end of file
+    test {Module scan hash ziplist} {
+        r hmset hh f1 v1 f2 v2
+        lsort [r scan.scan_key hh]
+    } {{f1 v1} {f2 v2}}
+
+    test {Module scan hash dict} {
+        r config set hash-max-ziplist-entries 2
+        r hmset hh f3 v3
+        lsort [r scan.scan_key hh]
+    } {{f1 v1} {f2 v2} {f3 v3}}
+
+    test {Module scan zset ziplist} {
+        r zadd zz 1 f1 2 f2
+        lsort [r scan.scan_key zz]
+    } {{f1 1} {f2 2}}
+
+    test {Module scan zset dict} {
+        r config set zset-max-ziplist-entries 2
+        r zadd zz 3 f3
+        lsort [r scan.scan_key zz]
+    } {{f1 1} {f2 2} {f3 3}}
+
+    test {Module scan set intset} {
+        r sadd ss 1 2
+        lsort [r scan.scan_key ss]
+    } {{1 {}} {2 {}}}
+
+    test {Module scan set dict} {
+        r config set set-max-intset-entries 2
+        r sadd ss 3
+        lsort [r scan.scan_key ss]
+    } {{1 {}} {2 {}} {3 {}}}
+}