Modules: zset lex iterator #3.

1 files changed, 36 insertions, 0 deletions

diff --git a/src/modules/helloworld.c b/src/modules/helloworld.c
index 738983250..785d401b2 100644
--- a/src/modules/helloworld.c
+++ b/src/modules/helloworld.c
@@ -334,6 +334,7 @@ int HelloMoreExpire_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv,
  * should match.*/
 int HelloZsumRange_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
     double score_start, score_end;
+    if (argc != 4) return RedisModule_WrongArity(ctx);
 
     if (RedisModule_StringToDouble(argv[2],&score_start) != REDISMODULE_OK ||
         RedisModule_StringToDouble(argv[3],&score_end) != REDISMODULE_OK)
@@ -379,6 +380,41 @@ int HelloZsumRange_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, i
     return REDISMODULE_OK;
 }
 
+/* HELLO.LEXRANGE key min_lex max_lex min_age max_age
+ * This command expects a sorted set stored at key in the following form:
+ * - All the elements have score 0.
+ * - Elements are pairs of "<name>:<age>", for example "Anna:52".
+ * The command will return all the sorted set items that are lexicographically
+ * between the specified range (using the same format as ZRANGEBYLEX)
+ * and having an age between min_age and max_age. */
+int HelloZsumRange_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    RedisModule_AutoMemory(ctx); /* Use automatic memory management. */
+
+    if (argc != 6) return RedisModule_WrongArity(ctx);
+
+    RedisModuleKey *key = RedisModule_OpenKey(ctx,argv[1],
+        REDISMODULE_READ|REDISMODULE_WRITE);
+    if (RedisModule_KeyType(key) != REDISMODULE_KEYTYPE_ZSET) {
+        return RedisModule_ReplyWithError(ctx,REDISMODULE_ERRORMSG_WRONGTYPE);
+    }
+
+    RedisModule_ReplyWithArray(ctx,REDISMODULE_POSTPONED_ARRAY_LEN);
+    RedisModule_ZsetFirstInLexRange(key,argv[2],argv[3]);
+    int arraylen = 0;
+    while(!RedisModule_ZsetRangeEndReached(key)) {
+        double score;
+        RedisModuleString *ele = RedisModule_ZsetRangeCurrentElement(key,&score);
+        RedisModule_ReplyWithString(ctx,ele);
+        RedisModule_FreeString(ctx,ele);
+        RedisModule_ZsetRangeNext(key);
+        arraylen++;
+    }
+    RedisModule_ZsetRangeStop(key);
+    RedisModule_SetArrayLength(ctx,arraylen);
+    RedisModule_CloseKey(key);
+    return REDISMODULE_OK;
+}
+
 /* This function must be present on each Redis module. It is used in order to
  * register the commands into the Redis server. */
 int RedisModule_OnLoad(RedisModuleCtx *ctx) {