From 4a1f1cc0d74bc58dc5b2514bfda7fc445a4cb446 Mon Sep 17 00:00:00 2001
From: antirez <antirez@gmail.com>
Date: Mon, 28 Oct 2013 11:17:32 +0100
Subject: [PATCH] SSCAN implemented.

---
 src/redis.c | 2 ++
 src/redis.h | 4 +++-
 src/t_set.c | 8 ++++++++
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/redis.c b/src/redis.c
index ccbf6a5c..6cfa0ec5 100644
--- a/src/redis.c
+++ b/src/redis.c
@@ -165,6 +165,7 @@ struct redisCommand redisCommandTable[] = {
     {"sdiff",sdiffCommand,-2,"rS",0,NULL,1,-1,1,0,0},
     {"sdiffstore",sdiffstoreCommand,-3,"wm",0,NULL,1,-1,1,0,0},
     {"smembers",sinterCommand,2,"rS",0,NULL,1,1,1,0,0},
+    {"sscan",sscanCommand,-3,"rR",0,NULL,1,1,1,0,0},
     {"zadd",zaddCommand,-4,"wm",0,NULL,1,1,1,0,0},
     {"zincrby",zincrbyCommand,4,"wm",0,NULL,1,1,1,0,0},
     {"zrem",zremCommand,-3,"w",0,NULL,1,1,1,0,0},
@@ -1227,6 +1228,7 @@ void createSharedObjects(void) {
     shared.emptymultibulk = createObject(REDIS_STRING,sdsnew("*0\r\n"));
     shared.pong = createObject(REDIS_STRING,sdsnew("+PONG\r\n"));
     shared.queued = createObject(REDIS_STRING,sdsnew("+QUEUED\r\n"));
+    shared.emptyscan = createObject(REDIS_STRING,sdsnew("*2\r\n$1\r\n0\r\n*0\r\n"));
     shared.wrongtypeerr = createObject(REDIS_STRING,sdsnew(
         "-WRONGTYPE Operation against a key holding the wrong kind of value\r\n"));
     shared.nokeyerr = createObject(REDIS_STRING,sdsnew(
diff --git a/src/redis.h b/src/redis.h
index 7b643017..7d0a733e 100644
--- a/src/redis.h
+++ b/src/redis.h
@@ -504,7 +504,7 @@ struct sharedObjectsStruct {
     *masterdownerr, *roslaveerr, *execaborterr, *noautherr, *noreplicaserr,
     *oomerr, *plus, *messagebulk, *pmessagebulk, *subscribebulk,
     *unsubscribebulk, *psubscribebulk, *punsubscribebulk, *del, *rpop, *lpop,
-    *lpush,
+    *lpush, *emptyscan,
     *select[REDIS_SHARED_SELECT_CMDS],
     *integers[REDIS_SHARED_INTEGERS],
     *mbulkhdr[REDIS_SHARED_BULKHDR_LEN], /* "*<value>\r\n" */
@@ -1194,6 +1194,7 @@ void signalFlushedDb(int dbid);
 unsigned int getKeysInSlot(unsigned int hashslot, robj **keys, unsigned int count);
 unsigned int countKeysInSlot(unsigned int hashslot);
 int verifyClusterConfigWithData(void);
+void scanGenericCommand(redisClient *c, robj *o);
 
 /* API to get key arguments from commands */
 #define REDIS_GETKEYS_ALL 0
@@ -1286,6 +1287,7 @@ void sunionCommand(redisClient *c);
 void sunionstoreCommand(redisClient *c);
 void sdiffCommand(redisClient *c);
 void sdiffstoreCommand(redisClient *c);
+void sscanCommand(redisClient *c);
 void syncCommand(redisClient *c);
 void flushdbCommand(redisClient *c);
 void flushallCommand(redisClient *c);
diff --git a/src/t_set.c b/src/t_set.c
index ab65e23f..ebffc5dc 100644
--- a/src/t_set.c
+++ b/src/t_set.c
@@ -906,3 +906,11 @@ void sdiffCommand(redisClient *c) {
 void sdiffstoreCommand(redisClient *c) {
     sunionDiffGenericCommand(c,c->argv+2,c->argc-2,c->argv[1],REDIS_OP_DIFF);
 }
+
+void sscanCommand(redisClient *c) {
+    robj *set;
+
+    if ((set = lookupKeyReadOrReply(c,c->argv[1],shared.emptyscan)) == NULL ||
+        checkType(c,set,REDIS_SET)) return;
+    scanGenericCommand(c,set);
+}