X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/dd88747b786a4e5f9f4135e355d0d483e991d54e..08ee9b570f4a9a181c3ed2242c5b2f6a88eddc41:/redis.c

diff --git a/redis.c b/redis.c
index 69e4bfce..38aad0a8 100644
--- a/redis.c
+++ b/redis.c
@@ -27,7 +27,7 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
-#define REDIS_VERSION "1.3.4"
+#define REDIS_VERSION "1.3.8"
 
 #include "fmacros.h"
 #include "config.h"
@@ -86,12 +86,12 @@
 #define REDIS_MAXIDLETIME       (60*5)  /* default client timeout */
 #define REDIS_IOBUF_LEN         1024
 #define REDIS_LOADBUF_LEN       1024
-#define REDIS_STATIC_ARGS       4
+#define REDIS_STATIC_ARGS       8
 #define REDIS_DEFAULT_DBNUM     16
 #define REDIS_CONFIGLINE_MAX    1024
 #define REDIS_OBJFREELIST_MAX   1000000 /* Max number of objects to cache */
 #define REDIS_MAX_SYNC_TIME     60      /* Slave can't take more to sync */
-#define REDIS_EXPIRELOOKUPS_PER_CRON    100 /* try to expire 100 keys/second */
+#define REDIS_EXPIRELOOKUPS_PER_CRON    10 /* lookup 10 expires per loop */
 #define REDIS_MAX_WRITE_PER_EVENT (1024*64)
 #define REDIS_REQUEST_MAX_SIZE (1024*1024*256) /* max bytes in inline command */
 
@@ -111,6 +111,7 @@
    config file and the server is using more than maxmemory bytes of memory.
    In short this commands are denied on low memory conditions. */
 #define REDIS_CMD_DENYOOM       4
+#define REDIS_CMD_FORCE_REPLICATION 8 /* Force replication even if dirty is 0 */
 
 /* Object types */
 #define REDIS_STRING 0
@@ -236,7 +237,9 @@ static char* strencoding[] = {
 
 /* We can print the stacktrace, so our assert is defined this way: */
 #define redisAssert(_e) ((_e)?(void)0 : (_redisAssert(#_e,__FILE__,__LINE__),_exit(1)))
+#define redisPanic(_e) _redisPanic(#_e,__FILE__,__LINE__),_exit(1)
 static void _redisAssert(char *estr, char *file, int line);
+static void _redisPanic(char *msg, char *file, int line);
 
 /*================================= Data types ============================== */
 
@@ -327,6 +330,8 @@ typedef struct redisClient {
                              * is >= blockingto then the operation timed out. */
     list *io_keys;          /* Keys this client is waiting to be loaded from the
                              * swap file in order to continue. */
+    dict *pubsub_channels;  /* channels a client is interested in (SUBSCRIBE) */
+    list *pubsub_patterns;  /* patterns a client is interested in (SUBSCRIBE) */
 } redisClient;
 
 struct saveparam {
@@ -339,8 +344,6 @@ struct redisServer {
     int port;
     int fd;
     redisDb *db;
-    dict *sharingpool;          /* Poll used for object sharing */
-    unsigned int sharingpoolsize;
     long long dirty;            /* changes to DB from the last save */
     list *clients;
     list *slaves, *monitors;
@@ -353,6 +356,7 @@ struct redisServer {
     time_t stat_starttime;         /* server start time */
     long long stat_numcommands;    /* number of processed commands */
     long long stat_numconnections; /* number of connections received */
+    long long stat_expiredkeys;   /* number of expired keys */
     /* Configuration */
     int verbosity;
     int glueoutputbuf;
@@ -377,6 +381,7 @@ struct redisServer {
     char *requirepass;
     int shareobjects;
     int rdbcompression;
+    int activerehashing;
     /* Replication related */
     int isslave;
     char *masterauth;
@@ -434,15 +439,28 @@ struct redisServer {
     unsigned long long vm_stats_swapped_objects;
     unsigned long long vm_stats_swapouts;
     unsigned long long vm_stats_swapins;
+    /* Pubsub */
+    dict *pubsub_channels; /* Map channels to list of subscribed clients */
+    list *pubsub_patterns; /* A list of pubsub_patterns */
+    /* Misc */
     FILE *devnull;
 };
 
+typedef struct pubsubPattern {
+    redisClient *client;
+    robj *pattern;
+} pubsubPattern;
+
 typedef void redisCommandProc(redisClient *c);
 struct redisCommand {
     char *name;
     redisCommandProc *proc;
     int arity;
     int flags;
+    /* Use a function to determine which keys need to be loaded
+     * in the background prior to executing this command. Takes precedence
+     * over vm_firstkey and others, ignored when NULL */
+    redisCommandProc *vm_preload_proc;
     /* What keys should be loaded in background when calling this command? */
     int vm_firstkey; /* The first argument that's a key (0 = no keys) */
     int vm_lastkey;  /* THe last argument that's a key */
@@ -490,13 +508,16 @@ typedef struct zset {
 
 /* Our shared "common" objects */
 
+#define REDIS_SHARED_INTEGERS 10000
 struct sharedObjectsStruct {
     robj *crlf, *ok, *err, *emptybulk, *czero, *cone, *pong, *space,
     *colon, *nullbulk, *nullmultibulk, *queued,
     *emptymultibulk, *wrongtypeerr, *nokeyerr, *syntaxerr, *sameobjecterr,
     *outofrangeerr, *plus,
     *select0, *select1, *select2, *select3, *select4,
-    *select5, *select6, *select7, *select8, *select9;
+    *select5, *select6, *select7, *select8, *select9,
+    *messagebulk, *subscribebulk, *unsubscribebulk, *mbulk3,
+    *psubscribebulk, *punsubscribebulk, *integers[REDIS_SHARED_INTEGERS];
 } shared;
 
 /* Global vars that are actally used as constants. The following double
@@ -516,7 +537,7 @@ typedef struct iojob {
     robj *val;  /* the value to swap for REDIS_IOREQ_*_SWAP, otherwise this
                  * field is populated by the I/O thread for REDIS_IOREQ_LOAD. */
     off_t page; /* Swap page where to read/write the object */
-    off_t pages; /* Swap pages needed to safe object. PREPARE_SWAP return val */
+    off_t pages; /* Swap pages needed to save object. PREPARE_SWAP return val */
     int canceled; /* True if this command was canceled by blocking side of VM */
     pthread_t thread; /* ID of the thread processing this entry */
 } iojob;
@@ -536,11 +557,10 @@ static void incrRefCount(robj *o);
 static int rdbSaveBackground(char *filename);
 static robj *createStringObject(char *ptr, size_t len);
 static robj *dupStringObject(robj *o);
-static void replicationFeedSlaves(list *slaves, struct redisCommand *cmd, int dictid, robj **argv, int argc);
+static void replicationFeedSlaves(list *slaves, int dictid, robj **argv, int argc);
 static void feedAppendOnlyFile(struct redisCommand *cmd, int dictid, robj **argv, int argc);
 static int syncWithMaster(void);
-static robj *tryObjectSharing(robj *o);
-static int tryObjectEncoding(robj *o);
+static robj *tryObjectEncoding(robj *o);
 static robj *getDecodedObject(robj *o);
 static int removeExpire(redisDb *db, robj *key);
 static int expireIfNeeded(redisDb *db, robj *key);
@@ -587,6 +607,7 @@ static robj *vmReadObjectFromSwap(off_t page, int type);
 static void waitEmptyIOJobsQueue(void);
 static void vmReopenSwapFile(void);
 static int vmFreePage(off_t page);
+static void zunionInterBlockClientOnSwappedKeys(redisClient *c);
 static int blockClientOnSwappedKeys(struct redisCommand *cmd, redisClient *c);
 static int dontWaitForSwappedKey(redisClient *c, robj *key);
 static void handleClientsBlockedOnSwappedKey(redisDb *db, robj *key);
@@ -595,6 +616,12 @@ static struct redisCommand *lookupCommand(char *name);
 static void call(redisClient *c, struct redisCommand *cmd);
 static void resetClient(redisClient *c);
 static void convertToRealHash(robj *o);
+static int pubsubUnsubscribeAllChannels(redisClient *c, int notify);
+static int pubsubUnsubscribeAllPatterns(redisClient *c, int notify);
+static void freePubsubPattern(void *p);
+static int listMatchPubsubPattern(void *a, void *b);
+static int compareStringObjects(robj *a, robj *b);
+static void usage();
 
 static void authCommand(redisClient *c);
 static void pingCommand(redisClient *c);
@@ -680,116 +707,144 @@ static void substrCommand(redisClient *c);
 static void zrankCommand(redisClient *c);
 static void zrevrankCommand(redisClient *c);
 static void hsetCommand(redisClient *c);
+static void hsetnxCommand(redisClient *c);
 static void hgetCommand(redisClient *c);
+static void hmsetCommand(redisClient *c);
+static void hmgetCommand(redisClient *c);
 static void hdelCommand(redisClient *c);
 static void hlenCommand(redisClient *c);
 static void zremrangebyrankCommand(redisClient *c);
 static void zunionCommand(redisClient *c);
 static void zinterCommand(redisClient *c);
+static void hkeysCommand(redisClient *c);
+static void hvalsCommand(redisClient *c);
+static void hgetallCommand(redisClient *c);
+static void hexistsCommand(redisClient *c);
+static void configCommand(redisClient *c);
+static void hincrbyCommand(redisClient *c);
+static void subscribeCommand(redisClient *c);
+static void unsubscribeCommand(redisClient *c);
+static void psubscribeCommand(redisClient *c);
+static void punsubscribeCommand(redisClient *c);
+static void publishCommand(redisClient *c);
 
 /*================================= Globals ================================= */
 
 /* Global vars */
 static struct redisServer server; /* server global state */
 static struct redisCommand cmdTable[] = {
-    {"get",getCommand,2,REDIS_CMD_INLINE,1,1,1},
-    {"set",setCommand,3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,0,0,0},
-    {"setnx",setnxCommand,3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,0,0,0},
-    {"append",appendCommand,3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,1,1,1},
-    {"substr",substrCommand,4,REDIS_CMD_INLINE,1,1,1},
-    {"del",delCommand,-2,REDIS_CMD_INLINE,0,0,0},
-    {"exists",existsCommand,2,REDIS_CMD_INLINE,1,1,1},
-    {"incr",incrCommand,2,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,1,1,1},
-    {"decr",decrCommand,2,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,1,1,1},
-    {"mget",mgetCommand,-2,REDIS_CMD_INLINE,1,-1,1},
-    {"rpush",rpushCommand,3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,1,1,1},
-    {"lpush",lpushCommand,3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,1,1,1},
-    {"rpop",rpopCommand,2,REDIS_CMD_INLINE,1,1,1},
-    {"lpop",lpopCommand,2,REDIS_CMD_INLINE,1,1,1},
-    {"brpop",brpopCommand,-3,REDIS_CMD_INLINE,1,1,1},
-    {"blpop",blpopCommand,-3,REDIS_CMD_INLINE,1,1,1},
-    {"llen",llenCommand,2,REDIS_CMD_INLINE,1,1,1},
-    {"lindex",lindexCommand,3,REDIS_CMD_INLINE,1,1,1},
-    {"lset",lsetCommand,4,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,1,1,1},
-    {"lrange",lrangeCommand,4,REDIS_CMD_INLINE,1,1,1},
-    {"ltrim",ltrimCommand,4,REDIS_CMD_INLINE,1,1,1},
-    {"lrem",lremCommand,4,REDIS_CMD_BULK,1,1,1},
-    {"rpoplpush",rpoplpushcommand,3,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,1,2,1},
-    {"sadd",saddCommand,3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,1,1,1},
-    {"srem",sremCommand,3,REDIS_CMD_BULK,1,1,1},
-    {"smove",smoveCommand,4,REDIS_CMD_BULK,1,2,1},
-    {"sismember",sismemberCommand,3,REDIS_CMD_BULK,1,1,1},
-    {"scard",scardCommand,2,REDIS_CMD_INLINE,1,1,1},
-    {"spop",spopCommand,2,REDIS_CMD_INLINE,1,1,1},
-    {"srandmember",srandmemberCommand,2,REDIS_CMD_INLINE,1,1,1},
-    {"sinter",sinterCommand,-2,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,1,-1,1},
-    {"sinterstore",sinterstoreCommand,-3,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,2,-1,1},
-    {"sunion",sunionCommand,-2,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,1,-1,1},
-    {"sunionstore",sunionstoreCommand,-3,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,2,-1,1},
-    {"sdiff",sdiffCommand,-2,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,1,-1,1},
-    {"sdiffstore",sdiffstoreCommand,-3,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,2,-1,1},
-    {"smembers",sinterCommand,2,REDIS_CMD_INLINE,1,1,1},
-    {"zadd",zaddCommand,4,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,1,1,1},
-    {"zincrby",zincrbyCommand,4,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,1,1,1},
-    {"zrem",zremCommand,3,REDIS_CMD_BULK,1,1,1},
-    {"zremrangebyscore",zremrangebyscoreCommand,4,REDIS_CMD_INLINE,1,1,1},
-    {"zremrangebyrank",zremrangebyrankCommand,4,REDIS_CMD_INLINE,1,1,1},
-    {"zunion",zunionCommand,-4,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,0,0,0},
-    {"zinter",zinterCommand,-4,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,0,0,0},
-    {"zrange",zrangeCommand,-4,REDIS_CMD_INLINE,1,1,1},
-    {"zrangebyscore",zrangebyscoreCommand,-4,REDIS_CMD_INLINE,1,1,1},
-    {"zcount",zcountCommand,4,REDIS_CMD_INLINE,1,1,1},
-    {"zrevrange",zrevrangeCommand,-4,REDIS_CMD_INLINE,1,1,1},
-    {"zcard",zcardCommand,2,REDIS_CMD_INLINE,1,1,1},
-    {"zscore",zscoreCommand,3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,1,1,1},
-    {"zrank",zrankCommand,3,REDIS_CMD_BULK,1,1,1},
-    {"zrevrank",zrevrankCommand,3,REDIS_CMD_BULK,1,1,1},
-    {"hset",hsetCommand,4,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,1,1,1},
-    {"hget",hgetCommand,3,REDIS_CMD_BULK,1,1,1},
-    {"hdel",hdelCommand,3,REDIS_CMD_BULK,1,1,1},
-    {"hlen",hlenCommand,2,REDIS_CMD_INLINE,1,1,1},
-    {"incrby",incrbyCommand,3,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,1,1,1},
-    {"decrby",decrbyCommand,3,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,1,1,1},
-    {"getset",getsetCommand,3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,1,1,1},
-    {"mset",msetCommand,-3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,1,-1,2},
-    {"msetnx",msetnxCommand,-3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,1,-1,2},
-    {"randomkey",randomkeyCommand,1,REDIS_CMD_INLINE,0,0,0},
-    {"select",selectCommand,2,REDIS_CMD_INLINE,0,0,0},
-    {"move",moveCommand,3,REDIS_CMD_INLINE,1,1,1},
-    {"rename",renameCommand,3,REDIS_CMD_INLINE,1,1,1},
-    {"renamenx",renamenxCommand,3,REDIS_CMD_INLINE,1,1,1},
-    {"expire",expireCommand,3,REDIS_CMD_INLINE,0,0,0},
-    {"expireat",expireatCommand,3,REDIS_CMD_INLINE,0,0,0},
-    {"keys",keysCommand,2,REDIS_CMD_INLINE,0,0,0},
-    {"dbsize",dbsizeCommand,1,REDIS_CMD_INLINE,0,0,0},
-    {"auth",authCommand,2,REDIS_CMD_INLINE,0,0,0},
-    {"ping",pingCommand,1,REDIS_CMD_INLINE,0,0,0},
-    {"echo",echoCommand,2,REDIS_CMD_BULK,0,0,0},
-    {"save",saveCommand,1,REDIS_CMD_INLINE,0,0,0},
-    {"bgsave",bgsaveCommand,1,REDIS_CMD_INLINE,0,0,0},
-    {"bgrewriteaof",bgrewriteaofCommand,1,REDIS_CMD_INLINE,0,0,0},
-    {"shutdown",shutdownCommand,1,REDIS_CMD_INLINE,0,0,0},
-    {"lastsave",lastsaveCommand,1,REDIS_CMD_INLINE,0,0,0},
-    {"type",typeCommand,2,REDIS_CMD_INLINE,1,1,1},
-    {"multi",multiCommand,1,REDIS_CMD_INLINE,0,0,0},
-    {"exec",execCommand,1,REDIS_CMD_INLINE,0,0,0},
-    {"discard",discardCommand,1,REDIS_CMD_INLINE,0,0,0},
-    {"sync",syncCommand,1,REDIS_CMD_INLINE,0,0,0},
-    {"flushdb",flushdbCommand,1,REDIS_CMD_INLINE,0,0,0},
-    {"flushall",flushallCommand,1,REDIS_CMD_INLINE,0,0,0},
-    {"sort",sortCommand,-2,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,1,1,1},
-    {"info",infoCommand,1,REDIS_CMD_INLINE,0,0,0},
-    {"monitor",monitorCommand,1,REDIS_CMD_INLINE,0,0,0},
-    {"ttl",ttlCommand,2,REDIS_CMD_INLINE,1,1,1},
-    {"slaveof",slaveofCommand,3,REDIS_CMD_INLINE,0,0,0},
-    {"debug",debugCommand,-2,REDIS_CMD_INLINE,0,0,0},
-    {NULL,NULL,0,0,0,0,0}
+    {"get",getCommand,2,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"set",setCommand,3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,NULL,0,0,0},
+    {"setnx",setnxCommand,3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,NULL,0,0,0},
+    {"append",appendCommand,3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,NULL,1,1,1},
+    {"substr",substrCommand,4,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"del",delCommand,-2,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"exists",existsCommand,2,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"incr",incrCommand,2,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,NULL,1,1,1},
+    {"decr",decrCommand,2,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,NULL,1,1,1},
+    {"mget",mgetCommand,-2,REDIS_CMD_INLINE,NULL,1,-1,1},
+    {"rpush",rpushCommand,3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,NULL,1,1,1},
+    {"lpush",lpushCommand,3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,NULL,1,1,1},
+    {"rpop",rpopCommand,2,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"lpop",lpopCommand,2,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"brpop",brpopCommand,-3,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"blpop",blpopCommand,-3,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"llen",llenCommand,2,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"lindex",lindexCommand,3,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"lset",lsetCommand,4,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,NULL,1,1,1},
+    {"lrange",lrangeCommand,4,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"ltrim",ltrimCommand,4,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"lrem",lremCommand,4,REDIS_CMD_BULK,NULL,1,1,1},
+    {"rpoplpush",rpoplpushcommand,3,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,NULL,1,2,1},
+    {"sadd",saddCommand,3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,NULL,1,1,1},
+    {"srem",sremCommand,3,REDIS_CMD_BULK,NULL,1,1,1},
+    {"smove",smoveCommand,4,REDIS_CMD_BULK,NULL,1,2,1},
+    {"sismember",sismemberCommand,3,REDIS_CMD_BULK,NULL,1,1,1},
+    {"scard",scardCommand,2,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"spop",spopCommand,2,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"srandmember",srandmemberCommand,2,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"sinter",sinterCommand,-2,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,NULL,1,-1,1},
+    {"sinterstore",sinterstoreCommand,-3,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,NULL,2,-1,1},
+    {"sunion",sunionCommand,-2,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,NULL,1,-1,1},
+    {"sunionstore",sunionstoreCommand,-3,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,NULL,2,-1,1},
+    {"sdiff",sdiffCommand,-2,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,NULL,1,-1,1},
+    {"sdiffstore",sdiffstoreCommand,-3,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,NULL,2,-1,1},
+    {"smembers",sinterCommand,2,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"zadd",zaddCommand,4,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,NULL,1,1,1},
+    {"zincrby",zincrbyCommand,4,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,NULL,1,1,1},
+    {"zrem",zremCommand,3,REDIS_CMD_BULK,NULL,1,1,1},
+    {"zremrangebyscore",zremrangebyscoreCommand,4,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"zremrangebyrank",zremrangebyrankCommand,4,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"zunion",zunionCommand,-4,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,zunionInterBlockClientOnSwappedKeys,0,0,0},
+    {"zinter",zinterCommand,-4,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,zunionInterBlockClientOnSwappedKeys,0,0,0},
+    {"zrange",zrangeCommand,-4,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"zrangebyscore",zrangebyscoreCommand,-4,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"zcount",zcountCommand,4,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"zrevrange",zrevrangeCommand,-4,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"zcard",zcardCommand,2,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"zscore",zscoreCommand,3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,NULL,1,1,1},
+    {"zrank",zrankCommand,3,REDIS_CMD_BULK,NULL,1,1,1},
+    {"zrevrank",zrevrankCommand,3,REDIS_CMD_BULK,NULL,1,1,1},
+    {"hset",hsetCommand,4,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,NULL,1,1,1},
+    {"hsetnx",hsetnxCommand,4,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,NULL,1,1,1},
+    {"hget",hgetCommand,3,REDIS_CMD_BULK,NULL,1,1,1},
+    {"hmset",hmsetCommand,-4,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,NULL,1,1,1},
+    {"hmget",hmgetCommand,-3,REDIS_CMD_BULK,NULL,1,1,1},
+    {"hincrby",hincrbyCommand,4,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,NULL,1,1,1},
+    {"hdel",hdelCommand,3,REDIS_CMD_BULK,NULL,1,1,1},
+    {"hlen",hlenCommand,2,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"hkeys",hkeysCommand,2,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"hvals",hvalsCommand,2,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"hgetall",hgetallCommand,2,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"hexists",hexistsCommand,3,REDIS_CMD_BULK,NULL,1,1,1},
+    {"incrby",incrbyCommand,3,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,NULL,1,1,1},
+    {"decrby",decrbyCommand,3,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,NULL,1,1,1},
+    {"getset",getsetCommand,3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,NULL,1,1,1},
+    {"mset",msetCommand,-3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,NULL,1,-1,2},
+    {"msetnx",msetnxCommand,-3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM,NULL,1,-1,2},
+    {"randomkey",randomkeyCommand,1,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"select",selectCommand,2,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"move",moveCommand,3,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"rename",renameCommand,3,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"renamenx",renamenxCommand,3,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"expire",expireCommand,3,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"expireat",expireatCommand,3,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"keys",keysCommand,2,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"dbsize",dbsizeCommand,1,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"auth",authCommand,2,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"ping",pingCommand,1,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"echo",echoCommand,2,REDIS_CMD_BULK,NULL,0,0,0},
+    {"save",saveCommand,1,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"bgsave",bgsaveCommand,1,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"bgrewriteaof",bgrewriteaofCommand,1,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"shutdown",shutdownCommand,1,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"lastsave",lastsaveCommand,1,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"type",typeCommand,2,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"multi",multiCommand,1,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"exec",execCommand,1,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,NULL,0,0,0},
+    {"discard",discardCommand,1,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"sync",syncCommand,1,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"flushdb",flushdbCommand,1,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"flushall",flushallCommand,1,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"sort",sortCommand,-2,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,NULL,1,1,1},
+    {"info",infoCommand,1,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"monitor",monitorCommand,1,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"ttl",ttlCommand,2,REDIS_CMD_INLINE,NULL,1,1,1},
+    {"slaveof",slaveofCommand,3,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"debug",debugCommand,-2,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"config",configCommand,-2,REDIS_CMD_BULK,NULL,0,0,0},
+    {"subscribe",subscribeCommand,-2,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"unsubscribe",unsubscribeCommand,-1,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"psubscribe",psubscribeCommand,-2,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"punsubscribe",punsubscribeCommand,-1,REDIS_CMD_INLINE,NULL,0,0,0},
+    {"publish",publishCommand,3,REDIS_CMD_BULK|REDIS_CMD_FORCE_REPLICATION,NULL,0,0,0},
+    {NULL,NULL,0,0,NULL,0,0,0}
 };
 
 /*============================ Utility functions ============================ */
 
 /* Glob-style pattern matching. */
-int stringmatchlen(const char *pattern, int patternLen,
+static int stringmatchlen(const char *pattern, int patternLen,
         const char *string, int stringLen, int nocase)
 {
     while(patternLen) {
@@ -911,6 +966,10 @@ int stringmatchlen(const char *pattern, int patternLen,
     return 0;
 }
 
+static int stringmatch(const char *pattern, const char *string, int nocase) {
+    return stringmatchlen(pattern,strlen(pattern),string,strlen(string),nocase);
+}
+
 static void redisLog(int level, const char *fmt, ...) {
     va_list ap;
     FILE *fp;
@@ -992,6 +1051,10 @@ static int dictEncObjKeyCompare(void *privdata, const void *key1,
     robj *o1 = (robj*) key1, *o2 = (robj*) key2;
     int cmp;
 
+    if (o1->encoding == REDIS_ENCODING_INT &&
+        o2->encoding == REDIS_ENCODING_INT &&
+        o1->ptr == o2->ptr) return 1;
+
     o1 = getDecodedObject(o1);
     o2 = getDecodedObject(o2);
     cmp = sdsDictKeyCompare(privdata,o1->ptr,o2->ptr);
@@ -1085,6 +1148,8 @@ static dictType keylistDictType = {
     dictListDestructor          /* val destructor */
 };
 
+static void version();
+
 /* ========================= Random utility functions ======================= */
 
 /* Redis generally does not try to recover from out of memory conditions
@@ -1111,7 +1176,9 @@ static void closeTimedoutClients(void) {
         if (server.maxidletime &&
             !(c->flags & REDIS_SLAVE) &&    /* no timeout for slaves */
             !(c->flags & REDIS_MASTER) &&   /* no timeout for masters */
-             (now - c->lastinteraction > server.maxidletime))
+            dictSize(c->pubsub_channels) == 0 && /* no timeout for pubsub */
+            listLength(c->pubsub_patterns) == 0 &&
+            (now - c->lastinteraction > server.maxidletime))
         {
             redisLog(REDIS_VERBOSE,"Closing idle client");
             freeClient(c);
@@ -1139,16 +1206,28 @@ static void tryResizeHashTables(void) {
     int j;
 
     for (j = 0; j < server.dbnum; j++) {
-        if (htNeedsResize(server.db[j].dict)) {
-            redisLog(REDIS_VERBOSE,"The hash table %d is too sparse, resize it...",j);
+        if (htNeedsResize(server.db[j].dict))
             dictResize(server.db[j].dict);
-            redisLog(REDIS_VERBOSE,"Hash table %d resized.",j);
-        }
         if (htNeedsResize(server.db[j].expires))
             dictResize(server.db[j].expires);
     }
 }
 
+/* Our hash table implementation performs rehashing incrementally while
+ * we write/read from the hash table. Still if the server is idle, the hash
+ * table will use two tables for a long time. So we try to use 1 millisecond
+ * of CPU time at every serverCron() loop in order to rehash some key. */
+static void incrementallyRehash(void) {
+    int j;
+
+    for (j = 0; j < server.dbnum; j++) {
+        if (dictIsRehashing(server.db[j].dict)) {
+            dictRehashMilliseconds(server.db[j].dict,1);
+            break; /* already used our millisecond for this loop... */
+        }
+    }
+}
+
 /* A background saving child (BGSAVE) terminated its work. Handle this. */
 void backgroundSaveDoneHandler(int statloc) {
     int exitcode = WEXITSTATUS(statloc);
@@ -1163,7 +1242,7 @@ void backgroundSaveDoneHandler(int statloc) {
         redisLog(REDIS_WARNING, "Background saving error");
     } else {
         redisLog(REDIS_WARNING,
-            "Background saving terminated by signal");
+            "Background saving terminated by signal %d", WTERMSIG(statloc));
         rdbRemoveTempFile(server.bgsavechildpid);
     }
     server.bgsavechildpid = -1;
@@ -1224,7 +1303,8 @@ void backgroundRewriteDoneHandler(int statloc) {
         redisLog(REDIS_WARNING, "Background append only file rewriting error");
     } else {
         redisLog(REDIS_WARNING,
-            "Background append only file rewriting terminated by signal");
+            "Background append only file rewriting terminated by signal %d",
+            WTERMSIG(statloc));
     }
 cleanup:
     sdsfree(server.bgrewritebuf);
@@ -1233,6 +1313,19 @@ cleanup:
     server.bgrewritechildpid = -1;
 }
 
+/* This function is called once a background process of some kind terminates,
+ * as we want to avoid resizing the hash tables when there is a child in order
+ * to play well with copy-on-write (otherwise when a resize happens lots of
+ * memory pages are copied). The goal of this function is to update the ability
+ * for dict.c to resize the hash tables accordingly to the fact we have o not
+ * running childs. */
+static void updateDictResizePolicy(void) {
+    if (server.bgsavechildpid == -1 && server.bgrewritechildpid == -1)
+        dictEnableResize();
+    else
+        dictDisableResize();
+}
+
 static int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientData) {
     int j, loops = server.cronloops++;
     REDIS_NOTUSED(eventLoop);
@@ -1252,7 +1345,7 @@ static int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientD
         size = dictSlots(server.db[j].dict);
         used = dictSize(server.db[j].dict);
         vkeys = dictSize(server.db[j].expires);
-        if (!(loops % 5) && (used || vkeys)) {
+        if (!(loops % 50) && (used || vkeys)) {
             redisLog(REDIS_VERBOSE,"DB %d: %lld keys (%lld volatile) in %lld slots HT.",j,used,vkeys,size);
             /* dictPrintStats(server.dict); */
         }
@@ -1264,19 +1357,21 @@ static int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientD
      * if we resize the HT while there is the saving child at work actually
      * a lot of memory movements in the parent will cause a lot of pages
      * copied. */
-    if (server.bgsavechildpid == -1) tryResizeHashTables();
+    if (server.bgsavechildpid == -1 && server.bgrewritechildpid == -1) {
+        if (!(loops % 10)) tryResizeHashTables();
+        if (server.activerehashing) incrementallyRehash();
+    }
 
     /* Show information about connected clients */
-    if (!(loops % 5)) {
-        redisLog(REDIS_VERBOSE,"%d clients connected (%d slaves), %zu bytes in use, %d shared objects",
+    if (!(loops % 50)) {
+        redisLog(REDIS_VERBOSE,"%d clients connected (%d slaves), %zu bytes in use",
             listLength(server.clients)-listLength(server.slaves),
             listLength(server.slaves),
-            zmalloc_used_memory(),
-            dictSize(server.sharingpool));
+            zmalloc_used_memory());
     }
 
     /* Close connections of timedout clients */
-    if ((server.maxidletime && !(loops % 10)) || server.blpop_blocked_clients)
+    if ((server.maxidletime && !(loops % 100)) || server.blpop_blocked_clients)
         closeTimedoutClients();
 
     /* Check if a background saving or AOF rewrite in progress terminated */
@@ -1290,6 +1385,7 @@ static int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientD
             } else {
                 backgroundRewriteDoneHandler(statloc);
             }
+            updateDictResizePolicy();
         }
     } else {
         /* If there is not a background saving in progress check if
@@ -1334,6 +1430,7 @@ static int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientD
                 if (now > t) {
                     deleteKey(db,dictGetEntryKey(de));
                     expired++;
+                    server.stat_expiredkeys++;
                 }
             }
         } while (expired > REDIS_EXPIRELOOKUPS_PER_CRON/4);
@@ -1351,7 +1448,7 @@ static int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientD
             retval = (server.vm_max_threads == 0) ?
                         vmSwapOneObjectBlocking() :
                         vmSwapOneObjectThreaded();
-            if (retval == REDIS_ERR && (loops % 30) == 0 &&
+            if (retval == REDIS_ERR && !(loops % 300) &&
                 zmalloc_used_memory() >
                 (server.vm_max_memory+server.vm_max_memory/10))
             {
@@ -1366,13 +1463,13 @@ static int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientD
     }
 
     /* Check if we should connect to a MASTER */
-    if (server.replstate == REDIS_REPL_CONNECT) {
+    if (server.replstate == REDIS_REPL_CONNECT && !(loops % 10)) {
         redisLog(REDIS_NOTICE,"Connecting to MASTER...");
         if (syncWithMaster() == REDIS_OK) {
             redisLog(REDIS_NOTICE,"MASTER <-> SLAVE sync succeeded");
         }
     }
-    return 1000;
+    return 100;
 }
 
 /* This function gets called every time Redis is entering the
@@ -1408,6 +1505,8 @@ static void beforeSleep(struct aeEventLoop *eventLoop) {
 }
 
 static void createSharedObjects(void) {
+    int j;
+
     shared.crlf = createObject(REDIS_STRING,sdsnew("\r\n"));
     shared.ok = createObject(REDIS_STRING,sdsnew("+OK\r\n"));
     shared.err = createObject(REDIS_STRING,sdsnew("-ERR\r\n"));
@@ -1442,6 +1541,16 @@ static void createSharedObjects(void) {
     shared.select7 = createStringObject("select 7\r\n",10);
     shared.select8 = createStringObject("select 8\r\n",10);
     shared.select9 = createStringObject("select 9\r\n",10);
+    shared.messagebulk = createStringObject("$7\r\nmessage\r\n",13);
+    shared.subscribebulk = createStringObject("$9\r\nsubscribe\r\n",15);
+    shared.unsubscribebulk = createStringObject("$11\r\nunsubscribe\r\n",18);
+    shared.psubscribebulk = createStringObject("$10\r\npsubscribe\r\n",17);
+    shared.punsubscribebulk = createStringObject("$12\r\npunsubscribe\r\n",19);
+    shared.mbulk3 = createStringObject("*3\r\n",4);
+    for (j = 0; j < REDIS_SHARED_INTEGERS; j++) {
+        shared.integers[j] = createObject(REDIS_STRING,(void*)(long)j);
+        shared.integers[j]->encoding = REDIS_ENCODING_INT;
+    }
 }
 
 static void appendServerSaveParams(time_t seconds, int changes) {
@@ -1472,13 +1581,13 @@ static void initServerConfig() {
     server.lastfsync = time(NULL);
     server.appendfd = -1;
     server.appendseldb = -1; /* Make sure the first time will not match */
-    server.pidfile = "/var/run/redis.pid";
-    server.dbfilename = "dump.rdb";
-    server.appendfilename = "appendonly.aof";
+    server.pidfile = zstrdup("/var/run/redis.pid");
+    server.dbfilename = zstrdup("dump.rdb");
+    server.appendfilename = zstrdup("appendonly.aof");
     server.requirepass = NULL;
     server.shareobjects = 0;
     server.rdbcompression = 1;
-    server.sharingpoolsize = 1024;
+    server.activerehashing = 1;
     server.maxclients = 0;
     server.blpop_blocked_clients = 0;
     server.maxmemory = 0;
@@ -1531,7 +1640,6 @@ static void initServer() {
     createSharedObjects();
     server.el = aeCreateEventLoop();
     server.db = zmalloc(sizeof(redisDb)*server.dbnum);
-    server.sharingpool = dictCreate(&setDictType,NULL);
     server.fd = anetTcpServer(server.neterr, server.port, server.bindaddr);
     if (server.fd == -1) {
         redisLog(REDIS_WARNING, "Opening TCP port: %s", server.neterr);
@@ -1545,6 +1653,10 @@ static void initServer() {
             server.db[j].io_keys = dictCreate(&keylistDictType,NULL);
         server.db[j].id = j;
     }
+    server.pubsub_channels = dictCreate(&keylistDictType,NULL);
+    server.pubsub_patterns = listCreate();
+    listSetFreeMethod(server.pubsub_patterns,freePubsubPattern);
+    listSetMatchMethod(server.pubsub_patterns,listMatchPubsubPattern);
     server.cronloops = 0;
     server.bgsavechildpid = -1;
     server.bgrewritechildpid = -1;
@@ -1553,6 +1665,7 @@ static void initServer() {
     server.dirty = 0;
     server.stat_numcommands = 0;
     server.stat_numconnections = 0;
+    server.stat_expiredkeys = 0;
     server.stat_starttime = time(NULL);
     server.unixtime = time(NULL);
     aeCreateTimeEvent(server.el, 1, serverCron, NULL, NULL);
@@ -1602,7 +1715,7 @@ static void loadServerConfig(char *filename) {
         fp = stdin;
     else {
         if ((fp = fopen(filename,"r")) == NULL) {
-            redisLog(REDIS_WARNING,"Fatal error, can't open config file");
+            redisLog(REDIS_WARNING, "Fatal error, can't open config file '%s'", filename);
             exit(1);
         }
     }
@@ -1684,6 +1797,8 @@ static void loadServerConfig(char *filename) {
             if (server.dbnum < 1) {
                 err = "Invalid number of databases"; goto loaderr;
             }
+        } else if (!strcasecmp(argv[0],"include") && argc == 2) {
+            loadServerConfig(argv[1]);
         } else if (!strcasecmp(argv[0],"maxclients") && argc == 2) {
             server.maxclients = atoi(argv[1]);
         } else if (!strcasecmp(argv[0],"maxmemory") && argc == 2) {
@@ -1706,10 +1821,9 @@ static void loadServerConfig(char *filename) {
             if ((server.rdbcompression = yesnotoi(argv[1])) == -1) {
                 err = "argument must be 'yes' or 'no'"; goto loaderr;
             }
-        } else if (!strcasecmp(argv[0],"shareobjectspoolsize") && argc == 2) {
-            server.sharingpoolsize = atoi(argv[1]);
-            if (server.sharingpoolsize < 1) {
-                err = "invalid object sharing pool size"; goto loaderr;
+        } else if (!strcasecmp(argv[0],"activerehashing") && argc == 2) {
+            if ((server.activerehashing = yesnotoi(argv[1])) == -1) {
+                err = "argument must be 'yes' or 'no'"; goto loaderr;
             }
         } else if (!strcasecmp(argv[0],"daemonize") && argc == 2) {
             if ((server.daemonize = yesnotoi(argv[1])) == -1) {
@@ -1733,8 +1847,10 @@ static void loadServerConfig(char *filename) {
         } else if (!strcasecmp(argv[0],"requirepass") && argc == 2) {
             server.requirepass = zstrdup(argv[1]);
         } else if (!strcasecmp(argv[0],"pidfile") && argc == 2) {
+            zfree(server.pidfile);
             server.pidfile = zstrdup(argv[1]);
         } else if (!strcasecmp(argv[0],"dbfilename") && argc == 2) {
+            zfree(server.dbfilename);
             server.dbfilename = zstrdup(argv[1]);
         } else if (!strcasecmp(argv[0],"vm-enabled") && argc == 2) {
             if ((server.vm_enabled = yesnotoi(argv[1])) == -1) {
@@ -1800,6 +1916,12 @@ static void freeClient(redisClient *c) {
     if (c->flags & REDIS_BLOCKED)
         unblockClientWaitingData(c);
 
+    /* Unsubscribe from all the pubsub channels */
+    pubsubUnsubscribeAllChannels(c,0);
+    pubsubUnsubscribeAllPatterns(c,0);
+    dictRelease(c->pubsub_channels);
+    listRelease(c->pubsub_patterns);
+    /* Obvious cleanup */
     aeDeleteFileEvent(server.el,c->fd,AE_READABLE);
     aeDeleteFileEvent(server.el,c->fd,AE_WRITABLE);
     listRelease(c->reply);
@@ -1822,7 +1944,7 @@ static void freeClient(redisClient *c) {
         dontWaitForSwappedKey(c,ln->value);
     }
     listRelease(c->io_keys);
-    /* Other cleanup */
+    /* Master/slave cleanup */
     if (c->flags & REDIS_SLAVE) {
         if (c->replstate == REDIS_REPL_SEND_BULK && c->repldbfd != -1)
             close(c->repldbfd);
@@ -1835,6 +1957,7 @@ static void freeClient(redisClient *c) {
         server.master = NULL;
         server.replstate = REDIS_REPL_CONNECT;
     }
+    /* Release memory */
     zfree(c->argv);
     zfree(c->mbargv);
     freeClientMultiState(c);
@@ -1878,7 +2001,7 @@ static void sendReplyToClient(aeEventLoop *el, int fd, void *privdata, int mask)
 
     /* Use writev() if we have enough buffers to send */
     if (!server.glueoutputbuf &&
-        listLength(c->reply) > REDIS_WRITEV_THRESHOLD && 
+        listLength(c->reply) > REDIS_WRITEV_THRESHOLD &&
         !(c->flags & REDIS_MASTER))
     {
         sendReplyToClientWritev(el, fd, privdata, mask);
@@ -1956,7 +2079,7 @@ static void sendReplyToClientWritev(aeEventLoop *el, int fd, void *privdata, int
             o = listNodeValue(node);
             objlen = sdslen(o->ptr);
 
-            if (totwritten + objlen - offset > REDIS_MAX_WRITE_PER_EVENT) 
+            if (totwritten + objlen - offset > REDIS_MAX_WRITE_PER_EVENT)
                 break;
 
             if(ion == REDIS_WRITEV_IOVEC_COUNT)
@@ -2004,7 +2127,7 @@ static void sendReplyToClientWritev(aeEventLoop *el, int fd, void *privdata, int
         }
     }
 
-    if (totwritten > 0) 
+    if (totwritten > 0)
         c->lastinteraction = time(NULL);
 
     if (listLength(c->reply) == 0) {
@@ -2035,12 +2158,15 @@ static void call(redisClient *c, struct redisCommand *cmd) {
 
     dirty = server.dirty;
     cmd->proc(c);
-    if (server.appendonly && server.dirty-dirty)
+    dirty = server.dirty-dirty;
+
+    if (server.appendonly && dirty)
         feedAppendOnlyFile(cmd,c->db->id,c->argv,c->argc);
-    if (server.dirty-dirty && listLength(server.slaves))
-        replicationFeedSlaves(server.slaves,cmd,c->db->id,c->argv,c->argc);
+    if ((dirty || cmd->flags & REDIS_CMD_FORCE_REPLICATION) &&
+        listLength(server.slaves))
+        replicationFeedSlaves(server.slaves,c->db->id,c->argv,c->argc);
     if (listLength(server.monitors))
-        replicationFeedSlaves(server.monitors,cmd,c->db->id,c->argv,c->argc);
+        replicationFeedSlaves(server.monitors,c->db->id,c->argv,c->argc);
     server.stat_numcommands++;
 }
 
@@ -2150,10 +2276,6 @@ static int processCommand(redisClient *c) {
                 cmd->name));
         resetClient(c);
         return 1;
-    } else if (server.maxmemory && cmd->flags & REDIS_CMD_DENYOOM && zmalloc_used_memory() > server.maxmemory) {
-        addReplySds(c,sdsnew("-ERR command not allowed when used memory > 'maxmemory'\r\n"));
-        resetClient(c);
-        return 1;
     } else if (cmd->flags & REDIS_CMD_BULK && c->bulklen == -1) {
         /* This is a bulk command, we have to read the last argument yet. */
         int bulklen = atoi(c->argv[c->argc-1]->ptr);
@@ -2182,15 +2304,9 @@ static int processCommand(redisClient *c) {
             return 1;
         }
     }
-    /* Let's try to share objects on the command arguments vector */
-    if (server.shareobjects) {
-        int j;
-        for(j = 1; j < c->argc; j++)
-            c->argv[j] = tryObjectSharing(c->argv[j]);
-    }
     /* Let's try to encode the bulk object to save space. */
     if (cmd->flags & REDIS_CMD_BULK)
-        tryObjectEncoding(c->argv[c->argc-1]);
+        c->argv[c->argc-1] = tryObjectEncoding(c->argv[c->argc-1]);
 
     /* Check if the user is authenticated */
     if (server.requirepass && !c->authenticated && cmd->proc != authCommand) {
@@ -2199,6 +2315,25 @@ static int processCommand(redisClient *c) {
         return 1;
     }
 
+    /* Handle the maxmemory directive */
+    if (server.maxmemory && (cmd->flags & REDIS_CMD_DENYOOM) &&
+        zmalloc_used_memory() > server.maxmemory)
+    {
+        addReplySds(c,sdsnew("-ERR command not allowed when used memory > 'maxmemory'\r\n"));
+        resetClient(c);
+        return 1;
+    }
+
+    /* Only allow SUBSCRIBE and UNSUBSCRIBE in the context of Pub/Sub */
+    if ((dictSize(c->pubsub_channels) > 0 || listLength(c->pubsub_patterns) > 0)
+        &&
+        cmd->proc != subscribeCommand && cmd->proc != unsubscribeCommand &&
+        cmd->proc != psubscribeCommand && cmd->proc != punsubscribeCommand) {
+        addReplySds(c,sdsnew("-ERR only (P)SUBSCRIBE / (P)UNSUBSCRIBE / QUIT allowed in this context\r\n"));
+        resetClient(c);
+        return 1;
+    }
+
     /* Exec the command */
     if (c->flags & REDIS_MULTI && cmd->proc != execCommand && cmd->proc != discardCommand) {
         queueMultiCommand(c,cmd);
@@ -2214,34 +2349,36 @@ static int processCommand(redisClient *c) {
     return 1;
 }
 
-static void replicationFeedSlaves(list *slaves, struct redisCommand *cmd, int dictid, robj **argv, int argc) {
+static void replicationFeedSlaves(list *slaves, int dictid, robj **argv, int argc) {
     listNode *ln;
     listIter li;
     int outc = 0, j;
     robj **outv;
-    /* (args*2)+1 is enough room for args, spaces, newlines */
-    robj *static_outv[REDIS_STATIC_ARGS*2+1];
+    /* We need 1+(ARGS*3) objects since commands are using the new protocol
+     * and we one 1 object for the first "*<count>\r\n" multibulk count, then
+     * for every additional object we have "$<count>\r\n" + object + "\r\n". */
+    robj *static_outv[REDIS_STATIC_ARGS*3+1];
+    robj *lenobj;
 
     if (argc <= REDIS_STATIC_ARGS) {
         outv = static_outv;
     } else {
-        outv = zmalloc(sizeof(robj*)*(argc*2+1));
+        outv = zmalloc(sizeof(robj*)*(argc*3+1));
     }
-    
-    for (j = 0; j < argc; j++) {
-        if (j != 0) outv[outc++] = shared.space;
-        if ((cmd->flags & REDIS_CMD_BULK) && j == argc-1) {
-            robj *lenobj;
 
-            lenobj = createObject(REDIS_STRING,
-                sdscatprintf(sdsempty(),"%lu\r\n",
-                    (unsigned long) stringObjectLen(argv[j])));
-            lenobj->refcount = 0;
-            outv[outc++] = lenobj;
-        }
+    lenobj = createObject(REDIS_STRING,
+            sdscatprintf(sdsempty(), "*%d\r\n", argc));
+    lenobj->refcount = 0;
+    outv[outc++] = lenobj;
+    for (j = 0; j < argc; j++) {
+        lenobj = createObject(REDIS_STRING,
+            sdscatprintf(sdsempty(),"$%lu\r\n",
+                (unsigned long) stringObjectLen(argv[j])));
+        lenobj->refcount = 0;
+        outv[outc++] = lenobj;
         outv[outc++] = argv[j];
+        outv[outc++] = shared.crlf;
     }
-    outv[outc++] = shared.crlf;
 
     /* Increment all the refcounts at start and decrement at end in order to
      * be sure to free objects if there is no slave in a replication state
@@ -2301,7 +2438,7 @@ again:
         if (p) {
             sds query, *argv;
             int argc, j;
-            
+
             query = c->querybuf;
             c->querybuf = sdsempty();
             querylen = 1+(p-(query));
@@ -2393,8 +2530,7 @@ static void readQueryFromClient(aeEventLoop *el, int fd, void *privdata, int mas
     } else {
         return;
     }
-    if (!(c->flags & REDIS_BLOCKED))
-        processInputBuffer(c);
+    processInputBuffer(c);
 }
 
 static int selectDb(redisClient *c, int id) {
@@ -2409,6 +2545,10 @@ static void *dupClientReplyValue(void *o) {
     return o;
 }
 
+static int listMatchObjects(void *a, void *b) {
+    return compareStringObjects(a,b) == 0;
+}
+
 static redisClient *createClient(int fd) {
     redisClient *c = zmalloc(sizeof(*c));
 
@@ -2436,6 +2576,10 @@ static redisClient *createClient(int fd) {
     c->blockingkeysnum = 0;
     c->io_keys = listCreate();
     listSetFreeMethod(c->io_keys,decrRefCount);
+    c->pubsub_channels = dictCreate(&setDictType,NULL);
+    c->pubsub_patterns = listCreate();
+    listSetFreeMethod(c->pubsub_patterns,decrRefCount);
+    listSetMatchMethod(c->pubsub_patterns,listMatchObjects);
     if (aeCreateFileEvent(server.el, c->fd, AE_READABLE,
         readQueryFromClient, c) == AE_ERR) {
         freeClient(c);
@@ -2489,6 +2633,21 @@ static void addReplyLong(redisClient *c, long l) {
     addReplySds(c,sdsnewlen(buf,len));
 }
 
+static void addReplyLongLong(redisClient *c, long long ll) {
+    char buf[128];
+    size_t len;
+
+    if (ll == 0) {
+        addReply(c,shared.czero);
+        return;
+    } else if (ll == 1) {
+        addReply(c,shared.cone);
+        return;
+    }
+    len = snprintf(buf,sizeof(buf),":%lld\r\n",ll);
+    addReplySds(c,sdsnewlen(buf,len));
+}
+
 static void addReplyUlong(redisClient *c, unsigned long ul) {
     char buf[128];
     size_t len;
@@ -2531,6 +2690,17 @@ static void addReplyBulk(redisClient *c, robj *obj) {
     addReply(c,shared.crlf);
 }
 
+/* In the CONFIG command we need to add vanilla C string as bulk replies */
+static void addReplyBulkCString(redisClient *c, char *s) {
+    if (s == NULL) {
+        addReply(c,shared.nullbulk);
+    } else {
+        robj *o = createStringObject(s,strlen(s));
+        addReplyBulk(c,o);
+        decrRefCount(o);
+    }
+}
+
 static void acceptHandler(aeEventLoop *el, int fd, void *privdata, int mask) {
     int cport, cfd;
     char cip[128];
@@ -2605,6 +2775,23 @@ static robj *createStringObject(char *ptr, size_t len) {
     return createObject(REDIS_STRING,sdsnewlen(ptr,len));
 }
 
+static robj *createStringObjectFromLongLong(long long value) {
+    robj *o;
+    if (value >= 0 && value < REDIS_SHARED_INTEGERS) {
+        incrRefCount(shared.integers[value]);
+        o = shared.integers[value];
+    } else {
+        o = createObject(REDIS_STRING, NULL);
+        if (value >= LONG_MIN && value <= LONG_MAX) {
+            o->encoding = REDIS_ENCODING_INT;
+            o->ptr = (void*)((long)value);
+        } else {
+            o->ptr = sdscatprintf(sdsempty(),"%lld",value);
+        }
+    }
+    return o;
+}
+
 static robj *dupStringObject(robj *o) {
     assert(o->encoding == REDIS_ENCODING_RAW);
     return createStringObject(o->ptr,sdslen(o->ptr));
@@ -2671,27 +2858,24 @@ static void freeHashObject(robj *o) {
         zfree(o->ptr);
         break;
     default:
-        redisAssert(0);
+        redisPanic("Unknown hash encoding type");
         break;
     }
 }
 
 static void incrRefCount(robj *o) {
-    redisAssert(!server.vm_enabled || o->storage == REDIS_VM_MEMORY);
     o->refcount++;
 }
 
 static void decrRefCount(void *obj) {
     robj *o = obj;
 
+    if (o->refcount <= 0) redisPanic("decrRefCount against refcount <= 0");
     /* Object is a key of a swapped out value, or in the process of being
      * loaded. */
     if (server.vm_enabled &&
         (o->storage == REDIS_VM_SWAPPED || o->storage == REDIS_VM_LOADING))
     {
-        if (o->storage == REDIS_VM_SWAPPED || o->storage == REDIS_VM_LOADING) {
-            redisAssert(o->refcount == 1);
-        }
         if (o->storage == REDIS_VM_LOADING) vmCancelThreadedIOJob(obj);
         redisAssert(o->type == REDIS_STRING);
         freeStringObject(o);
@@ -2714,7 +2898,7 @@ static void decrRefCount(void *obj) {
         case REDIS_SET: freeSetObject(o); break;
         case REDIS_ZSET: freeZsetObject(o); break;
         case REDIS_HASH: freeHashObject(o); break;
-        default: redisAssert(0 != 0); break;
+        default: redisPanic("Unknown object type"); break;
         }
         if (server.vm_enabled) pthread_mutex_lock(&server.obj_freelist_mutex);
         if (listLength(server.objfreelist) > REDIS_OBJFREELIST_MAX ||
@@ -2804,51 +2988,6 @@ static int deleteKey(redisDb *db, robj *key) {
     return retval == DICT_OK;
 }
 
-/* Try to share an object against the shared objects pool */
-static robj *tryObjectSharing(robj *o) {
-    struct dictEntry *de;
-    unsigned long c;
-
-    if (o == NULL || server.shareobjects == 0) return o;
-
-    redisAssert(o->type == REDIS_STRING);
-    de = dictFind(server.sharingpool,o);
-    if (de) {
-        robj *shared = dictGetEntryKey(de);
-
-        c = ((unsigned long) dictGetEntryVal(de))+1;
-        dictGetEntryVal(de) = (void*) c;
-        incrRefCount(shared);
-        decrRefCount(o);
-        return shared;
-    } else {
-        /* Here we are using a stream algorihtm: Every time an object is
-         * shared we increment its count, everytime there is a miss we
-         * recrement the counter of a random object. If this object reaches
-         * zero we remove the object and put the current object instead. */
-        if (dictSize(server.sharingpool) >=
-                server.sharingpoolsize) {
-            de = dictGetRandomKey(server.sharingpool);
-            redisAssert(de != NULL);
-            c = ((unsigned long) dictGetEntryVal(de))-1;
-            dictGetEntryVal(de) = (void*) c;
-            if (c == 0) {
-                dictDelete(server.sharingpool,de->key);
-            }
-        } else {
-            c = 0; /* If the pool is empty we want to add this object */
-        }
-        if (c == 0) {
-            int retval;
-
-            retval = dictAdd(server.sharingpool,o,(void*)1);
-            redisAssert(retval == DICT_OK);
-            incrRefCount(o);
-        }
-        return o;
-    }
-}
-
 /* Check if the nul-terminated string 's' can be represented by a long
  * (that is, is a number that fits into long without any other space or
  * character before or after the digits).
@@ -2859,7 +2998,7 @@ static int isStringRepresentableAsLong(sds s, long *longval) {
     char buf[32], *endptr;
     long value;
     int slen;
-    
+
     value = strtol(s, &endptr, 10);
     if (endptr[0] != '\0') return REDIS_ERR;
     slen = snprintf(buf,32,"%ld",value);
@@ -2872,36 +3011,42 @@ static int isStringRepresentableAsLong(sds s, long *longval) {
 }
 
 /* Try to encode a string object in order to save space */
-static int tryObjectEncoding(robj *o) {
+static robj *tryObjectEncoding(robj *o) {
     long value;
     sds s = o->ptr;
 
     if (o->encoding != REDIS_ENCODING_RAW)
-        return REDIS_ERR; /* Already encoded */
+        return o; /* Already encoded */
 
-    /* It's not save to encode shared objects: shared objects can be shared
+    /* It's not safe to encode shared objects: shared objects can be shared
      * everywhere in the "object space" of Redis. Encoded objects can only
      * appear as "values" (and not, for instance, as keys) */
-     if (o->refcount > 1) return REDIS_ERR;
+     if (o->refcount > 1) return o;
 
     /* Currently we try to encode only strings */
     redisAssert(o->type == REDIS_STRING);
 
     /* Check if we can represent this string as a long integer */
-    if (isStringRepresentableAsLong(s,&value) == REDIS_ERR) return REDIS_ERR;
+    if (isStringRepresentableAsLong(s,&value) == REDIS_ERR) return o;
 
     /* Ok, this object can be encoded */
-    o->encoding = REDIS_ENCODING_INT;
-    sdsfree(o->ptr);
-    o->ptr = (void*) value;
-    return REDIS_OK;
+    if (value >= 0 && value < REDIS_SHARED_INTEGERS) {
+        decrRefCount(o);
+        incrRefCount(shared.integers[value]);
+        return shared.integers[value];
+    } else {
+        o->encoding = REDIS_ENCODING_INT;
+        sdsfree(o->ptr);
+        o->ptr = (void*) value;
+        return o;
+    }
 }
 
 /* Get a decoded version of an encoded object (returned as a new object).
  * If the object is already raw-encoded just increment the ref count. */
 static robj *getDecodedObject(robj *o) {
     robj *dec;
-    
+
     if (o->encoding == REDIS_ENCODING_RAW) {
         incrRefCount(o);
         return o;
@@ -2913,7 +3058,7 @@ static robj *getDecodedObject(robj *o) {
         dec = createStringObject(buf,strlen(buf));
         return dec;
     } else {
-        redisAssert(1 != 1);
+        redisPanic("Unknown encoding type");
     }
 }
 
@@ -2959,6 +3104,97 @@ static size_t stringObjectLen(robj *o) {
     }
 }
 
+static int getDoubleFromObject(robj *o, double *target) {
+    double value;
+    char *eptr;
+
+    if (o == NULL) {
+        value = 0;
+    } else {
+        redisAssert(o->type == REDIS_STRING);
+        if (o->encoding == REDIS_ENCODING_RAW) {
+            value = strtod(o->ptr, &eptr);
+            if (eptr[0] != '\0') return REDIS_ERR;
+        } else if (o->encoding == REDIS_ENCODING_INT) {
+            value = (long)o->ptr;
+        } else {
+            redisAssert(1 != 1);
+        }
+    }
+
+    *target = value;
+    return REDIS_OK;
+}
+
+static int getDoubleFromObjectOrReply(redisClient *c, robj *o, double *target, const char *msg) {
+    double value;
+    if (getDoubleFromObject(o, &value) != REDIS_OK) {
+        if (msg != NULL) {
+            addReplySds(c, sdscatprintf(sdsempty(), "-ERR %s\r\n", msg));
+        } else {
+            addReplySds(c, sdsnew("-ERR value is not a double\r\n"));
+        }
+        return REDIS_ERR;
+    }
+
+    *target = value;
+    return REDIS_OK;
+}
+
+static int getLongLongFromObject(robj *o, long long *target) {
+    long long value;
+    char *eptr;
+
+    if (o == NULL) {
+        value = 0;
+    } else {
+        redisAssert(o->type == REDIS_STRING);
+        if (o->encoding == REDIS_ENCODING_RAW) {
+            value = strtoll(o->ptr, &eptr, 10);
+            if (eptr[0] != '\0') return REDIS_ERR;
+        } else if (o->encoding == REDIS_ENCODING_INT) {
+            value = (long)o->ptr;
+        } else {
+            redisAssert(1 != 1);
+        }
+    }
+
+    *target = value;
+    return REDIS_OK;
+}
+
+static int getLongLongFromObjectOrReply(redisClient *c, robj *o, long long *target, const char *msg) {
+    long long value;
+    if (getLongLongFromObject(o, &value) != REDIS_OK) {
+        if (msg != NULL) {
+            addReplySds(c, sdscatprintf(sdsempty(), "-ERR %s\r\n", msg));
+        } else {
+            addReplySds(c, sdsnew("-ERR value is not an integer\r\n"));
+        }
+        return REDIS_ERR;
+    }
+
+    *target = value;
+    return REDIS_OK;
+}
+
+static int getLongFromObjectOrReply(redisClient *c, robj *o, long *target, const char *msg) {
+    long long value;
+
+    if (getLongLongFromObjectOrReply(c, o, &value, msg) != REDIS_OK) return REDIS_ERR;
+    if (value < LONG_MIN || value > LONG_MAX) {
+        if (msg != NULL) {
+            addReplySds(c, sdscatprintf(sdsempty(), "-ERR %s\r\n", msg));
+        } else {
+            addReplySds(c, sdsnew("-ERR value is out of range\r\n"));
+        }
+        return REDIS_ERR;
+    }
+
+    *target = value;
+    return REDIS_OK;
+}
+
 /*============================ RDB saving/loading =========================== */
 
 static int rdbSaveType(FILE *fp, unsigned char type) {
@@ -3212,7 +3448,7 @@ static int rdbSaveObject(FILE *fp, robj *o) {
             dictReleaseIterator(di);
         }
     } else {
-        redisAssert(0 != 0);
+        redisPanic("Unknown object type");
     }
     return 0;
 }
@@ -3231,7 +3467,7 @@ static off_t rdbSavedObjectLen(robj *o, FILE *fp) {
 /* Return the number of pages required to save this object in the swap file */
 static off_t rdbSavedObjectPages(robj *o, FILE *fp) {
     off_t bytes = rdbSavedObjectLen(o,fp);
-    
+
     return (bytes+(server.vm_page_size-1))/server.vm_page_size;
 }
 
@@ -3314,7 +3550,7 @@ static int rdbSave(char *filename) {
     fflush(fp);
     fsync(fileno(fp));
     fclose(fp);
-    
+
     /* Use RENAME to make sure the DB file is changed atomically only
      * if the generate DB file is ok. */
     if (rename(tmpfile,filename) == -1) {
@@ -3358,6 +3594,7 @@ static int rdbSaveBackground(char *filename) {
         }
         redisLog(REDIS_NOTICE,"Background saving started by pid %d",childpid);
         server.bgsavechildpid = childpid;
+        updateDictResizePolicy();
         return REDIS_OK;
     }
     return REDIS_OK; /* unreached */
@@ -3432,7 +3669,7 @@ static robj *rdbLoadIntegerObject(FILE *fp, int enctype) {
         val = (int32_t)v;
     } else {
         val = 0; /* anti-warning */
-        redisAssert(0!=0);
+        redisPanic("Unknown RDB integer encoding type");
     }
     return createObject(REDIS_STRING,sdscatprintf(sdsempty(),"%lld",val));
 }
@@ -3467,11 +3704,11 @@ static robj *rdbLoadStringObject(FILE*fp) {
         case REDIS_RDB_ENC_INT8:
         case REDIS_RDB_ENC_INT16:
         case REDIS_RDB_ENC_INT32:
-            return tryObjectSharing(rdbLoadIntegerObject(fp,len));
+            return rdbLoadIntegerObject(fp,len);
         case REDIS_RDB_ENC_LZF:
-            return tryObjectSharing(rdbLoadLzfStringObject(fp));
+            return rdbLoadLzfStringObject(fp);
         default:
-            redisAssert(0!=0);
+            redisPanic("Unknown RDB encoding type");
         }
     }
 
@@ -3481,7 +3718,7 @@ static robj *rdbLoadStringObject(FILE*fp) {
         sdsfree(val);
         return NULL;
     }
-    return tryObjectSharing(createObject(REDIS_STRING,val));
+    return createObject(REDIS_STRING,val);
 }
 
 /* For information about double serialization check rdbSaveDoubleValue() */
@@ -3511,7 +3748,7 @@ static robj *rdbLoadObject(int type, FILE *fp) {
     if (type == REDIS_STRING) {
         /* Read string value */
         if ((o = rdbLoadStringObject(fp)) == NULL) return NULL;
-        tryObjectEncoding(o);
+        o = tryObjectEncoding(o);
     } else if (type == REDIS_LIST || type == REDIS_SET) {
         /* Read list/set value */
         uint32_t listlen;
@@ -3527,7 +3764,7 @@ static robj *rdbLoadObject(int type, FILE *fp) {
             robj *ele;
 
             if ((ele = rdbLoadStringObject(fp)) == NULL) return NULL;
-            tryObjectEncoding(ele);
+            ele = tryObjectEncoding(ele);
             if (type == REDIS_LIST) {
                 listAddNodeTail((list*)o->ptr,ele);
             } else {
@@ -3548,7 +3785,7 @@ static robj *rdbLoadObject(int type, FILE *fp) {
             double *score = zmalloc(sizeof(double));
 
             if ((ele = rdbLoadStringObject(fp)) == NULL) return NULL;
-            tryObjectEncoding(ele);
+            ele = tryObjectEncoding(ele);
             if (rdbLoadDoubleValue(fp,score) == -1) return NULL;
             dictAdd(zs->dict,ele,score);
             zslInsert(zs->zsl,*score,ele);
@@ -3587,15 +3824,13 @@ static robj *rdbLoadObject(int type, FILE *fp) {
                 decrRefCount(key);
                 decrRefCount(val);
             } else {
-                tryObjectEncoding(key);
-                tryObjectEncoding(val);
+                key = tryObjectEncoding(key);
+                val = tryObjectEncoding(val);
                 dictAdd((dict*)o->ptr,key,val);
-                incrRefCount(key);
-                incrRefCount(val);
             }
         }
     } else {
-        redisAssert(0 != 0);
+        redisPanic("Unknown object type");
     }
     return o;
 }
@@ -3745,7 +3980,7 @@ static void setnxCommand(redisClient *c) {
 
 static int getGenericCommand(redisClient *c) {
     robj *o;
-    
+
     if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.nullbulk)) == NULL)
         return REDIS_OK;
 
@@ -3776,7 +4011,7 @@ static void getsetCommand(redisClient *c) {
 
 static void mgetCommand(redisClient *c) {
     int j;
-  
+
     addReplySds(c,sdscatprintf(sdsempty(),"*%d\r\n",c->argc-1));
     for (j = 1; j < c->argc; j++) {
         robj *o = lookupKeyRead(c->db,c->argv[j]);
@@ -3816,7 +4051,7 @@ static void msetGenericCommand(redisClient *c, int nx) {
     for (j = 1; j < c->argc; j += 2) {
         int retval;
 
-        tryObjectEncoding(c->argv[j+1]);
+        c->argv[j+1] = tryObjectEncoding(c->argv[j+1]);
         retval = dictAdd(c->db->dict,c->argv[j],c->argv[j+1]);
         if (retval == DICT_ERR) {
             dictReplace(c->db->dict,c->argv[j],c->argv[j+1]);
@@ -3843,28 +4078,14 @@ static void incrDecrCommand(redisClient *c, long long incr) {
     long long value;
     int retval;
     robj *o;
-    
+
     o = lookupKeyWrite(c->db,c->argv[1]);
-    if (o == NULL) {
-        value = 0;
-    } else {
-        if (o->type != REDIS_STRING) {
-            value = 0;
-        } else {
-            char *eptr;
 
-            if (o->encoding == REDIS_ENCODING_RAW)
-                value = strtoll(o->ptr, &eptr, 10);
-            else if (o->encoding == REDIS_ENCODING_INT)
-                value = (long)o->ptr;
-            else
-                redisAssert(1 != 1);
-        }
-    }
+    if (getLongLongFromObjectOrReply(c, o, &value, NULL) != REDIS_OK) return;
 
     value += incr;
     o = createObject(REDIS_STRING,sdscatprintf(sdsempty(),"%lld",value));
-    tryObjectEncoding(o);
+    o = tryObjectEncoding(o);
     retval = dictAdd(c->db->dict,c->argv[1],o);
     if (retval == DICT_ERR) {
         dictReplace(c->db->dict,c->argv[1],o);
@@ -3887,12 +4108,16 @@ static void decrCommand(redisClient *c) {
 }
 
 static void incrbyCommand(redisClient *c) {
-    long long incr = strtoll(c->argv[2]->ptr, NULL, 10);
+    long long incr;
+
+    if (getLongLongFromObjectOrReply(c, c->argv[2], &incr, NULL) != REDIS_OK) return;
     incrDecrCommand(c,incr);
 }
 
 static void decrbyCommand(redisClient *c) {
-    long long incr = strtoll(c->argv[2]->ptr, NULL, 10);
+    long long incr;
+
+    if (getLongLongFromObjectOrReply(c, c->argv[2], &incr, NULL) != REDIS_OK) return;
     incrDecrCommand(c,-incr);
 }
 
@@ -3910,7 +4135,7 @@ static void appendCommand(redisClient *c) {
         totlen = stringObjectLen(c->argv[2]);
     } else {
         dictEntry *de;
-       
+
         de = dictFind(c->db->dict,c->argv[1]);
         assert(de != NULL);
 
@@ -3999,7 +4224,7 @@ static void existsCommand(redisClient *c) {
 
 static void selectCommand(redisClient *c) {
     int id = atoi(c->argv[1]->ptr);
-    
+
     if (selectDb(c,id) == REDIS_ERR) {
         addReplySds(c,sdsnew("-ERR invalid DB index\r\n"));
     } else {
@@ -4009,7 +4234,7 @@ static void selectCommand(redisClient *c) {
 
 static void randomkeyCommand(redisClient *c) {
     dictEntry *de;
-   
+
     while(1) {
         de = dictGetRandomKey(c->db->dict);
         if (!de || expireIfNeeded(c->db,dictGetEntryKey(de)) == 0) break;
@@ -4137,7 +4362,7 @@ static void shutdownCommand(redisClient *c) {
              * in the next cron() Redis will be notified that the background
              * saving aborted, handling special stuff like slaves pending for
              * synchronization... */
-            redisLog(REDIS_WARNING,"Error trying to save the DB, can't exit"); 
+            redisLog(REDIS_WARNING,"Error trying to save the DB, can't exit");
             addReplySds(c,
                 sdsnew("-ERR can't quit, problems saving the DB\r\n"));
         }
@@ -4281,7 +4506,7 @@ static void llenCommand(redisClient *c) {
 
     if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
         checkType(c,o,REDIS_LIST)) return;
-    
+
     l = o->ptr;
     addReplyUlong(c,listLength(l));
 }
@@ -4349,6 +4574,7 @@ static void popGenericCommand(redisClient *c, int where) {
         robj *ele = listNodeValue(ln);
         addReplyBulk(c,ele);
         listDelNode(list,ln);
+        if (listLength(list) == 0) deleteKey(c->db,c->argv[1]);
         server.dirty++;
     }
 }
@@ -4371,8 +4597,8 @@ static void lrangeCommand(redisClient *c) {
     listNode *ln;
     robj *ele;
 
-    if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.nullmultibulk)) == NULL ||
-        checkType(c,o,REDIS_LIST)) return;
+    if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.emptymultibulk)) == NULL
+         || checkType(c,o,REDIS_LIST)) return;
     list = o->ptr;
     llen = listLength(list);
 
@@ -4441,6 +4667,7 @@ static void ltrimCommand(redisClient *c) {
         ln = listLast(list);
         listDelNode(list,ln);
     }
+    if (listLength(list) == 0) deleteKey(c->db,c->argv[1]);
     server.dirty++;
     addReply(c,shared.ok);
 }
@@ -4474,6 +4701,7 @@ static void lremCommand(redisClient *c) {
         }
         ln = next;
     }
+    if (listLength(list) == 0) deleteKey(c->db,c->argv[1]);
     addReplySds(c,sdscatprintf(sdsempty(),":%d\r\n",removed));
 }
 
@@ -4533,6 +4761,7 @@ static void rpoplpushcommand(redisClient *c) {
 
         /* Finally remove the element from the source list */
         listDelNode(srclist,ln);
+        if (listLength(srclist) == 0) deleteKey(c->db,c->argv[1]);
         server.dirty++;
     }
 }
@@ -4571,6 +4800,7 @@ static void sremCommand(redisClient *c) {
     if (dictDelete(set->ptr,c->argv[2]) == DICT_OK) {
         server.dirty++;
         if (htNeedsResize(set->ptr)) dictResize(set->ptr);
+        if (dictSize((dict*)set->ptr) == 0) deleteKey(c->db,c->argv[1]);
         addReply(c,shared.cone);
     } else {
         addReply(c,shared.czero);
@@ -4600,6 +4830,8 @@ static void smoveCommand(redisClient *c) {
         addReply(c,shared.czero);
         return;
     }
+    if (dictSize((dict*)srcset->ptr) == 0 && srcset != dstset)
+        deleteKey(c->db,c->argv[1]);
     server.dirty++;
     /* Add the element to the destination set */
     if (!dstset) {
@@ -4630,7 +4862,7 @@ static void scardCommand(redisClient *c) {
 
     if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
         checkType(c,o,REDIS_SET)) return;
-    
+
     s = o->ptr;
     addReplyUlong(c,dictSize(s));
 }
@@ -4651,6 +4883,7 @@ static void spopCommand(redisClient *c) {
         addReplyBulk(c,ele);
         dictDelete(set->ptr,ele);
         if (htNeedsResize(set->ptr)) dictResize(set->ptr);
+        if (dictSize((dict*)set->ptr) == 0) deleteKey(c->db,c->argv[1]);
         server.dirty++;
     }
 }
@@ -4698,7 +4931,7 @@ static void sinterGenericCommand(redisClient *c, robj **setskeys, unsigned long
                     server.dirty++;
                 addReply(c,shared.czero);
             } else {
-                addReply(c,shared.nullmultibulk);
+                addReply(c,shared.emptymultibulk);
             }
             return;
         }
@@ -4752,18 +4985,20 @@ static void sinterGenericCommand(redisClient *c, robj **setskeys, unsigned long
     dictReleaseIterator(di);
 
     if (dstkey) {
-        /* Store the resulting set into the target */
+        /* Store the resulting set into the target, if the intersection
+         * is not an empty set. */
         deleteKey(c->db,dstkey);
-        dictAdd(c->db->dict,dstkey,dstset);
-        incrRefCount(dstkey);
-    }
-
-    if (!dstkey) {
-        lenobj->ptr = sdscatprintf(sdsempty(),"*%lu\r\n",cardinality);
-    } else {
-        addReplySds(c,sdscatprintf(sdsempty(),":%lu\r\n",
-            dictSize((dict*)dstset->ptr)));
+        if (dictSize((dict*)dstset->ptr) > 0) {
+            dictAdd(c->db->dict,dstkey,dstset);
+            incrRefCount(dstkey);
+            addReplyLong(c,dictSize((dict*)dstset->ptr));
+        } else {
+            decrRefCount(dstset);
+            addReply(c,shared.czero);
+        }
         server.dirty++;
+    } else {
+        lenobj->ptr = sdscatprintf(sdsempty(),"*%lu\r\n",cardinality);
     }
     zfree(dv);
 }
@@ -4836,7 +5071,8 @@ static void sunionDiffGenericCommand(redisClient *c, robj **setskeys, int setsnu
         }
         dictReleaseIterator(di);
 
-        if (op == REDIS_OP_DIFF && cardinality == 0) break; /* result set is empty */
+        /* result set is empty? Exit asap. */
+        if (op == REDIS_OP_DIFF && cardinality == 0) break;
     }
 
     /* Output the content of the resulting set, if not in STORE mode */
@@ -4850,20 +5086,19 @@ static void sunionDiffGenericCommand(redisClient *c, robj **setskeys, int setsnu
             addReplyBulk(c,ele);
         }
         dictReleaseIterator(di);
+        decrRefCount(dstset);
     } else {
         /* If we have a target key where to store the resulting set
          * create this key with the result set inside */
         deleteKey(c->db,dstkey);
-        dictAdd(c->db->dict,dstkey,dstset);
-        incrRefCount(dstkey);
-    }
-
-    /* Cleanup */
-    if (!dstkey) {
-        decrRefCount(dstset);
-    } else {
-        addReplySds(c,sdscatprintf(sdsempty(),":%lu\r\n",
-            dictSize((dict*)dstset->ptr)));
+        if (dictSize((dict*)dstset->ptr) > 0) {
+            dictAdd(c->db->dict,dstkey,dstset);
+            incrRefCount(dstkey);
+            addReplyLong(c,dictSize((dict*)dstset->ptr));
+        } else {
+            decrRefCount(dstset);
+            addReply(c,shared.czero);
+        }
         server.dirty++;
     }
     zfree(dv);
@@ -4918,7 +5153,7 @@ static zskiplistNode *zslCreateNode(int level, double score, robj *obj) {
 static zskiplist *zslCreate(void) {
     int j;
     zskiplist *zsl;
-    
+
     zsl = zmalloc(sizeof(*zsl));
     zsl->level = 1;
     zsl->length = 0;
@@ -4960,7 +5195,7 @@ static int zslRandomLevel(void) {
     int level = 1;
     while ((random()&0xFFFF) < (ZSKIPLIST_P * 0xFFFF))
         level += 1;
-    return level;
+    return (level<ZSKIPLIST_MAXLEVEL) ? level : ZSKIPLIST_MAXLEVEL;
 }
 
 static void zslInsert(zskiplist *zsl, double score, robj *obj) {
@@ -5251,7 +5486,7 @@ static void zaddGenericCommand(redisClient *c, robj *key, robj *ele, double scor
     } else {
         dictEntry *de;
         double *oldscore;
-        
+
         /* case 2: Score update operation */
         de = dictFind(zs->dict,ele);
         redisAssert(de != NULL);
@@ -5280,14 +5515,14 @@ static void zaddGenericCommand(redisClient *c, robj *key, robj *ele, double scor
 static void zaddCommand(redisClient *c) {
     double scoreval;
 
-    scoreval = strtod(c->argv[2]->ptr,NULL);
+    if (getDoubleFromObjectOrReply(c, c->argv[2], &scoreval, NULL) != REDIS_OK) return;
     zaddGenericCommand(c,c->argv[1],c->argv[3],scoreval,0);
 }
 
 static void zincrbyCommand(redisClient *c) {
     double scoreval;
 
-    scoreval = strtod(c->argv[2]->ptr,NULL);
+    if (getDoubleFromObjectOrReply(c, c->argv[2], &scoreval, NULL) != REDIS_OK) return;
     zaddGenericCommand(c,c->argv[1],c->argv[3],scoreval,1);
 }
 
@@ -5315,35 +5550,43 @@ static void zremCommand(redisClient *c) {
     /* Delete from the hash table */
     dictDelete(zs->dict,c->argv[2]);
     if (htNeedsResize(zs->dict)) dictResize(zs->dict);
+    if (dictSize(zs->dict) == 0) deleteKey(c->db,c->argv[1]);
     server.dirty++;
     addReply(c,shared.cone);
 }
 
 static void zremrangebyscoreCommand(redisClient *c) {
-    double min = strtod(c->argv[2]->ptr,NULL);
-    double max = strtod(c->argv[3]->ptr,NULL);
+    double min;
+    double max;
     long deleted;
     robj *zsetobj;
     zset *zs;
 
+    if ((getDoubleFromObjectOrReply(c, c->argv[2], &min, NULL) != REDIS_OK) ||
+        (getDoubleFromObjectOrReply(c, c->argv[3], &max, NULL) != REDIS_OK)) return;
+
     if ((zsetobj = lookupKeyWriteOrReply(c,c->argv[1],shared.czero)) == NULL ||
         checkType(c,zsetobj,REDIS_ZSET)) return;
 
     zs = zsetobj->ptr;
     deleted = zslDeleteRangeByScore(zs->zsl,min,max,zs->dict);
     if (htNeedsResize(zs->dict)) dictResize(zs->dict);
+    if (dictSize(zs->dict) == 0) deleteKey(c->db,c->argv[1]);
     server.dirty += deleted;
     addReplyLong(c,deleted);
 }
 
 static void zremrangebyrankCommand(redisClient *c) {
-    int start = atoi(c->argv[2]->ptr);
-    int end = atoi(c->argv[3]->ptr);
+    long start;
+    long end;
     int llen;
     long deleted;
     robj *zsetobj;
     zset *zs;
 
+    if ((getLongFromObjectOrReply(c, c->argv[2], &start, NULL) != REDIS_OK) ||
+        (getLongFromObjectOrReply(c, c->argv[3], &end, NULL) != REDIS_OK)) return;
+
     if ((zsetobj = lookupKeyWriteOrReply(c,c->argv[1],shared.czero)) == NULL ||
         checkType(c,zsetobj,REDIS_ZSET)) return;
     zs = zsetobj->ptr;
@@ -5366,6 +5609,7 @@ static void zremrangebyrankCommand(redisClient *c) {
      * use 1-based rank */
     deleted = zslDeleteRangeByRank(zs->zsl,start+1,end+1,zs->dict);
     if (htNeedsResize(zs->dict)) dictResize(zs->dict);
+    if (dictSize(zs->dict) == 0) deleteKey(c->db,c->argv[1]);
     server.dirty += deleted;
     addReplyLong(c, deleted);
 }
@@ -5383,8 +5627,26 @@ static int qsortCompareZsetopsrcByCardinality(const void *s1, const void *s2) {
     return size1 - size2;
 }
 
+#define REDIS_AGGR_SUM 1
+#define REDIS_AGGR_MIN 2
+#define REDIS_AGGR_MAX 3
+
+inline static void zunionInterAggregate(double *target, double val, int aggregate) {
+    if (aggregate == REDIS_AGGR_SUM) {
+        *target = *target + val;
+    } else if (aggregate == REDIS_AGGR_MIN) {
+        *target = val < *target ? val : *target;
+    } else if (aggregate == REDIS_AGGR_MAX) {
+        *target = val > *target ? val : *target;
+    } else {
+        /* safety net */
+        redisPanic("Unknown ZUNION/INTER aggregate type");
+    }
+}
+
 static void zunionInterGenericCommand(redisClient *c, robj *dstkey, int op) {
     int i, j, zsetnum;
+    int aggregate = REDIS_AGGR_SUM;
     zsetopsrc *src;
     robj *dstobj;
     zset *dstzset;
@@ -5425,19 +5687,29 @@ static void zunionInterGenericCommand(redisClient *c, robj *dstkey, int op) {
 
     /* parse optional extra arguments */
     if (j < c->argc) {
-        int remaining = c->argc-j;
+        int remaining = c->argc - j;
 
         while (remaining) {
-            if (!strcasecmp(c->argv[j]->ptr,"weights")) {
+            if (remaining >= (zsetnum + 1) && !strcasecmp(c->argv[j]->ptr,"weights")) {
+                j++; remaining--;
+                for (i = 0; i < zsetnum; i++, j++, remaining--) {
+                    if (getDoubleFromObjectOrReply(c, c->argv[j], &src[i].weight, NULL) != REDIS_OK)
+                        return;
+                }
+            } else if (remaining >= 2 && !strcasecmp(c->argv[j]->ptr,"aggregate")) {
                 j++; remaining--;
-                if (remaining < zsetnum) {
+                if (!strcasecmp(c->argv[j]->ptr,"sum")) {
+                    aggregate = REDIS_AGGR_SUM;
+                } else if (!strcasecmp(c->argv[j]->ptr,"min")) {
+                    aggregate = REDIS_AGGR_MIN;
+                } else if (!strcasecmp(c->argv[j]->ptr,"max")) {
+                    aggregate = REDIS_AGGR_MAX;
+                } else {
                     zfree(src);
-                    addReplySds(c,sdsnew("-ERR not enough weights for ZUNION/ZINTER\r\n"));
+                    addReply(c,shared.syntaxerr);
                     return;
                 }
-                for (i = 0; i < zsetnum; i++, j++, remaining--) {
-                    src[i].weight = strtod(c->argv[j]->ptr, NULL);
-                }
+                j++; remaining--;
             } else {
                 zfree(src);
                 addReply(c,shared.syntaxerr);
@@ -5446,27 +5718,28 @@ static void zunionInterGenericCommand(redisClient *c, robj *dstkey, int op) {
         }
     }
 
+    /* sort sets from the smallest to largest, this will improve our
+     * algorithm's performance */
+    qsort(src,zsetnum,sizeof(zsetopsrc), qsortCompareZsetopsrcByCardinality);
+
     dstobj = createZsetObject();
     dstzset = dstobj->ptr;
 
     if (op == REDIS_OP_INTER) {
-        /* sort sets from the smallest to largest, this will improve our
-         * algorithm's performance */
-        qsort(src,zsetnum,sizeof(zsetopsrc), qsortCompareZsetopsrcByCardinality);
-
         /* skip going over all entries if the smallest zset is NULL or empty */
         if (src[0].dict && dictSize(src[0].dict) > 0) {
             /* precondition: as src[0].dict is non-empty and the zsets are ordered
              * from small to large, all src[i > 0].dict are non-empty too */
             di = dictGetIterator(src[0].dict);
             while((de = dictNext(di)) != NULL) {
-                double *score = zmalloc(sizeof(double));
-                *score = 0.0;
+                double *score = zmalloc(sizeof(double)), value;
+                *score = src[0].weight * (*(double*)dictGetEntryVal(de));
 
-                for (j = 0; j < zsetnum; j++) {
-                    dictEntry *other = (j == 0) ? de : dictFind(src[j].dict,dictGetEntryKey(de));
+                for (j = 1; j < zsetnum; j++) {
+                    dictEntry *other = dictFind(src[j].dict,dictGetEntryKey(de));
                     if (other) {
-                        *score = *score + src[j].weight * (*(double*)dictGetEntryVal(other));
+                        value = src[j].weight * (*(double*)dictGetEntryVal(other));
+                        zunionInterAggregate(score, value, aggregate);
                     } else {
                         break;
                     }
@@ -5494,14 +5767,16 @@ static void zunionInterGenericCommand(redisClient *c, robj *dstkey, int op) {
                 /* skip key when already processed */
                 if (dictFind(dstzset->dict,dictGetEntryKey(de)) != NULL) continue;
 
-                double *score = zmalloc(sizeof(double));
-                *score = 0.0;
-                for (j = 0; j < zsetnum; j++) {
-                    if (!src[j].dict) continue;
+                double *score = zmalloc(sizeof(double)), value;
+                *score = src[i].weight * (*(double*)dictGetEntryVal(de));
 
-                    dictEntry *other = (i == j) ? de : dictFind(src[j].dict,dictGetEntryKey(de));
+                /* because the zsets are sorted by size, its only possible
+                 * for sets at larger indices to hold this entry */
+                for (j = (i+1); j < zsetnum; j++) {
+                    dictEntry *other = dictFind(src[j].dict,dictGetEntryKey(de));
                     if (other) {
-                        *score = *score + src[j].weight * (*(double*)dictGetEntryVal(other));
+                        value = src[j].weight * (*(double*)dictGetEntryVal(other));
+                        zunionInterAggregate(score, value, aggregate);
                     }
                 }
 
@@ -5519,11 +5794,15 @@ static void zunionInterGenericCommand(redisClient *c, robj *dstkey, int op) {
     }
 
     deleteKey(c->db,dstkey);
-    dictAdd(c->db->dict,dstkey,dstobj);
-    incrRefCount(dstkey);
-
-    addReplyLong(c, dstzset->zsl->length);
-    server.dirty++;
+    if (dstzset->zsl->length) {
+        dictAdd(c->db->dict,dstkey,dstobj);
+        incrRefCount(dstkey);
+        addReplyLong(c, dstzset->zsl->length);
+        server.dirty++;
+    } else {
+        decrRefCount(dstobj);
+        addReply(c, shared.czero);
+    }
     zfree(src);
 }
 
@@ -5537,8 +5816,8 @@ static void zinterCommand(redisClient *c) {
 
 static void zrangeGenericCommand(redisClient *c, int reverse) {
     robj *o;
-    int start = atoi(c->argv[2]->ptr);
-    int end = atoi(c->argv[3]->ptr);
+    long start;
+    long end;
     int withscores = 0;
     int llen;
     int rangelen, j;
@@ -5547,6 +5826,9 @@ static void zrangeGenericCommand(redisClient *c, int reverse) {
     zskiplistNode *ln;
     robj *ele;
 
+    if ((getLongFromObjectOrReply(c, c->argv[2], &start, NULL) != REDIS_OK) ||
+        (getLongFromObjectOrReply(c, c->argv[3], &end, NULL) != REDIS_OK)) return;
+
     if (c->argc == 5 && !strcasecmp(c->argv[4]->ptr,"withscores")) {
         withscores = 1;
     } else if (c->argc >= 5) {
@@ -5554,8 +5836,8 @@ static void zrangeGenericCommand(redisClient *c, int reverse) {
         return;
     }
 
-    if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.nullmultibulk)) == NULL ||
-        checkType(c,o,REDIS_ZSET)) return;
+    if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.emptymultibulk)) == NULL
+         || checkType(c,o,REDIS_ZSET)) return;
     zsetobj = o->ptr;
     zsl = zsetobj->zsl;
     llen = zsl->length;
@@ -5661,7 +5943,7 @@ static void genericZrangebyscoreCommand(redisClient *c, int justcount) {
     /* Ok, lookup the key and get the range */
     o = lookupKeyRead(c->db,c->argv[1]);
     if (o == NULL) {
-        addReply(c,justcount ? shared.czero : shared.nullmultibulk);
+        addReply(c,justcount ? shared.czero : shared.emptymultibulk);
     } else {
         if (o->type != REDIS_ZSET) {
             addReply(c,shared.wrongtypeerr);
@@ -5798,125 +6080,390 @@ static void zrevrankCommand(redisClient *c) {
     zrankGenericCommand(c, 1);
 }
 
-/* =================================== Hashes =============================== */
-static void hsetCommand(redisClient *c) {
-    int update = 0;
-    robj *o = lookupKeyWrite(c->db,c->argv[1]);
+/* ========================= Hashes utility functions ======================= */
+#define REDIS_HASH_KEY 1
+#define REDIS_HASH_VALUE 2
 
-    if (o == NULL) {
-        o = createHashObject();
-        dictAdd(c->db->dict,c->argv[1],o);
-        incrRefCount(c->argv[1]);
-    } else {
-        if (o->type != REDIS_HASH) {
-            addReply(c,shared.wrongtypeerr);
+/* Check the length of a number of objects to see if we need to convert a
+ * zipmap to a real hash. Note that we only check string encoded objects
+ * as their string length can be queried in constant time. */
+static void hashTryConversion(robj *subject, robj **argv, int start, int end) {
+    int i;
+    if (subject->encoding != REDIS_ENCODING_ZIPMAP) return;
+
+    for (i = start; i <= end; i++) {
+        if (argv[i]->encoding == REDIS_ENCODING_RAW &&
+            sdslen(argv[i]->ptr) > server.hash_max_zipmap_value)
+        {
+            convertToRealHash(subject);
             return;
         }
     }
-    /* We want to convert the zipmap into an hash table right now if the
-     * entry to be added is too big. Note that we check if the object
-     * is integer encoded before to try fetching the length in the test below.
-     * This is because integers are small, but currently stringObjectLen()
-     * performs a slow conversion: not worth it. */
-    if (o->encoding == REDIS_ENCODING_ZIPMAP &&
-        ((c->argv[2]->encoding == REDIS_ENCODING_RAW &&
-          sdslen(c->argv[2]->ptr) > server.hash_max_zipmap_value) ||
-         (c->argv[3]->encoding == REDIS_ENCODING_RAW &&
-          sdslen(c->argv[3]->ptr) > server.hash_max_zipmap_value)))
-    {
-        convertToRealHash(o);
+}
+
+/* Encode given objects in-place when the hash uses a dict. */
+static void hashTryObjectEncoding(robj *subject, robj **o1, robj **o2) {
+    if (subject->encoding == REDIS_ENCODING_HT) {
+        if (o1) *o1 = tryObjectEncoding(*o1);
+        if (o2) *o2 = tryObjectEncoding(*o2);
     }
+}
 
+/* Get the value from a hash identified by key. Returns either a string
+ * object or NULL if the value cannot be found. The refcount of the object
+ * is always increased by 1 when the value was found. */
+static robj *hashGet(robj *o, robj *key) {
+    robj *value = NULL;
     if (o->encoding == REDIS_ENCODING_ZIPMAP) {
-        unsigned char *zm = o->ptr;
-        robj *valobj = getDecodedObject(c->argv[3]);
-
-        zm = zipmapSet(zm,c->argv[2]->ptr,sdslen(c->argv[2]->ptr),
-            valobj->ptr,sdslen(valobj->ptr),&update);
-        decrRefCount(valobj);
-        o->ptr = zm;
-
-        /* And here there is the second check for hash conversion...
-         * we want to do it only if the operation was not just an update as
-         * zipmapLen() is O(N). */
-        if (!update && zipmapLen(zm) > server.hash_max_zipmap_entries)
-            convertToRealHash(o);
+        unsigned char *v;
+        unsigned int vlen;
+        key = getDecodedObject(key);
+        if (zipmapGet(o->ptr,key->ptr,sdslen(key->ptr),&v,&vlen)) {
+            value = createStringObject((char*)v,vlen);
+        }
+        decrRefCount(key);
     } else {
-        tryObjectEncoding(c->argv[2]);
-        /* note that c->argv[3] is already encoded, as the latest arg
-         * of a bulk command is always integer encoded if possible. */
-        if (dictAdd(o->ptr,c->argv[2],c->argv[3]) == DICT_OK) {
-            incrRefCount(c->argv[2]);
-        } else {
-            update = 1;
+        dictEntry *de = dictFind(o->ptr,key);
+        if (de != NULL) {
+            value = dictGetEntryVal(de);
+            incrRefCount(value);
         }
-        incrRefCount(c->argv[3]);
     }
-    server.dirty++;
-    addReplySds(c,sdscatprintf(sdsempty(),":%d\r\n",update == 0));
+    return value;
 }
 
-static void hgetCommand(redisClient *c) {
-    robj *o;
-
-    if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.nullbulk)) == NULL ||
-        checkType(c,o,REDIS_HASH)) return;
-
+/* Test if the key exists in the given hash. Returns 1 if the key
+ * exists and 0 when it doesn't. */
+static int hashExists(robj *o, robj *key) {
     if (o->encoding == REDIS_ENCODING_ZIPMAP) {
-        unsigned char *zm = o->ptr;
-        unsigned char *val;
-        unsigned int vlen;
+        key = getDecodedObject(key);
+        if (zipmapExists(o->ptr,key->ptr,sdslen(key->ptr))) {
+            decrRefCount(key);
+            return 1;
+        }
+        decrRefCount(key);
+    } else {
+        if (dictFind(o->ptr,key) != NULL) {
+            return 1;
+        }
+    }
+    return 0;
+}
 
-        if (zipmapGet(zm,c->argv[2]->ptr,sdslen(c->argv[2]->ptr), &val,&vlen)) {
-            addReplySds(c,sdscatprintf(sdsempty(),"$%u\r\n", vlen));
-            addReplySds(c,sdsnewlen(val,vlen));
-            addReply(c,shared.crlf);
-            return;
+/* Add an element, discard the old if the key already exists.
+ * Return 0 on insert and 1 on update. */
+static int hashSet(robj *o, robj *key, robj *value) {
+    int update = 0;
+    if (o->encoding == REDIS_ENCODING_ZIPMAP) {
+        key = getDecodedObject(key);
+        value = getDecodedObject(value);
+        o->ptr = zipmapSet(o->ptr,
+            key->ptr,sdslen(key->ptr),
+            value->ptr,sdslen(value->ptr), &update);
+        decrRefCount(key);
+        decrRefCount(value);
+
+        /* Check if the zipmap needs to be upgraded to a real hash table */
+        if (zipmapLen(o->ptr) > server.hash_max_zipmap_entries)
+            convertToRealHash(o);
+    } else {
+        if (dictReplace(o->ptr,key,value)) {
+            /* Insert */
+            incrRefCount(key);
         } else {
-            addReply(c,shared.nullbulk);
-            return;
+            /* Update */
+            update = 1;
         }
+        incrRefCount(value);
+    }
+    return update;
+}
+
+/* Delete an element from a hash.
+ * Return 1 on deleted and 0 on not found. */
+static int hashDelete(robj *o, robj *key) {
+    int deleted = 0;
+    if (o->encoding == REDIS_ENCODING_ZIPMAP) {
+        key = getDecodedObject(key);
+        o->ptr = zipmapDel(o->ptr,key->ptr,sdslen(key->ptr), &deleted);
+        decrRefCount(key);
     } else {
-        struct dictEntry *de;
+        deleted = dictDelete((dict*)o->ptr,key) == DICT_OK;
+        /* Always check if the dictionary needs a resize after a delete. */
+        if (deleted && htNeedsResize(o->ptr)) dictResize(o->ptr);
+    }
+    return deleted;
+}
 
-        de = dictFind(o->ptr,c->argv[2]);
-        if (de == NULL) {
-            addReply(c,shared.nullbulk);
+/* Return the number of elements in a hash. */
+static unsigned long hashLength(robj *o) {
+    return (o->encoding == REDIS_ENCODING_ZIPMAP) ?
+        zipmapLen((unsigned char*)o->ptr) : dictSize((dict*)o->ptr);
+}
+
+/* Structure to hold hash iteration abstration. Note that iteration over
+ * hashes involves both fields and values. Because it is possible that
+ * not both are required, store pointers in the iterator to avoid
+ * unnecessary memory allocation for fields/values. */
+typedef struct {
+    int encoding;
+    unsigned char *zi;
+    unsigned char *zk, *zv;
+    unsigned int zklen, zvlen;
+
+    dictIterator *di;
+    dictEntry *de;
+} hashIterator;
+
+static hashIterator *hashInitIterator(robj *subject) {
+    hashIterator *hi = zmalloc(sizeof(hashIterator));
+    hi->encoding = subject->encoding;
+    if (hi->encoding == REDIS_ENCODING_ZIPMAP) {
+        hi->zi = zipmapRewind(subject->ptr);
+    } else if (hi->encoding == REDIS_ENCODING_HT) {
+        hi->di = dictGetIterator(subject->ptr);
+    } else {
+        redisAssert(NULL);
+    }
+    return hi;
+}
+
+static void hashReleaseIterator(hashIterator *hi) {
+    if (hi->encoding == REDIS_ENCODING_HT) {
+        dictReleaseIterator(hi->di);
+    }
+    zfree(hi);
+}
+
+/* Move to the next entry in the hash. Return REDIS_OK when the next entry
+ * could be found and REDIS_ERR when the iterator reaches the end. */
+static int hashNext(hashIterator *hi) {
+    if (hi->encoding == REDIS_ENCODING_ZIPMAP) {
+        if ((hi->zi = zipmapNext(hi->zi, &hi->zk, &hi->zklen,
+            &hi->zv, &hi->zvlen)) == NULL) return REDIS_ERR;
+    } else {
+        if ((hi->de = dictNext(hi->di)) == NULL) return REDIS_ERR;
+    }
+    return REDIS_OK;
+}
+
+/* Get key or value object at current iteration position.
+ * This increases the refcount of the field object by 1. */
+static robj *hashCurrent(hashIterator *hi, int what) {
+    robj *o;
+    if (hi->encoding == REDIS_ENCODING_ZIPMAP) {
+        if (what & REDIS_HASH_KEY) {
+            o = createStringObject((char*)hi->zk,hi->zklen);
         } else {
-            robj *e = dictGetEntryVal(de);
+            o = createStringObject((char*)hi->zv,hi->zvlen);
+        }
+    } else {
+        if (what & REDIS_HASH_KEY) {
+            o = dictGetEntryKey(hi->de);
+        } else {
+            o = dictGetEntryVal(hi->de);
+        }
+        incrRefCount(o);
+    }
+    return o;
+}
 
-            addReplyBulk(c,e);
+static robj *hashLookupWriteOrCreate(redisClient *c, robj *key) {
+    robj *o = lookupKeyWrite(c->db,key);
+    if (o == NULL) {
+        o = createHashObject();
+        dictAdd(c->db->dict,key,o);
+        incrRefCount(key);
+    } else {
+        if (o->type != REDIS_HASH) {
+            addReply(c,shared.wrongtypeerr);
+            return NULL;
         }
     }
+    return o;
 }
 
-static void hdelCommand(redisClient *c) {
+/* ============================= Hash commands ============================== */
+static void hsetCommand(redisClient *c) {
+    int update;
     robj *o;
-    int deleted = 0;
 
+    if ((o = hashLookupWriteOrCreate(c,c->argv[1])) == NULL) return;
+    hashTryConversion(o,c->argv,2,3);
+    hashTryObjectEncoding(o,&c->argv[2], &c->argv[3]);
+    update = hashSet(o,c->argv[2],c->argv[3]);
+    addReply(c, update ? shared.czero : shared.cone);
+    server.dirty++;
+}
+
+static void hsetnxCommand(redisClient *c) {
+    robj *o;
+    if ((o = hashLookupWriteOrCreate(c,c->argv[1])) == NULL) return;
+    hashTryConversion(o,c->argv,2,3);
+
+    if (hashExists(o, c->argv[2])) {
+        addReply(c, shared.czero);
+    } else {
+        hashTryObjectEncoding(o,&c->argv[2], &c->argv[3]);
+        hashSet(o,c->argv[2],c->argv[3]);
+        addReply(c, shared.cone);
+        server.dirty++;
+    }
+}
+
+static void hmsetCommand(redisClient *c) {
+    int i;
+    robj *o;
+
+    if ((c->argc % 2) == 1) {
+        addReplySds(c,sdsnew("-ERR wrong number of arguments for HMSET\r\n"));
+        return;
+    }
+
+    if ((o = hashLookupWriteOrCreate(c,c->argv[1])) == NULL) return;
+    hashTryConversion(o,c->argv,2,c->argc-1);
+    for (i = 2; i < c->argc; i += 2) {
+        hashTryObjectEncoding(o,&c->argv[i], &c->argv[i+1]);
+        hashSet(o,c->argv[i],c->argv[i+1]);
+    }
+    addReply(c, shared.ok);
+    server.dirty++;
+}
+
+static void hincrbyCommand(redisClient *c) {
+    long long value, incr;
+    robj *o, *current, *new;
+
+    if (getLongLongFromObjectOrReply(c,c->argv[3],&incr,NULL) != REDIS_OK) return;
+    if ((o = hashLookupWriteOrCreate(c,c->argv[1])) == NULL) return;
+    if ((current = hashGet(o,c->argv[2])) != NULL) {
+        if (current->encoding == REDIS_ENCODING_RAW)
+            value = strtoll(current->ptr,NULL,10);
+        else if (current->encoding == REDIS_ENCODING_INT)
+            value = (long)current->ptr;
+        else
+            redisAssert(1 != 1);
+        decrRefCount(current);
+    } else {
+        value = 0;
+    }
+
+    value += incr;
+    new = createStringObjectFromLongLong(value);
+    hashTryObjectEncoding(o,&c->argv[2],NULL);
+    hashSet(o,c->argv[2],new);
+    decrRefCount(new);
+    addReplyLongLong(c,value);
+    server.dirty++;
+}
+
+static void hgetCommand(redisClient *c) {
+    robj *o, *value;
+    if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.nullbulk)) == NULL ||
+        checkType(c,o,REDIS_HASH)) return;
+
+    if ((value = hashGet(o,c->argv[2])) != NULL) {
+        addReplyBulk(c,value);
+        decrRefCount(value);
+    } else {
+        addReply(c,shared.nullbulk);
+    }
+}
+
+static void hmgetCommand(redisClient *c) {
+    int i;
+    robj *o, *value;
+    o = lookupKeyRead(c->db,c->argv[1]);
+    if (o != NULL && o->type != REDIS_HASH) {
+        addReply(c,shared.wrongtypeerr);
+    }
+
+    /* Note the check for o != NULL happens inside the loop. This is
+     * done because objects that cannot be found are considered to be
+     * an empty hash. The reply should then be a series of NULLs. */
+    addReplySds(c,sdscatprintf(sdsempty(),"*%d\r\n",c->argc-2));
+    for (i = 2; i < c->argc; i++) {
+        if (o != NULL && (value = hashGet(o,c->argv[i])) != NULL) {
+            addReplyBulk(c,value);
+            decrRefCount(value);
+        } else {
+            addReply(c,shared.nullbulk);
+        }
+    }
+}
+
+static void hdelCommand(redisClient *c) {
+    robj *o;
     if ((o = lookupKeyWriteOrReply(c,c->argv[1],shared.czero)) == NULL ||
         checkType(c,o,REDIS_HASH)) return;
 
-    if (o->encoding == REDIS_ENCODING_ZIPMAP) {
-        o->ptr = zipmapDel((unsigned char*) o->ptr,
-            (unsigned char*) c->argv[2]->ptr,
-            sdslen(c->argv[2]->ptr), &deleted);
+    if (hashDelete(o,c->argv[2])) {
+        if (hashLength(o) == 0) deleteKey(c->db,c->argv[1]);
+        addReply(c,shared.cone);
+        server.dirty++;
     } else {
-        deleted = dictDelete((dict*)o->ptr,c->argv[2]) == DICT_OK;
+        addReply(c,shared.czero);
     }
-    addReply(c,deleted ? shared.cone : shared.czero);
 }
 
 static void hlenCommand(redisClient *c) {
     robj *o;
-    unsigned long len;
+    if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
+        checkType(c,o,REDIS_HASH)) return;
 
+    addReplyUlong(c,hashLength(o));
+}
+
+static void genericHgetallCommand(redisClient *c, int flags) {
+    robj *o, *lenobj, *obj;
+    unsigned long count = 0;
+    hashIterator *hi;
+
+    if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.emptymultibulk)) == NULL
+        || checkType(c,o,REDIS_HASH)) return;
+
+    lenobj = createObject(REDIS_STRING,NULL);
+    addReply(c,lenobj);
+    decrRefCount(lenobj);
+
+    hi = hashInitIterator(o);
+    while (hashNext(hi) != REDIS_ERR) {
+        if (flags & REDIS_HASH_KEY) {
+            obj = hashCurrent(hi,REDIS_HASH_KEY);
+            addReplyBulk(c,obj);
+            decrRefCount(obj);
+            count++;
+        }
+        if (flags & REDIS_HASH_VALUE) {
+            obj = hashCurrent(hi,REDIS_HASH_VALUE);
+            addReplyBulk(c,obj);
+            decrRefCount(obj);
+            count++;
+        }
+    }
+    hashReleaseIterator(hi);
+
+    lenobj->ptr = sdscatprintf(sdsempty(),"*%lu\r\n",count);
+}
+
+static void hkeysCommand(redisClient *c) {
+    genericHgetallCommand(c,REDIS_HASH_KEY);
+}
+
+static void hvalsCommand(redisClient *c) {
+    genericHgetallCommand(c,REDIS_HASH_VALUE);
+}
+
+static void hgetallCommand(redisClient *c) {
+    genericHgetallCommand(c,REDIS_HASH_KEY|REDIS_HASH_VALUE);
+}
+
+static void hexistsCommand(redisClient *c) {
+    robj *o;
     if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
         checkType(c,o,REDIS_HASH)) return;
 
-    len = (o->encoding == REDIS_ENCODING_ZIPMAP) ?
-            zipmapLen((unsigned char*)o->ptr) : dictSize((dict*)o->ptr);
-    addReplyUlong(c,len);
+    addReply(c, hashExists(o,c->argv[2]) ? shared.cone : shared.czero);
 }
 
 static void convertToRealHash(robj *o) {
@@ -5931,8 +6478,8 @@ static void convertToRealHash(robj *o) {
 
         keyobj = createStringObject((char*)key,klen);
         valobj = createStringObject((char*)val,vlen);
-        tryObjectEncoding(keyobj);
-        tryObjectEncoding(valobj);
+        keyobj = tryObjectEncoding(keyobj);
+        valobj = tryObjectEncoding(valobj);
         dictAdd(dict,keyobj,valobj);
     }
     o->encoding = REDIS_ENCODING_HT;
@@ -5952,6 +6499,10 @@ static void flushdbCommand(redisClient *c) {
 static void flushallCommand(redisClient *c) {
     server.dirty += emptyDb();
     addReply(c,shared.ok);
+    if (server.bgsavechildpid != -1) {
+        kill(server.bgsavechildpid,SIGKILL);
+        rdbRemoveTempFile(server.bgsavechildpid);
+    }
     rdbSave(server.dbfilename);
     server.dirty++;
 }
@@ -5964,23 +6515,26 @@ static redisSortOperation *createSortOperation(int type, robj *pattern) {
 }
 
 /* Return the value associated to the key with a name obtained
- * substituting the first occurence of '*' in 'pattern' with 'subst' */
+ * substituting the first occurence of '*' in 'pattern' with 'subst'.
+ * The returned object will always have its refcount increased by 1
+ * when it is non-NULL. */
 static robj *lookupKeyByPattern(redisDb *db, robj *pattern, robj *subst) {
-    char *p;
+    char *p, *f;
     sds spat, ssub;
-    robj keyobj;
-    int prefixlen, sublen, postfixlen;
+    robj keyobj, fieldobj, *o;
+    int prefixlen, sublen, postfixlen, fieldlen;
     /* Expoit the internal sds representation to create a sds string allocated on the stack in order to make this function faster */
     struct {
         long len;
         long free;
         char buf[REDIS_SORTKEY_MAX+1];
-    } keyname;
+    } keyname, fieldname;
 
     /* If the pattern is "#" return the substitution object itself in order
      * to implement the "SORT ... GET #" feature. */
     spat = pattern->ptr;
     if (spat[0] == '#' && spat[1] == '\0') {
+        incrRefCount(subst);
         return subst;
     }
 
@@ -5997,20 +6551,47 @@ static robj *lookupKeyByPattern(redisDb *db, robj *pattern, robj *subst) {
         return NULL;
     }
 
+    /* Find out if we're dealing with a hash dereference. */
+    if ((f = strstr(p+1, "->")) != NULL) {
+        fieldlen = sdslen(spat)-(f-spat);
+        /* this also copies \0 character */
+        memcpy(fieldname.buf,f+2,fieldlen-1);
+        fieldname.len = fieldlen-2;
+    } else {
+        fieldlen = 0;
+    }
+
     prefixlen = p-spat;
     sublen = sdslen(ssub);
-    postfixlen = sdslen(spat)-(prefixlen+1);
+    postfixlen = sdslen(spat)-(prefixlen+1)-fieldlen;
     memcpy(keyname.buf,spat,prefixlen);
     memcpy(keyname.buf+prefixlen,ssub,sublen);
     memcpy(keyname.buf+prefixlen+sublen,p+1,postfixlen);
     keyname.buf[prefixlen+sublen+postfixlen] = '\0';
     keyname.len = prefixlen+sublen+postfixlen;
-
-    initStaticStringObject(keyobj,((char*)&keyname)+(sizeof(long)*2))
     decrRefCount(subst);
 
-    /* printf("lookup '%s' => %p\n", keyname.buf,de); */
-    return lookupKeyRead(db,&keyobj);
+    /* Lookup substituted key */
+    initStaticStringObject(keyobj,((char*)&keyname)+(sizeof(long)*2));
+    o = lookupKeyRead(db,&keyobj);
+    if (o == NULL) return NULL;
+
+    if (fieldlen > 0) {
+        if (o->type != REDIS_HASH || fieldname.len < 1) return NULL;
+
+        /* Retrieve value from hash by the field name. This operation
+         * already increases the refcount of the returned object. */
+        initStaticStringObject(fieldobj,((char*)&fieldname)+(sizeof(long)*2));
+        o = hashGet(o, &fieldobj);
+    } else {
+        if (o->type != REDIS_STRING) return NULL;
+
+        /* Every object that this function returns needs to have its refcount
+         * increased. sortCommand decreases it again. */
+        incrRefCount(o);
+    }
+
+    return o;
 }
 
 /* sortCompare() is used by qsort in sortCommand(). Given that qsort_r with
@@ -6045,14 +6626,8 @@ static int sortCompare(const void *s1, const void *s2) {
                 cmp = strcoll(so1->u.cmpobj->ptr,so2->u.cmpobj->ptr);
             }
         } else {
-            /* Compare elements directly */
-            robj *dec1, *dec2;
-
-            dec1 = getDecodedObject(so1->obj);
-            dec2 = getDecodedObject(so2->obj);
-            cmp = strcoll(dec1->ptr,dec2->ptr);
-            decrRefCount(dec1);
-            decrRefCount(dec2);
+            /* Compare elements directly. */
+            cmp = compareStringObjects(so1->obj,so2->obj);
         }
     }
     return server.sort_desc ? -cmp : cmp;
@@ -6073,7 +6648,7 @@ static void sortCommand(redisClient *c) {
     /* Lookup the key to sort. It must be of the right types */
     sortval = lookupKeyRead(c->db,c->argv[1]);
     if (sortval == NULL) {
-        addReply(c,shared.nullmultibulk);
+        addReply(c,shared.emptymultibulk);
         return;
     }
     if (sortval->type != REDIS_SET && sortval->type != REDIS_LIST &&
@@ -6135,7 +6710,7 @@ static void sortCommand(redisClient *c) {
     case REDIS_LIST: vectorlen = listLength((list*)sortval->ptr); break;
     case REDIS_SET: vectorlen =  dictSize((dict*)sortval->ptr); break;
     case REDIS_ZSET: vectorlen = dictSize(((zset*)sortval->ptr)->dict); break;
-    default: vectorlen = 0; redisAssert(0); /* Avoid GCC warning */
+    default: vectorlen = 0; redisPanic("Bad SORT type"); /* Avoid GCC warning */
     }
     vector = zmalloc(sizeof(redisSortObject)*vectorlen);
     j = 0;
@@ -6179,38 +6754,36 @@ static void sortCommand(redisClient *c) {
     /* Now it's time to load the right scores in the sorting vector */
     if (dontsort == 0) {
         for (j = 0; j < vectorlen; j++) {
+            robj *byval;
             if (sortby) {
-                robj *byval;
-
+                /* lookup value to sort by */
                 byval = lookupKeyByPattern(c->db,sortby,vector[j].obj);
-                if (!byval || byval->type != REDIS_STRING) continue;
-                if (alpha) {
-                    vector[j].u.cmpobj = getDecodedObject(byval);
-                } else {
-                    if (byval->encoding == REDIS_ENCODING_RAW) {
-                        vector[j].u.score = strtod(byval->ptr,NULL);
-                    } else {
-                        /* Don't need to decode the object if it's
-                         * integer-encoded (the only encoding supported) so
-                         * far. We can just cast it */
-                        if (byval->encoding == REDIS_ENCODING_INT) {
-                            vector[j].u.score = (long)byval->ptr;
-                        } else
-                            redisAssert(1 != 1);
-                    }
-                }
+                if (!byval) continue;
             } else {
-                if (!alpha) {
-                    if (vector[j].obj->encoding == REDIS_ENCODING_RAW)
-                        vector[j].u.score = strtod(vector[j].obj->ptr,NULL);
-                    else {
-                        if (vector[j].obj->encoding == REDIS_ENCODING_INT)
-                            vector[j].u.score = (long) vector[j].obj->ptr;
-                        else
-                            redisAssert(1 != 1);
-                    }
+                /* use object itself to sort by */
+                byval = vector[j].obj;
+            }
+
+            if (alpha) {
+                if (sortby) vector[j].u.cmpobj = getDecodedObject(byval);
+            } else {
+                if (byval->encoding == REDIS_ENCODING_RAW) {
+                    vector[j].u.score = strtod(byval->ptr,NULL);
+                } else if (byval->encoding == REDIS_ENCODING_INT) {
+                    /* Don't need to decode the object if it's
+                     * integer-encoded (the only encoding supported) so
+                     * far. We can just cast it */
+                    vector[j].u.score = (long)byval->ptr;
+                } else {
+                    redisAssert(1 != 1);
                 }
             }
+
+            /* when the object was retrieved using lookupKeyByPattern,
+             * its refcount needs to be decreased. */
+            if (sortby) {
+                decrRefCount(byval);
+            }
         }
     }
 
@@ -6252,10 +6825,11 @@ static void sortCommand(redisClient *c) {
                     vector[j].obj);
 
                 if (sop->type == REDIS_SORT_GET) {
-                    if (!val || val->type != REDIS_STRING) {
+                    if (!val) {
                         addReply(c,shared.nullbulk);
                     } else {
                         addReplyBulk(c,val);
+                        decrRefCount(val);
                     }
                 } else {
                     redisAssert(sop->type == REDIS_SORT_GET); /* always fails */
@@ -6282,11 +6856,14 @@ static void sortCommand(redisClient *c) {
                     vector[j].obj);
 
                 if (sop->type == REDIS_SORT_GET) {
-                    if (!val || val->type != REDIS_STRING) {
+                    if (!val) {
                         listAddNodeTail(listPtr,createStringObject("",0));
                     } else {
+                        /* We should do a incrRefCount on val because it is
+                         * added to the list, but also a decrRefCount because
+                         * it is returned by lookupKeyByPattern. This results
+                         * in doing nothing at all. */
                         listAddNodeTail(listPtr,val);
-                        incrRefCount(val);
                     }
                 } else {
                     redisAssert(sop->type == REDIS_SORT_GET); /* always fails */
@@ -6307,7 +6884,7 @@ static void sortCommand(redisClient *c) {
     decrRefCount(sortval);
     listRelease(operations);
     for (j = 0; j < vectorlen; j++) {
-        if (sortby && alpha && vector[j].u.cmpobj)
+        if (alpha && vector[j].u.cmpobj)
             decrRefCount(vector[j].u.cmpobj);
     }
     zfree(vector);
@@ -6343,9 +6920,6 @@ static sds genRedisInfoString(void) {
     int j;
     char hmem[64];
 
-    server.hash_max_zipmap_entries = REDIS_HASH_MAX_ZIPMAP_ENTRIES;
-    server.hash_max_zipmap_value = REDIS_HASH_MAX_ZIPMAP_VALUE;
-  
     bytesToHuman(hmem,zmalloc_used_memory());
     info = sdscatprintf(sdsempty(),
         "redis_version:%s\r\n"
@@ -6365,8 +6939,11 @@ static sds genRedisInfoString(void) {
         "bgrewriteaof_in_progress:%d\r\n"
         "total_connections_received:%lld\r\n"
         "total_commands_processed:%lld\r\n"
+        "expired_keys:%lld\r\n"
         "hash_max_zipmap_entries:%ld\r\n"
         "hash_max_zipmap_value:%ld\r\n"
+        "pubsub_channels:%ld\r\n"
+        "pubsub_patterns:%u\r\n"
         "vm_enabled:%d\r\n"
         "role:%s\r\n"
         ,REDIS_VERSION,
@@ -6386,8 +6963,11 @@ static sds genRedisInfoString(void) {
         server.bgrewritechildpid != -1,
         server.stat_numconnections,
         server.stat_numcommands,
+        server.stat_expiredkeys,
         server.hash_max_zipmap_entries,
         server.hash_max_zipmap_value,
+        dictSize(server.pubsub_channels),
+        listLength(server.pubsub_patterns),
         server.vm_enabled != 0,
         server.masterhost == NULL ? "master" : "slave"
     );
@@ -6509,6 +7089,7 @@ static int expireIfNeeded(redisDb *db, robj *key) {
 
     /* Delete the key */
     dictDelete(db->expires,key);
+    server.stat_expiredkeys++;
     return dictDelete(db->dict,key) == DICT_OK;
 }
 
@@ -6521,19 +7102,25 @@ static int deleteIfVolatile(redisDb *db, robj *key) {
 
     /* Delete the key */
     server.dirty++;
+    server.stat_expiredkeys++;
     dictDelete(db->expires,key);
     return dictDelete(db->dict,key) == DICT_OK;
 }
 
-static void expireGenericCommand(redisClient *c, robj *key, time_t seconds) {
+static void expireGenericCommand(redisClient *c, robj *key, robj *param, long offset) {
     dictEntry *de;
+    time_t seconds;
+
+    if (getLongFromObjectOrReply(c, param, &seconds, NULL) != REDIS_OK) return;
+
+    seconds -= offset;
 
     de = dictFind(c->db->dict,key);
     if (de == NULL) {
         addReply(c,shared.czero);
         return;
     }
-    if (seconds < 0) {
+    if (seconds <= 0) {
         if (deleteKey(c->db,key)) server.dirty++;
         addReply(c, shared.cone);
         return;
@@ -6550,11 +7137,11 @@ static void expireGenericCommand(redisClient *c, robj *key, time_t seconds) {
 }
 
 static void expireCommand(redisClient *c) {
-    expireGenericCommand(c,c->argv[1],strtol(c->argv[2]->ptr,NULL,10));
+    expireGenericCommand(c,c->argv[1],c->argv[2],0);
 }
 
 static void expireatCommand(redisClient *c) {
-    expireGenericCommand(c,c->argv[1],strtol(c->argv[2]->ptr,NULL,10)-time(NULL));
+    expireGenericCommand(c,c->argv[1],c->argv[2],time(NULL));
 }
 
 static void ttlCommand(redisClient *c) {
@@ -6798,7 +7385,7 @@ static void blockingPopGenericCommand(redisClient *c, int where) {
                      * non-blocking POP operation */
                     robj *argv[2], **orig_argv;
                     int orig_argc;
-                   
+
                     /* We need to alter the command arguments before to call
                      * popGenericCommand() as the command takes a single key. */
                     orig_argv = c->argv;
@@ -7035,7 +7622,7 @@ static void updateSlavesWaitingBgsave(int bgsaveerr) {
             slave->replstate = REDIS_REPL_WAIT_BGSAVE_END;
         } else if (slave->replstate == REDIS_REPL_WAIT_BGSAVE_END) {
             struct redis_stat buf;
-           
+
             if (bgsaveerr != REDIS_OK) {
                 freeClient(slave);
                 redisLog(REDIS_WARNING,"SYNC failed. BGSAVE child returned an error");
@@ -7433,14 +8020,9 @@ int loadAppendOnlyFile(char *filename) {
             redisLog(REDIS_WARNING,"Unknown command '%s' reading the append only file", argv[0]->ptr);
             exit(1);
         }
-        /* Try object sharing and encoding */
-        if (server.shareobjects) {
-            int j;
-            for(j = 1; j < argc; j++)
-                argv[j] = tryObjectSharing(argv[j]);
-        }
+        /* Try object encoding */
         if (cmd->flags & REDIS_CMD_BULK)
-            tryObjectEncoding(argv[argc-1]);
+            argv[argc-1] = tryObjectEncoding(argv[argc-1]);
         /* Run the command in the context of a fake client */
         fakeClient->argc = argc;
         fakeClient->argv = argv;
@@ -7677,7 +8259,7 @@ static int rewriteAppendOnlyFile(char *filename) {
                     dictReleaseIterator(di);
                 }
             } else {
-                redisAssert(0 != 0);
+                redisPanic("Unknown object type");
             }
             /* Save the expire time */
             if (expiretime != -1) {
@@ -7697,7 +8279,7 @@ static int rewriteAppendOnlyFile(char *filename) {
     fflush(fp);
     fsync(fileno(fp));
     fclose(fp);
-    
+
     /* Use RENAME to make sure the DB file is changed atomically only
      * if the generate DB file is ok. */
     if (rename(tmpfile,filename) == -1) {
@@ -7756,6 +8338,7 @@ static int rewriteAppendOnlyFileBackground(void) {
         redisLog(REDIS_NOTICE,
             "Background append only file rewriting started by pid %d",childpid);
         server.bgrewritechildpid = childpid;
+        updateDictResizePolicy();
         /* We set appendseldb to -1 in order to force the next call to the
          * feedAppendOnlyFile() to issue a SELECT command, so the differences
          * accumulated by the parent into server.bgrewritebuf will start
@@ -7814,7 +8397,7 @@ static void aofRemoveTempFile(pid_t childpid) {
 static void expandVmSwapFilename(void) {
     char *p = strstr(server.vm_swap_file,"%p");
     sds new;
-    
+
     if (!p) return;
     new = sdsempty();
     *p = '\0';
@@ -7939,7 +8522,7 @@ static int vmFreePage(off_t page) {
 }
 
 /* Find N contiguous free pages storing the first page of the cluster in *first.
- * Returns REDIS_OK if it was able to find N contiguous pages, otherwise 
+ * Returns REDIS_OK if it was able to find N contiguous pages, otherwise
  * REDIS_ERR is returned.
  *
  * This function uses a simple algorithm: we try to allocate
@@ -7950,7 +8533,7 @@ static int vmFreePage(off_t page) {
  * we try to find less populated places doing a forward jump of
  * REDIS_VM_MAX_RANDOM_JUMP, then we start scanning again a few pages
  * without hurry, and then we jump again and so forth...
- * 
+ *
  * This function can be improved using a free list to avoid to guess
  * too much, since we could collect data about freed pages.
  *
@@ -8177,6 +8760,38 @@ static double computeObjectSwappability(robj *o) {
             if (z) asize += sizeof(zskiplistNode)*dictSize(d);
         }
         break;
+    case REDIS_HASH:
+        if (o->encoding == REDIS_ENCODING_ZIPMAP) {
+            unsigned char *p = zipmapRewind((unsigned char*)o->ptr);
+            unsigned int len = zipmapLen((unsigned char*)o->ptr);
+            unsigned int klen, vlen;
+            unsigned char *key, *val;
+
+            if ((p = zipmapNext(p,&key,&klen,&val,&vlen)) == NULL) {
+                klen = 0;
+                vlen = 0;
+            }
+            asize = len*(klen+vlen+3);
+        } else if (o->encoding == REDIS_ENCODING_HT) {
+            d = o->ptr;
+            asize = sizeof(dict)+(sizeof(struct dictEntry*)*dictSlots(d));
+            if (dictSize(d)) {
+                long elesize;
+                robj *ele;
+
+                de = dictGetRandomKey(d);
+                ele = dictGetEntryKey(de);
+                elesize = (ele->encoding == REDIS_ENCODING_RAW) ?
+                                (sizeof(*o)+sdslen(ele->ptr)) :
+                                sizeof(*o);
+                ele = dictGetEntryVal(de);
+                elesize = (ele->encoding == REDIS_ENCODING_RAW) ?
+                                (sizeof(*o)+sdslen(ele->ptr)) :
+                                sizeof(*o);
+                asize += (sizeof(struct dictEntry)+elesize)*dictSize(d);
+            }
+        }
+        break;
     }
     return (double)age*log(1+asize);
 }
@@ -8291,7 +8906,10 @@ static void freeIOJob(iojob *j) {
         j->type == REDIS_IOJOB_DO_SWAP ||
         j->type == REDIS_IOJOB_LOAD) && j->val != NULL)
         decrRefCount(j->val);
-    decrRefCount(j->key);
+    /* We don't decrRefCount the j->key field as we did't incremented
+     * the count creating IO Jobs. This is because the key field here is
+     * just used as an indentifier and if a key is removed the Job should
+     * never be touched again. */
     zfree(j);
 }
 
@@ -8464,7 +9082,7 @@ again:
             iojob *job = ln->value;
 
             if (job->canceled) continue; /* Skip this, already canceled. */
-            if (compareStringObjects(job->key,o) == 0) {
+            if (job->key == o) {
                 redisLog(REDIS_DEBUG,"*** CANCELED %p (%s) (type %d) (LIST ID %d)\n",
                     (void*)job, (char*)o->ptr, job->type, i);
                 /* Mark the pages as free since the swap didn't happened
@@ -8569,7 +9187,7 @@ static void *IOThreadEntryPoint(void *arg) {
         listDelNode(server.io_processing,ln);
         listAddNodeTail(server.io_processed,j);
         unlockThreadedIO();
-        
+
         /* Signal the main thread there is new stuff to process */
         assert(write(server.io_ready_pipe_write,"x",1) == 1);
     }
@@ -8579,13 +9197,18 @@ static void *IOThreadEntryPoint(void *arg) {
 static void spawnIOThread(void) {
     pthread_t thread;
     sigset_t mask, omask;
+    int err;
 
     sigemptyset(&mask);
     sigaddset(&mask,SIGCHLD);
     sigaddset(&mask,SIGHUP);
     sigaddset(&mask,SIGPIPE);
     pthread_sigmask(SIG_SETMASK, &mask, &omask);
-    pthread_create(&thread,&server.io_threads_attr,IOThreadEntryPoint,NULL);
+    while ((err = pthread_create(&thread,&server.io_threads_attr,IOThreadEntryPoint,NULL)) != 0) {
+        redisLog(REDIS_WARNING,"Unable to spawn an I/O thread: %s",
+            strerror(err));
+        usleep(1000000);
+    }
     pthread_sigmask(SIG_SETMASK, &omask, NULL);
     server.io_active_threads++;
 }
@@ -8642,14 +9265,14 @@ static void queueIOJob(iojob *j) {
 
 static int vmSwapObjectThreaded(robj *key, robj *val, redisDb *db) {
     iojob *j;
-    
+
     assert(key->storage == REDIS_VM_MEMORY);
     assert(key->refcount == 1);
 
     j = zmalloc(sizeof(*j));
     j->type = REDIS_IOJOB_PREPARE_SWAP;
     j->db = db;
-    j->key = dupStringObject(key);
+    j->key = key;
     j->val = val;
     incrRefCount(val);
     j->canceled = 0;
@@ -8686,7 +9309,7 @@ static int waitForSwappedKey(redisClient *c, robj *key) {
         vmCancelThreadedIOJob(o);
         return 0;
     }
-    
+
     /* OK: the key is either swapped, or being loaded just now. */
 
     /* Add the key to the list of keys this client is waiting for.
@@ -8717,7 +9340,7 @@ static int waitForSwappedKey(redisClient *c, robj *key) {
         j = zmalloc(sizeof(*j));
         j->type = REDIS_IOJOB_LOAD;
         j->db = c->db;
-        j->key = dupStringObject(key);
+        j->key = o;
         j->key->vtype = o->vtype;
         j->page = o->vm.page;
         j->val = NULL;
@@ -8730,6 +9353,15 @@ static int waitForSwappedKey(redisClient *c, robj *key) {
     return 1;
 }
 
+/* Preload keys needed for the ZUNION and ZINTER commands. */
+static void zunionInterBlockClientOnSwappedKeys(redisClient *c) {
+    int i, num;
+    num = atoi(c->argv[2]->ptr);
+    for (i = 0; i < num; i++) {
+        waitForSwappedKey(c,c->argv[3+i]);
+    }
+}
+
 /* Is this client attempting to run a command against swapped keys?
  * If so, block it ASAP, load the keys in background, then resume it.
  *
@@ -8743,11 +9375,16 @@ static int waitForSwappedKey(redisClient *c, robj *key) {
 static int blockClientOnSwappedKeys(struct redisCommand *cmd, redisClient *c) {
     int j, last;
 
-    if (cmd->vm_firstkey == 0) return 0;
-    last = cmd->vm_lastkey;
-    if (last < 0) last = c->argc+last;
-    for (j = cmd->vm_firstkey; j <= last; j += cmd->vm_keystep)
-        waitForSwappedKey(c,c->argv[j]);
+    if (cmd->vm_preload_proc != NULL) {
+        cmd->vm_preload_proc(c);
+    } else {
+        if (cmd->vm_firstkey == 0) return 0;
+        last = cmd->vm_lastkey;
+        if (last < 0) last = c->argc+last;
+        for (j = cmd->vm_firstkey; j <= last; j += cmd->vm_keystep)
+            waitForSwappedKey(c,c->argv[j]);
+    }
+
     /* If the client was blocked for at least one key, mark it as blocked. */
     if (listLength(c->io_keys)) {
         c->flags |= REDIS_IO_WAIT;
@@ -8817,6 +9454,353 @@ static void handleClientsBlockedOnSwappedKey(redisDb *db, robj *key) {
     }
 }
 
+/* =========================== Remote Configuration ========================= */
+
+static void configSetCommand(redisClient *c) {
+    robj *o = getDecodedObject(c->argv[3]);
+    if (!strcasecmp(c->argv[2]->ptr,"dbfilename")) {
+        zfree(server.dbfilename);
+        server.dbfilename = zstrdup(o->ptr);
+    } else if (!strcasecmp(c->argv[2]->ptr,"requirepass")) {
+        zfree(server.requirepass);
+        server.requirepass = zstrdup(o->ptr);
+    } else if (!strcasecmp(c->argv[2]->ptr,"masterauth")) {
+        zfree(server.masterauth);
+        server.masterauth = zstrdup(o->ptr);
+    } else if (!strcasecmp(c->argv[2]->ptr,"maxmemory")) {
+        server.maxmemory = strtoll(o->ptr, NULL, 10);
+    } else {
+        addReplySds(c,sdscatprintf(sdsempty(),
+            "-ERR not supported CONFIG parameter %s\r\n",
+            (char*)c->argv[2]->ptr));
+        decrRefCount(o);
+        return;
+    }
+    decrRefCount(o);
+    addReply(c,shared.ok);
+}
+
+static void configGetCommand(redisClient *c) {
+    robj *o = getDecodedObject(c->argv[2]);
+    robj *lenobj = createObject(REDIS_STRING,NULL);
+    char *pattern = o->ptr;
+    int matches = 0;
+
+    addReply(c,lenobj);
+    decrRefCount(lenobj);
+
+    if (stringmatch(pattern,"dbfilename",0)) {
+        addReplyBulkCString(c,"dbfilename");
+        addReplyBulkCString(c,server.dbfilename);
+        matches++;
+    }
+    if (stringmatch(pattern,"requirepass",0)) {
+        addReplyBulkCString(c,"requirepass");
+        addReplyBulkCString(c,server.requirepass);
+        matches++;
+    }
+    if (stringmatch(pattern,"masterauth",0)) {
+        addReplyBulkCString(c,"masterauth");
+        addReplyBulkCString(c,server.masterauth);
+        matches++;
+    }
+    if (stringmatch(pattern,"maxmemory",0)) {
+        char buf[128];
+
+        snprintf(buf,128,"%llu\n",server.maxmemory);
+        addReplyBulkCString(c,"maxmemory");
+        addReplyBulkCString(c,buf);
+        matches++;
+    }
+    decrRefCount(o);
+    lenobj->ptr = sdscatprintf(sdsempty(),"*%d\r\n",matches*2);
+}
+
+static void configCommand(redisClient *c) {
+    if (!strcasecmp(c->argv[1]->ptr,"set")) {
+        if (c->argc != 4) goto badarity;
+        configSetCommand(c);
+    } else if (!strcasecmp(c->argv[1]->ptr,"get")) {
+        if (c->argc != 3) goto badarity;
+        configGetCommand(c);
+    } else if (!strcasecmp(c->argv[1]->ptr,"resetstat")) {
+        if (c->argc != 2) goto badarity;
+        server.stat_numcommands = 0;
+        server.stat_numconnections = 0;
+        server.stat_expiredkeys = 0;
+        server.stat_starttime = time(NULL);
+        addReply(c,shared.ok);
+    } else {
+        addReplySds(c,sdscatprintf(sdsempty(),
+            "-ERR CONFIG subcommand must be one of GET, SET, RESETSTAT\r\n"));
+    }
+    return;
+
+badarity:
+    addReplySds(c,sdscatprintf(sdsempty(),
+        "-ERR Wrong number of arguments for CONFIG %s\r\n",
+        (char*) c->argv[1]->ptr));
+}
+
+/* =========================== Pubsub implementation ======================== */
+
+static void freePubsubPattern(void *p) {
+    pubsubPattern *pat = p;
+
+    decrRefCount(pat->pattern);
+    zfree(pat);
+}
+
+static int listMatchPubsubPattern(void *a, void *b) {
+    pubsubPattern *pa = a, *pb = b;
+
+    return (pa->client == pb->client) &&
+           (compareStringObjects(pa->pattern,pb->pattern) == 0);
+}
+
+/* Subscribe a client to a channel. Returns 1 if the operation succeeded, or
+ * 0 if the client was already subscribed to that channel. */
+static int pubsubSubscribeChannel(redisClient *c, robj *channel) {
+    struct dictEntry *de;
+    list *clients = NULL;
+    int retval = 0;
+
+    /* Add the channel to the client -> channels hash table */
+    if (dictAdd(c->pubsub_channels,channel,NULL) == DICT_OK) {
+        retval = 1;
+        incrRefCount(channel);
+        /* Add the client to the channel -> list of clients hash table */
+        de = dictFind(server.pubsub_channels,channel);
+        if (de == NULL) {
+            clients = listCreate();
+            dictAdd(server.pubsub_channels,channel,clients);
+            incrRefCount(channel);
+        } else {
+            clients = dictGetEntryVal(de);
+        }
+        listAddNodeTail(clients,c);
+    }
+    /* Notify the client */
+    addReply(c,shared.mbulk3);
+    addReply(c,shared.subscribebulk);
+    addReplyBulk(c,channel);
+    addReplyLong(c,dictSize(c->pubsub_channels)+listLength(c->pubsub_patterns));
+    return retval;
+}
+
+/* Unsubscribe a client from a channel. Returns 1 if the operation succeeded, or
+ * 0 if the client was not subscribed to the specified channel. */
+static int pubsubUnsubscribeChannel(redisClient *c, robj *channel, int notify) {
+    struct dictEntry *de;
+    list *clients;
+    listNode *ln;
+    int retval = 0;
+
+    /* Remove the channel from the client -> channels hash table */
+    incrRefCount(channel); /* channel may be just a pointer to the same object
+                            we have in the hash tables. Protect it... */
+    if (dictDelete(c->pubsub_channels,channel) == DICT_OK) {
+        retval = 1;
+        /* Remove the client from the channel -> clients list hash table */
+        de = dictFind(server.pubsub_channels,channel);
+        assert(de != NULL);
+        clients = dictGetEntryVal(de);
+        ln = listSearchKey(clients,c);
+        assert(ln != NULL);
+        listDelNode(clients,ln);
+        if (listLength(clients) == 0) {
+            /* Free the list and associated hash entry at all if this was
+             * the latest client, so that it will be possible to abuse
+             * Redis PUBSUB creating millions of channels. */
+            dictDelete(server.pubsub_channels,channel);
+        }
+    }
+    /* Notify the client */
+    if (notify) {
+        addReply(c,shared.mbulk3);
+        addReply(c,shared.unsubscribebulk);
+        addReplyBulk(c,channel);
+        addReplyLong(c,dictSize(c->pubsub_channels)+
+                       listLength(c->pubsub_patterns));
+
+    }
+    decrRefCount(channel); /* it is finally safe to release it */
+    return retval;
+}
+
+/* Subscribe a client to a pattern. Returns 1 if the operation succeeded, or 0 if the clinet was already subscribed to that pattern. */
+static int pubsubSubscribePattern(redisClient *c, robj *pattern) {
+    int retval = 0;
+
+    if (listSearchKey(c->pubsub_patterns,pattern) == NULL) {
+        retval = 1;
+        pubsubPattern *pat;
+        listAddNodeTail(c->pubsub_patterns,pattern);
+        incrRefCount(pattern);
+        pat = zmalloc(sizeof(*pat));
+        pat->pattern = getDecodedObject(pattern);
+        pat->client = c;
+        listAddNodeTail(server.pubsub_patterns,pat);
+    }
+    /* Notify the client */
+    addReply(c,shared.mbulk3);
+    addReply(c,shared.psubscribebulk);
+    addReplyBulk(c,pattern);
+    addReplyLong(c,dictSize(c->pubsub_channels)+listLength(c->pubsub_patterns));
+    return retval;
+}
+
+/* Unsubscribe a client from a channel. Returns 1 if the operation succeeded, or
+ * 0 if the client was not subscribed to the specified channel. */
+static int pubsubUnsubscribePattern(redisClient *c, robj *pattern, int notify) {
+    listNode *ln;
+    pubsubPattern pat;
+    int retval = 0;
+
+    incrRefCount(pattern); /* Protect the object. May be the same we remove */
+    if ((ln = listSearchKey(c->pubsub_patterns,pattern)) != NULL) {
+        retval = 1;
+        listDelNode(c->pubsub_patterns,ln);
+        pat.client = c;
+        pat.pattern = pattern;
+        ln = listSearchKey(server.pubsub_patterns,&pat);
+        listDelNode(server.pubsub_patterns,ln);
+    }
+    /* Notify the client */
+    if (notify) {
+        addReply(c,shared.mbulk3);
+        addReply(c,shared.punsubscribebulk);
+        addReplyBulk(c,pattern);
+        addReplyLong(c,dictSize(c->pubsub_channels)+
+                       listLength(c->pubsub_patterns));
+    }
+    decrRefCount(pattern);
+    return retval;
+}
+
+/* Unsubscribe from all the channels. Return the number of channels the
+ * client was subscribed from. */
+static int pubsubUnsubscribeAllChannels(redisClient *c, int notify) {
+    dictIterator *di = dictGetIterator(c->pubsub_channels);
+    dictEntry *de;
+    int count = 0;
+
+    while((de = dictNext(di)) != NULL) {
+        robj *channel = dictGetEntryKey(de);
+
+        count += pubsubUnsubscribeChannel(c,channel,notify);
+    }
+    dictReleaseIterator(di);
+    return count;
+}
+
+/* Unsubscribe from all the patterns. Return the number of patterns the
+ * client was subscribed from. */
+static int pubsubUnsubscribeAllPatterns(redisClient *c, int notify) {
+    listNode *ln;
+    listIter li;
+    int count = 0;
+
+    listRewind(c->pubsub_patterns,&li);
+    while ((ln = listNext(&li)) != NULL) {
+        robj *pattern = ln->value;
+
+        count += pubsubUnsubscribePattern(c,pattern,notify);
+    }
+    return count;
+}
+
+/* Publish a message */
+static int pubsubPublishMessage(robj *channel, robj *message) {
+    int receivers = 0;
+    struct dictEntry *de;
+    listNode *ln;
+    listIter li;
+
+    /* Send to clients listening for that channel */
+    de = dictFind(server.pubsub_channels,channel);
+    if (de) {
+        list *list = dictGetEntryVal(de);
+        listNode *ln;
+        listIter li;
+
+        listRewind(list,&li);
+        while ((ln = listNext(&li)) != NULL) {
+            redisClient *c = ln->value;
+
+            addReply(c,shared.mbulk3);
+            addReply(c,shared.messagebulk);
+            addReplyBulk(c,channel);
+            addReplyBulk(c,message);
+            receivers++;
+        }
+    }
+    /* Send to clients listening to matching channels */
+    if (listLength(server.pubsub_patterns)) {
+        listRewind(server.pubsub_patterns,&li);
+        channel = getDecodedObject(channel);
+        while ((ln = listNext(&li)) != NULL) {
+            pubsubPattern *pat = ln->value;
+
+            if (stringmatchlen((char*)pat->pattern->ptr,
+                                sdslen(pat->pattern->ptr),
+                                (char*)channel->ptr,
+                                sdslen(channel->ptr),0)) {
+                addReply(pat->client,shared.mbulk3);
+                addReply(pat->client,shared.messagebulk);
+                addReplyBulk(pat->client,channel);
+                addReplyBulk(pat->client,message);
+                receivers++;
+            }
+        }
+        decrRefCount(channel);
+    }
+    return receivers;
+}
+
+static void subscribeCommand(redisClient *c) {
+    int j;
+
+    for (j = 1; j < c->argc; j++)
+        pubsubSubscribeChannel(c,c->argv[j]);
+}
+
+static void unsubscribeCommand(redisClient *c) {
+    if (c->argc == 1) {
+        pubsubUnsubscribeAllChannels(c,1);
+        return;
+    } else {
+        int j;
+
+        for (j = 1; j < c->argc; j++)
+            pubsubUnsubscribeChannel(c,c->argv[j],1);
+    }
+}
+
+static void psubscribeCommand(redisClient *c) {
+    int j;
+
+    for (j = 1; j < c->argc; j++)
+        pubsubSubscribePattern(c,c->argv[j]);
+}
+
+static void punsubscribeCommand(redisClient *c) {
+    if (c->argc == 1) {
+        pubsubUnsubscribeAllPatterns(c,1);
+        return;
+    } else {
+        int j;
+
+        for (j = 1; j < c->argc; j++)
+            pubsubUnsubscribePattern(c,c->argv[j],1);
+    }
+}
+
+static void publishCommand(redisClient *c) {
+    int receivers = pubsubPublishMessage(c->argv[1],c->argv[2]);
+    addReplyLong(c,receivers);
+}
+
 /* ================================= Debugging ============================== */
 
 static void debugCommand(redisClient *c) {
@@ -8875,6 +9859,9 @@ static void debugCommand(redisClient *c) {
                 (void*)key, key->refcount, (unsigned long long) key->vm.page,
                 (unsigned long long) key->vm.usedpages));
         }
+    } else if (!strcasecmp(c->argv[1]->ptr,"swapin") && c->argc == 3) {
+        lookupKeyRead(c->db,c->argv[2]);
+        addReply(c,shared.ok);
     } else if (!strcasecmp(c->argv[1]->ptr,"swapout") && c->argc == 3) {
         dictEntry *de = dictFind(c->db->dict,c->argv[2]);
         robj *key, *val;
@@ -8906,7 +9893,7 @@ static void debugCommand(redisClient *c) {
         }
     } else {
         addReplySds(c,sdsnew(
-            "-ERR Syntax error, try DEBUG [SEGFAULT|OBJECT <key>|SWAPOUT <key>|RELOAD]\r\n"));
+            "-ERR Syntax error, try DEBUG [SEGFAULT|OBJECT <key>|SWAPIN <key>|SWAPOUT <key>|RELOAD]\r\n"));
     }
 }
 
@@ -8919,6 +9906,15 @@ static void _redisAssert(char *estr, char *file, int line) {
 #endif
 }
 
+static void _redisPanic(char *msg, char *file, int line) {
+    redisLog(REDIS_WARNING,"!!! Software Failure. Press left mouse button to continue");
+    redisLog(REDIS_WARNING,"Guru Meditation: %s #%s:%d",msg,file,line);
+#ifdef HAVE_BACKTRACE
+    redisLog(REDIS_WARNING,"(forcing SIGSEGV in order to print the stack trace)");
+    *((char*)-1) = 'x';
+#endif
+}
+
 /* =================================== Main! ================================ */
 
 #ifdef __linux__
@@ -8967,16 +9963,29 @@ static void daemonize(void) {
     }
 }
 
+static void version() {
+    printf("Redis server version %s\n", REDIS_VERSION);
+    exit(0);
+}
+
+static void usage() {
+    fprintf(stderr,"Usage: ./redis-server [/path/to/redis.conf]\n");
+    fprintf(stderr,"       ./redis-server - (read config from stdin)\n");
+    exit(1);
+}
+
 int main(int argc, char **argv) {
     time_t start;
 
     initServerConfig();
     if (argc == 2) {
+        if (strcmp(argv[1], "-v") == 0 ||
+            strcmp(argv[1], "--version") == 0) version();
+        if (strcmp(argv[1], "--help") == 0) usage();
         resetServerSaveParams();
         loadServerConfig(argv[1]);
-    } else if (argc > 2) {
-        fprintf(stderr,"Usage: ./redis-server [/path/to/redis.conf]\n");
-        exit(1);
+    } else if ((argc > 2)) {
+        usage();
     } else {
         redisLog(REDIS_WARNING,"Warning: no config file specified, using the default config. In order to specify a config file use 'redis-server /path/to/redis.conf'");
     }
@@ -9022,7 +10031,7 @@ static void *getMcontextEip(ucontext_t *uc) {
     return (void*) uc->uc_mcontext->__ss.__rip;
   #else
     return (void*) uc->uc_mcontext->__ss.__eip;
-  #endif 
+  #endif
 #elif defined(__i386__) || defined(__X86_64__) || defined(__x86_64__)
     return (void*) uc->uc_mcontext.gregs[REG_EIP]; /* Linux 32/64 bit */
 #elif defined(__ia64__) /* Linux IA64 */
@@ -9047,7 +10056,7 @@ static void segvHandler(int sig, siginfo_t *info, void *secret) {
     redisLog(REDIS_WARNING, "%s",infostring);
     /* It's not safe to sdsfree() the returned string under memory
      * corruption conditions. Let it leak as we are going to abort */
-    
+
     trace_size = backtrace(trace, 100);
     /* overwrite sigaction with caller's address */
     if (getMcontextEip(uc) != NULL) {