X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/1812e0246cc6dbae16a7fc90be2d8e4866299fe0..96d8b4eeba2503c9f679e41963220a72ee5baeda:/redis.c

diff --git a/redis.c b/redis.c
index 41ebe18a..470191da 100644
--- a/redis.c
+++ b/redis.c
@@ -57,6 +57,11 @@
 #include <sys/time.h>
 #include <sys/resource.h>
 #include <limits.h>
+#include <math.h>
+
+#if defined(__sun)
+#include "solarisfixes.h"
+#endif
 
 #include "redis.h"
 #include "ae.h"     /* Event driven programming library */
@@ -167,11 +172,8 @@
 
 /* Sort operations */
 #define REDIS_SORT_GET 0
-#define REDIS_SORT_DEL 1
-#define REDIS_SORT_INCR 2
-#define REDIS_SORT_DECR 3
-#define REDIS_SORT_ASC 4
-#define REDIS_SORT_DESC 5
+#define REDIS_SORT_ASC 1
+#define REDIS_SORT_DESC 2
 #define REDIS_SORTKEY_MAX 1024
 
 /* Log levels */
@@ -182,6 +184,13 @@
 /* Anti-warning macro... */
 #define REDIS_NOTUSED(V) ((void) V)
 
+#define ZSKIPLIST_MAXLEVEL 32 /* Should be enough for 2^32 elements */
+#define ZSKIPLIST_P 0.25      /* Skiplist P = 1/4 */
+
+/* Append only defines */
+#define APPENDFSYNC_NO 0
+#define APPENDFSYNC_ALWAYS 1
+#define APPENDFSYNC_EVERYSEC 2
 
 /*================================= Data types ============================== */
 
@@ -254,6 +263,11 @@ struct redisServer {
     int maxidletime;
     int dbnum;
     int daemonize;
+    int appendonly;
+    int appendfsync;
+    time_t lastfsync;
+    int appendfd;
+    int appendseldb;
     char *pidfile;
     int bgsaveinprogress;
     pid_t bgsavechildpid;
@@ -262,10 +276,12 @@ struct redisServer {
     char *logfile;
     char *bindaddr;
     char *dbfilename;
+    char *appendfilename;
     char *requirepass;
     int shareobjects;
     /* Replication related */
     int isslave;
+    char *masterauth;
     char *masterhost;
     int masterport;
     redisClient *master;    /* client that is master for this slave */
@@ -305,11 +321,28 @@ typedef struct _redisSortOperation {
     robj *pattern;
 } redisSortOperation;
 
+/* ZSETs use a specialized version of Skiplists */
+
+typedef struct zskiplistNode {
+    struct zskiplistNode **forward;
+    struct zskiplistNode *backward;
+    double score;
+    robj *obj;
+} zskiplistNode;
+
+typedef struct zskiplist {
+    struct zskiplistNode *header, *tail;
+    unsigned long length;
+    int level;
+} zskiplist;
+
 typedef struct zset {
     dict *dict;
-    tree *tree;
+    zskiplist *zsl;
 } zset;
 
+/* Our shared "common" objects */
+
 struct sharedObjectsStruct {
     robj *crlf, *ok, *err, *emptybulk, *czero, *cone, *pong, *space,
     *colon, *nullbulk, *nullmultibulk,
@@ -319,6 +352,12 @@ struct sharedObjectsStruct {
     *select5, *select6, *select7, *select8, *select9;
 } shared;
 
+/* Global vars that are actally used as constants. The following double
+ * values are used for double on-disk serialization, and are initialized
+ * at runtime to avoid strange compiler optimizations. */
+
+static double R_Zero, R_PosInf, R_NegInf, R_Nan;
+
 /*================================ Prototypes =============================== */
 
 static void freeStringObject(robj *o);
@@ -334,6 +373,7 @@ static void incrRefCount(robj *o);
 static int rdbSaveBackground(char *filename);
 static robj *createStringObject(char *ptr, size_t len);
 static void replicationFeedSlaves(list *slaves, struct redisCommand *cmd, 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);
@@ -351,6 +391,9 @@ static void setupSigSegvAction(void);
 static void rdbRemoveTempFile(pid_t childpid);
 static size_t stringObjectLen(robj *o);
 static void processInputBuffer(redisClient *c);
+static zskiplist *zslCreate(void);
+static void zslFree(zskiplist *zsl);
+static void zslInsert(zskiplist *zsl, double score, robj *obj);
 
 static void authCommand(redisClient *c);
 static void pingCommand(redisClient *c);
@@ -403,16 +446,26 @@ static void flushdbCommand(redisClient *c);
 static void flushallCommand(redisClient *c);
 static void sortCommand(redisClient *c);
 static void lremCommand(redisClient *c);
+static void rpoplpushcommand(redisClient *c);
 static void infoCommand(redisClient *c);
 static void mgetCommand(redisClient *c);
 static void monitorCommand(redisClient *c);
 static void expireCommand(redisClient *c);
+static void expireatCommand(redisClient *c);
 static void getsetCommand(redisClient *c);
 static void ttlCommand(redisClient *c);
 static void slaveofCommand(redisClient *c);
 static void debugCommand(redisClient *c);
 static void msetCommand(redisClient *c);
 static void msetnxCommand(redisClient *c);
+static void zaddCommand(redisClient *c);
+static void zrangeCommand(redisClient *c);
+static void zrangebyscoreCommand(redisClient *c);
+static void zrevrangeCommand(redisClient *c);
+static void zcardCommand(redisClient *c);
+static void zremCommand(redisClient *c);
+static void zscoreCommand(redisClient *c);
+static void zremrangebyscoreCommand(redisClient *c);
 
 /*================================= Globals ================================= */
 
@@ -437,6 +490,7 @@ static struct redisCommand cmdTable[] = {
     {"lrange",lrangeCommand,4,REDIS_CMD_INLINE},
     {"ltrim",ltrimCommand,4,REDIS_CMD_INLINE},
     {"lrem",lremCommand,4,REDIS_CMD_BULK},
+    {"rpoplpush",rpoplpushcommand,3,REDIS_CMD_BULK},
     {"sadd",saddCommand,3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM},
     {"srem",sremCommand,3,REDIS_CMD_BULK},
     {"smove",smoveCommand,4,REDIS_CMD_BULK},
@@ -451,6 +505,14 @@ static struct redisCommand cmdTable[] = {
     {"sdiff",sdiffCommand,-2,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM},
     {"sdiffstore",sdiffstoreCommand,-3,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM},
     {"smembers",sinterCommand,2,REDIS_CMD_INLINE},
+    {"zadd",zaddCommand,4,REDIS_CMD_BULK|REDIS_CMD_DENYOOM},
+    {"zrem",zremCommand,3,REDIS_CMD_BULK},
+    {"zremrangebyscore",zremrangebyscoreCommand,4,REDIS_CMD_INLINE},
+    {"zrange",zrangeCommand,4,REDIS_CMD_INLINE},
+    {"zrangebyscore",zrangebyscoreCommand,4,REDIS_CMD_INLINE},
+    {"zrevrange",zrevrangeCommand,4,REDIS_CMD_INLINE},
+    {"zcard",zcardCommand,2,REDIS_CMD_INLINE},
+    {"zscore",zscoreCommand,3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM},
     {"incrby",incrbyCommand,3,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM},
     {"decrby",decrbyCommand,3,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM},
     {"getset",getsetCommand,3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM},
@@ -462,6 +524,7 @@ static struct redisCommand cmdTable[] = {
     {"rename",renameCommand,3,REDIS_CMD_INLINE},
     {"renamenx",renamenxCommand,3,REDIS_CMD_INLINE},
     {"expire",expireCommand,3,REDIS_CMD_INLINE},
+    {"expireat",expireatCommand,3,REDIS_CMD_INLINE},
     {"keys",keysCommand,2,REDIS_CMD_INLINE},
     {"dbsize",dbsizeCommand,1,REDIS_CMD_INLINE},
     {"auth",authCommand,2,REDIS_CMD_INLINE},
@@ -483,6 +546,7 @@ static struct redisCommand cmdTable[] = {
     {"debug",debugCommand,-2,REDIS_CMD_INLINE},
     {NULL,NULL,0,0}
 };
+
 /*============================ Utility functions ============================ */
 
 /* Glob-style pattern matching. */
@@ -622,7 +686,7 @@ static void redisLog(int level, const char *fmt, ...) {
         time_t now;
 
         now = time(NULL);
-        strftime(buf,64,"%d %b %H:%M:%S",gmtime(&now));
+        strftime(buf,64,"%d %b %H:%M:%S",localtime(&now));
         fprintf(fp,"%s %c ",buf,c[level]);
         vfprintf(fp, fmt, ap);
         fprintf(fp,"\n");
@@ -879,14 +943,21 @@ static int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientD
          }
     }
 
-    /* Try to expire a few timed out keys */
+    /* Try to expire a few timed out keys. The algorithm used is adaptive and
+     * will use few CPU cycles if there are few expiring keys, otherwise
+     * it will get more aggressive to avoid that too much memory is used by
+     * keys that can be removed from the keyspace. */
     for (j = 0; j < server.dbnum; j++) {
+        int expired;
         redisDb *db = server.db+j;
-        int num = dictSize(db->expires);
 
-        if (num) {
+        /* Continue to expire if at the end of the cycle more than 25%
+         * of the keys were expired. */
+        do {
+            int num = dictSize(db->expires);
             time_t now = time(NULL);
 
+            expired = 0;
             if (num > REDIS_EXPIRELOOKUPS_PER_CRON)
                 num = REDIS_EXPIRELOOKUPS_PER_CRON;
             while (num--) {
@@ -897,9 +968,10 @@ static int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientD
                 t = (time_t) dictGetEntryVal(de);
                 if (now > t) {
                     deleteKey(db,dictGetEntryKey(de));
+                    expired++;
                 }
             }
-        }
+        } while (expired > REDIS_EXPIRELOOKUPS_PER_CRON/4);
     }
 
     /* Check if we should connect to a MASTER */
@@ -951,13 +1023,12 @@ static void createSharedObjects(void) {
 
 static void appendServerSaveParams(time_t seconds, int changes) {
     server.saveparams = zrealloc(server.saveparams,sizeof(struct saveparam)*(server.saveparamslen+1));
-    if (server.saveparams == NULL) oom("appendServerSaveParams");
     server.saveparams[server.saveparamslen].seconds = seconds;
     server.saveparams[server.saveparamslen].changes = changes;
     server.saveparamslen++;
 }
 
-static void ResetServerSaveParams() {
+static void resetServerSaveParams() {
     zfree(server.saveparams);
     server.saveparams = NULL;
     server.saveparamslen = 0;
@@ -973,24 +1044,37 @@ static void initServerConfig() {
     server.bindaddr = NULL;
     server.glueoutputbuf = 1;
     server.daemonize = 0;
+    server.appendonly = 0;
+    server.appendfsync = APPENDFSYNC_ALWAYS;
+    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.log";
     server.requirepass = NULL;
     server.shareobjects = 0;
     server.sharingpoolsize = 1024;
     server.maxclients = 0;
     server.maxmemory = 0;
-    ResetServerSaveParams();
+    resetServerSaveParams();
 
     appendServerSaveParams(60*60,1);  /* save after 1 hour and 1 change */
     appendServerSaveParams(300,100);  /* save after 5 minutes and 100 changes */
     appendServerSaveParams(60,10000); /* save after 1 minute and 10000 changes */
     /* Replication related */
     server.isslave = 0;
+    server.masterauth = NULL;
     server.masterhost = NULL;
     server.masterport = 6379;
     server.master = NULL;
     server.replstate = REDIS_REPL_NONE;
+
+    /* Double constants initialization */
+    R_Zero = 0.0;
+    R_PosInf = 1.0/R_Zero;
+    R_NegInf = -1.0/R_Zero;
+    R_Nan = R_Zero/R_Zero;
 }
 
 static void initServer() {
@@ -1008,8 +1092,6 @@ static void initServer() {
     server.el = aeCreateEventLoop();
     server.db = zmalloc(sizeof(redisDb)*server.dbnum);
     server.sharingpool = dictCreate(&setDictType,NULL);
-    if (!server.db || !server.clients || !server.slaves || !server.monitors || !server.el || !server.objfreelist)
-        oom("server initialization"); /* Fatal OOM */
     server.fd = anetTcpServer(server.neterr, server.port, server.bindaddr);
     if (server.fd == -1) {
         redisLog(REDIS_WARNING, "Opening TCP port: %s", server.neterr);
@@ -1029,7 +1111,16 @@ static void initServer() {
     server.stat_numcommands = 0;
     server.stat_numconnections = 0;
     server.stat_starttime = time(NULL);
-    aeCreateTimeEvent(server.el, 1000, serverCron, NULL, NULL);
+    aeCreateTimeEvent(server.el, 1, serverCron, NULL, NULL);
+
+    if (server.appendonly) {
+        server.appendfd = open(server.appendfilename,O_WRONLY|O_APPEND|O_CREAT,0644);
+        if (server.appendfd == -1) {
+            redisLog(REDIS_WARNING, "Can't open the append-only file: %s",
+                strerror(errno));
+            exit(1);
+        }
+    }
 }
 
 /* Empty the whole database */
@@ -1152,6 +1243,8 @@ static void loadServerConfig(char *filename) {
             server.masterhost = sdsnew(argv[1]);
             server.masterport = atoi(argv[2]);
             server.replstate = REDIS_REPL_CONNECT;
+        } else if (!strcasecmp(argv[0],"masterauth") && argc == 2) {
+        	server.masterauth = zstrdup(argv[1]);
         } else if (!strcasecmp(argv[0],"glueoutputbuf") && argc == 2) {
             if ((server.glueoutputbuf = yesnotoi(argv[1])) == -1) {
                 err = "argument must be 'yes' or 'no'"; goto loaderr;
@@ -1169,6 +1262,21 @@ static void loadServerConfig(char *filename) {
             if ((server.daemonize = yesnotoi(argv[1])) == -1) {
                 err = "argument must be 'yes' or 'no'"; goto loaderr;
             }
+        } else if (!strcasecmp(argv[0],"appendonly") && argc == 2) {
+            if ((server.appendonly = yesnotoi(argv[1])) == -1) {
+                err = "argument must be 'yes' or 'no'"; goto loaderr;
+            }
+        } else if (!strcasecmp(argv[0],"appendfsync") && argc == 2) {
+            if (!strcasecmp(argv[1],"no")) {
+                server.appendfsync = APPENDFSYNC_NO;
+            } else if (!strcasecmp(argv[1],"always")) {
+                server.appendfsync = APPENDFSYNC_ALWAYS;
+            } else if (!strcasecmp(argv[1],"everysec")) {
+                server.appendfsync = APPENDFSYNC_EVERYSEC;
+            } else {
+                err = "argument must be 'no', 'always' or 'everysec'";
+                goto loaderr;
+            }
         } else if (!strcasecmp(argv[0],"requirepass") && argc == 2) {
           server.requirepass = zstrdup(argv[1]);
         } else if (!strcasecmp(argv[0],"pidfile") && argc == 2) {
@@ -1260,7 +1368,7 @@ static void glueReplyBuffersIfNeeded(redisClient *c) {
         }
         /* Now the output buffer is empty, add the new single element */
         o = createObject(REDIS_STRING,sdsnewlen(buf,totlen));
-        if (!listAddNodeTail(c->reply,o)) oom("listAddNodeTail");
+        listAddNodeTail(c->reply,o);
     }
 }
 
@@ -1297,10 +1405,10 @@ static void sendReplyToClient(aeEventLoop *el, int fd, void *privdata, int mask)
             c->sentlen = 0;
         }
         /* Note that we avoid to send more thank REDIS_MAX_WRITE_PER_EVENT
-         * bytes, in a single threaded server it's a good idea to server
+         * bytes, in a single threaded server it's a good idea to serve
          * other clients as well, even if a very large request comes from
          * super fast link that is always able to accept data (in real world
-         * terms think to 'KEYS *' against the loopback interfae) */
+         * scenario think about 'KEYS *' against the loopback interfae) */
         if (totwritten > REDIS_MAX_WRITE_PER_EVENT) break;
     }
     if (nwritten == -1) {
@@ -1484,7 +1592,9 @@ static int processCommand(redisClient *c) {
     /* Exec the command */
     dirty = server.dirty;
     cmd->proc(c);
-    if (server.dirty-dirty != 0 && listLength(server.slaves))
+    if (server.appendonly && server.dirty-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 (listLength(server.monitors))
         replicationFeedSlaves(server.monitors,cmd,c->db->id,c->argv,c->argc);
@@ -1510,7 +1620,6 @@ static void replicationFeedSlaves(list *slaves, struct redisCommand *cmd, int di
         outv = static_outv;
     } else {
         outv = zmalloc(sizeof(robj*)*(argc*2+1));
-        if (!outv) oom("replicationFeedSlaves");
     }
     
     for (j = 0; j < argc; j++) {
@@ -1598,12 +1707,10 @@ again:
                 return;
             }
             argv = sdssplitlen(query,sdslen(query)," ",1,&argc);
-            if (argv == NULL) oom("sdssplitlen");
             sdsfree(query);
 
             if (c->argv) zfree(c->argv);
             c->argv = zmalloc(sizeof(robj*)*argc);
-            if (c->argv == NULL) oom("allocating arguments list for client");
 
             for (j = 0; j < argc; j++) {
                 if (sdslen(argv[j])) {
@@ -1707,7 +1814,7 @@ static redisClient *createClient(int fd) {
     c->lastinteraction = time(NULL);
     c->authenticated = 0;
     c->replstate = REDIS_REPL_NONE;
-    if ((c->reply = listCreate()) == NULL) oom("listCreate");
+    c->reply = listCreate();
     listSetFreeMethod(c->reply,decrRefCount);
     listSetDupMethod(c->reply,dupClientReplyValue);
     if (aeCreateFileEvent(server.el, c->fd, AE_READABLE,
@@ -1715,7 +1822,7 @@ static redisClient *createClient(int fd) {
         freeClient(c);
         return NULL;
     }
-    if (!listAddNodeTail(server.clients,c)) oom("listAddNodeTail");
+    listAddNodeTail(server.clients,c);
     return c;
 }
 
@@ -1730,7 +1837,7 @@ static void addReply(redisClient *c, robj *obj) {
     } else {
         incrRefCount(obj);
     }
-    if (!listAddNodeTail(c->reply,obj)) oom("listAddNodeTail");
+    listAddNodeTail(c->reply,obj);
 }
 
 static void addReplySds(redisClient *c, sds s) {
@@ -1786,7 +1893,9 @@ static void acceptHandler(aeEventLoop *el, int fd, void *privdata, int mask) {
         char *err = "-ERR max number of clients reached\r\n";
 
         /* That's a best effort error message, don't check write errors */
-        (void) write(c->fd,err,strlen(err));
+        if (write(c->fd,err,strlen(err)) == -1) {
+            /* Nothing to do, Just to avoid the warning... */
+        }
         freeClient(c);
         return;
     }
@@ -1805,7 +1914,6 @@ static robj *createObject(int type, void *ptr) {
     } else {
         o = zmalloc(sizeof(*o));
     }
-    if (!o) oom("createObject");
     o->type = type;
     o->encoding = REDIS_ENCODING_RAW;
     o->ptr = ptr;
@@ -1820,21 +1928,21 @@ static robj *createStringObject(char *ptr, size_t len) {
 static robj *createListObject(void) {
     list *l = listCreate();
 
-    if (!l) oom("listCreate");
     listSetFreeMethod(l,decrRefCount);
     return createObject(REDIS_LIST,l);
 }
 
 static robj *createSetObject(void) {
     dict *d = dictCreate(&setDictType,NULL);
-    if (!d) oom("dictCreate");
     return createObject(REDIS_SET,d);
 }
 
 static robj *createZsetObject(void) {
-    dict *d = dictCreate(&zsetDictType,NULL);
-    if (!d) oom("dictCreate");
-    return createObject(REDIS_ZSET,d);
+    zset *zs = zmalloc(sizeof(*zs));
+
+    zs->dict = dictCreate(&zsetDictType,NULL);
+    zs->zsl = zslCreate();
+    return createObject(REDIS_ZSET,zs);
 }
 
 static void freeStringObject(robj *o) {
@@ -1851,6 +1959,14 @@ static void freeSetObject(robj *o) {
     dictRelease((dict*) o->ptr);
 }
 
+static void freeZsetObject(robj *o) {
+    zset *zs = o->ptr;
+
+    dictRelease(zs->dict);
+    zslFree(zs->zsl);
+    zfree(zs);
+}
+
 static void freeHashObject(robj *o) {
     dictRelease((dict*) o->ptr);
 }
@@ -1875,6 +1991,7 @@ static void decrRefCount(void *obj) {
         case REDIS_STRING: freeStringObject(o); break;
         case REDIS_LIST: freeListObject(o); break;
         case REDIS_SET: freeSetObject(o); break;
+        case REDIS_ZSET: freeZsetObject(o); break;
         case REDIS_HASH: freeHashObject(o); break;
         default: assert(0 != 0); break;
         }
@@ -2023,23 +2140,31 @@ static robj *getDecodedObject(const robj *o) {
     }
 }
 
+/* Compare two string objects via strcmp() or alike.
+ * Note that the objects may be integer-encoded. In such a case we
+ * use snprintf() to get a string representation of the numbers on the stack
+ * and compare the strings, it's much faster than calling getDecodedObject(). */
 static int compareStringObjects(robj *a, robj *b) {
     assert(a->type == REDIS_STRING && b->type == REDIS_STRING);
-
-    if (a->encoding == REDIS_ENCODING_INT && b->encoding == REDIS_ENCODING_INT){
-        return (long)a->ptr - (long)b->ptr;
+    char bufa[128], bufb[128], *astr, *bstr;
+    int bothsds = 1;
+
+    if (a == b) return 0;
+    if (a->encoding != REDIS_ENCODING_RAW) {
+        snprintf(bufa,sizeof(bufa),"%ld",(long) a->ptr);
+        astr = bufa;
+        bothsds = 0;
     } else {
-        int retval;
-
-        incrRefCount(a);
-        incrRefCount(b);
-        if (a->encoding != REDIS_ENCODING_RAW) a = getDecodedObject(a);
-        if (b->encoding != REDIS_ENCODING_RAW) b = getDecodedObject(a);
-        retval = sdscmp(a->ptr,b->ptr);
-        decrRefCount(a);
-        decrRefCount(b);
-        return retval;
+        astr = a->ptr;
     }
+    if (b->encoding != REDIS_ENCODING_RAW) {
+        snprintf(bufb,sizeof(bufb),"%ld",(long) b->ptr);
+        bstr = bufb;
+        bothsds = 0;
+    } else {
+        bstr = b->ptr;
+    }
+    return bothsds ? sdscmp(astr,bstr) : strcmp(astr,bstr);
 }
 
 static size_t stringObjectLen(robj *o) {
@@ -2204,6 +2329,33 @@ static int rdbSaveStringObject(FILE *fp, robj *obj) {
     }
 }
 
+/* Save a double value. Doubles are saved as strings prefixed by an unsigned
+ * 8 bit integer specifing the length of the representation.
+ * This 8 bit integer has special values in order to specify the following
+ * conditions:
+ * 253: not a number
+ * 254: + inf
+ * 255: - inf
+ */
+static int rdbSaveDoubleValue(FILE *fp, double val) {
+    unsigned char buf[128];
+    int len;
+
+    if (isnan(val)) {
+        buf[0] = 253;
+        len = 1;
+    } else if (!isfinite(val)) {
+        len = 1;
+        buf[0] = (val < 0) ? 255 : 254;
+    } else {
+        snprintf((char*)buf+1,sizeof(buf)-1,"%.17g",val);
+        buf[0] = strlen((char*)buf);
+        len = buf[0]+1;
+    }
+    if (fwrite(buf,len,1,fp) == 0) return -1;
+    return 0;
+}
+
 /* Save the DB on disk. Return REDIS_ERR on error, REDIS_OK on success */
 static int rdbSave(char *filename) {
     dictIterator *di = NULL;
@@ -2271,7 +2423,6 @@ static int rdbSave(char *filename) {
                 dictIterator *di = dictGetIterator(set);
                 dictEntry *de;
 
-                if (!set) oom("dictGetIteraotr");
                 if (rdbSaveLen(fp,dictSize(set)) == -1) goto werr;
                 while((de = dictNext(di)) != NULL) {
                     robj *eleobj = dictGetEntryKey(de);
@@ -2279,6 +2430,21 @@ static int rdbSave(char *filename) {
                     if (rdbSaveStringObject(fp,eleobj) == -1) goto werr;
                 }
                 dictReleaseIterator(di);
+            } else if (o->type == REDIS_ZSET) {
+                /* Save a set value */
+                zset *zs = o->ptr;
+                dictIterator *di = dictGetIterator(zs->dict);
+                dictEntry *de;
+
+                if (rdbSaveLen(fp,dictSize(zs->dict)) == -1) goto werr;
+                while((de = dictNext(di)) != NULL) {
+                    robj *eleobj = dictGetEntryKey(de);
+                    double *score = dictGetEntryVal(de);
+
+                    if (rdbSaveStringObject(fp,eleobj) == -1) goto werr;
+                    if (rdbSaveDoubleValue(fp,*score) == -1) goto werr;
+                }
+                dictReleaseIterator(di);
             } else {
                 assert(0 != 0);
             }
@@ -2296,7 +2462,7 @@ static int rdbSave(char *filename) {
     /* Use RENAME to make sure the DB file is changed atomically only
      * if the generate DB file is ok. */
     if (rename(tmpfile,filename) == -1) {
-        redisLog(REDIS_WARNING,"Error moving temp DB file on the final destionation: %s", strerror(errno));
+        redisLog(REDIS_WARNING,"Error moving temp DB file on the final destination: %s", strerror(errno));
         unlink(tmpfile);
         return REDIS_ERR;
     }
@@ -2467,6 +2633,23 @@ static robj *rdbLoadStringObject(FILE*fp, int rdbver) {
     return tryObjectSharing(createObject(REDIS_STRING,val));
 }
 
+/* For information about double serialization check rdbSaveDoubleValue() */
+static int rdbLoadDoubleValue(FILE *fp, double *val) {
+    char buf[128];
+    unsigned char len;
+
+    if (fread(&len,1,1,fp) == 0) return -1;
+    switch(len) {
+    case 255: *val = R_NegInf; return 0;
+    case 254: *val = R_PosInf; return 0;
+    case 253: *val = R_Nan; return 0;
+    default:
+        if (fread(buf,len,1,fp) == 0) return -1;
+        sscanf(buf, "%lg", val);
+        return 0;
+    }
+}
+
 static int rdbLoad(char *filename) {
     FILE *fp;
     robj *keyobj = NULL;
@@ -2536,13 +2719,32 @@ static int rdbLoad(char *filename) {
                 if ((ele = rdbLoadStringObject(fp,rdbver)) == NULL) goto eoferr;
                 tryObjectEncoding(ele);
                 if (type == REDIS_LIST) {
-                    if (!listAddNodeTail((list*)o->ptr,ele))
-                        oom("listAddNodeTail");
+                    listAddNodeTail((list*)o->ptr,ele);
                 } else {
-                    if (dictAdd((dict*)o->ptr,ele,NULL) == DICT_ERR)
-                        oom("dictAdd");
+                    dictAdd((dict*)o->ptr,ele,NULL);
                 }
             }
+        } else if (type == REDIS_ZSET) {
+            /* Read list/set value */
+            uint32_t zsetlen;
+            zset *zs;
+
+            if ((zsetlen = rdbLoadLen(fp,rdbver,NULL)) == REDIS_RDB_LENERR)
+                goto eoferr;
+            o = createZsetObject();
+            zs = o->ptr;
+            /* Load every single element of the list/set */
+            while(zsetlen--) {
+                robj *ele;
+                double *score = zmalloc(sizeof(double));
+
+                if ((ele = rdbLoadStringObject(fp,rdbver)) == NULL) goto eoferr;
+                tryObjectEncoding(ele);
+                if (rdbLoadDoubleValue(fp,score) == -1) goto eoferr;
+                dictAdd(zs->dict,ele,score);
+                zslInsert(zs->zsl,*score,ele);
+                incrRefCount(ele); /* added to skiplist */
+            }
         } else {
             assert(0 != 0);
         }
@@ -2566,7 +2768,7 @@ static int rdbLoad(char *filename) {
 
 eoferr: /* unexpected end of file is handled here with a fatal exit */
     if (keyobj) decrRefCount(keyobj);
-    redisLog(REDIS_WARNING,"Short read or OOM loading DB. Unrecoverable error, exiting now.");
+    redisLog(REDIS_WARNING,"Short read or OOM loading DB. Unrecoverable error, aborting now.");
     exit(1);
     return REDIS_ERR; /* Just to avoid warning */
 }
@@ -2579,7 +2781,7 @@ static void authCommand(redisClient *c) {
       addReply(c,shared.ok);
     } else {
       c->authenticated = 0;
-      addReply(c,shared.err);
+      addReplySds(c,sdscatprintf(sdsempty(),"-ERR invalid password\r\n"));
     }
 }
 
@@ -2793,7 +2995,6 @@ static void keysCommand(redisClient *c) {
     robj *lenobj = createObject(REDIS_STRING,NULL);
 
     di = dictGetIterator(c->db->dict);
-    if (!di) oom("dictGetIterator");
     addReply(c,lenobj);
     decrRefCount(lenobj);
     while((de = dictNext(di)) != NULL) {
@@ -2838,6 +3039,7 @@ static void typeCommand(redisClient *c) {
         case REDIS_STRING: type = "+string"; break;
         case REDIS_LIST: type = "+list"; break;
         case REDIS_SET: type = "+set"; break;
+        case REDIS_ZSET: type = "+zset"; break;
         default: type = "unknown"; break;
         }
     }
@@ -2989,9 +3191,9 @@ static void pushGenericCommand(redisClient *c, int where) {
         lobj = createListObject();
         list = lobj->ptr;
         if (where == REDIS_HEAD) {
-            if (!listAddNodeHead(list,c->argv[2])) oom("listAddNodeHead");
+            listAddNodeHead(list,c->argv[2]);
         } else {
-            if (!listAddNodeTail(list,c->argv[2])) oom("listAddNodeTail");
+            listAddNodeTail(list,c->argv[2]);
         }
         dictAdd(c->db->dict,c->argv[1],lobj);
         incrRefCount(c->argv[1]);
@@ -3003,9 +3205,9 @@ static void pushGenericCommand(redisClient *c, int where) {
         }
         list = lobj->ptr;
         if (where == REDIS_HEAD) {
-            if (!listAddNodeHead(list,c->argv[2])) oom("listAddNodeHead");
+            listAddNodeHead(list,c->argv[2]);
         } else {
-            if (!listAddNodeTail(list,c->argv[2])) oom("listAddNodeTail");
+            listAddNodeTail(list,c->argv[2]);
         }
         incrRefCount(c->argv[2]);
     }
@@ -3270,6 +3472,70 @@ static void lremCommand(redisClient *c) {
     }
 }
 
+/* This is the semantic of this command:
+ *  RPOPLPUSH srclist dstlist:
+ *   IF LLEN(srclist) > 0
+ *     element = RPOP srclist
+ *     LPUSH dstlist element
+ *     RETURN element
+ *   ELSE
+ *     RETURN nil
+ *   END
+ *  END
+ *
+ * The idea is to be able to get an element from a list in a reliable way
+ * since the element is not just returned but pushed against another list
+ * as well. This command was originally proposed by Ezra Zygmuntowicz.
+ */
+static void rpoplpushcommand(redisClient *c) {
+    robj *sobj;
+
+    sobj = lookupKeyWrite(c->db,c->argv[1]);
+    if (sobj == NULL) {
+        addReply(c,shared.nullbulk);
+    } else {
+        if (sobj->type != REDIS_LIST) {
+            addReply(c,shared.wrongtypeerr);
+        } else {
+            list *srclist = sobj->ptr;
+            listNode *ln = listLast(srclist);
+
+            if (ln == NULL) {
+                addReply(c,shared.nullbulk);
+            } else {
+                robj *dobj = lookupKeyWrite(c->db,c->argv[2]);
+                robj *ele = listNodeValue(ln);
+                list *dstlist;
+
+                if (dobj == NULL) {
+
+                    /* Create the list if the key does not exist */
+                    dobj = createListObject();
+                    dictAdd(c->db->dict,c->argv[2],dobj);
+                    incrRefCount(c->argv[2]);
+                } else if (dobj->type != REDIS_LIST) {
+                    addReply(c,shared.wrongtypeerr);
+                    return;
+                }
+                /* Add the element to the target list */
+                dstlist = dobj->ptr;
+                listAddNodeHead(dstlist,ele);
+                incrRefCount(ele);
+
+                /* Send the element to the client as reply as well */
+                addReplyBulkLen(c,ele);
+                addReply(c,ele);
+                addReply(c,shared.crlf);
+
+                /* Finally remove the element from the source list */
+                listDelNode(srclist,ln);
+                server.dirty++;
+            }
+        }
+    }
+}
+
+
 /* ==================================== Sets ================================ */
 
 static void saddCommand(redisClient *c) {
@@ -3454,7 +3720,6 @@ static void sinterGenericCommand(redisClient *c, robj **setskeys, int setsnum, r
     robj *lenobj = NULL, *dstset = NULL;
     int j, cardinality = 0;
 
-    if (!dv) oom("sinterGenericCommand");
     for (j = 0; j < setsnum; j++) {
         robj *setobj;
 
@@ -3501,7 +3766,6 @@ static void sinterGenericCommand(redisClient *c, robj **setskeys, int setsnum, r
      * the element against all the other sets, if at least one set does
      * not include the element it is discarded */
     di = dictGetIterator(dv[0]);
-    if (!di) oom("dictGetIterator");
 
     while((de = dictNext(di)) != NULL) {
         robj *ele;
@@ -3558,7 +3822,6 @@ static void sunionDiffGenericCommand(redisClient *c, robj **setskeys, int setsnu
     robj *dstset = NULL;
     int j, cardinality = 0;
 
-    if (!dv) oom("sunionDiffGenericCommand");
     for (j = 0; j < setsnum; j++) {
         robj *setobj;
 
@@ -3589,7 +3852,6 @@ static void sunionDiffGenericCommand(redisClient *c, robj **setskeys, int setsnu
         if (!dv[j]) continue; /* non existing keys are like empty sets */
 
         di = dictGetIterator(dv[j]);
-        if (!di) oom("dictGetIterator");
 
         while((de = dictNext(di)) != NULL) {
             robj *ele;
@@ -3616,7 +3878,6 @@ static void sunionDiffGenericCommand(redisClient *c, robj **setskeys, int setsnu
     if (!dstkey) {
         addReplySds(c,sdscatprintf(sdsempty(),"*%d\r\n",cardinality));
         di = dictGetIterator(dstset->ptr);
-        if (!di) oom("dictGetIterator");
         while((de = dictNext(di)) != NULL) {
             robj *ele;
 
@@ -3661,142 +3922,617 @@ static void sdiffstoreCommand(redisClient *c) {
     sunionDiffGenericCommand(c,c->argv+2,c->argc-2,c->argv[1],REDIS_OP_DIFF);
 }
 
-static void flushdbCommand(redisClient *c) {
-    server.dirty += dictSize(c->db->dict);
-    dictEmpty(c->db->dict);
-    dictEmpty(c->db->expires);
-    addReply(c,shared.ok);
-}
+/* ==================================== ZSets =============================== */
 
-static void flushallCommand(redisClient *c) {
-    server.dirty += emptyDb();
-    addReply(c,shared.ok);
-    rdbSave(server.dbfilename);
-    server.dirty++;
+/* ZSETs are ordered sets using two data structures to hold the same elements
+ * in order to get O(log(N)) INSERT and REMOVE operations into a sorted
+ * data structure.
+ *
+ * The elements are added to an hash table mapping Redis objects to scores.
+ * At the same time the elements are added to a skip list mapping scores
+ * to Redis objects (so objects are sorted by scores in this "view"). */
+
+/* This skiplist implementation is almost a C translation of the original
+ * algorithm described by William Pugh in "Skip Lists: A Probabilistic
+ * Alternative to Balanced Trees", modified in three ways:
+ * a) this implementation allows for repeated values.
+ * b) the comparison is not just by key (our 'score') but by satellite data.
+ * c) there is a back pointer, so it's a doubly linked list with the back
+ * pointers being only at "level 1". This allows to traverse the list
+ * from tail to head, useful for ZREVRANGE. */
+
+static zskiplistNode *zslCreateNode(int level, double score, robj *obj) {
+    zskiplistNode *zn = zmalloc(sizeof(*zn));
+
+    zn->forward = zmalloc(sizeof(zskiplistNode*) * level);
+    zn->score = score;
+    zn->obj = obj;
+    return zn;
 }
 
-static redisSortOperation *createSortOperation(int type, robj *pattern) {
-    redisSortOperation *so = zmalloc(sizeof(*so));
-    if (!so) oom("createSortOperation");
-    so->type = type;
-    so->pattern = pattern;
-    return so;
+static zskiplist *zslCreate(void) {
+    int j;
+    zskiplist *zsl;
+    
+    zsl = zmalloc(sizeof(*zsl));
+    zsl->level = 1;
+    zsl->length = 0;
+    zsl->header = zslCreateNode(ZSKIPLIST_MAXLEVEL,0,NULL);
+    for (j = 0; j < ZSKIPLIST_MAXLEVEL; j++)
+        zsl->header->forward[j] = NULL;
+    zsl->header->backward = NULL;
+    zsl->tail = NULL;
+    return zsl;
+}
+
+static void zslFreeNode(zskiplistNode *node) {
+    decrRefCount(node->obj);
+    zfree(node->forward);
+    zfree(node);
+}
+
+static void zslFree(zskiplist *zsl) {
+    zskiplistNode *node = zsl->header->forward[0], *next;
+
+    zfree(zsl->header->forward);
+    zfree(zsl->header);
+    while(node) {
+        next = node->forward[0];
+        zslFreeNode(node);
+        node = next;
+    }
+    zfree(zsl);
+}
+
+static int zslRandomLevel(void) {
+    int level = 1;
+    while ((random()&0xFFFF) < (ZSKIPLIST_P * 0xFFFF))
+        level += 1;
+    return level;
+}
+
+static void zslInsert(zskiplist *zsl, double score, robj *obj) {
+    zskiplistNode *update[ZSKIPLIST_MAXLEVEL], *x;
+    int i, level;
+
+    x = zsl->header;
+    for (i = zsl->level-1; i >= 0; i--) {
+        while (x->forward[i] &&
+            (x->forward[i]->score < score ||
+                (x->forward[i]->score == score &&
+                compareStringObjects(x->forward[i]->obj,obj) < 0)))
+            x = x->forward[i];
+        update[i] = x;
+    }
+    /* we assume the key is not already inside, since we allow duplicated
+     * scores, and the re-insertion of score and redis object should never
+     * happpen since the caller of zslInsert() should test in the hash table
+     * if the element is already inside or not. */
+    level = zslRandomLevel();
+    if (level > zsl->level) {
+        for (i = zsl->level; i < level; i++)
+            update[i] = zsl->header;
+        zsl->level = level;
+    }
+    x = zslCreateNode(level,score,obj);
+    for (i = 0; i < level; i++) {
+        x->forward[i] = update[i]->forward[i];
+        update[i]->forward[i] = x;
+    }
+    x->backward = (update[0] == zsl->header) ? NULL : update[0];
+    if (x->forward[0])
+        x->forward[0]->backward = x;
+    else
+        zsl->tail = x;
+    zsl->length++;
+}
+
+/* Delete an element with matching score/object from the skiplist. */
+static int zslDelete(zskiplist *zsl, double score, robj *obj) {
+    zskiplistNode *update[ZSKIPLIST_MAXLEVEL], *x;
+    int i;
+
+    x = zsl->header;
+    for (i = zsl->level-1; i >= 0; i--) {
+        while (x->forward[i] &&
+            (x->forward[i]->score < score ||
+                (x->forward[i]->score == score &&
+                compareStringObjects(x->forward[i]->obj,obj) < 0)))
+            x = x->forward[i];
+        update[i] = x;
+    }
+    /* We may have multiple elements with the same score, what we need
+     * is to find the element with both the right score and object. */
+    x = x->forward[0];
+    if (x && score == x->score && compareStringObjects(x->obj,obj) == 0) {
+        for (i = 0; i < zsl->level; i++) {
+            if (update[i]->forward[i] != x) break;
+            update[i]->forward[i] = x->forward[i];
+        }
+        if (x->forward[0]) {
+            x->forward[0]->backward = (x->backward == zsl->header) ?
+                                        NULL : x->backward;
+        } else {
+            zsl->tail = x->backward;
+        }
+        zslFreeNode(x);
+        while(zsl->level > 1 && zsl->header->forward[zsl->level-1] == NULL)
+            zsl->level--;
+        zsl->length--;
+        return 1;
+    } else {
+        return 0; /* not found */
+    }
+    return 0; /* not found */
+}
+
+/* Delete all the elements with score between min and max from the skiplist.
+ * Min and mx are inclusive, so a score >= min || score <= max is deleted.
+ * Note that this function takes the reference to the hash table view of the
+ * sorted set, in order to remove the elements from the hash table too. */
+static unsigned long zslDeleteRange(zskiplist *zsl, double min, double max, dict *dict) {
+    zskiplistNode *update[ZSKIPLIST_MAXLEVEL], *x;
+    unsigned long removed = 0;
+    int i;
+
+    x = zsl->header;
+    for (i = zsl->level-1; i >= 0; i--) {
+        while (x->forward[i] && x->forward[i]->score < min)
+            x = x->forward[i];
+        update[i] = x;
+    }
+    /* We may have multiple elements with the same score, what we need
+     * is to find the element with both the right score and object. */
+    x = x->forward[0];
+    while (x && x->score <= max) {
+        zskiplistNode *next;
+
+        for (i = 0; i < zsl->level; i++) {
+            if (update[i]->forward[i] != x) break;
+            update[i]->forward[i] = x->forward[i];
+        }
+        if (x->forward[0]) {
+            x->forward[0]->backward = (x->backward == zsl->header) ?
+                                        NULL : x->backward;
+        } else {
+            zsl->tail = x->backward;
+        }
+        next = x->forward[0];
+        dictDelete(dict,x->obj);
+        zslFreeNode(x);
+        while(zsl->level > 1 && zsl->header->forward[zsl->level-1] == NULL)
+            zsl->level--;
+        zsl->length--;
+        removed++;
+        x = next;
+    }
+    return removed; /* not found */
 }
 
-/* Return the value associated to the key with a name obtained
- * substituting the first occurence of '*' in 'pattern' with 'subst' */
-static robj *lookupKeyByPattern(redisDb *db, robj *pattern, robj *subst) {
-    char *p;
-    sds spat, ssub;
-    robj keyobj;
-    int prefixlen, sublen, postfixlen;
-    /* 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;
+/* Find the first node having a score equal or greater than the specified one.
+ * Returns NULL if there is no match. */
+static zskiplistNode *zslFirstWithScore(zskiplist *zsl, double score) {
+    zskiplistNode *x;
+    int i;
 
-    if (subst->encoding == REDIS_ENCODING_RAW)
-        incrRefCount(subst);
-    else {
-        subst = getDecodedObject(subst);
+    x = zsl->header;
+    for (i = zsl->level-1; i >= 0; i--) {
+        while (x->forward[i] && x->forward[i]->score < score)
+            x = x->forward[i];
     }
+    /* We may have multiple elements with the same score, what we need
+     * is to find the element with both the right score and object. */
+    return x->forward[0];
+}
 
-    spat = pattern->ptr;
-    ssub = subst->ptr;
-    if (sdslen(spat)+sdslen(ssub)-1 > REDIS_SORTKEY_MAX) return NULL;
-    p = strchr(spat,'*');
-    if (!p) return NULL;
+/* The actual Z-commands implementations */
 
-    prefixlen = p-spat;
-    sublen = sdslen(ssub);
-    postfixlen = sdslen(spat)-(prefixlen+1);
-    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;
+static void zaddCommand(redisClient *c) {
+    robj *zsetobj;
+    zset *zs;
+    double *score;
 
-    keyobj.refcount = 1;
-    keyobj.type = REDIS_STRING;
-    keyobj.ptr = ((char*)&keyname)+(sizeof(long)*2);
+    zsetobj = lookupKeyWrite(c->db,c->argv[1]);
+    if (zsetobj == NULL) {
+        zsetobj = createZsetObject();
+        dictAdd(c->db->dict,c->argv[1],zsetobj);
+        incrRefCount(c->argv[1]);
+    } else {
+        if (zsetobj->type != REDIS_ZSET) {
+            addReply(c,shared.wrongtypeerr);
+            return;
+        }
+    }
+    score = zmalloc(sizeof(double));
+    *score = strtod(c->argv[2]->ptr,NULL);
+    zs = zsetobj->ptr;
+    if (dictAdd(zs->dict,c->argv[3],score) == DICT_OK) {
+        /* case 1: New element */
+        incrRefCount(c->argv[3]); /* added to hash */
+        zslInsert(zs->zsl,*score,c->argv[3]);
+        incrRefCount(c->argv[3]); /* added to skiplist */
+        server.dirty++;
+        addReply(c,shared.cone);
+    } else {
+        dictEntry *de;
+        double *oldscore;
+        
+        /* case 2: Score update operation */
+        de = dictFind(zs->dict,c->argv[3]);
+        assert(de != NULL);
+        oldscore = dictGetEntryVal(de);
+        if (*score != *oldscore) {
+            int deleted;
+
+            deleted = zslDelete(zs->zsl,*oldscore,c->argv[3]);
+            assert(deleted != 0);
+            zslInsert(zs->zsl,*score,c->argv[3]);
+            incrRefCount(c->argv[3]);
+            dictReplace(zs->dict,c->argv[3],score);
+            server.dirty++;
+        } else {
+            zfree(score);
+        }
+        addReply(c,shared.czero);
+    }
+}
 
-    decrRefCount(subst);
+static void zremCommand(redisClient *c) {
+    robj *zsetobj;
+    zset *zs;
 
-    /* printf("lookup '%s' => %p\n", keyname.buf,de); */
-    return lookupKeyRead(db,&keyobj);
+    zsetobj = lookupKeyWrite(c->db,c->argv[1]);
+    if (zsetobj == NULL) {
+        addReply(c,shared.czero);
+    } else {
+        dictEntry *de;
+        double *oldscore;
+        int deleted;
+
+        if (zsetobj->type != REDIS_ZSET) {
+            addReply(c,shared.wrongtypeerr);
+            return;
+        }
+        zs = zsetobj->ptr;
+        de = dictFind(zs->dict,c->argv[2]);
+        if (de == NULL) {
+            addReply(c,shared.czero);
+            return;
+        }
+        /* Delete from the skiplist */
+        oldscore = dictGetEntryVal(de);
+        deleted = zslDelete(zs->zsl,*oldscore,c->argv[2]);
+        assert(deleted != 0);
+
+        /* Delete from the hash table */
+        dictDelete(zs->dict,c->argv[2]);
+        if (htNeedsResize(zs->dict)) dictResize(zs->dict);
+        server.dirty++;
+        addReply(c,shared.cone);
+    }
 }
 
-/* sortCompare() is used by qsort in sortCommand(). Given that qsort_r with
- * the additional parameter is not standard but a BSD-specific we have to
- * pass sorting parameters via the global 'server' structure */
-static int sortCompare(const void *s1, const void *s2) {
-    const redisSortObject *so1 = s1, *so2 = s2;
-    int cmp;
+static void zremrangebyscoreCommand(redisClient *c) {
+    double min = strtod(c->argv[2]->ptr,NULL);
+    double max = strtod(c->argv[3]->ptr,NULL);
+    robj *zsetobj;
+    zset *zs;
 
-    if (!server.sort_alpha) {
-        /* Numeric sorting. Here it's trivial as we precomputed scores */
-        if (so1->u.score > so2->u.score) {
-            cmp = 1;
-        } else if (so1->u.score < so2->u.score) {
-            cmp = -1;
-        } else {
-            cmp = 0;
-        }
+    zsetobj = lookupKeyWrite(c->db,c->argv[1]);
+    if (zsetobj == NULL) {
+        addReply(c,shared.czero);
     } else {
-        /* Alphanumeric sorting */
-        if (server.sort_bypattern) {
-            if (!so1->u.cmpobj || !so2->u.cmpobj) {
-                /* At least one compare object is NULL */
-                if (so1->u.cmpobj == so2->u.cmpobj)
-                    cmp = 0;
-                else if (so1->u.cmpobj == NULL)
-                    cmp = -1;
-                else
-                    cmp = 1;
-            } else {
-                /* We have both the objects, use strcoll */
-                cmp = strcoll(so1->u.cmpobj->ptr,so2->u.cmpobj->ptr);
-            }
-        } else {
-            /* Compare elements directly */
-            if (so1->obj->encoding == REDIS_ENCODING_RAW &&
-                so2->obj->encoding == REDIS_ENCODING_RAW) {
-                cmp = strcoll(so1->obj->ptr,so2->obj->ptr);
-            } else {
-                robj *dec1, *dec2;
+        long deleted;
 
-                dec1 = so1->obj->encoding == REDIS_ENCODING_RAW ?
-                    so1->obj : getDecodedObject(so1->obj);
-                dec2 = so2->obj->encoding == REDIS_ENCODING_RAW ?
-                    so2->obj : getDecodedObject(so2->obj);
-                cmp = strcoll(dec1->ptr,dec2->ptr);
-                if (dec1 != so1->obj) decrRefCount(dec1);
-                if (dec2 != so2->obj) decrRefCount(dec2);
-            }
+        if (zsetobj->type != REDIS_ZSET) {
+            addReply(c,shared.wrongtypeerr);
+            return;
         }
+        zs = zsetobj->ptr;
+        deleted = zslDeleteRange(zs->zsl,min,max,zs->dict);
+        if (htNeedsResize(zs->dict)) dictResize(zs->dict);
+        server.dirty += deleted;
+        addReplySds(c,sdscatprintf(sdsempty(),":%lu\r\n",deleted));
     }
-    return server.sort_desc ? -cmp : cmp;
 }
 
-/* The SORT command is the most complex command in Redis. Warning: this code
- * is optimized for speed and a bit less for readability */
-static void sortCommand(redisClient *c) {
-    list *operations;
-    int outputlen = 0;
-    int desc = 0, alpha = 0;
-    int limit_start = 0, limit_count = -1, start, end;
-    int j, dontsort = 0, vectorlen;
-    int getop = 0; /* GET operation counter */
-    robj *sortval, *sortby = NULL;
-    redisSortObject *vector; /* Resulting vector to sort */
+static void zrangeGenericCommand(redisClient *c, int reverse) {
+    robj *o;
+    int start = atoi(c->argv[2]->ptr);
+    int end = atoi(c->argv[3]->ptr);
 
-    /* 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.nokeyerr);
-        return;
+    o = lookupKeyRead(c->db,c->argv[1]);
+    if (o == NULL) {
+        addReply(c,shared.nullmultibulk);
+    } else {
+        if (o->type != REDIS_ZSET) {
+            addReply(c,shared.wrongtypeerr);
+        } else {
+            zset *zsetobj = o->ptr;
+            zskiplist *zsl = zsetobj->zsl;
+            zskiplistNode *ln;
+
+            int llen = zsl->length;
+            int rangelen, j;
+            robj *ele;
+
+            /* convert negative indexes */
+            if (start < 0) start = llen+start;
+            if (end < 0) end = llen+end;
+            if (start < 0) start = 0;
+            if (end < 0) end = 0;
+
+            /* indexes sanity checks */
+            if (start > end || start >= llen) {
+                /* Out of range start or start > end result in empty list */
+                addReply(c,shared.emptymultibulk);
+                return;
+            }
+            if (end >= llen) end = llen-1;
+            rangelen = (end-start)+1;
+
+            /* Return the result in form of a multi-bulk reply */
+            if (reverse) {
+                ln = zsl->tail;
+                while (start--)
+                    ln = ln->backward;
+            } else {
+                ln = zsl->header->forward[0];
+                while (start--)
+                    ln = ln->forward[0];
+            }
+
+            addReplySds(c,sdscatprintf(sdsempty(),"*%d\r\n",rangelen));
+            for (j = 0; j < rangelen; j++) {
+                ele = ln->obj;
+                addReplyBulkLen(c,ele);
+                addReply(c,ele);
+                addReply(c,shared.crlf);
+                ln = reverse ? ln->backward : ln->forward[0];
+            }
+        }
+    }
+}
+
+static void zrangeCommand(redisClient *c) {
+    zrangeGenericCommand(c,0);
+}
+
+static void zrevrangeCommand(redisClient *c) {
+    zrangeGenericCommand(c,1);
+}
+
+static void zrangebyscoreCommand(redisClient *c) {
+    robj *o;
+    double min = strtod(c->argv[2]->ptr,NULL);
+    double max = strtod(c->argv[3]->ptr,NULL);
+
+    o = lookupKeyRead(c->db,c->argv[1]);
+    if (o == NULL) {
+        addReply(c,shared.nullmultibulk);
+    } else {
+        if (o->type != REDIS_ZSET) {
+            addReply(c,shared.wrongtypeerr);
+        } else {
+            zset *zsetobj = o->ptr;
+            zskiplist *zsl = zsetobj->zsl;
+            zskiplistNode *ln;
+            robj *ele, *lenobj;
+            unsigned int rangelen = 0;
+
+            /* Get the first node with the score >= min */
+            ln = zslFirstWithScore(zsl,min);
+            if (ln == NULL) {
+                /* No element matching the speciifed interval */
+                addReply(c,shared.emptymultibulk);
+                return;
+            }
+
+            /* We don't know in advance how many matching elements there
+             * are in the list, so we push this object that will represent
+             * the multi-bulk length in the output buffer, and will "fix"
+             * it later */
+            lenobj = createObject(REDIS_STRING,NULL);
+            addReply(c,lenobj);
+
+            while(ln && ln->score <= max) {
+                ele = ln->obj;
+                addReplyBulkLen(c,ele);
+                addReply(c,ele);
+                addReply(c,shared.crlf);
+                ln = ln->forward[0];
+                rangelen++;
+            }
+            lenobj->ptr = sdscatprintf(sdsempty(),"*%d\r\n",rangelen);
+        }
+    }
+}
+
+static void zcardCommand(redisClient *c) {
+    robj *o;
+    zset *zs;
+    
+    o = lookupKeyRead(c->db,c->argv[1]);
+    if (o == NULL) {
+        addReply(c,shared.czero);
+        return;
+    } else {
+        if (o->type != REDIS_ZSET) {
+            addReply(c,shared.wrongtypeerr);
+        } else {
+            zs = o->ptr;
+            addReplySds(c,sdscatprintf(sdsempty(),":%d\r\n",zs->zsl->length));
+        }
+    }
+}
+
+static void zscoreCommand(redisClient *c) {
+    robj *o;
+    zset *zs;
+    
+    o = lookupKeyRead(c->db,c->argv[1]);
+    if (o == NULL) {
+        addReply(c,shared.nullbulk);
+        return;
+    } else {
+        if (o->type != REDIS_ZSET) {
+            addReply(c,shared.wrongtypeerr);
+        } else {
+            dictEntry *de;
+
+            zs = o->ptr;
+            de = dictFind(zs->dict,c->argv[2]);
+            if (!de) {
+                addReply(c,shared.nullbulk);
+            } else {
+                char buf[128];
+                double *score = dictGetEntryVal(de);
+
+                snprintf(buf,sizeof(buf),"%.17g",*score);
+                addReplySds(c,sdscatprintf(sdsempty(),"$%d\r\n%s\r\n",
+                    strlen(buf),buf));
+            }
+        }
+    }
+}
+
+/* ========================= Non type-specific commands  ==================== */
+
+static void flushdbCommand(redisClient *c) {
+    server.dirty += dictSize(c->db->dict);
+    dictEmpty(c->db->dict);
+    dictEmpty(c->db->expires);
+    addReply(c,shared.ok);
+}
+
+static void flushallCommand(redisClient *c) {
+    server.dirty += emptyDb();
+    addReply(c,shared.ok);
+    rdbSave(server.dbfilename);
+    server.dirty++;
+}
+
+static redisSortOperation *createSortOperation(int type, robj *pattern) {
+    redisSortOperation *so = zmalloc(sizeof(*so));
+    so->type = type;
+    so->pattern = pattern;
+    return so;
+}
+
+/* Return the value associated to the key with a name obtained
+ * substituting the first occurence of '*' in 'pattern' with 'subst' */
+static robj *lookupKeyByPattern(redisDb *db, robj *pattern, robj *subst) {
+    char *p;
+    sds spat, ssub;
+    robj keyobj;
+    int prefixlen, sublen, postfixlen;
+    /* 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;
+
+    if (subst->encoding == REDIS_ENCODING_RAW)
+        incrRefCount(subst);
+    else {
+        subst = getDecodedObject(subst);
+    }
+
+    spat = pattern->ptr;
+    ssub = subst->ptr;
+    if (sdslen(spat)+sdslen(ssub)-1 > REDIS_SORTKEY_MAX) return NULL;
+    p = strchr(spat,'*');
+    if (!p) return NULL;
+
+    prefixlen = p-spat;
+    sublen = sdslen(ssub);
+    postfixlen = sdslen(spat)-(prefixlen+1);
+    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;
+
+    keyobj.refcount = 1;
+    keyobj.type = REDIS_STRING;
+    keyobj.ptr = ((char*)&keyname)+(sizeof(long)*2);
+
+    decrRefCount(subst);
+
+    /* printf("lookup '%s' => %p\n", keyname.buf,de); */
+    return lookupKeyRead(db,&keyobj);
+}
+
+/* sortCompare() is used by qsort in sortCommand(). Given that qsort_r with
+ * the additional parameter is not standard but a BSD-specific we have to
+ * pass sorting parameters via the global 'server' structure */
+static int sortCompare(const void *s1, const void *s2) {
+    const redisSortObject *so1 = s1, *so2 = s2;
+    int cmp;
+
+    if (!server.sort_alpha) {
+        /* Numeric sorting. Here it's trivial as we precomputed scores */
+        if (so1->u.score > so2->u.score) {
+            cmp = 1;
+        } else if (so1->u.score < so2->u.score) {
+            cmp = -1;
+        } else {
+            cmp = 0;
+        }
+    } else {
+        /* Alphanumeric sorting */
+        if (server.sort_bypattern) {
+            if (!so1->u.cmpobj || !so2->u.cmpobj) {
+                /* At least one compare object is NULL */
+                if (so1->u.cmpobj == so2->u.cmpobj)
+                    cmp = 0;
+                else if (so1->u.cmpobj == NULL)
+                    cmp = -1;
+                else
+                    cmp = 1;
+            } else {
+                /* We have both the objects, use strcoll */
+                cmp = strcoll(so1->u.cmpobj->ptr,so2->u.cmpobj->ptr);
+            }
+        } else {
+            /* Compare elements directly */
+            if (so1->obj->encoding == REDIS_ENCODING_RAW &&
+                so2->obj->encoding == REDIS_ENCODING_RAW) {
+                cmp = strcoll(so1->obj->ptr,so2->obj->ptr);
+            } else {
+                robj *dec1, *dec2;
+
+                dec1 = so1->obj->encoding == REDIS_ENCODING_RAW ?
+                    so1->obj : getDecodedObject(so1->obj);
+                dec2 = so2->obj->encoding == REDIS_ENCODING_RAW ?
+                    so2->obj : getDecodedObject(so2->obj);
+                cmp = strcoll(dec1->ptr,dec2->ptr);
+                if (dec1 != so1->obj) decrRefCount(dec1);
+                if (dec2 != so2->obj) decrRefCount(dec2);
+            }
+        }
+    }
+    return server.sort_desc ? -cmp : cmp;
+}
+
+/* The SORT command is the most complex command in Redis. Warning: this code
+ * is optimized for speed and a bit less for readability */
+static void sortCommand(redisClient *c) {
+    list *operations;
+    int outputlen = 0;
+    int desc = 0, alpha = 0;
+    int limit_start = 0, limit_count = -1, start, end;
+    int j, dontsort = 0, vectorlen;
+    int getop = 0; /* GET operation counter */
+    robj *sortval, *sortby = NULL, *storekey = NULL;
+    redisSortObject *vector; /* Resulting vector to sort */
+
+    /* 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.nokeyerr);
+        return;
     }
     if (sortval->type != REDIS_SET && sortval->type != REDIS_LIST) {
         addReply(c,shared.wrongtypeerr);
@@ -3827,6 +4563,9 @@ static void sortCommand(redisClient *c) {
             limit_start = atoi(c->argv[j+1]->ptr);
             limit_count = atoi(c->argv[j+2]->ptr);
             j+=2;
+        } else if (!strcasecmp(c->argv[j]->ptr,"store") && leftargs >= 1) {
+            storekey = c->argv[j+1];
+            j++;
         } else if (!strcasecmp(c->argv[j]->ptr,"by") && leftargs >= 1) {
             sortby = c->argv[j+1];
             /* If the BY pattern does not contain '*', i.e. it is constant,
@@ -3838,18 +4577,6 @@ static void sortCommand(redisClient *c) {
                 REDIS_SORT_GET,c->argv[j+1]));
             getop++;
             j++;
-        } else if (!strcasecmp(c->argv[j]->ptr,"del") && leftargs >= 1) {
-            listAddNodeTail(operations,createSortOperation(
-                REDIS_SORT_DEL,c->argv[j+1]));
-            j++;
-        } else if (!strcasecmp(c->argv[j]->ptr,"incr") && leftargs >= 1) {
-            listAddNodeTail(operations,createSortOperation(
-                REDIS_SORT_INCR,c->argv[j+1]));
-            j++;
-        } else if (!strcasecmp(c->argv[j]->ptr,"get") && leftargs >= 1) {
-            listAddNodeTail(operations,createSortOperation(
-                REDIS_SORT_DECR,c->argv[j+1]));
-            j++;
         } else {
             decrRefCount(sortval);
             listRelease(operations);
@@ -3864,7 +4591,6 @@ static void sortCommand(redisClient *c) {
         listLength((list*)sortval->ptr) :
         dictSize((dict*)sortval->ptr);
     vector = zmalloc(sizeof(redisSortObject)*vectorlen);
-    if (!vector) oom("allocating objects vector for SORT");
     j = 0;
     if (sortval->type == REDIS_LIST) {
         list *list = sortval->ptr;
@@ -3884,7 +4610,6 @@ static void sortCommand(redisClient *c) {
         dictEntry *setele;
 
         di = dictGetIterator(set);
-        if (!di) oom("dictGetIterator");
         while((setele = dictNext(di)) != NULL) {
             vector[j].obj = dictGetEntryKey(setele);
             vector[j].u.score = 0;
@@ -3958,32 +4683,72 @@ static void sortCommand(redisClient *c) {
     /* Send command output to the output buffer, performing the specified
      * GET/DEL/INCR/DECR operations if any. */
     outputlen = getop ? getop*(end-start+1) : end-start+1;
-    addReplySds(c,sdscatprintf(sdsempty(),"*%d\r\n",outputlen));
-    for (j = start; j <= end; j++) {
-        listNode *ln;
-        if (!getop) {
-            addReplyBulkLen(c,vector[j].obj);
-            addReply(c,vector[j].obj);
-            addReply(c,shared.crlf);
+    if (storekey == NULL) {
+        /* STORE option not specified, sent the sorting result to client */
+        addReplySds(c,sdscatprintf(sdsempty(),"*%d\r\n",outputlen));
+        for (j = start; j <= end; j++) {
+            listNode *ln;
+            if (!getop) {
+                addReplyBulkLen(c,vector[j].obj);
+                addReply(c,vector[j].obj);
+                addReply(c,shared.crlf);
+            }
+            listRewind(operations);
+            while((ln = listYield(operations))) {
+                redisSortOperation *sop = ln->value;
+                robj *val = lookupKeyByPattern(c->db,sop->pattern,
+                    vector[j].obj);
+
+                if (sop->type == REDIS_SORT_GET) {
+                    if (!val || val->type != REDIS_STRING) {
+                        addReply(c,shared.nullbulk);
+                    } else {
+                        addReplyBulkLen(c,val);
+                        addReply(c,val);
+                        addReply(c,shared.crlf);
+                    }
+                } else {
+                    assert(sop->type == REDIS_SORT_GET); /* always fails */
+                }
+            }
         }
-        listRewind(operations);
-        while((ln = listYield(operations))) {
-            redisSortOperation *sop = ln->value;
-            robj *val = lookupKeyByPattern(c->db,sop->pattern,
-                vector[j].obj);
+    } else {
+        robj *listObject = createListObject();
+        list *listPtr = (list*) listObject->ptr;
 
-            if (sop->type == REDIS_SORT_GET) {
-                if (!val || val->type != REDIS_STRING) {
-                    addReply(c,shared.nullbulk);
+        /* STORE option specified, set the sorting result as a List object */
+        for (j = start; j <= end; j++) {
+            listNode *ln;
+            if (!getop) {
+                listAddNodeTail(listPtr,vector[j].obj);
+                incrRefCount(vector[j].obj);
+            }
+            listRewind(operations);
+            while((ln = listYield(operations))) {
+                redisSortOperation *sop = ln->value;
+                robj *val = lookupKeyByPattern(c->db,sop->pattern,
+                    vector[j].obj);
+
+                if (sop->type == REDIS_SORT_GET) {
+                    if (!val || val->type != REDIS_STRING) {
+                        listAddNodeTail(listPtr,createStringObject("",0));
+                    } else {
+                        listAddNodeTail(listPtr,val);
+                        incrRefCount(val);
+                    }
                 } else {
-                    addReplyBulkLen(c,val);
-                    addReply(c,val);
-                    addReply(c,shared.crlf);
+                    assert(sop->type == REDIS_SORT_GET); /* always fails */
                 }
-            } else if (sop->type == REDIS_SORT_DEL) {
-                /* TODO */
             }
         }
+        if (dictReplace(c->db->dict,storekey,listObject)) {
+            incrRefCount(storekey);
+        }
+        /* Note: we add 1 because the DB is dirty anyway since even if the
+         * SORT result is empty a new key is set and maybe the old content
+         * replaced. */
+        server.dirty += 1+outputlen;
+        addReplySds(c,sdscatprintf(sdsempty(),":%d\r\n",outputlen));
     }
 
     /* Cleanup */
@@ -4039,7 +4804,7 @@ static void infoCommand(redisClient *c) {
             server.masterport,
             (server.replstate == REDIS_REPL_CONNECTED) ?
                 "up" : "down",
-            (int)(time(NULL)-server.master->lastinteraction)
+            server.master ? ((int)(time(NULL)-server.master->lastinteraction)) : -1
         );
     }
     for (j = 0; j < server.dbnum; j++) {
@@ -4063,7 +4828,7 @@ static void monitorCommand(redisClient *c) {
 
     c->flags |= (REDIS_SLAVE|REDIS_MONITOR);
     c->slaveseldb = 0;
-    if (!listAddNodeTail(server.monitors,c)) oom("listAddNodeTail");
+    listAddNodeTail(server.monitors,c);
     addReply(c,shared.ok);
 }
 
@@ -4127,21 +4892,21 @@ static int deleteIfVolatile(redisDb *db, robj *key) {
     return dictDelete(db->dict,key) == DICT_OK;
 }
 
-static void expireCommand(redisClient *c) {
+static void expireGenericCommand(redisClient *c, robj *key, time_t seconds) {
     dictEntry *de;
-    int seconds = atoi(c->argv[2]->ptr);
 
-    de = dictFind(c->db->dict,c->argv[1]);
+    de = dictFind(c->db->dict,key);
     if (de == NULL) {
         addReply(c,shared.czero);
         return;
     }
-    if (seconds <= 0) {
-        addReply(c, shared.czero);
+    if (seconds < 0) {
+        if (deleteKey(c->db,key)) server.dirty++;
+        addReply(c, shared.cone);
         return;
     } else {
         time_t when = time(NULL)+seconds;
-        if (setExpire(c->db,c->argv[1],when)) {
+        if (setExpire(c->db,key,when)) {
             addReply(c,shared.cone);
             server.dirty++;
         } else {
@@ -4151,6 +4916,14 @@ static void expireCommand(redisClient *c) {
     }
 }
 
+static void expireCommand(redisClient *c) {
+    expireGenericCommand(c,c->argv[1],strtol(c->argv[2]->ptr,NULL,10));
+}
+
+static void expireatCommand(redisClient *c) {
+    expireGenericCommand(c,c->argv[1],strtol(c->argv[2]->ptr,NULL,10)-time(NULL));
+}
+
 static void ttlCommand(redisClient *c) {
     time_t expire;
     int ttl = -1;
@@ -4303,7 +5076,6 @@ static void syncCommand(redisClient *c) {
              * another slave. Set the right state, and copy the buffer. */
             listRelease(c->reply);
             c->reply = listDup(slave->reply);
-            if (!c->reply) oom("listDup copying slave reply list");
             c->replstate = REDIS_REPL_WAIT_BGSAVE_END;
             redisLog(REDIS_NOTICE,"Waiting for end of BGSAVE for SYNC");
         } else {
@@ -4325,7 +5097,7 @@ static void syncCommand(redisClient *c) {
     c->repldbfd = -1;
     c->flags |= REDIS_SLAVE;
     c->slaveseldb = 0;
-    if (!listAddNodeTail(server.slaves,c)) oom("listAddNodeTail");
+    listAddNodeTail(server.slaves,c);
     return;
 }
 
@@ -4439,7 +5211,7 @@ static void updateSlavesWaitingBgsave(int bgsaveerr) {
 }
 
 static int syncWithMaster(void) {
-    char buf[1024], tmpfile[256];
+    char buf[1024], tmpfile[256], authcmd[1024];
     int dumpsize;
     int fd = anetTcpConnect(NULL,server.masterhost,server.masterport);
     int dfd;
@@ -4449,6 +5221,30 @@ static int syncWithMaster(void) {
             strerror(errno));
         return REDIS_ERR;
     }
+
+    /* AUTH with the master if required. */
+    if(server.masterauth) {
+    	snprintf(authcmd, 1024, "AUTH %s\r\n", server.masterauth);
+    	if (syncWrite(fd, authcmd, strlen(server.masterauth)+7, 5) == -1) {
+            close(fd);
+            redisLog(REDIS_WARNING,"Unable to AUTH to MASTER: %s",
+                strerror(errno));
+            return REDIS_ERR;
+    	}
+        /* Read the AUTH result.  */
+        if (syncReadLine(fd,buf,1024,3600) == -1) {
+            close(fd);
+            redisLog(REDIS_WARNING,"I/O error reading auth result from MASTER: %s",
+                strerror(errno));
+            return REDIS_ERR;
+        }
+        if (buf[0] != '+') {
+            close(fd);
+            redisLog(REDIS_WARNING,"Cannot AUTH to MASTER, is the masterauth password correct?");
+            return REDIS_ERR;
+        }
+    }
+
     /* Issue the SYNC command */
     if (syncWrite(fd,"SYNC \r\n",7,5) == -1) {
         close(fd);
@@ -4463,6 +5259,11 @@ static int syncWithMaster(void) {
             strerror(errno));
         return REDIS_ERR;
     }
+    if (buf[0] != '$') {
+        close(fd);
+        redisLog(REDIS_WARNING,"Bad protocol from MASTER, the first byte is not '$', are you sure the host and port are right?");
+        return REDIS_ERR;
+    }
     dumpsize = atoi(buf+1);
     redisLog(REDIS_NOTICE,"Receiving %d bytes data dump from MASTER",dumpsize);
     /* Read the bulk write data on a temp file */
@@ -4586,6 +5387,198 @@ static void freeMemoryIfNeeded(void) {
     }
 }
 
+/* ============================== Append Only file ========================== */
+
+static void feedAppendOnlyFile(struct redisCommand *cmd, int dictid, robj **argv, int argc) {
+    sds buf = sdsempty();
+    int j;
+    ssize_t nwritten;
+    time_t now;
+    robj *tmpargv[3];
+
+    /* The DB this command was targetting is not the same as the last command
+     * we appendend. To issue a SELECT command is needed. */
+    if (dictid != server.appendseldb) {
+        char seldb[64];
+
+        snprintf(seldb,sizeof(seldb),"%d",dictid);
+        buf = sdscatprintf(buf,"*2\r\n$6\r\nSELECT\r\n$%d\r\n%s\r\n",
+            strlen(seldb),seldb);
+        server.appendseldb = dictid;
+    }
+
+    /* "Fix" the argv vector if the command is EXPIRE. We want to translate
+     * EXPIREs into EXPIREATs calls */
+    if (cmd->proc == expireCommand) {
+        long when;
+
+        tmpargv[0] = createStringObject("EXPIREAT",8);
+        tmpargv[1] = argv[1];
+        incrRefCount(argv[1]);
+        when = time(NULL)+strtol(argv[2]->ptr,NULL,10);
+        tmpargv[2] = createObject(REDIS_STRING,
+            sdscatprintf(sdsempty(),"%ld",when));
+        argv = tmpargv;
+    }
+
+    /* Append the actual command */
+    buf = sdscatprintf(buf,"*%d\r\n",argc);
+    for (j = 0; j < argc; j++) {
+        robj *o = argv[j];
+
+        if (o->encoding != REDIS_ENCODING_RAW)
+            o = getDecodedObject(o);
+        buf = sdscatprintf(buf,"$%d\r\n",sdslen(o->ptr));
+        buf = sdscatlen(buf,o->ptr,sdslen(o->ptr));
+        buf = sdscatlen(buf,"\r\n",2);
+        if (o != argv[j])
+            decrRefCount(o);
+    }
+
+    /* Free the objects from the modified argv for EXPIREAT */
+    if (cmd->proc == expireCommand) {
+        for (j = 0; j < 3; j++)
+            decrRefCount(argv[j]);
+    }
+
+    /* We want to perform a single write. This should be guaranteed atomic
+     * at least if the filesystem we are writing is a real physical one.
+     * While this will save us against the server being killed I don't think
+     * there is much to do about the whole server stopping for power problems
+     * or alike */
+     nwritten = write(server.appendfd,buf,sdslen(buf));
+     if (nwritten != (signed)sdslen(buf)) {
+        /* Ooops, we are in troubles. The best thing to do for now is
+         * to simply exit instead to give the illusion that everything is
+         * working as expected. */
+         if (nwritten == -1) {
+            redisLog(REDIS_WARNING,"Exiting on error writing to the append-only file: %s",strerror(errno));
+         } else {
+            redisLog(REDIS_WARNING,"Exiting on short write while writing to the append-only file: %s",strerror(errno));
+         }
+         exit(1);
+    }
+    now = time(NULL);
+    if (server.appendfsync == APPENDFSYNC_ALWAYS ||
+        (server.appendfsync == APPENDFSYNC_EVERYSEC &&
+         now-server.lastfsync > 1))
+    {
+        fsync(server.appendfd); /* Let's try to get this data on the disk */
+        server.lastfsync = now;
+    }
+}
+
+/* In Redis commands are always executed in the context of a client, so in
+ * order to load the append only file we need to create a fake client. */
+static struct redisClient *createFakeClient(void) {
+    struct redisClient *c = zmalloc(sizeof(*c));
+
+    selectDb(c,0);
+    c->fd = -1;
+    c->querybuf = sdsempty();
+    c->argc = 0;
+    c->argv = NULL;
+    c->flags = 0;
+    /* We set the fake client as a slave waiting for the synchronization
+     * so that Redis will not try to send replies to this client. */
+    c->replstate = REDIS_REPL_WAIT_BGSAVE_START;
+    c->reply = listCreate();
+    listSetFreeMethod(c->reply,decrRefCount);
+    listSetDupMethod(c->reply,dupClientReplyValue);
+    return c;
+}
+
+static void freeFakeClient(struct redisClient *c) {
+    sdsfree(c->querybuf);
+    listRelease(c->reply);
+    zfree(c);
+}
+
+/* Replay the append log file. On error REDIS_OK is returned. On non fatal
+ * error (the append only file is zero-length) REDIS_ERR is returned. On
+ * fatal error an error message is logged and the program exists. */
+int loadAppendOnlyFile(char *filename) {
+    struct redisClient *fakeClient;
+    FILE *fp = fopen(filename,"r");
+    struct redis_stat sb;
+
+    if (redis_fstat(fileno(fp),&sb) != -1 && sb.st_size == 0)
+        return REDIS_ERR;
+
+    if (fp == NULL) {
+        redisLog(REDIS_WARNING,"Fatal error: can't open the append log file for reading: %s",strerror(errno));
+        exit(1);
+    }
+
+    fakeClient = createFakeClient();
+    while(1) {
+        int argc, j;
+        unsigned long len;
+        robj **argv;
+        char buf[128];
+        sds argsds;
+        struct redisCommand *cmd;
+
+        if (fgets(buf,sizeof(buf),fp) == NULL) {
+            if (feof(fp))
+                break;
+            else
+                goto readerr;
+        }
+        if (buf[0] != '*') goto fmterr;
+        argc = atoi(buf+1);
+        argv = zmalloc(sizeof(robj*)*argc);
+        for (j = 0; j < argc; j++) {
+            if (fgets(buf,sizeof(buf),fp) == NULL) goto readerr;
+            if (buf[0] != '$') goto fmterr;
+            len = strtol(buf+1,NULL,10);
+            argsds = sdsnewlen(NULL,len);
+            if (fread(argsds,len,1,fp) == 0) goto fmterr;
+            argv[j] = createObject(REDIS_STRING,argsds);
+            if (fread(buf,2,1,fp) == 0) goto fmterr; /* discard CRLF */
+        }
+
+        /* Command lookup */
+        cmd = lookupCommand(argv[0]->ptr);
+        if (!cmd) {
+            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]);
+        }
+        if (cmd->flags & REDIS_CMD_BULK)
+            tryObjectEncoding(argv[argc-1]);
+        /* Run the command in the context of a fake client */
+        fakeClient->argc = argc;
+        fakeClient->argv = argv;
+        cmd->proc(fakeClient);
+        /* Discard the reply objects list from the fake client */
+        while(listLength(fakeClient->reply))
+            listDelNode(fakeClient->reply,listFirst(fakeClient->reply));
+        /* Clean up, ready for the next command */
+        for (j = 0; j < argc; j++) decrRefCount(argv[j]);
+        zfree(argv);
+    }
+    fclose(fp);
+    freeFakeClient(fakeClient);
+    return REDIS_OK;
+
+readerr:
+    if (feof(fp)) {
+        redisLog(REDIS_WARNING,"Unexpected end of file reading the append only file");
+    } else {
+        redisLog(REDIS_WARNING,"Unrecoverable error reading the append only file: %s", strerror(errno));
+    }
+    exit(1);
+fmterr:
+    redisLog(REDIS_WARNING,"Bad file format reading the append only file");
+    exit(1);
+}
+
 /* ================================= Debugging ============================== */
 
 static void debugCommand(redisClient *c) {
@@ -4610,132 +5603,90 @@ static void debugCommand(redisClient *c) {
     }
 }
 
-#ifdef HAVE_BACKTRACE
-static struct redisFunctionSym symsTable[] = {
-{"compareStringObjects", (unsigned long)compareStringObjects},
-{"isStringRepresentableAsLong", (unsigned long)isStringRepresentableAsLong},
-{"dictEncObjKeyCompare", (unsigned long)dictEncObjKeyCompare},
-{"dictEncObjHash", (unsigned long)dictEncObjHash},
-{"incrDecrCommand", (unsigned long)incrDecrCommand},
-{"freeStringObject", (unsigned long)freeStringObject},
-{"freeListObject", (unsigned long)freeListObject},
-{"freeSetObject", (unsigned long)freeSetObject},
-{"decrRefCount", (unsigned long)decrRefCount},
-{"createObject", (unsigned long)createObject},
-{"freeClient", (unsigned long)freeClient},
-{"rdbLoad", (unsigned long)rdbLoad},
-{"rdbSaveStringObject", (unsigned long)rdbSaveStringObject},
-{"rdbSaveStringObjectRaw", (unsigned long)rdbSaveStringObjectRaw},
-{"addReply", (unsigned long)addReply},
-{"addReplySds", (unsigned long)addReplySds},
-{"incrRefCount", (unsigned long)incrRefCount},
-{"rdbSaveBackground", (unsigned long)rdbSaveBackground},
-{"createStringObject", (unsigned long)createStringObject},
-{"replicationFeedSlaves", (unsigned long)replicationFeedSlaves},
-{"syncWithMaster", (unsigned long)syncWithMaster},
-{"tryObjectSharing", (unsigned long)tryObjectSharing},
-{"tryObjectEncoding", (unsigned long)tryObjectEncoding},
-{"getDecodedObject", (unsigned long)getDecodedObject},
-{"removeExpire", (unsigned long)removeExpire},
-{"expireIfNeeded", (unsigned long)expireIfNeeded},
-{"deleteIfVolatile", (unsigned long)deleteIfVolatile},
-{"deleteKey", (unsigned long)deleteKey},
-{"getExpire", (unsigned long)getExpire},
-{"setExpire", (unsigned long)setExpire},
-{"updateSlavesWaitingBgsave", (unsigned long)updateSlavesWaitingBgsave},
-{"freeMemoryIfNeeded", (unsigned long)freeMemoryIfNeeded},
-{"authCommand", (unsigned long)authCommand},
-{"pingCommand", (unsigned long)pingCommand},
-{"echoCommand", (unsigned long)echoCommand},
-{"setCommand", (unsigned long)setCommand},
-{"setnxCommand", (unsigned long)setnxCommand},
-{"getCommand", (unsigned long)getCommand},
-{"delCommand", (unsigned long)delCommand},
-{"existsCommand", (unsigned long)existsCommand},
-{"incrCommand", (unsigned long)incrCommand},
-{"decrCommand", (unsigned long)decrCommand},
-{"incrbyCommand", (unsigned long)incrbyCommand},
-{"decrbyCommand", (unsigned long)decrbyCommand},
-{"selectCommand", (unsigned long)selectCommand},
-{"randomkeyCommand", (unsigned long)randomkeyCommand},
-{"keysCommand", (unsigned long)keysCommand},
-{"dbsizeCommand", (unsigned long)dbsizeCommand},
-{"lastsaveCommand", (unsigned long)lastsaveCommand},
-{"saveCommand", (unsigned long)saveCommand},
-{"bgsaveCommand", (unsigned long)bgsaveCommand},
-{"shutdownCommand", (unsigned long)shutdownCommand},
-{"moveCommand", (unsigned long)moveCommand},
-{"renameCommand", (unsigned long)renameCommand},
-{"renamenxCommand", (unsigned long)renamenxCommand},
-{"lpushCommand", (unsigned long)lpushCommand},
-{"rpushCommand", (unsigned long)rpushCommand},
-{"lpopCommand", (unsigned long)lpopCommand},
-{"rpopCommand", (unsigned long)rpopCommand},
-{"llenCommand", (unsigned long)llenCommand},
-{"lindexCommand", (unsigned long)lindexCommand},
-{"lrangeCommand", (unsigned long)lrangeCommand},
-{"ltrimCommand", (unsigned long)ltrimCommand},
-{"typeCommand", (unsigned long)typeCommand},
-{"lsetCommand", (unsigned long)lsetCommand},
-{"saddCommand", (unsigned long)saddCommand},
-{"sremCommand", (unsigned long)sremCommand},
-{"smoveCommand", (unsigned long)smoveCommand},
-{"sismemberCommand", (unsigned long)sismemberCommand},
-{"scardCommand", (unsigned long)scardCommand},
-{"spopCommand", (unsigned long)spopCommand},
-{"srandmemberCommand", (unsigned long)srandmemberCommand},
-{"sinterCommand", (unsigned long)sinterCommand},
-{"sinterstoreCommand", (unsigned long)sinterstoreCommand},
-{"sunionCommand", (unsigned long)sunionCommand},
-{"sunionstoreCommand", (unsigned long)sunionstoreCommand},
-{"sdiffCommand", (unsigned long)sdiffCommand},
-{"sdiffstoreCommand", (unsigned long)sdiffstoreCommand},
-{"syncCommand", (unsigned long)syncCommand},
-{"flushdbCommand", (unsigned long)flushdbCommand},
-{"flushallCommand", (unsigned long)flushallCommand},
-{"sortCommand", (unsigned long)sortCommand},
-{"lremCommand", (unsigned long)lremCommand},
-{"infoCommand", (unsigned long)infoCommand},
-{"mgetCommand", (unsigned long)mgetCommand},
-{"monitorCommand", (unsigned long)monitorCommand},
-{"expireCommand", (unsigned long)expireCommand},
-{"getsetCommand", (unsigned long)getsetCommand},
-{"ttlCommand", (unsigned long)ttlCommand},
-{"slaveofCommand", (unsigned long)slaveofCommand},
-{"debugCommand", (unsigned long)debugCommand},
-{"processCommand", (unsigned long)processCommand},
-{"setupSigSegvAction", (unsigned long)setupSigSegvAction},
-{"readQueryFromClient", (unsigned long)readQueryFromClient},
-{"rdbRemoveTempFile", (unsigned long)rdbRemoveTempFile},
-{"msetGenericCommand", (unsigned long)msetGenericCommand},
-{"msetCommand", (unsigned long)msetCommand},
-{"msetnxCommand", (unsigned long)msetnxCommand},
-{NULL,0}
-};
+/* =================================== Main! ================================ */
 
-/* This function try to convert a pointer into a function name. It's used in
- * oreder to provide a backtrace under segmentation fault that's able to
- * display functions declared as static (otherwise the backtrace is useless). */
-static char *findFuncName(void *pointer, unsigned long *offset){
-    int i, ret = -1;
-    unsigned long off, minoff = 0;
+#ifdef __linux__
+int linuxOvercommitMemoryValue(void) {
+    FILE *fp = fopen("/proc/sys/vm/overcommit_memory","r");
+    char buf[64];
 
-    /* Try to match against the Symbol with the smallest offset */
-    for (i=0; symsTable[i].pointer; i++) {
-        unsigned long lp = (unsigned long) pointer;
+    if (!fp) return -1;
+    if (fgets(buf,64,fp) == NULL) {
+        fclose(fp);
+        return -1;
+    }
+    fclose(fp);
 
-        if (lp != (unsigned long)-1 && lp >= symsTable[i].pointer) {
-            off=lp-symsTable[i].pointer;
-            if (ret < 0 || off < minoff) {
-                minoff=off;
-                ret=i;
-            }
-        }
+    return atoi(buf);
+}
+
+void linuxOvercommitMemoryWarning(void) {
+    if (linuxOvercommitMemoryValue() == 0) {
+        redisLog(REDIS_WARNING,"WARNING overcommit_memory is set to 0! Background save may fail under low condition memory. To fix this issue add 'vm.overcommit_memory = 1' to /etc/sysctl.conf and then reboot or run the command 'sysctl vm.overcommit_memory=1' for this to take effect.");
     }
-    if (ret == -1) return NULL;
-    *offset = minoff;
-    return symsTable[ret].name;
 }
+#endif /* __linux__ */
+
+static void daemonize(void) {
+    int fd;
+    FILE *fp;
+
+    if (fork() != 0) exit(0); /* parent exits */
+    setsid(); /* create a new session */
+
+    /* Every output goes to /dev/null. If Redis is daemonized but
+     * the 'logfile' is set to 'stdout' in the configuration file
+     * it will not log at all. */
+    if ((fd = open("/dev/null", O_RDWR, 0)) != -1) {
+        dup2(fd, STDIN_FILENO);
+        dup2(fd, STDOUT_FILENO);
+        dup2(fd, STDERR_FILENO);
+        if (fd > STDERR_FILENO) close(fd);
+    }
+    /* Try to write the pid file */
+    fp = fopen(server.pidfile,"w");
+    if (fp) {
+        fprintf(fp,"%d\n",getpid());
+        fclose(fp);
+    }
+}
+
+int main(int argc, char **argv) {
+    initServerConfig();
+    if (argc == 2) {
+        resetServerSaveParams();
+        loadServerConfig(argv[1]);
+    } else if (argc > 2) {
+        fprintf(stderr,"Usage: ./redis-server [/path/to/redis.conf]\n");
+        exit(1);
+    } 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'");
+    }
+    initServer();
+    if (server.daemonize) daemonize();
+    redisLog(REDIS_NOTICE,"Server started, Redis version " REDIS_VERSION);
+#ifdef __linux__
+    linuxOvercommitMemoryWarning();
+#endif
+    if (server.appendonly) {
+        if (loadAppendOnlyFile(server.appendfilename) == REDIS_OK)
+            redisLog(REDIS_NOTICE,"DB loaded from append only file");
+    } else {
+        if (rdbLoad(server.dbfilename) == REDIS_OK)
+            redisLog(REDIS_NOTICE,"DB loaded from disk");
+    }
+    if (aeCreateFileEvent(server.el, server.fd, AE_READABLE,
+        acceptHandler, NULL, NULL) == AE_ERR) oom("creating file event");
+    redisLog(REDIS_NOTICE,"The server is now ready to accept connections on port %d", server.port);
+    aeMain(server.el);
+    aeDeleteEventLoop(server.el);
+    return 0;
+}
+
+/* ============================= Backtrace support ========================= */
+
+#ifdef HAVE_BACKTRACE
+static char *findFuncName(void *pointer, unsigned long *offset);
 
 static void *getMcontextEip(ucontext_t *uc) {
 #if defined(__FreeBSD__)
@@ -4745,7 +5696,7 @@ static void *getMcontextEip(ucontext_t *uc) {
 #elif defined(__APPLE__) && !defined(MAC_OS_X_VERSION_10_6)
     return (void*) uc->uc_mcontext->__ss.__eip;
 #elif defined(__APPLE__) && defined(MAC_OS_X_VERSION_10_6)
-  #ifdef _STRUCT_X86_THREAD_STATE64
+  #if defined(_STRUCT_X86_THREAD_STATE64) && !defined(__i386__)
     return (void*) uc->uc_mcontext->__ss.__rip;
   #else
     return (void*) uc->uc_mcontext->__ss.__eip;
@@ -4831,82 +5782,39 @@ static void setupSigSegvAction(void) {
     sigaction (SIGBUS, &act, NULL);
     return;
 }
-#else /* HAVE_BACKTRACE */
-static void setupSigSegvAction(void) {
-}
-#endif /* HAVE_BACKTRACE */
 
-/* =================================== Main! ================================ */
+#include "staticsymbols.h"
+/* This function try to convert a pointer into a function name. It's used in
+ * oreder to provide a backtrace under segmentation fault that's able to
+ * display functions declared as static (otherwise the backtrace is useless). */
+static char *findFuncName(void *pointer, unsigned long *offset){
+    int i, ret = -1;
+    unsigned long off, minoff = 0;
 
-#ifdef __linux__
-int linuxOvercommitMemoryValue(void) {
-    FILE *fp = fopen("/proc/sys/vm/overcommit_memory","r");
-    char buf[64];
+    /* Try to match against the Symbol with the smallest offset */
+    for (i=0; symsTable[i].pointer; i++) {
+        unsigned long lp = (unsigned long) pointer;
 
-    if (!fp) return -1;
-    if (fgets(buf,64,fp) == NULL) {
-        fclose(fp);
-        return -1;
+        if (lp != (unsigned long)-1 && lp >= symsTable[i].pointer) {
+            off=lp-symsTable[i].pointer;
+            if (ret < 0 || off < minoff) {
+                minoff=off;
+                ret=i;
+            }
+        }
     }
-    fclose(fp);
-
-    return atoi(buf);
+    if (ret == -1) return NULL;
+    *offset = minoff;
+    return symsTable[ret].name;
 }
-
-void linuxOvercommitMemoryWarning(void) {
-    if (linuxOvercommitMemoryValue() == 0) {
-        redisLog(REDIS_WARNING,"WARNING overcommit_memory is set to 0! Background save may fail under low condition memory. To fix this issue add 'vm.overcommit_memory = 1' to /etc/sysctl.conf and then reboot or run the command 'sysctl vm.overcommit_memory=1' for this to take effect.");
-    }
+#else /* HAVE_BACKTRACE */
+static void setupSigSegvAction(void) {
 }
-#endif /* __linux__ */
+#endif /* HAVE_BACKTRACE */
 
-static void daemonize(void) {
-    int fd;
-    FILE *fp;
 
-    if (fork() != 0) exit(0); /* parent exits */
-    setsid(); /* create a new session */
 
-    /* Every output goes to /dev/null. If Redis is daemonized but
-     * the 'logfile' is set to 'stdout' in the configuration file
-     * it will not log at all. */
-    if ((fd = open("/dev/null", O_RDWR, 0)) != -1) {
-        dup2(fd, STDIN_FILENO);
-        dup2(fd, STDOUT_FILENO);
-        dup2(fd, STDERR_FILENO);
-        if (fd > STDERR_FILENO) close(fd);
-    }
-    /* Try to write the pid file */
-    fp = fopen(server.pidfile,"w");
-    if (fp) {
-        fprintf(fp,"%d\n",getpid());
-        fclose(fp);
-    }
-}
+/* The End */
+
+
 
-int main(int argc, char **argv) {
-    initServerConfig();
-    if (argc == 2) {
-        ResetServerSaveParams();
-        loadServerConfig(argv[1]);
-    } else if (argc > 2) {
-        fprintf(stderr,"Usage: ./redis-server [/path/to/redis.conf]\n");
-        exit(1);
-    } 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'");
-    }
-    initServer();
-    if (server.daemonize) daemonize();
-    redisLog(REDIS_NOTICE,"Server started, Redis version " REDIS_VERSION);
-#ifdef __linux__
-    linuxOvercommitMemoryWarning();
-#endif
-    if (rdbLoad(server.dbfilename) == REDIS_OK)
-        redisLog(REDIS_NOTICE,"DB loaded from disk");
-    if (aeCreateFileEvent(server.el, server.fd, AE_READABLE,
-        acceptHandler, NULL, NULL) == AE_ERR) oom("creating file event");
-    redisLog(REDIS_NOTICE,"The server is now ready to accept connections on port %d", server.port);
-    aeMain(server.el);
-    aeDeleteEventLoop(server.el);
-    return 0;
-}