X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/566c3c7a22c0ec217c40f7a95db2bb83c8cc16c7..4d16bb253c8807e45abcd776fcf6521c525a3f2b:/redis.c

diff --git a/redis.c b/redis.c
index de4f5763..b5bbd04d 100644
--- a/redis.c
+++ b/redis.c
@@ -27,7 +27,7 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
-#define REDIS_VERSION "1.3.8"
+#define REDIS_VERSION "1.3.10"
 
 #include "fmacros.h"
 #include "config.h"
@@ -37,8 +37,6 @@
 #include <string.h>
 #include <time.h>
 #include <unistd.h>
-#define __USE_POSIX199309
-#define __USE_UNIX98
 #include <signal.h>
 
 #ifdef HAVE_BACKTRACE
@@ -59,6 +57,7 @@
 #include <sys/resource.h>
 #include <sys/uio.h>
 #include <limits.h>
+#include <float.h>
 #include <math.h>
 #include <pthread.h>
 
@@ -75,7 +74,8 @@
 #include "zmalloc.h" /* total memory usage aware version of malloc/free */
 #include "lzf.h"    /* LZF compression library */
 #include "pqsort.h" /* Partial qsort for SORT+LIMIT */
-#include "zipmap.h"
+#include "zipmap.h" /* Compact dictionary-alike data structure */
+#include "sha1.h"   /* SHA1 is used for DEBUG DIGEST */
 
 /* Error codes */
 #define REDIS_OK                0
@@ -372,6 +372,7 @@ struct redisServer {
     pid_t bgsavechildpid;
     pid_t bgrewritechildpid;
     sds bgrewritebuf; /* buffer taken by parent during oppend only rewrite */
+    sds aofbuf;       /* AOF buffer, written before entering the event loop */
     struct saveparam *saveparams;
     int saveparamslen;
     char *logfile;
@@ -379,7 +380,6 @@ struct redisServer {
     char *dbfilename;
     char *appendfilename;
     char *requirepass;
-    int shareobjects;
     int rdbcompression;
     int activerehashing;
     /* Replication related */
@@ -452,6 +452,7 @@ typedef struct pubsubPattern {
 } pubsubPattern;
 
 typedef void redisCommandProc(redisClient *c);
+typedef void redisVmPreloadProc(redisClient *c, struct redisCommand *cmd, int argc, robj **argv);
 struct redisCommand {
     char *name;
     redisCommandProc *proc;
@@ -460,7 +461,7 @@ struct redisCommand {
     /* 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;
+    redisVmPreloadProc *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 */
@@ -516,8 +517,9 @@ struct sharedObjectsStruct {
     *outofrangeerr, *plus,
     *select0, *select1, *select2, *select3, *select4,
     *select5, *select6, *select7, *select8, *select9,
-    *messagebulk, *subscribebulk, *unsubscribebulk, *mbulk3,
-    *psubscribebulk, *punsubscribebulk, *integers[REDIS_SHARED_INTEGERS];
+    *messagebulk, *pmessagebulk, *subscribebulk, *unsubscribebulk, *mbulk3,
+    *mbulk4, *psubscribebulk, *punsubscribebulk,
+    *integers[REDIS_SHARED_INTEGERS];
 } shared;
 
 /* Global vars that are actally used as constants. The following double
@@ -558,6 +560,8 @@ static int rdbSaveBackground(char *filename);
 static robj *createStringObject(char *ptr, size_t len);
 static robj *dupStringObject(robj *o);
 static void replicationFeedSlaves(list *slaves, int dictid, robj **argv, int argc);
+static void replicationFeedMonitors(list *monitors, int dictid, robj **argv, int argc);
+static void flushAppendOnlyFile(void);
 static void feedAppendOnlyFile(struct redisCommand *cmd, int dictid, robj **argv, int argc);
 static int syncWithMaster(void);
 static robj *tryObjectEncoding(robj *o);
@@ -607,8 +611,9 @@ 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 void zunionInterBlockClientOnSwappedKeys(redisClient *c, struct redisCommand *cmd, int argc, robj **argv);
+static void execBlockClientOnSwappedKeys(redisClient *c, struct redisCommand *cmd, int argc, robj **argv);
+static int blockClientOnSwappedKeys(redisClient *c, struct redisCommand *cmd);
 static int dontWaitForSwappedKey(redisClient *c, robj *key);
 static void handleClientsBlockedOnSwappedKey(redisDb *db, robj *key);
 static void readQueryFromClient(aeEventLoop *el, int fd, void *privdata, int mask);
@@ -621,13 +626,17 @@ 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 int equalStringObjects(robj *a, robj *b);
 static void usage();
+static int rewriteAppendOnlyFileBackground(void);
+static int vmSwapObjectBlocking(robj *key, robj *val);
 
 static void authCommand(redisClient *c);
 static void pingCommand(redisClient *c);
 static void echoCommand(redisClient *c);
 static void setCommand(redisClient *c);
 static void setnxCommand(redisClient *c);
+static void setexCommand(redisClient *c);
 static void getCommand(redisClient *c);
 static void delCommand(redisClient *c);
 static void existsCommand(redisClient *c);
@@ -714,8 +723,8 @@ 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 zunionstoreCommand(redisClient *c);
+static void zinterstoreCommand(redisClient *c);
 static void hkeysCommand(redisClient *c);
 static void hvalsCommand(redisClient *c);
 static void hgetallCommand(redisClient *c);
@@ -736,6 +745,7 @@ static struct redisCommand cmdTable[] = {
     {"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},
+    {"setex",setexCommand,4,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},
@@ -775,8 +785,8 @@ static struct redisCommand cmdTable[] = {
     {"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},
+    {"zunionstore",zunionstoreCommand,-4,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,zunionInterBlockClientOnSwappedKeys,0,0,0},
+    {"zinterstore",zinterstoreCommand,-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},
@@ -821,7 +831,7 @@ static struct redisCommand cmdTable[] = {
     {"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},
+    {"exec",execCommand,1,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM,execBlockClientOnSwappedKeys,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},
@@ -970,6 +980,77 @@ static int stringmatch(const char *pattern, const char *string, int nocase) {
     return stringmatchlen(pattern,strlen(pattern),string,strlen(string),nocase);
 }
 
+/* Convert a string representing an amount of memory into the number of
+ * bytes, so for instance memtoll("1Gi") will return 1073741824 that is
+ * (1024*1024*1024).
+ *
+ * On parsing error, if *err is not NULL, it's set to 1, otherwise it's
+ * set to 0 */
+static long long memtoll(const char *p, int *err) {
+    const char *u;
+    char buf[128];
+    long mul; /* unit multiplier */
+    long long val;
+    unsigned int digits;
+
+    if (err) *err = 0;
+    /* Search the first non digit character. */
+    u = p;
+    if (*u == '-') u++;
+    while(*u && isdigit(*u)) u++;
+    if (*u == '\0' || !strcasecmp(u,"b")) {
+        mul = 1;
+    } else if (!strcasecmp(u,"k")) {
+        mul = 1000;
+    } else if (!strcasecmp(u,"kb")) {
+        mul = 1024;
+    } else if (!strcasecmp(u,"m")) {
+        mul = 1000*1000;
+    } else if (!strcasecmp(u,"mb")) {
+        mul = 1024*1024;
+    } else if (!strcasecmp(u,"g")) {
+        mul = 1000L*1000*1000;
+    } else if (!strcasecmp(u,"gb")) {
+        mul = 1024L*1024*1024;
+    } else {
+        if (err) *err = 1;
+        mul = 1;
+    }
+    digits = u-p;
+    if (digits >= sizeof(buf)) {
+        if (err) *err = 1;
+        return LLONG_MAX;
+    }
+    memcpy(buf,p,digits);
+    buf[digits] = '\0';
+    val = strtoll(buf,NULL,10);
+    return val*mul;
+}
+
+/* Convert a long long into a string. Returns the number of
+ * characters needed to represent the number, that can be shorter if passed
+ * buffer length is not enough to store the whole number. */
+static int ll2string(char *s, size_t len, long long value) {
+    char buf[32], *p;
+    unsigned long long v;
+    size_t l;
+
+    if (len == 0) return 0;
+    v = (value < 0) ? -value : value;
+    p = buf+31; /* point to the last character */
+    do {
+        *p-- = '0'+(v%10);
+        v /= 10;
+    } while(v);
+    if (value < 0) *p-- = '-';
+    p++;
+    l = 32-(p-buf);
+    if (l+1 > len) l = len-1; /* Make sure it fits, including the nul term */
+    memcpy(s,p,l);
+    s[l] = '\0';
+    return l;
+}
+
 static void redisLog(int level, const char *fmt, ...) {
     va_list ap;
     FILE *fp;
@@ -1052,8 +1133,8 @@ static int dictEncObjKeyCompare(void *privdata, const void *key1,
     int cmp;
 
     if (o1->encoding == REDIS_ENCODING_INT &&
-        o2->encoding == REDIS_ENCODING_INT &&
-        o1->ptr == o2->ptr) return 1;
+        o2->encoding == REDIS_ENCODING_INT)
+            return o1->ptr == o2->ptr;
 
     o1 = getDecodedObject(o1);
     o2 = getDecodedObject(o2);
@@ -1073,7 +1154,7 @@ static unsigned int dictEncObjHash(const void *key) {
             char buf[32];
             int len;
 
-            len = snprintf(buf,32,"%ld",(long)o->ptr);
+            len = ll2string(buf,32,(long)o->ptr);
             return dictGenHashFunction((unsigned char*)buf, len);
         } else {
             unsigned int hash;
@@ -1467,6 +1548,7 @@ static int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientD
         redisLog(REDIS_NOTICE,"Connecting to MASTER...");
         if (syncWithMaster() == REDIS_OK) {
             redisLog(REDIS_NOTICE,"MASTER <-> SLAVE sync succeeded");
+            if (server.appendonly) rewriteAppendOnlyFileBackground();
         }
     }
     return 100;
@@ -1478,6 +1560,7 @@ static int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientD
 static void beforeSleep(struct aeEventLoop *eventLoop) {
     REDIS_NOTUSED(eventLoop);
 
+    /* Awake clients that got all the swapped keys they requested */
     if (server.vm_enabled && listLength(server.io_ready_clients)) {
         listIter li;
         listNode *ln;
@@ -1502,6 +1585,8 @@ static void beforeSleep(struct aeEventLoop *eventLoop) {
                 processInputBuffer(c);
         }
     }
+    /* Write the AOF buffer on disk */
+    flushAppendOnlyFile();
 }
 
 static void createSharedObjects(void) {
@@ -1542,11 +1627,13 @@ static void createSharedObjects(void) {
     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.pmessagebulk = createStringObject("$8\r\npmessage\r\n",14);
     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);
+    shared.mbulk4 = createStringObject("*4\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;
@@ -1577,7 +1664,7 @@ static void initServerConfig() {
     server.glueoutputbuf = 1;
     server.daemonize = 0;
     server.appendonly = 0;
-    server.appendfsync = APPENDFSYNC_ALWAYS;
+    server.appendfsync = APPENDFSYNC_EVERYSEC;
     server.lastfsync = time(NULL);
     server.appendfd = -1;
     server.appendseldb = -1; /* Make sure the first time will not match */
@@ -1585,7 +1672,6 @@ static void initServerConfig() {
     server.dbfilename = zstrdup("dump.rdb");
     server.appendfilename = zstrdup("appendonly.aof");
     server.requirepass = NULL;
-    server.shareobjects = 0;
     server.rdbcompression = 1;
     server.activerehashing = 1;
     server.maxclients = 0;
@@ -1661,6 +1747,7 @@ static void initServer() {
     server.bgsavechildpid = -1;
     server.bgrewritechildpid = -1;
     server.bgrewritebuf = sdsempty();
+    server.aofbuf = sdsempty();
     server.lastsave = time(NULL);
     server.dirty = 0;
     server.stat_numcommands = 0;
@@ -1673,16 +1760,7 @@ static void initServer() {
         acceptHandler, NULL) == AE_ERR) oom("creating file event");
 
     if (server.appendonly) {
-        int flags = O_WRONLY|O_APPEND|O_CREAT;
-
-#ifdef HAVE_O_DIRECT
-        if (server.appendfsync == APPENDFSYNC_ALWAYS) {
-            flags |= O_DIRECT;
-            server.appendfsync = APPENDFSYNC_NO;
-        }
-#endif
-
-        server.appendfd = open(server.appendfilename,flags,0644);
+        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));
@@ -1811,7 +1889,7 @@ static void loadServerConfig(char *filename) {
         } else if (!strcasecmp(argv[0],"maxclients") && argc == 2) {
             server.maxclients = atoi(argv[1]);
         } else if (!strcasecmp(argv[0],"maxmemory") && argc == 2) {
-            server.maxmemory = strtoll(argv[1], NULL, 10);
+            server.maxmemory = memtoll(argv[1],NULL);
         } else if (!strcasecmp(argv[0],"slaveof") && argc == 3) {
             server.masterhost = sdsnew(argv[1]);
             server.masterport = atoi(argv[2]);
@@ -1822,10 +1900,6 @@ static void loadServerConfig(char *filename) {
             if ((server.glueoutputbuf = yesnotoi(argv[1])) == -1) {
                 err = "argument must be 'yes' or 'no'"; goto loaderr;
             }
-        } else if (!strcasecmp(argv[0],"shareobjects") && argc == 2) {
-            if ((server.shareobjects = yesnotoi(argv[1])) == -1) {
-                err = "argument must be 'yes' or 'no'"; goto loaderr;
-            }
         } else if (!strcasecmp(argv[0],"rdbcompression") && argc == 2) {
             if ((server.rdbcompression = yesnotoi(argv[1])) == -1) {
                 err = "argument must be 'yes' or 'no'"; goto loaderr;
@@ -1842,6 +1916,9 @@ static void loadServerConfig(char *filename) {
             if ((server.appendonly = yesnotoi(argv[1])) == -1) {
                 err = "argument must be 'yes' or 'no'"; goto loaderr;
             }
+        } else if (!strcasecmp(argv[0],"appendfilename") && argc == 2) {
+            zfree(server.appendfilename);
+            server.appendfilename = zstrdup(argv[1]);
         } else if (!strcasecmp(argv[0],"appendfsync") && argc == 2) {
             if (!strcasecmp(argv[1],"no")) {
                 server.appendfsync = APPENDFSYNC_NO;
@@ -1869,19 +1946,17 @@ static void loadServerConfig(char *filename) {
             zfree(server.vm_swap_file);
             server.vm_swap_file = zstrdup(argv[1]);
         } else if (!strcasecmp(argv[0],"vm-max-memory") && argc == 2) {
-            server.vm_max_memory = strtoll(argv[1], NULL, 10);
+            server.vm_max_memory = memtoll(argv[1],NULL);
         } else if (!strcasecmp(argv[0],"vm-page-size") && argc == 2) {
-            server.vm_page_size = strtoll(argv[1], NULL, 10);
+            server.vm_page_size = memtoll(argv[1], NULL);
         } else if (!strcasecmp(argv[0],"vm-pages") && argc == 2) {
-            server.vm_pages = strtoll(argv[1], NULL, 10);
+            server.vm_pages = memtoll(argv[1], NULL);
         } else if (!strcasecmp(argv[0],"vm-max-threads") && argc == 2) {
             server.vm_max_threads = strtoll(argv[1], NULL, 10);
         } else if (!strcasecmp(argv[0],"hash-max-zipmap-entries") && argc == 2){
-            server.hash_max_zipmap_entries = strtol(argv[1], NULL, 10);
+            server.hash_max_zipmap_entries = memtoll(argv[1], NULL);
         } else if (!strcasecmp(argv[0],"hash-max-zipmap-value") && argc == 2){
-            server.hash_max_zipmap_value = strtol(argv[1], NULL, 10);
-        } else if (!strcasecmp(argv[0],"vm-max-threads") && argc == 2) {
-            server.vm_max_threads = strtoll(argv[1], NULL, 10);
+            server.hash_max_zipmap_value = memtoll(argv[1], NULL);
         } else {
             err = "Bad directive or wrong number of arguments"; goto loaderr;
         }
@@ -2175,7 +2250,7 @@ static void call(redisClient *c, struct redisCommand *cmd) {
         listLength(server.slaves))
         replicationFeedSlaves(server.slaves,c->db->id,c->argv,c->argc);
     if (listLength(server.monitors))
-        replicationFeedSlaves(server.monitors,c->db->id,c->argv,c->argc);
+        replicationFeedMonitors(server.monitors,c->db->id,c->argv,c->argc);
     server.stat_numcommands++;
 }
 
@@ -2349,7 +2424,7 @@ static int processCommand(redisClient *c) {
         addReply(c,shared.queued);
     } else {
         if (server.vm_enabled && server.vm_max_threads > 0 &&
-            blockClientOnSwappedKeys(cmd,c)) return 1;
+            blockClientOnSwappedKeys(c,cmd)) return 1;
         call(c,cmd);
     }
 
@@ -2430,6 +2505,64 @@ static void replicationFeedSlaves(list *slaves, int dictid, robj **argv, int arg
     if (outv != static_outv) zfree(outv);
 }
 
+static sds sdscatrepr(sds s, char *p, size_t len) {
+    s = sdscatlen(s,"\"",1);
+    while(len--) {
+        switch(*p) {
+        case '\\':
+        case '"':
+            s = sdscatprintf(s,"\\%c",*p);
+            break;
+        case '\n': s = sdscatlen(s,"\\n",1); break;
+        case '\r': s = sdscatlen(s,"\\r",1); break;
+        case '\t': s = sdscatlen(s,"\\t",1); break;
+        case '\a': s = sdscatlen(s,"\\a",1); break;
+        case '\b': s = sdscatlen(s,"\\b",1); break;
+        default:
+            if (isprint(*p))
+                s = sdscatprintf(s,"%c",*p);
+            else
+                s = sdscatprintf(s,"\\x%02x",(unsigned char)*p);
+            break;
+        }
+        p++;
+    }
+    return sdscatlen(s,"\"",1);
+}
+
+static void replicationFeedMonitors(list *monitors, int dictid, robj **argv, int argc) {
+    listNode *ln;
+    listIter li;
+    int j;
+    sds cmdrepr = sdsnew("+");
+    robj *cmdobj;
+    struct timeval tv;
+
+    gettimeofday(&tv,NULL);
+    cmdrepr = sdscatprintf(cmdrepr,"%ld.%ld ",(long)tv.tv_sec,(long)tv.tv_usec);
+    if (dictid != 0) cmdrepr = sdscatprintf(cmdrepr,"(db %d) ", dictid);
+
+    for (j = 0; j < argc; j++) {
+        if (argv[j]->encoding == REDIS_ENCODING_INT) {
+            cmdrepr = sdscatprintf(cmdrepr, "%ld", (long)argv[j]->ptr);
+        } else {
+            cmdrepr = sdscatrepr(cmdrepr,(char*)argv[j]->ptr,
+                        sdslen(argv[j]->ptr));
+        }
+        if (j != argc-1)
+            cmdrepr = sdscatlen(cmdrepr," ",1);
+    }
+    cmdrepr = sdscatlen(cmdrepr,"\r\n",2);
+    cmdobj = createObject(REDIS_STRING,cmdrepr);
+
+    listRewind(monitors,&li);
+    while((ln = listNext(&li))) {
+        redisClient *monitor = ln->value;
+        addReply(monitor,cmdobj);
+    }
+    decrRefCount(cmdobj);
+}
+
 static void processInputBuffer(redisClient *c) {
 again:
     /* Before to process the input buffer, make sure the client is not
@@ -2555,7 +2688,7 @@ static void *dupClientReplyValue(void *o) {
 }
 
 static int listMatchObjects(void *a, void *b) {
-    return compareStringObjects(a,b) == 0;
+    return equalStringObjects(a,b);
 }
 
 static redisClient *createClient(int fd) {
@@ -2795,7 +2928,7 @@ static robj *createStringObjectFromLongLong(long long value) {
             o->encoding = REDIS_ENCODING_INT;
             o->ptr = (void*)((long)value);
         } else {
-            o->ptr = sdscatprintf(sdsempty(),"%lld",value);
+            o = createObject(REDIS_STRING,sdsfromlonglong(value));
         }
     }
     return o;
@@ -3010,7 +3143,7 @@ static int isStringRepresentableAsLong(sds s, long *longval) {
 
     value = strtol(s, &endptr, 10);
     if (endptr[0] != '\0') return REDIS_ERR;
-    slen = snprintf(buf,32,"%ld",value);
+    slen = ll2string(buf,32,value);
 
     /* If the number converted back into a string is not identical
      * then it's not possible to encode the string as integer */
@@ -3063,7 +3196,7 @@ static robj *getDecodedObject(robj *o) {
     if (o->type == REDIS_STRING && o->encoding == REDIS_ENCODING_INT) {
         char buf[32];
 
-        snprintf(buf,32,"%ld",(long)o->ptr);
+        ll2string(buf,32,(long)o->ptr);
         dec = createStringObject(buf,strlen(buf));
         return dec;
     } else {
@@ -3073,7 +3206,7 @@ static robj *getDecodedObject(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
+ * use ll2string() to get a string representation of the numbers on the stack
  * and compare the strings, it's much faster than calling getDecodedObject().
  *
  * Important note: if objects are not integer encoded, but binary-safe strings,
@@ -3086,14 +3219,14 @@ static int compareStringObjects(robj *a, robj *b) {
 
     if (a == b) return 0;
     if (a->encoding != REDIS_ENCODING_RAW) {
-        snprintf(bufa,sizeof(bufa),"%ld",(long) a->ptr);
+        ll2string(bufa,sizeof(bufa),(long) a->ptr);
         astr = bufa;
         bothsds = 0;
     } else {
         astr = a->ptr;
     }
     if (b->encoding != REDIS_ENCODING_RAW) {
-        snprintf(bufb,sizeof(bufb),"%ld",(long) b->ptr);
+        ll2string(bufb,sizeof(bufb),(long) b->ptr);
         bstr = bufb;
         bothsds = 0;
     } else {
@@ -3102,6 +3235,18 @@ static int compareStringObjects(robj *a, robj *b) {
     return bothsds ? sdscmp(astr,bstr) : strcmp(astr,bstr);
 }
 
+/* Equal string objects return 1 if the two objects are the same from the
+ * point of view of a string comparison, otherwise 0 is returned. Note that
+ * this function is faster then checking for (compareStringObject(a,b) == 0)
+ * because it can perform some more optimization. */
+static int equalStringObjects(robj *a, robj *b) {
+    if (a->encoding != REDIS_ENCODING_RAW && b->encoding != REDIS_ENCODING_RAW){
+        return a->ptr == b->ptr;
+    } else {
+        return compareStringObjects(a,b) == 0;
+    }
+}
+
 static size_t stringObjectLen(robj *o) {
     redisAssert(o->type == REDIS_STRING);
     if (o->encoding == REDIS_ENCODING_RAW) {
@@ -3109,7 +3254,7 @@ static size_t stringObjectLen(robj *o) {
     } else {
         char buf[32];
 
-        return snprintf(buf,32,"%ld",(long)o->ptr);
+        return ll2string(buf,32,(long)o->ptr);
     }
 }
 
@@ -3127,7 +3272,7 @@ static int getDoubleFromObject(robj *o, double *target) {
         } else if (o->encoding == REDIS_ENCODING_INT) {
             value = (long)o->ptr;
         } else {
-            redisAssert(1 != 1);
+            redisPanic("Unknown string encoding");
         }
     }
 
@@ -3164,7 +3309,7 @@ static int getLongLongFromObject(robj *o, long long *target) {
         } else if (o->encoding == REDIS_ENCODING_INT) {
             value = (long)o->ptr;
         } else {
-            redisAssert(1 != 1);
+            redisPanic("Unknown string encoding");
         }
     }
 
@@ -3240,22 +3385,12 @@ static int rdbSaveLen(FILE *fp, uint32_t len) {
     return 0;
 }
 
-/* String objects in the form "2391" "-100" without any space and with a
- * range of values that can fit in an 8, 16 or 32 bit signed value can be
- * encoded as integers to save space */
-static int rdbTryIntegerEncoding(char *s, size_t len, unsigned char *enc) {
-    long long value;
-    char *endptr, buf[32];
-
-    /* Check if it's possible to encode this value as a number */
-    value = strtoll(s, &endptr, 10);
-    if (endptr[0] != '\0') return 0;
-    snprintf(buf,32,"%lld",value);
-
-    /* If the number converted back into a string is not identical
-     * then it's not possible to encode the string as integer */
-    if (strlen(buf) != len || memcmp(buf,s,len)) return 0;
-
+/* Encode 'value' as an integer if possible (if integer will fit the
+ * supported range). If the function sucessful encoded the integer
+ * then the (up to 5 bytes) encoded representation is written in the
+ * string pointed by 'enc' and the length is returned. Otherwise
+ * 0 is returned. */
+static int rdbEncodeInteger(long long value, unsigned char *enc) {
     /* Finally check if it fits in our ranges */
     if (value >= -(1<<7) && value <= (1<<7)-1) {
         enc[0] = (REDIS_RDB_ENCVAL<<6)|REDIS_RDB_ENC_INT8;
@@ -3278,6 +3413,25 @@ static int rdbTryIntegerEncoding(char *s, size_t len, unsigned char *enc) {
     }
 }
 
+/* String objects in the form "2391" "-100" without any space and with a
+ * range of values that can fit in an 8, 16 or 32 bit signed value can be
+ * encoded as integers to save space */
+static int rdbTryIntegerEncoding(char *s, size_t len, unsigned char *enc) {
+    long long value;
+    char *endptr, buf[32];
+
+    /* Check if it's possible to encode this value as a number */
+    value = strtoll(s, &endptr, 10);
+    if (endptr[0] != '\0') return 0;
+    ll2string(buf,32,value);
+
+    /* If the number converted back into a string is not identical
+     * then it's not possible to encode the string as integer */
+    if (strlen(buf) != len || memcmp(buf,s,len)) return 0;
+
+    return rdbEncodeInteger(value,enc);
+}
+
 static int rdbSaveLzfStringObject(FILE *fp, unsigned char *s, size_t len) {
     size_t comprlen, outlen;
     unsigned char byte;
@@ -3341,6 +3495,21 @@ static int rdbSaveRawString(FILE *fp, unsigned char *s, size_t len) {
 static int rdbSaveStringObject(FILE *fp, robj *obj) {
     int retval;
 
+    /* Avoid to decode the object, then encode it again, if the
+     * object is alrady integer encoded. */
+    if (obj->encoding == REDIS_ENCODING_INT) {
+        long val = (long) obj->ptr;
+        unsigned char buf[5];
+        int enclen;
+
+        if ((enclen = rdbEncodeInteger(val,buf)) > 0) {
+            if (fwrite(buf,enclen,1,fp) == 0) return -1;
+            return 0;
+        }
+        /* otherwise... fall throught and continue with the usual
+         * code path. */
+    }
+
     /* Avoid incr/decr ref count business when possible.
      * This plays well with copy-on-write given that we are probably
      * in a child process (BGSAVE). Also this makes sure key objects
@@ -3375,7 +3544,23 @@ static int rdbSaveDoubleValue(FILE *fp, double val) {
         len = 1;
         buf[0] = (val < 0) ? 255 : 254;
     } else {
-        snprintf((char*)buf+1,sizeof(buf)-1,"%.17g",val);
+#if (DBL_MANT_DIG >= 52) && (LLONG_MAX == 0x7fffffffffffffffLL)
+        /* Check if the float is in a safe range to be casted into a
+         * long long. We are assuming that long long is 64 bit here.
+         * Also we are assuming that there are no implementations around where
+         * double has precision < 52 bit.
+         *
+         * Under this assumptions we test if a double is inside an interval
+         * where casting to long long is safe. Then using two castings we
+         * make sure the decimal part is zero. If all this is true we use
+         * integer printing function that is much faster. */
+        double min = -4503599627370495; /* (2^52)-1 */
+        double max = 4503599627370496; /* -(2^52) */
+        if (val > min && val < max && val == ((double)((long long)val)))
+            ll2string((char*)buf+1,sizeof(buf),(long long)val);
+        else
+#endif
+            snprintf((char*)buf+1,sizeof(buf)-1,"%.17g",val);
         buf[0] = strlen((char*)buf+1);
         len = buf[0]+1;
     }
@@ -3659,7 +3844,11 @@ static uint32_t rdbLoadLen(FILE *fp, int *isencoded) {
     }
 }
 
-static robj *rdbLoadIntegerObject(FILE *fp, int enctype) {
+/* Load an integer-encoded object from file 'fp', with the specified
+ * encoding type 'enctype'. If encode is true the function may return
+ * an integer-encoded object as reply, otherwise the returned object
+ * will always be encoded as a raw string. */
+static robj *rdbLoadIntegerObject(FILE *fp, int enctype, int encode) {
     unsigned char enc[4];
     long long val;
 
@@ -3680,7 +3869,10 @@ static robj *rdbLoadIntegerObject(FILE *fp, int enctype) {
         val = 0; /* anti-warning */
         redisPanic("Unknown RDB integer encoding type");
     }
-    return createObject(REDIS_STRING,sdscatprintf(sdsempty(),"%lld",val));
+    if (encode)
+        return createStringObjectFromLongLong(val);
+    else
+        return createObject(REDIS_STRING,sdsfromlonglong(val));
 }
 
 static robj *rdbLoadLzfStringObject(FILE*fp) {
@@ -3702,7 +3894,7 @@ err:
     return NULL;
 }
 
-static robj *rdbLoadStringObject(FILE*fp) {
+static robj *rdbGenericLoadStringObject(FILE*fp, int encode) {
     int isencoded;
     uint32_t len;
     sds val;
@@ -3713,7 +3905,7 @@ static robj *rdbLoadStringObject(FILE*fp) {
         case REDIS_RDB_ENC_INT8:
         case REDIS_RDB_ENC_INT16:
         case REDIS_RDB_ENC_INT32:
-            return rdbLoadIntegerObject(fp,len);
+            return rdbLoadIntegerObject(fp,len,encode);
         case REDIS_RDB_ENC_LZF:
             return rdbLoadLzfStringObject(fp);
         default:
@@ -3730,6 +3922,14 @@ static robj *rdbLoadStringObject(FILE*fp) {
     return createObject(REDIS_STRING,val);
 }
 
+static robj *rdbLoadStringObject(FILE *fp) {
+    return rdbGenericLoadStringObject(fp,0);
+}
+
+static robj *rdbLoadEncodedStringObject(FILE *fp) {
+    return rdbGenericLoadStringObject(fp,1);
+}
+
 /* For information about double serialization check rdbSaveDoubleValue() */
 static int rdbLoadDoubleValue(FILE *fp, double *val) {
     char buf[128];
@@ -3756,7 +3956,7 @@ static robj *rdbLoadObject(int type, FILE *fp) {
     redisLog(REDIS_DEBUG,"LOADING OBJECT %d (at %d)\n",type,ftell(fp));
     if (type == REDIS_STRING) {
         /* Read string value */
-        if ((o = rdbLoadStringObject(fp)) == NULL) return NULL;
+        if ((o = rdbLoadEncodedStringObject(fp)) == NULL) return NULL;
         o = tryObjectEncoding(o);
     } else if (type == REDIS_LIST || type == REDIS_SET) {
         /* Read list/set value */
@@ -3772,7 +3972,7 @@ static robj *rdbLoadObject(int type, FILE *fp) {
         while(listlen--) {
             robj *ele;
 
-            if ((ele = rdbLoadStringObject(fp)) == NULL) return NULL;
+            if ((ele = rdbLoadEncodedStringObject(fp)) == NULL) return NULL;
             ele = tryObjectEncoding(ele);
             if (type == REDIS_LIST) {
                 listAddNodeTail((list*)o->ptr,ele);
@@ -3793,7 +3993,7 @@ static robj *rdbLoadObject(int type, FILE *fp) {
             robj *ele;
             double *score = zmalloc(sizeof(double));
 
-            if ((ele = rdbLoadStringObject(fp)) == NULL) return NULL;
+            if ((ele = rdbLoadEncodedStringObject(fp)) == NULL) return NULL;
             ele = tryObjectEncoding(ele);
             if (rdbLoadDoubleValue(fp,score) == -1) return NULL;
             dictAdd(zs->dict,ele,score);
@@ -3846,13 +4046,13 @@ static robj *rdbLoadObject(int type, FILE *fp) {
 
 static int rdbLoad(char *filename) {
     FILE *fp;
-    robj *keyobj = NULL;
     uint32_t dbid;
     int type, retval, rdbver;
+    int swap_all_values = 0;
     dict *d = server.db[0].dict;
     redisDb *db = server.db+0;
     char buf[1024];
-    time_t expiretime = -1, now = time(NULL);
+    time_t expiretime, now = time(NULL);
     long long loadedkeys = 0;
 
     fp = fopen(filename,"r");
@@ -3871,8 +4071,9 @@ static int rdbLoad(char *filename) {
         return REDIS_ERR;
     }
     while(1) {
-        robj *o;
+        robj *key, *val;
 
+        expiretime = -1;
         /* Read type. */
         if ((type = rdbLoadType(fp)) == -1) goto eoferr;
         if (type == REDIS_EXPIRETIME) {
@@ -3894,36 +4095,61 @@ static int rdbLoad(char *filename) {
             continue;
         }
         /* Read key */
-        if ((keyobj = rdbLoadStringObject(fp)) == NULL) goto eoferr;
+        if ((key = rdbLoadStringObject(fp)) == NULL) goto eoferr;
         /* Read value */
-        if ((o = rdbLoadObject(type,fp)) == NULL) goto eoferr;
+        if ((val = rdbLoadObject(type,fp)) == NULL) goto eoferr;
+        /* Check if the key already expired */
+        if (expiretime != -1 && expiretime < now) {
+            decrRefCount(key);
+            decrRefCount(val);
+            continue;
+        }
         /* Add the new object in the hash table */
-        retval = dictAdd(d,keyobj,o);
+        retval = dictAdd(d,key,val);
         if (retval == DICT_ERR) {
-            redisLog(REDIS_WARNING,"Loading DB, duplicated key (%s) found! Unrecoverable error, exiting now.", keyobj->ptr);
+            redisLog(REDIS_WARNING,"Loading DB, duplicated key (%s) found! Unrecoverable error, exiting now.", key->ptr);
             exit(1);
         }
+        loadedkeys++;
         /* Set the expire time if needed */
-        if (expiretime != -1) {
-            setExpire(db,keyobj,expiretime);
-            /* Delete this key if already expired */
-            if (expiretime < now) deleteKey(db,keyobj);
-            expiretime = -1;
-        }
-        keyobj = o = NULL;
+        if (expiretime != -1) setExpire(db,key,expiretime);
+
         /* Handle swapping while loading big datasets when VM is on */
-        loadedkeys++;
-        if (server.vm_enabled && (loadedkeys % 5000) == 0) {
+
+        /* If we detecter we are hopeless about fitting something in memory
+         * we just swap every new key on disk. Directly...
+         * Note that's important to check for this condition before resorting
+         * to random sampling, otherwise we may try to swap already
+         * swapped keys. */
+        if (swap_all_values) {
+            dictEntry *de = dictFind(d,key);
+
+            /* de may be NULL since the key already expired */
+            if (de) {
+                key = dictGetEntryKey(de);
+                val = dictGetEntryVal(de);
+
+                if (vmSwapObjectBlocking(key,val) == REDIS_OK) {
+                    dictGetEntryVal(de) = NULL;
+                }
+            }
+            continue;
+        }
+
+        /* If we have still some hope of having some value fitting memory
+         * then we try random sampling. */
+        if (!swap_all_values && server.vm_enabled && (loadedkeys % 5000) == 0) {
             while (zmalloc_used_memory() > server.vm_max_memory) {
                 if (vmSwapOneObjectBlocking() == REDIS_ERR) break;
             }
+            if (zmalloc_used_memory() > server.vm_max_memory)
+                swap_all_values = 1; /* We are already using too much mem */
         }
     }
     fclose(fp);
     return REDIS_OK;
 
 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, aborting now.");
     exit(1);
     return REDIS_ERR; /* Just to avoid warning */
@@ -3951,40 +4177,55 @@ static void echoCommand(redisClient *c) {
 
 /*=================================== Strings =============================== */
 
-static void setGenericCommand(redisClient *c, int nx) {
+static void setGenericCommand(redisClient *c, int nx, robj *key, robj *val, robj *expire) {
     int retval;
+    long seconds = 0; /* initialized to avoid an harmness warning */
+
+    if (expire) {
+        if (getLongFromObjectOrReply(c, expire, &seconds, NULL) != REDIS_OK)
+            return;
+        if (seconds <= 0) {
+            addReplySds(c,sdsnew("-ERR invalid expire time in SETEX\r\n"));
+            return;
+        }
+    }
 
-    if (nx) deleteIfVolatile(c->db,c->argv[1]);
-    retval = dictAdd(c->db->dict,c->argv[1],c->argv[2]);
+    if (nx) deleteIfVolatile(c->db,key);
+    retval = dictAdd(c->db->dict,key,val);
     if (retval == DICT_ERR) {
         if (!nx) {
             /* If the key is about a swapped value, we want a new key object
              * to overwrite the old. So we delete the old key in the database.
              * This will also make sure that swap pages about the old object
              * will be marked as free. */
-            if (server.vm_enabled && deleteIfSwapped(c->db,c->argv[1]))
-                incrRefCount(c->argv[1]);
-            dictReplace(c->db->dict,c->argv[1],c->argv[2]);
-            incrRefCount(c->argv[2]);
+            if (server.vm_enabled && deleteIfSwapped(c->db,key))
+                incrRefCount(key);
+            dictReplace(c->db->dict,key,val);
+            incrRefCount(val);
         } else {
             addReply(c,shared.czero);
             return;
         }
     } else {
-        incrRefCount(c->argv[1]);
-        incrRefCount(c->argv[2]);
+        incrRefCount(key);
+        incrRefCount(val);
     }
     server.dirty++;
-    removeExpire(c->db,c->argv[1]);
+    removeExpire(c->db,key);
+    if (expire) setExpire(c->db,key,time(NULL)+seconds);
     addReply(c, nx ? shared.cone : shared.ok);
 }
 
 static void setCommand(redisClient *c) {
-    setGenericCommand(c,0);
+    setGenericCommand(c,0,c->argv[1],c->argv[2],NULL);
 }
 
 static void setnxCommand(redisClient *c) {
-    setGenericCommand(c,1);
+    setGenericCommand(c,1,c->argv[1],c->argv[2],NULL);
+}
+
+static void setexCommand(redisClient *c) {
+    setGenericCommand(c,0,c->argv[1],c->argv[3],c->argv[2]);
 }
 
 static int getGenericCommand(redisClient *c) {
@@ -4089,8 +4330,8 @@ static void incrDecrCommand(redisClient *c, long long incr) {
     robj *o;
 
     o = lookupKeyWrite(c->db,c->argv[1]);
-
-    if (getLongLongFromObjectOrReply(c, o, &value, NULL) != REDIS_OK) return;
+    if (o != NULL && checkType(c,o,REDIS_STRING)) return;
+    if (getLongLongFromObjectOrReply(c,o,&value,NULL) != REDIS_OK) return;
 
     value += incr;
     o = createObject(REDIS_STRING,sdscatprintf(sdsempty(),"%lld",value));
@@ -4228,7 +4469,12 @@ static void delCommand(redisClient *c) {
 }
 
 static void existsCommand(redisClient *c) {
-    addReply(c,lookupKeyRead(c->db,c->argv[1]) ? shared.cone : shared.czero);
+    expireIfNeeded(c->db,c->argv[1]);
+    if (dictFind(c->db->dict,c->argv[1])) {
+        addReply(c, shared.cone);
+    } else {
+        addReply(c, shared.czero);
+    }
 }
 
 static void selectCommand(redisClient *c) {
@@ -4243,18 +4489,25 @@ static void selectCommand(redisClient *c) {
 
 static void randomkeyCommand(redisClient *c) {
     dictEntry *de;
+    robj *key;
 
     while(1) {
         de = dictGetRandomKey(c->db->dict);
         if (!de || expireIfNeeded(c->db,dictGetEntryKey(de)) == 0) break;
     }
+
     if (de == NULL) {
-        addReply(c,shared.plus);
-        addReply(c,shared.crlf);
+        addReply(c,shared.nullbulk);
+        return;
+    }
+
+    key = dictGetEntryKey(de);
+    if (server.vm_enabled) {
+        key = dupStringObject(key);
+        addReplyBulk(c,key);
+        decrRefCount(key);
     } else {
-        addReply(c,shared.plus);
-        addReply(c,dictGetEntryKey(de));
-        addReply(c,shared.crlf);
+        addReplyBulk(c,key);
     }
 }
 
@@ -4363,7 +4616,6 @@ static void shutdownCommand(redisClient *c) {
                 unlink(server.pidfile);
             redisLog(REDIS_WARNING,"%zu bytes used at exit",zmalloc_used_memory());
             redisLog(REDIS_WARNING,"Server exit now, bye bye...");
-            if (server.vm_enabled) unlink(server.vm_swap_file);
             exit(0);
         } else {
             /* Ooops.. error saving! The best we can do is to continue
@@ -4702,7 +4954,7 @@ static void lremCommand(redisClient *c) {
         robj *ele = listNodeValue(ln);
 
         next = fromtail ? ln->prev : ln->next;
-        if (compareStringObjects(ele,c->argv[3]) == 0) {
+        if (equalStringObjects(ele,c->argv[3])) {
             listDelNode(list,ln);
             server.dirty++;
             removed++;
@@ -5306,7 +5558,7 @@ static int zslDelete(zskiplist *zsl, double score, robj *obj) {
     /* 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) {
+    if (x && score == x->score && equalStringObjects(x->obj,obj)) {
         zslDeleteNode(zsl, x, update);
         zslFreeNode(x);
         return 1;
@@ -5411,7 +5663,7 @@ static unsigned long zslGetRank(zskiplist *zsl, double score, robj *o) {
         }
 
         /* x might be equal to zsl->header, so test if obj is non-NULL */
-        if (x->obj && compareStringObjects(x->obj,o) == 0) {
+        if (x->obj && equalStringObjects(x->obj,o)) {
             return rank;
         }
     }
@@ -5665,7 +5917,7 @@ static void zunionInterGenericCommand(redisClient *c, robj *dstkey, int op) {
     /* expect zsetnum input keys to be given */
     zsetnum = atoi(c->argv[2]->ptr);
     if (zsetnum < 1) {
-        addReplySds(c,sdsnew("-ERR at least 1 input key is needed for ZUNION/ZINTER\r\n"));
+        addReplySds(c,sdsnew("-ERR at least 1 input key is needed for ZUNIONSTORE/ZINTERSTORE\r\n"));
         return;
     }
 
@@ -5815,11 +6067,11 @@ static void zunionInterGenericCommand(redisClient *c, robj *dstkey, int op) {
     zfree(src);
 }
 
-static void zunionCommand(redisClient *c) {
+static void zunionstoreCommand(redisClient *c) {
     zunionInterGenericCommand(c,c->argv[1], REDIS_OP_UNION);
 }
 
-static void zinterCommand(redisClient *c) {
+static void zinterstoreCommand(redisClient *c) {
     zunionInterGenericCommand(c,c->argv[1], REDIS_OP_INTER);
 }
 
@@ -6346,12 +6598,11 @@ static void hincrbyCommand(redisClient *c) {
     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);
+        if (getLongLongFromObjectOrReply(c,current,&value,
+            "hash value is not an integer") != REDIS_OK) {
+            decrRefCount(current);
+            return;
+        }
         decrRefCount(current);
     } else {
         value = 0;
@@ -7892,11 +8143,87 @@ static void freeMemoryIfNeeded(void) {
 
 /* ============================== Append Only file ========================== */
 
+/* Write the append only file buffer on disk.
+ *
+ * Since we are required to write the AOF before replying to the client,
+ * and the only way the client socket can get a write is entering when the
+ * the event loop, we accumulate all the AOF writes in a memory
+ * buffer and write it on disk using this function just before entering
+ * the event loop again. */
+static void flushAppendOnlyFile(void) {
+    time_t now;
+    ssize_t nwritten;
+
+    if (sdslen(server.aofbuf) == 0) return;
+
+    /* 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,server.aofbuf,sdslen(server.aofbuf));
+     if (nwritten != (signed)sdslen(server.aofbuf)) {
+        /* Ooops, we are in troubles. The best thing to do for now is
+         * aborting instead of giving 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);
+    }
+    sdsfree(server.aofbuf);
+    server.aofbuf = sdsempty();
+
+    /* Fsync if needed */
+    now = time(NULL);
+    if (server.appendfsync == APPENDFSYNC_ALWAYS ||
+        (server.appendfsync == APPENDFSYNC_EVERYSEC &&
+         now-server.lastfsync > 1))
+    {
+        /* aof_fsync is defined as fdatasync() for Linux in order to avoid
+         * flushing metadata. */
+        aof_fsync(server.appendfd); /* Let's try to get this data on the disk */
+        server.lastfsync = now;
+    }
+}
+
+static sds catAppendOnlyGenericCommand(sds buf, int argc, robj **argv) {
+    int j;
+    buf = sdscatprintf(buf,"*%d\r\n",argc);
+    for (j = 0; j < argc; j++) {
+        robj *o = getDecodedObject(argv[j]);
+        buf = sdscatprintf(buf,"$%lu\r\n",(unsigned long)sdslen(o->ptr));
+        buf = sdscatlen(buf,o->ptr,sdslen(o->ptr));
+        buf = sdscatlen(buf,"\r\n",2);
+        decrRefCount(o);
+    }
+    return buf;
+}
+
+static sds catAppendOnlyExpireAtCommand(sds buf, robj *key, robj *seconds) {
+    int argc = 3;
+    long when;
+    robj *argv[3];
+
+    /* Make sure we can use strtol */
+    seconds = getDecodedObject(seconds);
+    when = time(NULL)+strtol(seconds->ptr,NULL,10);
+    decrRefCount(seconds);
+
+    argv[0] = createStringObject("EXPIREAT",8);
+    argv[1] = key;
+    argv[2] = createObject(REDIS_STRING,
+        sdscatprintf(sdsempty(),"%ld",when));
+    buf = catAppendOnlyGenericCommand(buf, argc, argv);
+    decrRefCount(argv[0]);
+    decrRefCount(argv[2]);
+    return buf;
+}
+
 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
@@ -7910,55 +8237,26 @@ static void feedAppendOnlyFile(struct redisCommand *cmd, int dictid, robj **argv
         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);
+        /* Translate EXPIRE into EXPIREAT */
+        buf = catAppendOnlyExpireAtCommand(buf,argv[1],argv[2]);
+    } else if (cmd->proc == setexCommand) {
+        /* Translate SETEX to SET and EXPIREAT */
+        tmpargv[0] = createStringObject("SET",3);
         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];
-
-        o = getDecodedObject(o);
-        buf = sdscatprintf(buf,"$%lu\r\n",(unsigned long)sdslen(o->ptr));
-        buf = sdscatlen(buf,o->ptr,sdslen(o->ptr));
-        buf = sdscatlen(buf,"\r\n",2);
-        decrRefCount(o);
+        tmpargv[2] = argv[3];
+        buf = catAppendOnlyGenericCommand(buf,3,tmpargv);
+        decrRefCount(tmpargv[0]);
+        buf = catAppendOnlyExpireAtCommand(buf,argv[1],argv[2]);
+    } else {
+        buf = catAppendOnlyGenericCommand(buf,argc,argv);
     }
 
-    /* Free the objects from the modified argv for EXPIREAT */
-    if (cmd->proc == expireCommand) {
-        for (j = 0; j < 3; j++)
-            decrRefCount(argv[j]);
-    }
+    /* Append to the AOF buffer. This will be flushed on disk just before
+     * of re-entering the event loop, so before the client will get a
+     * positive reply about the operation performed. */
+    server.aofbuf = sdscatlen(server.aofbuf,buf,sdslen(buf));
 
-    /* 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);
-    }
     /* If a background append only file rewriting is in progress we want to
      * accumulate the differences between the child DB and the current one
      * in a buffer, so that when the child process will do its work we
@@ -7967,14 +8265,6 @@ static void feedAppendOnlyFile(struct redisCommand *cmd, int dictid, robj **argv
         server.bgrewritebuf = sdscatlen(server.bgrewritebuf,buf,sdslen(buf));
 
     sdsfree(buf);
-    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
@@ -7994,12 +8284,14 @@ static struct redisClient *createFakeClient(void) {
     c->reply = listCreate();
     listSetFreeMethod(c->reply,decrRefCount);
     listSetDupMethod(c->reply,dupClientReplyValue);
+    initClientMultiState(c);
     return c;
 }
 
 static void freeFakeClient(struct redisClient *c) {
     sdsfree(c->querybuf);
     listRelease(c->reply);
+    freeClientMultiState(c);
     zfree(c);
 }
 
@@ -8011,6 +8303,7 @@ int loadAppendOnlyFile(char *filename) {
     FILE *fp = fopen(filename,"r");
     struct redis_stat sb;
     unsigned long long loadedkeys = 0;
+    int appendonly = server.appendonly;
 
     if (redis_fstat(fileno(fp),&sb) != -1 && sb.st_size == 0)
         return REDIS_ERR;
@@ -8020,6 +8313,10 @@ int loadAppendOnlyFile(char *filename) {
         exit(1);
     }
 
+    /* Temporarily disable AOF, to prevent EXEC from feeding a MULTI
+     * to the same file we're about to read. */
+    server.appendonly = 0;
+
     fakeClient = createFakeClient();
     while(1) {
         int argc, j;
@@ -8075,8 +8372,14 @@ int loadAppendOnlyFile(char *filename) {
             }
         }
     }
+
+    /* This point can only be reached when EOF is reached without errors.
+     * If the client is in the middle of a MULTI/EXEC, log error and quit. */
+    if (fakeClient->flags & REDIS_MULTI) goto readerr;
+
     fclose(fp);
     freeFakeClient(fakeClient);
+    server.appendonly = appendonly;
     return REDIS_OK;
 
 readerr:
@@ -8426,42 +8729,38 @@ static void aofRemoveTempFile(pid_t childpid) {
 
 /* =================== Virtual Memory - Blocking Side  ====================== */
 
-/* substitute the first occurrence of '%p' with the process pid in the
- * swap file name. */
-static void expandVmSwapFilename(void) {
-    char *p = strstr(server.vm_swap_file,"%p");
-    sds new;
-
-    if (!p) return;
-    new = sdsempty();
-    *p = '\0';
-    new = sdscat(new,server.vm_swap_file);
-    new = sdscatprintf(new,"%ld",(long) getpid());
-    new = sdscat(new,p+2);
-    zfree(server.vm_swap_file);
-    server.vm_swap_file = new;
-}
-
 static void vmInit(void) {
     off_t totsize;
     int pipefds[2];
     size_t stacksize;
+    struct flock fl;
 
     if (server.vm_max_threads != 0)
         zmalloc_enable_thread_safeness(); /* we need thread safe zmalloc() */
 
-    expandVmSwapFilename();
     redisLog(REDIS_NOTICE,"Using '%s' as swap file",server.vm_swap_file);
+    /* Try to open the old swap file, otherwise create it */
     if ((server.vm_fp = fopen(server.vm_swap_file,"r+b")) == NULL) {
         server.vm_fp = fopen(server.vm_swap_file,"w+b");
     }
     if (server.vm_fp == NULL) {
         redisLog(REDIS_WARNING,
-            "Impossible to open the swap file: %s. Exiting.",
+            "Can't open the swap file: %s. Exiting.",
             strerror(errno));
         exit(1);
     }
     server.vm_fd = fileno(server.vm_fp);
+    /* Lock the swap file for writing, this is useful in order to avoid
+     * another instance to use the same swap file for a config error. */
+    fl.l_type = F_WRLCK;
+    fl.l_whence = SEEK_SET;
+    fl.l_start = fl.l_len = 0;
+    if (fcntl(server.vm_fd,F_SETLK,&fl) == -1) {
+        redisLog(REDIS_WARNING,
+            "Can't lock the swap file at '%s': %s. Make sure it is not used by another Redis instance.", server.vm_swap_file, strerror(errno));
+        exit(1);
+    }
+    /* Initialize */
     server.vm_next_page = 0;
     server.vm_near_pages = 0;
     server.vm_stats_used_pages = 0;
@@ -9387,12 +9686,56 @@ static int waitForSwappedKey(redisClient *c, robj *key) {
     return 1;
 }
 
-/* Preload keys needed for the ZUNION and ZINTER commands. */
-static void zunionInterBlockClientOnSwappedKeys(redisClient *c) {
+/* Preload keys for any command with first, last and step values for
+ * the command keys prototype, as defined in the command table. */
+static void waitForMultipleSwappedKeys(redisClient *c, struct redisCommand *cmd, int argc, robj **argv) {
+    int j, last;
+    if (cmd->vm_firstkey == 0) return;
+    last = cmd->vm_lastkey;
+    if (last < 0) last = argc+last;
+    for (j = cmd->vm_firstkey; j <= last; j += cmd->vm_keystep) {
+        redisAssert(j < argc);
+        waitForSwappedKey(c,argv[j]);
+    }
+}
+
+/* Preload keys needed for the ZUNIONSTORE and ZINTERSTORE commands.
+ * Note that the number of keys to preload is user-defined, so we need to
+ * apply a sanity check against argc. */
+static void zunionInterBlockClientOnSwappedKeys(redisClient *c, struct redisCommand *cmd, int argc, robj **argv) {
     int i, num;
-    num = atoi(c->argv[2]->ptr);
+    REDIS_NOTUSED(cmd);
+
+    num = atoi(argv[2]->ptr);
+    if (num > (argc-3)) return;
     for (i = 0; i < num; i++) {
-        waitForSwappedKey(c,c->argv[3+i]);
+        waitForSwappedKey(c,argv[3+i]);
+    }
+}
+
+/* Preload keys needed to execute the entire MULTI/EXEC block.
+ *
+ * This function is called by blockClientOnSwappedKeys when EXEC is issued,
+ * and will block the client when any command requires a swapped out value. */
+static void execBlockClientOnSwappedKeys(redisClient *c, struct redisCommand *cmd, int argc, robj **argv) {
+    int i, margc;
+    struct redisCommand *mcmd;
+    robj **margv;
+    REDIS_NOTUSED(cmd);
+    REDIS_NOTUSED(argc);
+    REDIS_NOTUSED(argv);
+
+    if (!(c->flags & REDIS_MULTI)) return;
+    for (i = 0; i < c->mstate.count; i++) {
+        mcmd = c->mstate.commands[i].cmd;
+        margc = c->mstate.commands[i].argc;
+        margv = c->mstate.commands[i].argv;
+
+        if (mcmd->vm_preload_proc != NULL) {
+            mcmd->vm_preload_proc(c,mcmd,margc,margv);
+        } else {
+            waitForMultipleSwappedKeys(c,mcmd,margc,margv);
+        }
     }
 }
 
@@ -9406,17 +9749,11 @@ static void zunionInterBlockClientOnSwappedKeys(redisClient *c) {
  *
  * Return 1 if the client is marked as blocked, 0 if the client can
  * continue as the keys it is going to access appear to be in memory. */
-static int blockClientOnSwappedKeys(struct redisCommand *cmd, redisClient *c) {
-    int j, last;
-
+static int blockClientOnSwappedKeys(redisClient *c, struct redisCommand *cmd) {
     if (cmd->vm_preload_proc != NULL) {
-        cmd->vm_preload_proc(c);
+        cmd->vm_preload_proc(c,cmd,c->argc,c->argv);
     } 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]);
+        waitForMultipleSwappedKeys(c,cmd,c->argc,c->argv);
     }
 
     /* If the client was blocked for at least one key, mark it as blocked. */
@@ -9443,7 +9780,7 @@ static int dontWaitForSwappedKey(redisClient *c, robj *key) {
     /* Remove the key from the list of keys this client is waiting for. */
     listRewind(c->io_keys,&li);
     while ((ln = listNext(&li)) != NULL) {
-        if (compareStringObjects(ln->value,key) == 0) {
+        if (equalStringObjects(ln->value,key)) {
             listDelNode(c->io_keys,ln);
             break;
         }
@@ -9503,6 +9840,50 @@ static void configSetCommand(redisClient *c) {
         server.masterauth = zstrdup(o->ptr);
     } else if (!strcasecmp(c->argv[2]->ptr,"maxmemory")) {
         server.maxmemory = strtoll(o->ptr, NULL, 10);
+    } else if (!strcasecmp(c->argv[2]->ptr,"appendfsync")) {
+        if (!strcasecmp(o->ptr,"no")) {
+            server.appendfsync = APPENDFSYNC_NO;
+        } else if (!strcasecmp(o->ptr,"everysec")) {
+            server.appendfsync = APPENDFSYNC_EVERYSEC;
+        } else if (!strcasecmp(o->ptr,"always")) {
+            server.appendfsync = APPENDFSYNC_ALWAYS;
+        } else {
+            goto badfmt;
+        }
+    } else if (!strcasecmp(c->argv[2]->ptr,"save")) {
+        int vlen, j;
+        sds *v = sdssplitlen(o->ptr,sdslen(o->ptr)," ",1,&vlen);
+
+        /* Perform sanity check before setting the new config:
+         * - Even number of args
+         * - Seconds >= 1, changes >= 0 */
+        if (vlen & 1) {
+            sdsfreesplitres(v,vlen);
+            goto badfmt;
+        }
+        for (j = 0; j < vlen; j++) {
+            char *eptr;
+            long val;
+
+            val = strtoll(v[j], &eptr, 10);
+            if (eptr[0] != '\0' ||
+                ((j & 1) == 0 && val < 1) ||
+                ((j & 1) == 1 && val < 0)) {
+                sdsfreesplitres(v,vlen);
+                goto badfmt;
+            }
+        }
+        /* Finally set the new config */
+        resetServerSaveParams();
+        for (j = 0; j < vlen; j += 2) {
+            time_t seconds;
+            int changes;
+
+            seconds = strtoll(v[j],NULL,10);
+            changes = strtoll(v[j+1],NULL,10);
+            appendServerSaveParams(seconds, changes);
+        }
+        sdsfreesplitres(v,vlen);
     } else {
         addReplySds(c,sdscatprintf(sdsempty(),
             "-ERR not supported CONFIG parameter %s\r\n",
@@ -9512,6 +9893,14 @@ static void configSetCommand(redisClient *c) {
     }
     decrRefCount(o);
     addReply(c,shared.ok);
+    return;
+
+badfmt: /* Bad format errors */
+    addReplySds(c,sdscatprintf(sdsempty(),
+        "-ERR invalid argument '%s' for CONFIG SET '%s'\r\n",
+            (char*)o->ptr,
+            (char*)c->argv[2]->ptr));
+    decrRefCount(o);
 }
 
 static void configGetCommand(redisClient *c) {
@@ -9546,6 +9935,35 @@ static void configGetCommand(redisClient *c) {
         addReplyBulkCString(c,buf);
         matches++;
     }
+    if (stringmatch(pattern,"appendfsync",0)) {
+        char *policy;
+
+        switch(server.appendfsync) {
+        case APPENDFSYNC_NO: policy = "no"; break;
+        case APPENDFSYNC_EVERYSEC: policy = "everysec"; break;
+        case APPENDFSYNC_ALWAYS: policy = "always"; break;
+        default: policy = "unknown"; break; /* too harmless to panic */
+        }
+        addReplyBulkCString(c,"appendfsync");
+        addReplyBulkCString(c,policy);
+        matches++;
+    }
+    if (stringmatch(pattern,"save",0)) {
+        sds buf = sdsempty();
+        int j;
+
+        for (j = 0; j < server.saveparamslen; j++) {
+            buf = sdscatprintf(buf,"%ld %d",
+                    server.saveparams[j].seconds,
+                    server.saveparams[j].changes);
+            if (j != server.saveparamslen-1)
+                buf = sdscatlen(buf," ",1);
+        }
+        addReplyBulkCString(c,"save");
+        addReplyBulkCString(c,buf);
+        sdsfree(buf);
+        matches++;
+    }
     decrRefCount(o);
     lenobj->ptr = sdscatprintf(sdsempty(),"*%d\r\n",matches*2);
 }
@@ -9589,7 +10007,7 @@ static int listMatchPubsubPattern(void *a, void *b) {
     pubsubPattern *pa = a, *pb = b;
 
     return (pa->client == pb->client) &&
-           (compareStringObjects(pa->pattern,pb->pattern) == 0);
+           (equalStringObjects(pa->pattern,pb->pattern));
 }
 
 /* Subscribe a client to a channel. Returns 1 if the operation succeeded, or
@@ -9780,8 +10198,9 @@ static int pubsubPublishMessage(robj *channel, robj *message) {
                                 sdslen(pat->pattern->ptr),
                                 (char*)channel->ptr,
                                 sdslen(channel->ptr),0)) {
-                addReply(pat->client,shared.mbulk3);
-                addReply(pat->client,shared.messagebulk);
+                addReply(pat->client,shared.mbulk4);
+                addReply(pat->client,shared.pmessagebulk);
+                addReplyBulk(pat->client,pat->pattern);
                 addReplyBulk(pat->client,channel);
                 addReplyBulk(pat->client,message);
                 receivers++;
@@ -9837,6 +10256,180 @@ static void publishCommand(redisClient *c) {
 
 /* ================================= Debugging ============================== */
 
+/* Compute the sha1 of string at 's' with 'len' bytes long.
+ * The SHA1 is then xored againt the string pointed by digest.
+ * Since xor is commutative, this operation is used in order to
+ * "add" digests relative to unordered elements.
+ *
+ * So digest(a,b,c,d) will be the same of digest(b,a,c,d) */
+static void xorDigest(unsigned char *digest, void *ptr, size_t len) {
+    SHA1_CTX ctx;
+    unsigned char hash[20], *s = ptr;
+    int j;
+
+    SHA1Init(&ctx);
+    SHA1Update(&ctx,s,len);
+    SHA1Final(hash,&ctx);
+
+    for (j = 0; j < 20; j++)
+        digest[j] ^= hash[j];
+}
+
+static void xorObjectDigest(unsigned char *digest, robj *o) {
+    o = getDecodedObject(o);
+    xorDigest(digest,o->ptr,sdslen(o->ptr));
+    decrRefCount(o);
+}
+
+/* This function instead of just computing the SHA1 and xoring it
+ * against diget, also perform the digest of "digest" itself and
+ * replace the old value with the new one.
+ *
+ * So the final digest will be:
+ *
+ * digest = SHA1(digest xor SHA1(data))
+ *
+ * This function is used every time we want to preserve the order so
+ * that digest(a,b,c,d) will be different than digest(b,c,d,a)
+ *
+ * Also note that mixdigest("foo") followed by mixdigest("bar")
+ * will lead to a different digest compared to "fo", "obar".
+ */
+static void mixDigest(unsigned char *digest, void *ptr, size_t len) {
+    SHA1_CTX ctx;
+    char *s = ptr;
+
+    xorDigest(digest,s,len);
+    SHA1Init(&ctx);
+    SHA1Update(&ctx,digest,20);
+    SHA1Final(digest,&ctx);
+}
+
+static void mixObjectDigest(unsigned char *digest, robj *o) {
+    o = getDecodedObject(o);
+    mixDigest(digest,o->ptr,sdslen(o->ptr));
+    decrRefCount(o);
+}
+
+/* Compute the dataset digest. Since keys, sets elements, hashes elements
+ * are not ordered, we use a trick: every aggregate digest is the xor
+ * of the digests of their elements. This way the order will not change
+ * the result. For list instead we use a feedback entering the output digest
+ * as input in order to ensure that a different ordered list will result in
+ * a different digest. */
+static void computeDatasetDigest(unsigned char *final) {
+    unsigned char digest[20];
+    char buf[128];
+    dictIterator *di = NULL;
+    dictEntry *de;
+    int j;
+    uint32_t aux;
+
+    memset(final,0,20); /* Start with a clean result */
+
+    for (j = 0; j < server.dbnum; j++) {
+        redisDb *db = server.db+j;
+
+        if (dictSize(db->dict) == 0) continue;
+        di = dictGetIterator(db->dict);
+
+        /* hash the DB id, so the same dataset moved in a different
+         * DB will lead to a different digest */
+        aux = htonl(j);
+        mixDigest(final,&aux,sizeof(aux));
+
+        /* Iterate this DB writing every entry */
+        while((de = dictNext(di)) != NULL) {
+            robj *key, *o;
+            time_t expiretime;
+
+            memset(digest,0,20); /* This key-val digest */
+            key = dictGetEntryKey(de);
+            mixObjectDigest(digest,key);
+            if (!server.vm_enabled || key->storage == REDIS_VM_MEMORY ||
+                key->storage == REDIS_VM_SWAPPING) {
+                o = dictGetEntryVal(de);
+                incrRefCount(o);
+            } else {
+                o = vmPreviewObject(key);
+            }
+            aux = htonl(o->type);
+            mixDigest(digest,&aux,sizeof(aux));
+            expiretime = getExpire(db,key);
+
+            /* Save the key and associated value */
+            if (o->type == REDIS_STRING) {
+                mixObjectDigest(digest,o);
+            } else if (o->type == REDIS_LIST) {
+                list *list = o->ptr;
+                listNode *ln;
+                listIter li;
+
+                listRewind(list,&li);
+                while((ln = listNext(&li))) {
+                    robj *eleobj = listNodeValue(ln);
+
+                    mixObjectDigest(digest,eleobj);
+                }
+            } else if (o->type == REDIS_SET) {
+                dict *set = o->ptr;
+                dictIterator *di = dictGetIterator(set);
+                dictEntry *de;
+
+                while((de = dictNext(di)) != NULL) {
+                    robj *eleobj = dictGetEntryKey(de);
+
+                    xorObjectDigest(digest,eleobj);
+                }
+                dictReleaseIterator(di);
+            } else if (o->type == REDIS_ZSET) {
+                zset *zs = o->ptr;
+                dictIterator *di = dictGetIterator(zs->dict);
+                dictEntry *de;
+
+                while((de = dictNext(di)) != NULL) {
+                    robj *eleobj = dictGetEntryKey(de);
+                    double *score = dictGetEntryVal(de);
+                    unsigned char eledigest[20];
+
+                    snprintf(buf,sizeof(buf),"%.17g",*score);
+                    memset(eledigest,0,20);
+                    mixObjectDigest(eledigest,eleobj);
+                    mixDigest(eledigest,buf,strlen(buf));
+                    xorDigest(digest,eledigest,20);
+                }
+                dictReleaseIterator(di);
+            } else if (o->type == REDIS_HASH) {
+                hashIterator *hi;
+                robj *obj;
+
+                hi = hashInitIterator(o);
+                while (hashNext(hi) != REDIS_ERR) {
+                    unsigned char eledigest[20];
+
+                    memset(eledigest,0,20);
+                    obj = hashCurrent(hi,REDIS_HASH_KEY);
+                    mixObjectDigest(eledigest,obj);
+                    decrRefCount(obj);
+                    obj = hashCurrent(hi,REDIS_HASH_VALUE);
+                    mixObjectDigest(eledigest,obj);
+                    decrRefCount(obj);
+                    xorDigest(digest,eledigest,20);
+                }
+                hashReleaseIterator(hi);
+            } else {
+                redisPanic("Unknown object type");
+            }
+            decrRefCount(o);
+            /* If the key has an expire, add it to the mix */
+            if (expiretime != -1) xorDigest(digest,"!!expire!!",10);
+            /* We can finally xor the key-val digest to the final digest */
+            xorDigest(final,digest,20);
+        }
+        dictReleaseIterator(di);
+    }
+}
+
 static void debugCommand(redisClient *c) {
     if (!strcasecmp(c->argv[1]->ptr,"segfault")) {
         *((char*)-1) = 'x';
@@ -9925,6 +10518,36 @@ static void debugCommand(redisClient *c) {
         } else {
             addReply(c,shared.err);
         }
+    } else if (!strcasecmp(c->argv[1]->ptr,"populate") && c->argc == 3) {
+        long keys, j;
+        robj *key, *val;
+        char buf[128];
+
+        if (getLongFromObjectOrReply(c, c->argv[2], &keys, NULL) != REDIS_OK)
+            return;
+        for (j = 0; j < keys; j++) {
+            snprintf(buf,sizeof(buf),"key:%lu",j);
+            key = createStringObject(buf,strlen(buf));
+            if (lookupKeyRead(c->db,key) != NULL) {
+                decrRefCount(key);
+                continue;
+            }
+            snprintf(buf,sizeof(buf),"value:%lu",j);
+            val = createStringObject(buf,strlen(buf));
+            dictAdd(c->db->dict,key,val);
+        }
+        addReply(c,shared.ok);
+    } else if (!strcasecmp(c->argv[1]->ptr,"digest") && c->argc == 2) {
+        unsigned char digest[20];
+        sds d = sdsnew("+");
+        int j;
+
+        computeDatasetDigest(digest);
+        for (j = 0; j < 20; j++)
+            d = sdscatprintf(d, "%02x",digest[j]);
+
+        d = sdscatlen(d,"\r\n",2);
+        addReplySds(c,d);
     } else {
         addReplySds(c,sdsnew(
             "-ERR Syntax error, try DEBUG [SEGFAULT|OBJECT <key>|SWAPIN <key>|SWAPOUT <key>|RELOAD]\r\n"));