diskstore bug fixing and negative cache proper implementation

[redis.git] / src / db.c

diff --git a/src/db.c b/src/db.c
index 6ac2b0d7428ab692cefc756a2f180e5d773d4358..ae40d2044fcd444ab077707c0c38fc7a39ebd9d9 100644 (file)
--- a/src/db.c
+++ b/src/db.c
@@ -11,30 +11,51 @@ robj *lookupKey(redisDb *db, robj *key) {
     if (de) {
         robj *val = dictGetEntryVal(de);
 
     if (de) {
         robj *val = dictGetEntryVal(de);
 

-        if (server.vm_enabled) {
-            if (val->storage == REDIS_VM_MEMORY ||
-                val->storage == REDIS_VM_SWAPPING)
-            {
-                /* If we were swapping the object out, cancel the operation */
-                if (val->storage == REDIS_VM_SWAPPING)
-                    vmCancelThreadedIOJob(val);
-                /* Update the access time for the aging algorithm. */
-                val->lru = server.lruclock;
-            } else {
-                int notify = (val->storage == REDIS_VM_LOADING);
-
-                /* Our value was swapped on disk. Bring it at home. */
-                redisAssert(val->type == REDIS_VMPOINTER);
-                val = vmLoadObject(val);
-                dictGetEntryVal(de) = val;
-
-                /* Clients blocked by the VM subsystem may be waiting for
-                 * this key... */
-                if (notify) handleClientsBlockedOnSwappedKey(db,key);
-            }
+        /* Update the access time for the aging algorithm.
+         * Don't do it if we have a saving child, as this will trigger
+         * a copy on write madness. */
+        if (server.bgsavechildpid == -1 && server.bgrewritechildpid == -1)
+            val->lru = server.lruclock;
+
+        if (server.ds_enabled &&
+            cacheScheduleIOGetFlags(db,key) & REDIS_IO_SAVEINPROG)
+        {
+            /* There is a save in progress for this object!
+             * Wait for it to get out. */
+            waitEmptyIOJobsQueue();
+            processAllPendingIOJobs();
+            redisAssert(!(cacheScheduleIOGetFlags(db,key) & REDIS_IO_SAVEINPROG));

         }
         }

+        server.stat_keyspace_hits++;

         return val;
     } else {
         return val;
     } else {

+        time_t expire;
+        robj *val;
+
+        /* Key not found in the in memory hash table, but if disk store is
+         * enabled we may have this key on disk. If so load it in memory
+         * in a blocking way. */
+        if (server.ds_enabled && cacheKeyMayExist(db,key)) {
+            if (cacheScheduleIOGetFlags(db,key) & REDIS_IO_SAVEINPROG) {
+                /* There is a save in progress for this object!
+                 * Wait for it to get out. */
+                waitEmptyIOJobsQueue();
+                processAllPendingIOJobs();
+                redisAssert((cacheScheduleIOGetFlags(db,key) & REDIS_IO_SAVEINPROG) == 0);
+            }
+
+            redisLog(REDIS_DEBUG,"Force loading key %s via lookup",
+                key->ptr);
+            val = dsGet(db,key,&expire);
+            if (val) {
+                int retval = dbAdd(db,key,val);
+                redisAssert(retval == REDIS_OK);
+                if (expire != -1) setExpire(db,key,expire);
+                server.stat_keyspace_hits++;
+                return val;
+            }
+        }
+        server.stat_keyspace_misses++;

         return NULL;
     }
 }
         return NULL;
     }
 }


@@ -72,6 +93,7 @@ int dbAdd(redisDb *db, robj *key, robj *val) {
     } else {
         sds copy = sdsdup(key->ptr);
         dictAdd(db->dict, copy, val);
     } else {
         sds copy = sdsdup(key->ptr);
         dictAdd(db->dict, copy, val);

+        if (server.ds_enabled) cacheSetKeyMayExist(db,key);

         return REDIS_OK;
     }
 }
         return REDIS_OK;
     }
 }


@@ -81,14 +103,19 @@ int dbAdd(redisDb *db, robj *key, robj *val) {
  *
  * On update (key already existed) 0 is returned. Otherwise 1. */
 int dbReplace(redisDb *db, robj *key, robj *val) {
  *
  * On update (key already existed) 0 is returned. Otherwise 1. */
 int dbReplace(redisDb *db, robj *key, robj *val) {

-    if (dictFind(db->dict,key->ptr) == NULL) {
+    robj *oldval;
+    int retval;
+
+    if ((oldval = dictFetchValue(db->dict,key->ptr)) == NULL) {

         sds copy = sdsdup(key->ptr);
         dictAdd(db->dict, copy, val);
         sds copy = sdsdup(key->ptr);
         dictAdd(db->dict, copy, val);

-        return 1;
+        retval = 1;

     } else {
         dictReplace(db->dict, key->ptr, val);
     } else {
         dictReplace(db->dict, key->ptr, val);

-        return 0;
+        retval = 0;

     }
     }

+    if (server.ds_enabled) cacheSetKeyMayExist(db,key);
+    return retval;

 }
 
 int dbExists(redisDb *db, robj *key) {
 }
 
 int dbExists(redisDb *db, robj *key) {


@@ -123,6 +150,14 @@ robj *dbRandomKey(redisDb *db) {
 
 /* Delete a key, value, and associated expiration entry if any, from the DB */
 int dbDelete(redisDb *db, robj *key) {
 
 /* Delete a key, value, and associated expiration entry if any, from the DB */
 int dbDelete(redisDb *db, robj *key) {

+    /* If diskstore is enabled make sure to awake waiting clients for this key
+     * as it is not really useful to wait for a key already deleted to be
+     * loaded from disk. */
+    if (server.ds_enabled) {
+        handleClientsBlockedOnSwappedKey(db,key);
+        cacheSetKeyDoesNotExist(db,key);
+    }
+

     /* Deleting an entry from the expires dict will not free the sds of
      * the key, because it is shared with the main dictionary. */
     if (dictSize(db->expires) > 0) dictDelete(db->expires,key->ptr);
     /* Deleting an entry from the expires dict will not free the sds of
      * the key, because it is shared with the main dictionary. */
     if (dictSize(db->expires) > 0) dictDelete(db->expires,key->ptr);


@@ -149,27 +184,50 @@ int selectDb(redisClient *c, int id) {
     return REDIS_OK;
 }
 
     return REDIS_OK;
 }
 

+/*-----------------------------------------------------------------------------
+ * Hooks for key space changes.
+ *
+ * Every time a key in the database is modified the function
+ * signalModifiedKey() is called.
+ *
+ * Every time a DB is flushed the function signalFlushDb() is called.
+ *----------------------------------------------------------------------------*/
+
+void signalModifiedKey(redisDb *db, robj *key) {
+    touchWatchedKey(db,key);
+    if (server.ds_enabled)
+        cacheScheduleIO(db,key,REDIS_IO_SAVE);
+}
+
+void signalFlushedDb(int dbid) {
+    touchWatchedKeysOnFlush(dbid);
+}
+

 /*-----------------------------------------------------------------------------
  * Type agnostic commands operating on the key space
  *----------------------------------------------------------------------------*/
 
 void flushdbCommand(redisClient *c) {
     server.dirty += dictSize(c->db->dict);
 /*-----------------------------------------------------------------------------
  * Type agnostic commands operating on the key space
  *----------------------------------------------------------------------------*/
 
 void flushdbCommand(redisClient *c) {
     server.dirty += dictSize(c->db->dict);

-    touchWatchedKeysOnFlush(c->db->id);
+    signalFlushedDb(c->db->id);

     dictEmpty(c->db->dict);
     dictEmpty(c->db->expires);
     dictEmpty(c->db->dict);
     dictEmpty(c->db->expires);

+    if (server.ds_enabled) dsFlushDb(c->db->id);

     addReply(c,shared.ok);
 }
 
 void flushallCommand(redisClient *c) {
     addReply(c,shared.ok);
 }
 
 void flushallCommand(redisClient *c) {

-    touchWatchedKeysOnFlush(-1);
+    signalFlushedDb(-1);

     server.dirty += emptyDb();
     addReply(c,shared.ok);
     if (server.bgsavechildpid != -1) {
         kill(server.bgsavechildpid,SIGKILL);
         rdbRemoveTempFile(server.bgsavechildpid);
     }
     server.dirty += emptyDb();
     addReply(c,shared.ok);
     if (server.bgsavechildpid != -1) {
         kill(server.bgsavechildpid,SIGKILL);
         rdbRemoveTempFile(server.bgsavechildpid);
     }

-    rdbSave(server.dbfilename);
+    if (server.ds_enabled)
+        dsFlushDb(-1);
+    else
+        rdbSave(server.dbfilename);

     server.dirty++;
 }
 
     server.dirty++;
 }
 


@@ -177,10 +235,22 @@ void delCommand(redisClient *c) {
     int deleted = 0, j;
 
     for (j = 1; j < c->argc; j++) {
     int deleted = 0, j;
 
     for (j = 1; j < c->argc; j++) {

+        if (server.ds_enabled) {
+            lookupKeyRead(c->db,c->argv[j]);
+            /* FIXME: this can be optimized a lot, no real need to load
+             * a possibly huge value. */
+        }

         if (dbDelete(c->db,c->argv[j])) {
         if (dbDelete(c->db,c->argv[j])) {

-            touchWatchedKey(c->db,c->argv[j]);
+            signalModifiedKey(c->db,c->argv[j]);

             server.dirty++;
             deleted++;
             server.dirty++;
             deleted++;

+        } else if (server.ds_enabled) {
+            if (cacheKeyMayExist(c->db,c->argv[j]) &&
+                dsExists(c->db,c->argv[j]))
+            {
+                cacheScheduleIO(c->db,c->argv[j],REDIS_IO_SAVE);
+                deleted = 1;
+            }

         }
     }
     addReplyLongLong(c,deleted);
         }
     }
     addReplyLongLong(c,deleted);


@@ -199,7 +269,7 @@ void selectCommand(redisClient *c) {
     int id = atoi(c->argv[1]->ptr);
 
     if (selectDb(c,id) == REDIS_ERR) {
     int id = atoi(c->argv[1]->ptr);
 
     if (selectDb(c,id) == REDIS_ERR) {

-        addReplySds(c,sdsnew("-ERR invalid DB index\r\n"));
+        addReplyError(c,"invalid DB index");

     } else {
         addReply(c,shared.ok);
     }
     } else {
         addReply(c,shared.ok);
     }


@@ -221,19 +291,17 @@ void keysCommand(redisClient *c) {
     dictIterator *di;
     dictEntry *de;
     sds pattern = c->argv[1]->ptr;
     dictIterator *di;
     dictEntry *de;
     sds pattern = c->argv[1]->ptr;

-    int plen = sdslen(pattern);
+    int plen = sdslen(pattern), allkeys;

     unsigned long numkeys = 0;
     unsigned long numkeys = 0;

-    robj *lenobj = createObject(REDIS_STRING,NULL);
+    void *replylen = addDeferredMultiBulkLength(c);

 
     di = dictGetIterator(c->db->dict);
 
     di = dictGetIterator(c->db->dict);

-    addReply(c,lenobj);
-    decrRefCount(lenobj);
+    allkeys = (pattern[0] == '*' && pattern[1] == '\0');

     while((de = dictNext(di)) != NULL) {
         sds key = dictGetEntryKey(de);
         robj *keyobj;
 
     while((de = dictNext(di)) != NULL) {
         sds key = dictGetEntryKey(de);
         robj *keyobj;
 

-        if ((pattern[0] == '*' && pattern[1] == '\0') ||
-            stringmatchlen(pattern,plen,key,sdslen(key),0)) {
+        if (allkeys || stringmatchlen(pattern,plen,key,sdslen(key),0)) {

             keyobj = createStringObject(key,sdslen(key));
             if (expireIfNeeded(c->db,keyobj) == 0) {
                 addReplyBulk(c,keyobj);
             keyobj = createStringObject(key,sdslen(key));
             if (expireIfNeeded(c->db,keyobj) == 0) {
                 addReplyBulk(c,keyobj);


@@ -243,17 +311,15 @@ void keysCommand(redisClient *c) {
         }
     }
     dictReleaseIterator(di);
         }
     }
     dictReleaseIterator(di);

-    lenobj->ptr = sdscatprintf(sdsempty(),"*%lu\r\n",numkeys);
+    setDeferredMultiBulkLength(c,replylen,numkeys);

 }
 
 void dbsizeCommand(redisClient *c) {
 }
 
 void dbsizeCommand(redisClient *c) {

-    addReplySds(c,
-        sdscatprintf(sdsempty(),":%lu\r\n",dictSize(c->db->dict)));
+    addReplyLongLong(c,dictSize(c->db->dict));

 }
 
 void lastsaveCommand(redisClient *c) {
 }
 
 void lastsaveCommand(redisClient *c) {

-    addReplySds(c,
-        sdscatprintf(sdsempty(),":%lu\r\n",server.lastsave));
+    addReplyLongLong(c,server.lastsave);

 }
 
 void typeCommand(redisClient *c) {
 }
 
 void typeCommand(redisClient *c) {


@@ -262,24 +328,23 @@ void typeCommand(redisClient *c) {
 
     o = lookupKeyRead(c->db,c->argv[1]);
     if (o == NULL) {
 
     o = lookupKeyRead(c->db,c->argv[1]);
     if (o == NULL) {

-        type = "+none";
+        type = "none";

     } else {
         switch(o->type) {
     } else {
         switch(o->type) {

-        case REDIS_STRING: type = "+string"; break;
-        case REDIS_LIST: type = "+list"; break;
-        case REDIS_SET: type = "+set"; break;
-        case REDIS_ZSET: type = "+zset"; break;
-        case REDIS_HASH: type = "+hash"; break;
-        default: type = "+unknown"; break;
+        case REDIS_STRING: type = "string"; break;
+        case REDIS_LIST: type = "list"; break;
+        case REDIS_SET: type = "set"; break;
+        case REDIS_ZSET: type = "zset"; break;
+        case REDIS_HASH: type = "hash"; break;
+        default: type = "unknown"; break;

         }
     }
         }
     }

-    addReplySds(c,sdsnew(type));
-    addReply(c,shared.crlf);
+    addReplyStatus(c,type);

 }
 
 void saveCommand(redisClient *c) {
     if (server.bgsavechildpid != -1) {
 }
 
 void saveCommand(redisClient *c) {
     if (server.bgsavechildpid != -1) {

-        addReplySds(c,sdsnew("-ERR background save in progress\r\n"));
+        addReplyError(c,"Background save already in progress");

         return;
     }
     if (rdbSave(server.dbfilename) == REDIS_OK) {
         return;
     }
     if (rdbSave(server.dbfilename) == REDIS_OK) {


@@ -291,12 +356,11 @@ void saveCommand(redisClient *c) {
 
 void bgsaveCommand(redisClient *c) {
     if (server.bgsavechildpid != -1) {
 
 void bgsaveCommand(redisClient *c) {
     if (server.bgsavechildpid != -1) {

-        addReplySds(c,sdsnew("-ERR background save already in progress\r\n"));
+        addReplyError(c,"Background save already in progress");

         return;
     }
     if (rdbSaveBackground(server.dbfilename) == REDIS_OK) {
         return;
     }
     if (rdbSaveBackground(server.dbfilename) == REDIS_OK) {

-        char *status = "+Background saving started\r\n";
-        addReplySds(c,sdsnew(status));
+        addReplyStatus(c,"Background saving started");

     } else {
         addReply(c,shared.err);
     }
     } else {
         addReply(c,shared.err);
     }


@@ -305,7 +369,7 @@ void bgsaveCommand(redisClient *c) {
 void shutdownCommand(redisClient *c) {
     if (prepareForShutdown() == REDIS_OK)
         exit(0);
 void shutdownCommand(redisClient *c) {
     if (prepareForShutdown() == REDIS_OK)
         exit(0);

-    addReplySds(c, sdsnew("-ERR Errors trying to SHUTDOWN. Check logs.\r\n"));
+    addReplyError(c,"Errors trying to SHUTDOWN. Check logs.");

 }
 
 void renameGenericCommand(redisClient *c, int nx) {
 }
 
 void renameGenericCommand(redisClient *c, int nx) {


@@ -330,8 +394,8 @@ void renameGenericCommand(redisClient *c, int nx) {
         dbReplace(c->db,c->argv[2],o);
     }
     dbDelete(c->db,c->argv[1]);
         dbReplace(c->db,c->argv[2],o);
     }
     dbDelete(c->db,c->argv[1]);

-    touchWatchedKey(c->db,c->argv[1]);
-    touchWatchedKey(c->db,c->argv[2]);
+    signalModifiedKey(c->db,c->argv[1]);
+    signalModifiedKey(c->db,c->argv[2]);

     server.dirty++;
     addReply(c,nx ? shared.cone : shared.ok);
 }
     server.dirty++;
     addReply(c,nx ? shared.cone : shared.ok);
 }


@@ -394,23 +458,16 @@ int removeExpire(redisDb *db, robj *key) {
     /* An expire may only be removed if there is a corresponding entry in the
      * main dict. Otherwise, the key will never be freed. */
     redisAssert(dictFind(db->dict,key->ptr) != NULL);
     /* An expire may only be removed if there is a corresponding entry in the
      * main dict. Otherwise, the key will never be freed. */
     redisAssert(dictFind(db->dict,key->ptr) != NULL);

-    if (dictDelete(db->expires,key->ptr) == DICT_OK) {
-        return 1;
-    } else {
-        return 0;
-    }
+    return dictDelete(db->expires,key->ptr) == DICT_OK;

 }
 
 }
 

-int setExpire(redisDb *db, robj *key, time_t when) {
+void setExpire(redisDb *db, robj *key, time_t when) {

     dictEntry *de;
 
     /* Reuse the sds from the main dict in the expire dict */
     dictEntry *de;
 
     /* Reuse the sds from the main dict in the expire dict */

-    redisAssert((de = dictFind(db->dict,key->ptr)) != NULL);
-    if (dictAdd(db->expires,dictGetEntryKey(de),(void*)when) == DICT_ERR) {
-        return 0;
-    } else {
-        return 1;
-    }
+    de = dictFind(db->dict,key->ptr);
+    redisAssert(de != NULL);
+    dictReplace(db->expires,dictGetEntryKey(de),(void*)when);

 }
 
 /* Return the expire time of the specified key, or -1 if no expire
 }
 
 /* Return the expire time of the specified key, or -1 if no expire


@@ -437,16 +494,14 @@ time_t getExpire(redisDb *db, robj *key) {
  * will be consistent even if we allow write operations against expiring
  * keys. */
 void propagateExpire(redisDb *db, robj *key) {
  * will be consistent even if we allow write operations against expiring
  * keys. */
 void propagateExpire(redisDb *db, robj *key) {

-    struct redisCommand *cmd;

     robj *argv[2];
 
     robj *argv[2];
 

-    cmd = lookupCommand("del");

     argv[0] = createStringObject("DEL",3);
     argv[1] = key;
     incrRefCount(key);
 
     if (server.appendonly)
     argv[0] = createStringObject("DEL",3);
     argv[1] = key;
     incrRefCount(key);
 
     if (server.appendonly)

-        feedAppendOnlyFile(cmd,db->id,argv,2);
+        feedAppendOnlyFile(server.delCommand,db->id,argv,2);

     if (listLength(server.slaves))
         replicationFeedSlaves(server.slaves,db->id,argv,2);
 
     if (listLength(server.slaves))
         replicationFeedSlaves(server.slaves,db->id,argv,2);
 


@@ -475,7 +530,6 @@ int expireIfNeeded(redisDb *db, robj *key) {
 
     /* Delete the key */
     server.stat_expiredkeys++;
 
     /* Delete the key */
     server.stat_expiredkeys++;

-    server.dirty++;

     propagateExpire(db,key);
     return dbDelete(db,key);
 }
     propagateExpire(db,key);
     return dbDelete(db,key);
 }


@@ -486,7 +540,7 @@ int expireIfNeeded(redisDb *db, robj *key) {
 
 void expireGenericCommand(redisClient *c, robj *key, robj *param, long offset) {
     dictEntry *de;
 
 void expireGenericCommand(redisClient *c, robj *key, robj *param, long offset) {
     dictEntry *de;

-    time_t seconds;
+    long seconds;

 
     if (getLongFromObjectOrReply(c, param, &seconds, NULL) != REDIS_OK) return;
 
 
     if (getLongFromObjectOrReply(c, param, &seconds, NULL) != REDIS_OK) return;
 


@@ -500,17 +554,14 @@ void expireGenericCommand(redisClient *c, robj *key, robj *param, long offset) {
     if (seconds <= 0) {
         if (dbDelete(c->db,key)) server.dirty++;
         addReply(c, shared.cone);
     if (seconds <= 0) {
         if (dbDelete(c->db,key)) server.dirty++;
         addReply(c, shared.cone);

-        touchWatchedKey(c->db,key);
+        signalModifiedKey(c->db,key);

         return;
     } else {
         time_t when = time(NULL)+seconds;
         return;
     } else {
         time_t when = time(NULL)+seconds;

-        if (setExpire(c->db,key,when)) {
-            addReply(c,shared.cone);
-            touchWatchedKey(c->db,key);
-            server.dirty++;
-        } else {
-            addReply(c,shared.czero);
-        }
+        setExpire(c->db,key,when);
+        addReply(c,shared.cone);
+        signalModifiedKey(c->db,key);
+        server.dirty++;

         return;
     }
 }
         return;
     }
 }


@@ -524,13 +575,28 @@ void expireatCommand(redisClient *c) {
 }
 
 void ttlCommand(redisClient *c) {
 }
 
 void ttlCommand(redisClient *c) {

-    time_t expire;
-    int ttl = -1;
+    time_t expire, ttl = -1;

 
     expire = getExpire(c->db,c->argv[1]);
     if (expire != -1) {
 
     expire = getExpire(c->db,c->argv[1]);
     if (expire != -1) {

-        ttl = (int) (expire-time(NULL));
+        ttl = (expire-time(NULL));

         if (ttl < 0) ttl = -1;
     }
         if (ttl < 0) ttl = -1;
     }

-    addReplySds(c,sdscatprintf(sdsempty(),":%d\r\n",ttl));
+    addReplyLongLong(c,(long long)ttl);
+}
+
+void persistCommand(redisClient *c) {
+    dictEntry *de;
+
+    de = dictFind(c->db->dict,c->argv[1]->ptr);
+    if (de == NULL) {
+        addReply(c,shared.czero);
+    } else {
+        if (removeExpire(c->db,c->argv[1])) {
+            addReply(c,shared.cone);
+            server.dirty++;
+        } else {
+            addReply(c,shared.czero);
+        }
+    }

 }
 }