diskstore bug fixing and negative cache proper implementation

[redis.git] / src / db.c

diff --git a/src/db.c b/src/db.c
index c985794d4aececaa026b827ffc90f68a4bb46dd3..ae40d2044fcd444ab077707c0c38fc7a39ebd9d9 100644 (file)
--- a/src/db.c
+++ b/src/db.c
@@ -34,12 +34,16 @@ robj *lookupKey(redisDb *db, robj *key) {
 
         /* 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.
-         * 
-         * FIXME: race condition here. If there was an already scheduled
-         * async loading of this key, what may happen is that the old
-         * key is loaded in memory if this gets deleted in the meantime. */
+         * 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);
@@ -89,9 +93,7 @@ int dbAdd(redisDb *db, robj *key, robj *val) {
     } else {
         sds copy = sdsdup(key->ptr);
         dictAdd(db->dict, copy, val);
-        if (server.ds_enabled) {
-            /* FIXME: remove entry from negative cache */
-        }
+        if (server.ds_enabled) cacheSetKeyMayExist(db,key);
         return REDIS_OK;
     }
 }
@@ -102,15 +104,18 @@ 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) {
     robj *oldval;
+    int retval;
 
     if ((oldval = dictFetchValue(db->dict,key->ptr)) == NULL) {
         sds copy = sdsdup(key->ptr);
         dictAdd(db->dict, copy, val);
-        return 1;
+        retval = 1;
     } 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) {
@@ -148,10 +153,10 @@ 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);
-
-    /* FIXME: we should mark this key as non existing on disk in the negative
-     * cache. */
+    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. */
@@ -196,8 +201,6 @@ void signalModifiedKey(redisDb *db, robj *key) {
 
 void signalFlushedDb(int dbid) {
     touchWatchedKeysOnFlush(dbid);
-    if (server.ds_enabled)
-        dsFlushDb(dbid);
 }
 
 /*-----------------------------------------------------------------------------
@@ -209,6 +212,7 @@ void flushdbCommand(redisClient *c) {
     signalFlushedDb(c->db->id);
     dictEmpty(c->db->dict);
     dictEmpty(c->db->expires);
+    if (server.ds_enabled) dsFlushDb(c->db->id);
     addReply(c,shared.ok);
 }
 
@@ -220,7 +224,10 @@ void flushallCommand(redisClient *c) {
         kill(server.bgsavechildpid,SIGKILL);
         rdbRemoveTempFile(server.bgsavechildpid);
     }
-    rdbSave(server.dbfilename);
+    if (server.ds_enabled)
+        dsFlushDb(-1);
+    else
+        rdbSave(server.dbfilename);
     server.dirty++;
 }