minor changes to doc and comments
[redis.git] / src / redis.c
index fb6eb46948a46b7f8f910f0f4d6044b90dcb8d34..65cf3ace9c045b1fbcffa6347aba51f37dc87626 100644 (file)
@@ -345,7 +345,7 @@ unsigned int dictEncObjHash(const void *key) {
     }
 }
 
-/* Sets type */
+/* Sets type and diskstore negative caching hash table */
 dictType setDictType = {
     dictEncObjHash,            /* hash function */
     NULL,                      /* key dup */
@@ -596,7 +596,7 @@ int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientData) {
             }
             updateDictResizePolicy();
         }
-    } else {
+    } else if (!server.ds_enabled) {
         /* If there is not a background saving in progress check if
          * we have to save now */
          time_t now = time(NULL);
@@ -618,28 +618,9 @@ int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientData) {
      * in order to guarantee a strict consistency. */
     if (server.masterhost == NULL) activeExpireCycle();
 
-    /* Swap a few keys on disk if we are over the memory limit and VM
-     * is enbled. Try to free objects from the free list first. */
-    if (vmCanSwapOut()) {
-        while (server.vm_enabled && zmalloc_used_memory() >
-                server.vm_max_memory)
-        {
-            int retval = (server.vm_max_threads == 0) ?
-                        vmSwapOneObjectBlocking() :
-                        vmSwapOneObjectThreaded();
-            if (retval == REDIS_ERR && !(loops % 300) &&
-                zmalloc_used_memory() >
-                (server.vm_max_memory+server.vm_max_memory/10))
-            {
-                redisLog(REDIS_WARNING,"WARNING: vm-max-memory limit exceeded by more than 10%% but unable to swap more objects out!");
-            }
-            /* Note that when using threade I/O we free just one object,
-             * because anyway when the I/O thread in charge to swap this
-             * object out will finish, the handler of completed jobs
-             * will try to swap more objects if we are still out of memory. */
-            if (retval == REDIS_ERR || server.vm_max_threads > 0) break;
-        }
-    }
+    /* Remove a few cached objects from memory if we are over the
+     * configured memory limit */
+    if (server.ds_enabled) cacheCron();
 
     /* Replication cron function -- used to reconnect to master and
      * to detect transfer failures. */
@@ -656,8 +637,8 @@ void beforeSleep(struct aeEventLoop *eventLoop) {
     listNode *ln;
     redisClient *c;
 
-    /* Awake clients that got all the swapped keys they requested */
-    if (server.vm_enabled && listLength(server.io_ready_clients)) {
+    /* Awake clients that got all the on disk keys they requested */
+    if (server.ds_enabled && listLength(server.io_ready_clients)) {
         listIter li;
 
         listRewind(server.io_ready_clients,&li);
@@ -668,7 +649,7 @@ void beforeSleep(struct aeEventLoop *eventLoop) {
             /* Resume the client. */
             listDelNode(server.io_ready_clients,ln);
             c->flags &= (~REDIS_IO_WAIT);
-            server.vm_blocked_clients--;
+            server.cache_blocked_clients--;
             aeCreateFileEvent(server.el, c->fd, AE_READABLE,
                 readQueryFromClient, c);
             cmd = lookupCommand(c->argv[0]->ptr);
@@ -787,13 +768,10 @@ void initServerConfig() {
     server.maxmemory = 0;
     server.maxmemory_policy = REDIS_MAXMEMORY_VOLATILE_LRU;
     server.maxmemory_samples = 3;
-    server.vm_enabled = 0;
-    server.vm_swap_file = zstrdup("/tmp/redis-%p.vm");
-    server.vm_page_size = 256;          /* 256 bytes per page */
-    server.vm_pages = 1024*1024*100;    /* 104 millions of pages */
-    server.vm_max_memory = 1024LL*1024*1024*1; /* 1 GB of RAM */
-    server.vm_max_threads = 4;
-    server.vm_blocked_clients = 0;
+    server.ds_enabled = 0;
+    server.ds_path = sdsnew("/tmp/redis.ds");
+    server.cache_max_memory = 64LL*1024*1024; /* 64 MB of RAM */
+    server.cache_blocked_clients = 0;
     server.hash_max_zipmap_entries = REDIS_HASH_MAX_ZIPMAP_ENTRIES;
     server.hash_max_zipmap_value = REDIS_HASH_MAX_ZIPMAP_VALUE;
     server.list_max_ziplist_entries = REDIS_LIST_MAX_ZIPLIST_ENTRIES;
@@ -848,6 +826,9 @@ void initServer() {
     server.slaves = listCreate();
     server.monitors = listCreate();
     server.unblocked_clients = listCreate();
+    server.cache_flush_queue = listCreate();
+    server.cache_flush_delay = 0;
+
     createSharedObjects();
     server.el = aeCreateEventLoop();
     server.db = zmalloc(sizeof(redisDb)*server.dbnum);
@@ -873,8 +854,10 @@ void initServer() {
         server.db[j].expires = dictCreate(&keyptrDictType,NULL);
         server.db[j].blocking_keys = dictCreate(&keylistDictType,NULL);
         server.db[j].watched_keys = dictCreate(&keylistDictType,NULL);
-        if (server.vm_enabled)
+        if (server.ds_enabled) {
             server.db[j].io_keys = dictCreate(&keylistDictType,NULL);
+            server.db[j].io_negcache = dictCreate(&setDictType,NULL);
+        }
         server.db[j].id = j;
     }
     server.pubsub_channels = dictCreate(&keylistDictType,NULL);
@@ -891,6 +874,7 @@ void initServer() {
     server.stat_numcommands = 0;
     server.stat_numconnections = 0;
     server.stat_expiredkeys = 0;
+    server.stat_evictedkeys = 0;
     server.stat_starttime = time(NULL);
     server.stat_keyspace_misses = 0;
     server.stat_keyspace_hits = 0;
@@ -910,7 +894,7 @@ void initServer() {
         }
     }
 
-    if (server.vm_enabled) vmInit();
+    if (server.ds_enabled) dsInit();
 }
 
 /* Populates the Redis Command Table starting from the hard coded list
@@ -1049,8 +1033,8 @@ int processCommand(redisClient *c) {
         queueMultiCommand(c,cmd);
         addReply(c,shared.queued);
     } else {
-        if (server.vm_enabled && server.vm_max_threads > 0 &&
-            blockClientOnSwappedKeys(c,cmd)) return REDIS_ERR;
+        if (server.ds_enabled && blockClientOnSwappedKeys(c,cmd))
+            return REDIS_ERR;
         call(c,cmd);
     }
     return REDIS_OK;
@@ -1068,10 +1052,11 @@ int prepareForShutdown() {
         kill(server.bgsavechildpid,SIGKILL);
         rdbRemoveTempFile(server.bgsavechildpid);
     }
-    if (server.appendonly) {
+    if (server.ds_enabled) {
+        /* FIXME: flush all objects on disk */
+    } else if (server.appendonly) {
         /* Append only file: fsync() the AOF and exit */
         aof_fsync(server.appendfd);
-        if (server.vm_enabled) unlink(server.vm_swap_file);
     } else if (server.saveparamslen > 0) {
         /* Snapshotting. Perform a SYNC SAVE and exit */
         if (rdbSave(server.dbfilename) != REDIS_OK) {
@@ -1177,13 +1162,14 @@ sds genRedisInfoString(void) {
         "total_connections_received:%lld\r\n"
         "total_commands_processed:%lld\r\n"
         "expired_keys:%lld\r\n"
+        "evicted_keys:%lld\r\n"
         "keyspace_hits:%lld\r\n"
         "keyspace_misses:%lld\r\n"
         "hash_max_zipmap_entries:%zu\r\n"
         "hash_max_zipmap_value:%zu\r\n"
         "pubsub_channels:%ld\r\n"
         "pubsub_patterns:%u\r\n"
-        "vm_enabled:%d\r\n"
+        "ds_enabled:%d\r\n"
         "role:%s\r\n"
         ,REDIS_VERSION,
         redisGitSHA1(),
@@ -1219,13 +1205,14 @@ sds genRedisInfoString(void) {
         server.stat_numconnections,
         server.stat_numcommands,
         server.stat_expiredkeys,
+        server.stat_evictedkeys,
         server.stat_keyspace_hits,
         server.stat_keyspace_misses,
         server.hash_max_zipmap_entries,
         server.hash_max_zipmap_value,
         dictSize(server.pubsub_channels),
         listLength(server.pubsub_patterns),
-        server.vm_enabled != 0,
+        server.ds_enabled != 0,
         server.masterhost == NULL ? "master" : "slave"
     );
     if (server.masterhost) {
@@ -1252,33 +1239,13 @@ sds genRedisInfoString(void) {
             );
         }
     }
-    if (server.vm_enabled) {
+    if (server.ds_enabled) {
         lockThreadedIO();
         info = sdscatprintf(info,
-            "vm_conf_max_memory:%llu\r\n"
-            "vm_conf_page_size:%llu\r\n"
-            "vm_conf_pages:%llu\r\n"
-            "vm_stats_used_pages:%llu\r\n"
-            "vm_stats_swapped_objects:%llu\r\n"
-            "vm_stats_swappin_count:%llu\r\n"
-            "vm_stats_swappout_count:%llu\r\n"
-            "vm_stats_io_newjobs_len:%lu\r\n"
-            "vm_stats_io_processing_len:%lu\r\n"
-            "vm_stats_io_processed_len:%lu\r\n"
-            "vm_stats_io_active_threads:%lu\r\n"
-            "vm_stats_blocked_clients:%lu\r\n"
-            ,(unsigned long long) server.vm_max_memory,
-            (unsigned long long) server.vm_page_size,
-            (unsigned long long) server.vm_pages,
-            (unsigned long long) server.vm_stats_used_pages,
-            (unsigned long long) server.vm_stats_swapped_objects,
-            (unsigned long long) server.vm_stats_swapins,
-            (unsigned long long) server.vm_stats_swapouts,
-            (unsigned long) listLength(server.io_newjobs),
-            (unsigned long) listLength(server.io_processing),
-            (unsigned long) listLength(server.io_processed),
-            (unsigned long) server.io_active_threads,
-            (unsigned long) server.vm_blocked_clients
+            "cache_max_memory:%llu\r\n"
+            "cache_blocked_clients:%lu\r\n"
+            ,(unsigned long long) server.cache_max_memory,
+            (unsigned long) server.cache_blocked_clients
         );
         unlockThreadedIO();
     }
@@ -1436,44 +1403,13 @@ void freeMemoryIfNeeded(void) {
             if (bestkey) {
                 robj *keyobj = createStringObject(bestkey,sdslen(bestkey));
                 dbDelete(db,keyobj);
-                server.stat_expiredkeys++;
+                server.stat_evictedkeys++;
                 decrRefCount(keyobj);
                 freed++;
             }
         }
         if (!freed) return; /* nothing to free... */
     }
-
-    while(0) {
-        int j, k, freed = 0;
-        for (j = 0; j < server.dbnum; j++) {
-            int minttl = -1;
-            sds minkey = NULL;
-            robj *keyobj = NULL;
-            struct dictEntry *de;
-
-            if (dictSize(server.db[j].expires)) {
-                freed = 1;
-                /* From a sample of three keys drop the one nearest to
-                 * the natural expire */
-                for (k = 0; k < 3; k++) {
-                    time_t t;
-
-                    de = dictGetRandomKey(server.db[j].expires);
-                    t = (time_t) dictGetEntryVal(de);
-                    if (minttl == -1 || t < minttl) {
-                        minkey = dictGetEntryKey(de);
-                        minttl = t;
-                    }
-                }
-                keyobj = createStringObject(minkey,sdslen(minkey));
-                dbDelete(server.db+j,keyobj);
-                server.stat_expiredkeys++;
-                decrRefCount(keyobj);
-            }
-        }
-        if (!freed) return; /* nothing to free... */
-    }
 }
 
 /* =================================== Main! ================================ */
@@ -1561,7 +1497,9 @@ int main(int argc, char **argv) {
     linuxOvercommitMemoryWarning();
 #endif
     start = time(NULL);
-    if (server.appendonly) {
+    if (server.ds_enabled) {
+        redisLog(REDIS_NOTICE,"DB not loaded (running with disk back end)");
+    } else if (server.appendonly) {
         if (loadAppendOnlyFile(server.appendfilename) == REDIS_OK)
             redisLog(REDIS_NOTICE,"DB loaded from append only file: %ld seconds",time(NULL)-start);
     } else {