TTL API change: TTL returns -2 for non existing keys.

[redis.git] / src / db.c

diff --git a/src/db.c b/src/db.c
index 616b1fa1f3ad4d40e357769be8cc2191c0c15c13..a73d1fbf5e0dc75c5d38379f33ce6f7bffd2d642 100644 (file)
--- a/src/db.c
+++ b/src/db.c
@@ -1,3 +1,32 @@
+/*
+ * Copyright (c) 2009-2012, Salvatore Sanfilippo <antirez at gmail dot com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+

 #include "redis.h"
 
 #include <signal.h>
 #include "redis.h"
 
 #include <signal.h>


@@ -10,28 +39,6 @@ void SlotToKeyDel(robj *key);
  * C-level DB API
  *----------------------------------------------------------------------------*/
 
  * C-level DB API
  *----------------------------------------------------------------------------*/
 

-/* Important notes on lookup and disk store.
- *
- * When disk store is enabled on lookup we can have different cases.
- *
- * a) The key is in memory:
- *    - If the key is not in IO_SAVEINPROG state we can access it.
- *      As if it's just IO_SAVE this means we have the key in the IO queue
- *      but can't be accessed by the IO thread (it requires to be
- *      translated into an IO Job by the cache cron function.)
- *    - If the key is in IO_SAVEINPROG we can't touch the key and have
- *      to blocking wait completion of operations.
- * b) The key is not in memory:
- *    - If it's marked as non existing on disk as well (negative cache)
- *      we don't need to perform the disk access.
- *    - if the key MAY EXIST, but is not in memory, and it is marked as IO_SAVE
- *      then the key can only be a deleted one. As IO_SAVE keys are never
- *      evicted (dirty state), so the only possibility is that key was deleted.
- *    - if the key MAY EXIST we need to blocking load it.
- *      We check that the key is not in IO_SAVEINPROG state before accessing
- *      the disk object. If it is in this state, we wait.
- */
-

 robj *lookupKey(redisDb *db, robj *key) {
     dictEntry *de = dictFind(db->dict,key->ptr);
     if (de) {
 robj *lookupKey(redisDb *db, robj *key) {
     dictEntry *de = dictFind(db->dict,key->ptr);
     if (de) {


@@ -40,19 +47,24 @@ robj *lookupKey(redisDb *db, robj *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. */
         /* 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)
+        if (server.rdb_child_pid == -1 && server.aof_child_pid == -1)

             val->lru = server.lruclock;
             val->lru = server.lruclock;

-        server.stat_keyspace_hits++;

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

-        server.stat_keyspace_misses++;

         return NULL;
     }
 }
 
 robj *lookupKeyRead(redisDb *db, robj *key) {
         return NULL;
     }
 }
 
 robj *lookupKeyRead(redisDb *db, robj *key) {

+    robj *val;
+

     expireIfNeeded(db,key);
     expireIfNeeded(db,key);

-    return lookupKey(db,key);
+    val = lookupKey(db,key);
+    if (val == NULL)
+        server.stat_keyspace_misses++;
+    else
+        server.stat_keyspace_hits++;
+    return val;

 }
 
 robj *lookupKeyWrite(redisDb *db, robj *key) {
 }
 
 robj *lookupKeyWrite(redisDb *db, robj *key) {


@@ -110,7 +122,7 @@ void setKey(redisDb *db, robj *key, robj *val) {
     }
     incrRefCount(val);
     removeExpire(db,key);
     }
     incrRefCount(val);
     removeExpire(db,key);

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

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


@@ -156,8 +168,6 @@ int dbDelete(redisDb *db, robj *key) {
     }
 }
 
     }
 }
 

-/* Empty the whole database.
- * If diskstore is enabled this function will just flush the in-memory cache. */

 long long emptyDb() {
     int j;
     long long removed = 0;
 long long emptyDb() {
     int j;
     long long removed = 0;


@@ -210,15 +220,15 @@ void flushallCommand(redisClient *c) {
     signalFlushedDb(-1);
     server.dirty += emptyDb();
     addReply(c,shared.ok);
     signalFlushedDb(-1);
     server.dirty += emptyDb();
     addReply(c,shared.ok);

-    if (server.bgsavechildpid != -1) {
-        kill(server.bgsavechildpid,SIGKILL);
-        rdbRemoveTempFile(server.bgsavechildpid);
+    if (server.rdb_child_pid != -1) {
+        kill(server.rdb_child_pid,SIGKILL);
+        rdbRemoveTempFile(server.rdb_child_pid);

     }
     if (server.saveparamslen > 0) {
         /* Normally rdbSave() will reset dirty, but we don't want this here
          * as otherwise FLUSHALL will not be replicated nor put into the AOF. */
         int saved_dirty = server.dirty;
     }
     if (server.saveparamslen > 0) {
         /* Normally rdbSave() will reset dirty, but we don't want this here
          * as otherwise FLUSHALL will not be replicated nor put into the AOF. */
         int saved_dirty = server.dirty;

-        rdbSave(server.dbfilename);
+        rdbSave(server.rdb_filename);

         server.dirty = saved_dirty;
     }
     server.dirty++;
         server.dirty = saved_dirty;
     }
     server.dirty++;


@@ -247,7 +257,11 @@ void existsCommand(redisClient *c) {
 }
 
 void selectCommand(redisClient *c) {
 }
 
 void selectCommand(redisClient *c) {

-    int id = atoi(c->argv[1]->ptr);
+    long id;
+
+    if (getLongFromObjectOrReply(c, c->argv[1], &id,
+        "invalid DB index") != REDIS_OK)
+        return;

 
     if (server.cluster_enabled && id != 0) {
         addReplyError(c,"SELECT is not allowed in cluster mode");
 
     if (server.cluster_enabled && id != 0) {
         addReplyError(c,"SELECT is not allowed in cluster mode");


@@ -280,7 +294,7 @@ void keysCommand(redisClient *c) {
     unsigned long numkeys = 0;
     void *replylen = addDeferredMultiBulkLength(c);
 
     unsigned long numkeys = 0;
     void *replylen = addDeferredMultiBulkLength(c);
 

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

     allkeys = (pattern[0] == '*' && pattern[1] == '\0');
     while((de = dictNext(di)) != NULL) {
         sds key = dictGetKey(de);
     allkeys = (pattern[0] == '*' && pattern[1] == '\0');
     while((de = dictNext(di)) != NULL) {
         sds key = dictGetKey(de);


@@ -483,9 +497,10 @@ long long getExpire(redisDb *db, robj *key) {
 void propagateExpire(redisDb *db, robj *key) {
     robj *argv[2];
 
 void propagateExpire(redisDb *db, robj *key) {
     robj *argv[2];
 

-    argv[0] = createStringObject("DEL",3);
+    argv[0] = shared.del;

     argv[1] = key;
     argv[1] = key;

-    incrRefCount(key);
+    incrRefCount(argv[0]);
+    incrRefCount(argv[1]);

 
     if (server.aof_state != REDIS_AOF_OFF)
         feedAppendOnlyFile(server.delCommand,db->id,argv,2);
 
     if (server.aof_state != REDIS_AOF_OFF)
         feedAppendOnlyFile(server.delCommand,db->id,argv,2);


@@ -512,7 +527,7 @@ int expireIfNeeded(redisDb *db, robj *key) {
      * that is, 0 if we think the key should be still valid, 1 if
      * we think the key is expired at this time. */
     if (server.masterhost != NULL) {
      * that is, 0 if we think the key should be still valid, 1 if
      * we think the key is expired at this time. */
     if (server.masterhost != NULL) {

-        return time(NULL) > when;
+        return mstime() > when;

     }
 
     /* Return when this key has not expired */
     }
 
     /* Return when this key has not expired */


@@ -528,24 +543,23 @@ int expireIfNeeded(redisDb *db, robj *key) {
  * Expires Commands
  *----------------------------------------------------------------------------*/
 
  * Expires Commands
  *----------------------------------------------------------------------------*/
 

-/* Given an string object return true if it contains exactly the "ms"
- * or "MS" string. This is used in order to check if the last argument
- * of EXPIRE, EXPIREAT or TTL is "ms" to switch into millisecond input/output */
-int stringObjectEqualsMs(robj *a) {
-    char *arg = a->ptr;
-    return tolower(arg[0]) == 'm' && tolower(arg[1]) == 's' && arg[2] == '\0';
-}
-
-void expireGenericCommand(redisClient *c, long long offset, int unit) {
+/* This is the generic command implementation for EXPIRE, PEXPIRE, EXPIREAT
+ * and PEXPIREAT. Because the commad second argument may be relative or absolute
+ * the "basetime" argument is used to signal what the base time is (either 0
+ * for *AT variants of the command, or the current time for relative expires).
+ *
+ * unit is either UNIT_SECONDS or UNIT_MILLISECONDS, and is only used for
+ * the argv[2] parameter. The basetime is always specified in milliesconds. */
+void expireGenericCommand(redisClient *c, long long basetime, int unit) {

     dictEntry *de;
     robj *key = c->argv[1], *param = c->argv[2];
     dictEntry *de;
     robj *key = c->argv[1], *param = c->argv[2];

-    long long milliseconds;
+    long long when; /* unix time in milliseconds when the key will expire. */

 
 

-    if (getLongLongFromObjectOrReply(c, param, &milliseconds, NULL) != REDIS_OK)
+    if (getLongLongFromObjectOrReply(c, param, &when, NULL) != REDIS_OK)

         return;
 
         return;
 

-    if (unit == UNIT_SECONDS) milliseconds *= 1000;
-    milliseconds -= offset;
+    if (unit == UNIT_SECONDS) when *= 1000;
+    when += basetime;

 
     de = dictFind(c->db->dict,key->ptr);
     if (de == NULL) {
 
     de = dictFind(c->db->dict,key->ptr);
     if (de == NULL) {


@@ -558,7 +572,7 @@ void expireGenericCommand(redisClient *c, long long offset, int unit) {
      *
      * Instead we take the other branch of the IF statement setting an expire
      * (possibly in the past) and wait for an explicit DEL from the master. */
      *
      * Instead we take the other branch of the IF statement setting an expire
      * (possibly in the past) and wait for an explicit DEL from the master. */

-    if (milliseconds <= 0 && !server.loading && !server.masterhost) {
+    if (when <= mstime() && !server.loading && !server.masterhost) {

         robj *aux;
 
         redisAssertWithInfo(c,key,dbDelete(c->db,key));
         robj *aux;
 
         redisAssertWithInfo(c,key,dbDelete(c->db,key));


@@ -572,7 +586,6 @@ void expireGenericCommand(redisClient *c, long long offset, int unit) {
         addReply(c, shared.cone);
         return;
     } else {
         addReply(c, shared.cone);
         return;
     } else {

-        long long when = mstime()+milliseconds;

         setExpire(c->db,key,when);
         addReply(c,shared.cone);
         signalModifiedKey(c->db,key);
         setExpire(c->db,key,when);
         addReply(c,shared.cone);
         signalModifiedKey(c->db,key);


@@ -582,25 +595,32 @@ void expireGenericCommand(redisClient *c, long long offset, int unit) {
 }
 
 void expireCommand(redisClient *c) {
 }
 
 void expireCommand(redisClient *c) {

-    expireGenericCommand(c,0,UNIT_SECONDS);
+    expireGenericCommand(c,mstime(),UNIT_SECONDS);

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

-    expireGenericCommand(c,mstime(),UNIT_SECONDS);
+    expireGenericCommand(c,0,UNIT_SECONDS);

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

-    expireGenericCommand(c,0,UNIT_MILLISECONDS);
+    expireGenericCommand(c,mstime(),UNIT_MILLISECONDS);

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

-    expireGenericCommand(c,mstime(),UNIT_MILLISECONDS);
+    expireGenericCommand(c,0,UNIT_MILLISECONDS);

 }
 
 void ttlGenericCommand(redisClient *c, int output_ms) {
     long long expire, ttl = -1;
 
     expire = getExpire(c->db,c->argv[1]);
 }
 
 void ttlGenericCommand(redisClient *c, int output_ms) {
     long long expire, ttl = -1;
 
     expire = getExpire(c->db,c->argv[1]);

+    /* If the key does not exist at all, return -2 */
+    if (expire == -1 && lookupKeyRead(c->db,c->argv[1]) == NULL) {
+        addReplyLongLong(c,-2);
+        return;
+    }
+    /* The key exists. Return -1 if it has no expire, or the actual
+     * TTL value otherwise. */

     if (expire != -1) {
         ttl = expire-mstime();
         if (ttl < 0) ttl = -1;
     if (expire != -1) {
         ttl = expire-mstime();
         if (ttl < 0) ttl = -1;