X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/75b41de8ca975d01c6371a98f9e552c934af5937..cb9b35c8cafc703ea5f2754b2961c9a3268c35d5:/src/t_list.c

diff --git a/src/t_list.c b/src/t_list.c
index 42e1d587..d5db6feb 100644
--- a/src/t_list.c
+++ b/src/t_list.c
@@ -274,14 +274,14 @@ void pushGenericCommand(redisClient *c, int where) {
             return;
         }
         if (handleClientsWaitingListPush(c,c->argv[1],c->argv[2])) {
-            touchWatchedKey(c->db,c->argv[1]);
+            signalModifiedKey(c->db,c->argv[1]);
             addReply(c,shared.cone);
             return;
         }
     }
     listTypePush(lobj,c->argv[2],where);
     addReplyLongLong(c,listTypeLength(lobj));
-    touchWatchedKey(c->db,c->argv[1]);
+    signalModifiedKey(c->db,c->argv[1]);
     server.dirty++;
 }
 
@@ -330,7 +330,7 @@ void pushxGenericCommand(redisClient *c, robj *refval, robj *val, int where) {
             if (subject->encoding == REDIS_ENCODING_ZIPLIST &&
                 ziplistLen(subject->ptr) > server.list_max_ziplist_entries)
                     listTypeConvert(subject,REDIS_ENCODING_LINKEDLIST);
-            touchWatchedKey(c->db,c->argv[1]);
+            signalModifiedKey(c->db,c->argv[1]);
             server.dirty++;
         } else {
             /* Notify client of a failed insert */
@@ -339,7 +339,7 @@ void pushxGenericCommand(redisClient *c, robj *refval, robj *val, int where) {
         }
     } else {
         listTypePush(subject,val,where);
-        touchWatchedKey(c->db,c->argv[1]);
+        signalModifiedKey(c->db,c->argv[1]);
         server.dirty++;
     }
 
@@ -427,7 +427,7 @@ void lsetCommand(redisClient *c) {
             o->ptr = ziplistInsert(o->ptr,p,value->ptr,sdslen(value->ptr));
             decrRefCount(value);
             addReply(c,shared.ok);
-            touchWatchedKey(c->db,c->argv[1]);
+            signalModifiedKey(c->db,c->argv[1]);
             server.dirty++;
         }
     } else if (o->encoding == REDIS_ENCODING_LINKEDLIST) {
@@ -439,7 +439,7 @@ void lsetCommand(redisClient *c) {
             listNodeValue(ln) = value;
             incrRefCount(value);
             addReply(c,shared.ok);
-            touchWatchedKey(c->db,c->argv[1]);
+            signalModifiedKey(c->db,c->argv[1]);
             server.dirty++;
         }
     } else {
@@ -458,7 +458,7 @@ void popGenericCommand(redisClient *c, int where) {
         addReplyBulk(c,value);
         decrRefCount(value);
         if (listTypeLength(o) == 0) dbDelete(c->db,c->argv[1]);
-        touchWatchedKey(c->db,c->argv[1]);
+        signalModifiedKey(c->db,c->argv[1]);
         server.dirty++;
     }
 }
@@ -472,12 +472,11 @@ void rpopCommand(redisClient *c) {
 }
 
 void lrangeCommand(redisClient *c) {
-    robj *o, *value;
+    robj *o;
     int start = atoi(c->argv[2]->ptr);
     int end = atoi(c->argv[3]->ptr);
     int llen;
-    int rangelen, j;
-    listTypeEntry entry;
+    int rangelen;
 
     if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.emptymultibulk)) == NULL
          || checkType(c,o,REDIS_LIST)) return;
@@ -499,14 +498,31 @@ void lrangeCommand(redisClient *c) {
 
     /* Return the result in form of a multi-bulk reply */
     addReplyMultiBulkLen(c,rangelen);
-    listTypeIterator *li = listTypeInitIterator(o,start,REDIS_TAIL);
-    for (j = 0; j < rangelen; j++) {
-        redisAssert(listTypeNext(li,&entry));
-        value = listTypeGet(&entry);
-        addReplyBulk(c,value);
-        decrRefCount(value);
+    if (o->encoding == REDIS_ENCODING_ZIPLIST) {
+        unsigned char *p = ziplistIndex(o->ptr,start);
+        unsigned char *vstr;
+        unsigned int vlen;
+        long long vlong;
+
+        while(rangelen--) {
+            ziplistGet(p,&vstr,&vlen,&vlong);
+            if (vstr) {
+                addReplyBulkCBuffer(c,vstr,vlen);
+            } else {
+                addReplyBulkLongLong(c,vlong);
+            }
+            p = ziplistNext(o->ptr,p);
+        }
+    } else if (o->encoding == REDIS_ENCODING_LINKEDLIST) {
+        listNode *ln = listIndex(o->ptr,start);
+
+        while(rangelen--) {
+            addReplyBulk(c,ln->value);
+            ln = ln->next;
+        }
+    } else {
+        redisPanic("List encoding is not LINKEDLIST nor ZIPLIST!");
     }
-    listTypeReleaseIterator(li);
 }
 
 void ltrimCommand(redisClient *c) {
@@ -557,7 +573,7 @@ void ltrimCommand(redisClient *c) {
         redisPanic("Unknown list encoding");
     }
     if (listTypeLength(o) == 0) dbDelete(c->db,c->argv[1]);
-    touchWatchedKey(c->db,c->argv[1]);
+    signalModifiedKey(c->db,c->argv[1]);
     server.dirty++;
     addReply(c,shared.ok);
 }
@@ -600,25 +616,43 @@ void lremCommand(redisClient *c) {
 
     if (listTypeLength(subject) == 0) dbDelete(c->db,c->argv[1]);
     addReplyLongLong(c,removed);
-    if (removed) touchWatchedKey(c->db,c->argv[1]);
+    if (removed) signalModifiedKey(c->db,c->argv[1]);
 }
 
 /* This is the semantic of this command:
  *  RPOPLPUSH srclist dstlist:
- *   IF LLEN(srclist) > 0
- *     element = RPOP srclist
- *     LPUSH dstlist element
- *     RETURN element
- *   ELSE
- *     RETURN nil
- *   END
+ *    IF LLEN(srclist) > 0
+ *      element = RPOP srclist
+ *      LPUSH dstlist element
+ *      RETURN element
+ *    ELSE
+ *      RETURN nil
+ *    END
  *  END
  *
  * The idea is to be able to get an element from a list in a reliable way
  * since the element is not just returned but pushed against another list
  * as well. This command was originally proposed by Ezra Zygmuntowicz.
  */
-void rpoplpushcommand(redisClient *c) {
+
+void rpoplpushHandlePush(redisClient *c, robj *dstkey, robj *dstobj, robj *value) {
+    if (!handleClientsWaitingListPush(c,dstkey,value)) {
+        /* Create the list if the key does not exist */
+        if (!dstobj) {
+            dstobj = createZiplistObject();
+            dbAdd(c->db,dstkey,dstobj);
+        } else {
+            signalModifiedKey(c->db,dstkey);
+            server.dirty++;
+        }
+        listTypePush(dstobj,value,REDIS_HEAD);
+    }
+
+    /* Always send the pushed value to the client. */
+    addReplyBulk(c,value);
+}
+
+void rpoplpushCommand(redisClient *c) {
     robj *sobj, *value;
     if ((sobj = lookupKeyWriteOrReply(c,c->argv[1],shared.nullbulk)) == NULL ||
         checkType(c,sobj,REDIS_LIST)) return;
@@ -629,27 +663,14 @@ void rpoplpushcommand(redisClient *c) {
         robj *dobj = lookupKeyWrite(c->db,c->argv[2]);
         if (dobj && checkType(c,dobj,REDIS_LIST)) return;
         value = listTypePop(sobj,REDIS_TAIL);
-
-        /* Add the element to the target list (unless it's directly
-         * passed to some BLPOP-ing client */
-        if (!handleClientsWaitingListPush(c,c->argv[2],value)) {
-            /* Create the list if the key does not exist */
-            if (!dobj) {
-                dobj = createZiplistObject();
-                dbAdd(c->db,c->argv[2],dobj);
-            }
-            listTypePush(dobj,value,REDIS_HEAD);
-        }
-
-        /* Send the element to the client as reply as well */
-        addReplyBulk(c,value);
+        rpoplpushHandlePush(c,c->argv[2],dobj,value);
 
         /* listTypePop returns an object with its refcount incremented */
         decrRefCount(value);
 
         /* Delete the source list when it is empty */
         if (listTypeLength(sobj) == 0) dbDelete(c->db,c->argv[1]);
-        touchWatchedKey(c->db,c->argv[1]);
+        signalModifiedKey(c->db,c->argv[1]);
         server.dirty++;
     }
 }
@@ -689,17 +710,23 @@ void rpoplpushcommand(redisClient *c) {
 
 /* Set a client in blocking mode for the specified key, with the specified
  * timeout */
-void blockForKeys(redisClient *c, robj **keys, int numkeys, time_t timeout) {
+void blockForKeys(redisClient *c, robj **keys, int numkeys, time_t timeout, robj *target) {
     dictEntry *de;
     list *l;
     int j;
 
-    c->blocking_keys = zmalloc(sizeof(robj*)*numkeys);
-    c->blocking_keys_num = numkeys;
-    c->blockingto = timeout;
+    c->bpop.keys = zmalloc(sizeof(robj*)*numkeys);
+    c->bpop.count = numkeys;
+    c->bpop.timeout = timeout;
+    c->bpop.target = target;
+
+    if (target != NULL) {
+        incrRefCount(target);
+    }
+
     for (j = 0; j < numkeys; j++) {
         /* Add the key in the client structure, to map clients -> keys */
-        c->blocking_keys[j] = keys[j];
+        c->bpop.keys[j] = keys[j];
         incrRefCount(keys[j]);
 
         /* And in the other "side", to map keys -> clients */
@@ -719,7 +746,7 @@ void blockForKeys(redisClient *c, robj **keys, int numkeys, time_t timeout) {
     }
     /* Mark the client as a blocked client */
     c->flags |= REDIS_BLOCKED;
-    server.blpop_blocked_clients++;
+    server.bpop_blocked_clients++;
 }
 
 /* Unblock a client that's waiting in a blocking operation such as BLPOP */
@@ -728,30 +755,27 @@ void unblockClientWaitingData(redisClient *c) {
     list *l;
     int j;
 
-    redisAssert(c->blocking_keys != NULL);
+    redisAssert(c->bpop.keys != NULL);
     /* The client may wait for multiple keys, so unblock it for every key. */
-    for (j = 0; j < c->blocking_keys_num; j++) {
+    for (j = 0; j < c->bpop.count; j++) {
         /* Remove this client from the list of clients waiting for this key. */
-        de = dictFind(c->db->blocking_keys,c->blocking_keys[j]);
+        de = dictFind(c->db->blocking_keys,c->bpop.keys[j]);
         redisAssert(de != NULL);
         l = dictGetEntryVal(de);
         listDelNode(l,listSearchKey(l,c));
         /* If the list is empty we need to remove it to avoid wasting memory */
         if (listLength(l) == 0)
-            dictDelete(c->db->blocking_keys,c->blocking_keys[j]);
-        decrRefCount(c->blocking_keys[j]);
+            dictDelete(c->db->blocking_keys,c->bpop.keys[j]);
+        decrRefCount(c->bpop.keys[j]);
     }
+
     /* Cleanup the client structure */
-    zfree(c->blocking_keys);
-    c->blocking_keys = NULL;
+    zfree(c->bpop.keys);
+    c->bpop.keys = NULL;
+    c->bpop.target = NULL;
     c->flags &= (~REDIS_BLOCKED);
-    server.blpop_blocked_clients--;
-    /* We want to process data if there is some command waiting
-     * in the input buffer. Note that this is safe even if
-     * unblockClientWaitingData() gets called from freeClient() because
-     * freeClient() will be smart enough to call this function
-     * *after* c->querybuf was set to NULL. */
-    if (c->querybuf && sdslen(c->querybuf) > 0) processInputBuffer(c);
+    server.bpop_blocked_clients--;
+    listAddNodeTail(server.unblocked_clients,c);
 }
 
 /* This should be called from any function PUSHing into lists.
@@ -767,39 +791,81 @@ void unblockClientWaitingData(redisClient *c) {
 int handleClientsWaitingListPush(redisClient *c, robj *key, robj *ele) {
     struct dictEntry *de;
     redisClient *receiver;
-    list *l;
+    int numclients;
+    list *clients;
     listNode *ln;
+    robj *dstkey, *dstobj;
 
     de = dictFind(c->db->blocking_keys,key);
     if (de == NULL) return 0;
-    l = dictGetEntryVal(de);
-    ln = listFirst(l);
-    redisAssert(ln != NULL);
-    receiver = ln->value;
+    clients = dictGetEntryVal(de);
+    numclients = listLength(clients);
+
+    /* Try to handle the push as long as there are clients waiting for a push.
+     * Note that "numclients" is used because the list of clients waiting for a
+     * push on "key" is deleted by unblockClient() when empty.
+     *
+     * This loop will have more than 1 iteration when there is a BRPOPLPUSH
+     * that cannot push the target list because it does not contain a list. If
+     * this happens, it simply tries the next client waiting for a push. */
+    while (numclients--) {
+        ln = listFirst(clients);
+        redisAssert(ln != NULL);
+        receiver = ln->value;
+        dstkey = receiver->bpop.target;
+
+        /* This should remove the first element of the "clients" list. */
+        unblockClientWaitingData(receiver);
+        redisAssert(ln != listFirst(clients));
+
+        if (dstkey == NULL) {
+            /* BRPOP/BLPOP */
+            addReplyMultiBulkLen(receiver,2);
+            addReplyBulk(receiver,key);
+            addReplyBulk(receiver,ele);
+            return 1;
+        } else {
+            /* BRPOPLPUSH */
+            dstobj = lookupKeyWrite(receiver->db,dstkey);
+            if (dstobj && checkType(receiver,dstobj,REDIS_LIST)) {
+                decrRefCount(dstkey);
+            } else {
+                rpoplpushHandlePush(receiver,dstkey,dstobj,ele);
+                decrRefCount(dstkey);
+                return 1;
+            }
+        }
+    }
+
+    return 0;
+}
 
-    addReplyMultiBulkLen(receiver,2);
-    addReplyBulk(receiver,key);
-    addReplyBulk(receiver,ele);
-    unblockClientWaitingData(receiver);
-    return 1;
+int getTimeoutFromObjectOrReply(redisClient *c, robj *object, time_t *timeout) {
+    long tval;
+
+    if (getLongFromObjectOrReply(c,object,&tval,
+        "timeout is not an integer or out of range") != REDIS_OK)
+        return REDIS_ERR;
+
+    if (tval < 0) {
+        addReplyError(c,"timeout is negative");
+        return REDIS_ERR;
+    }
+
+    if (tval > 0) tval += time(NULL);
+    *timeout = tval;
+
+    return REDIS_OK;
 }
 
 /* Blocking RPOP/LPOP */
 void blockingPopGenericCommand(redisClient *c, int where) {
     robj *o;
-    long long lltimeout;
     time_t timeout;
     int j;
 
-    /* Make sure timeout is an integer value */
-    if (getLongLongFromObjectOrReply(c,c->argv[c->argc-1],&lltimeout,
-            "timeout is not an integer") != REDIS_OK) return;
-
-    /* Make sure the timeout is not negative */
-    if (lltimeout < 0) {
-        addReplyError(c,"timeout is negative");
+    if (getTimeoutFromObjectOrReply(c,c->argv[c->argc-1],&timeout) != REDIS_OK)
         return;
-    }
 
     for (j = 1; j < c->argc-1; j++) {
         o = lookupKeyWrite(c->db,c->argv[j]);
@@ -829,11 +895,13 @@ void blockingPopGenericCommand(redisClient *c, int where) {
                      * because it is... */
                     addReplyMultiBulkLen(c,2);
                     addReplyBulk(c,argv[1]);
+
                     popGenericCommand(c,where);
 
                     /* Fix the client structure with the original stuff */
                     c->argv = orig_argv;
                     c->argc = orig_argc;
+
                     return;
                 }
             }
@@ -848,9 +916,7 @@ void blockingPopGenericCommand(redisClient *c, int where) {
     }
 
     /* If the list is empty or the key does not exists we must block */
-    timeout = lltimeout;
-    if (timeout > 0) timeout += time(NULL);
-    blockForKeys(c,c->argv+1,c->argc-2,timeout);
+    blockForKeys(c, c->argv + 1, c->argc - 2, timeout, NULL);
 }
 
 void blpopCommand(redisClient *c) {
@@ -860,3 +926,34 @@ void blpopCommand(redisClient *c) {
 void brpopCommand(redisClient *c) {
     blockingPopGenericCommand(c,REDIS_TAIL);
 }
+
+void brpoplpushCommand(redisClient *c) {
+    time_t timeout;
+
+    if (getTimeoutFromObjectOrReply(c,c->argv[3],&timeout) != REDIS_OK)
+        return;
+
+    robj *key = lookupKeyWrite(c->db, c->argv[1]);
+
+    if (key == NULL) {
+        if (c->flags & REDIS_MULTI) {
+
+            /* Blocking against an empty list in a multi state
+             * returns immediately. */
+            addReply(c, shared.nullmultibulk);
+        } else {
+            /* The list is empty and the client blocks. */
+            blockForKeys(c, c->argv + 1, 1, timeout, c->argv[2]);
+        }
+    } else {
+        if (key->type != REDIS_LIST) {
+            addReply(c, shared.wrongtypeerr);
+        } else {
+
+            /* The list exists and has elements, so
+             * the regular rpoplpushCommand is executed. */
+            redisAssert(listTypeLength(key) > 0);
+            rpoplpushCommand(c);
+        }
+    }
+}