update RPOPLPUSH to support dual encoding

diff --git a/redis.c b/redis.c
index d230a1950a63c059c54afc13cf6d219097be0bb7..dc92d76f71f8e83e192fe739c3390921927faf44 100644 (file)
--- a/redis.c
+++ b/redis.c
@@ -4805,8 +4805,9 @@ static robj *lPop(robj *subject, int where) {
             } else {
                 value = createStringObjectFromLongLong(vval);
             }
+            /* We only need to delete an element when it exists */
+            subject->ptr = ziplistDelete(subject->ptr,&p);
         }
-        subject->ptr = ziplistDelete(subject->ptr,&p);
     } else if (subject->encoding == REDIS_ENCODING_LIST) {
         list *list = subject->ptr;
         listNode *ln;
@@ -5246,47 +5247,38 @@ static void lremCommand(redisClient *c) {
  * as well. This command was originally proposed by Ezra Zygmuntowicz.
  */
 static void rpoplpushcommand(redisClient *c) {
-    robj *sobj;
-    list *srclist;
-    listNode *ln;
-
+    robj *sobj, *value;
     if ((sobj = lookupKeyWriteOrReply(c,c->argv[1],shared.nullbulk)) == NULL ||
         checkType(c,sobj,REDIS_LIST)) return;
-    srclist = sobj->ptr;
-    ln = listLast(srclist);
 
-    if (ln == NULL) {
+    if (lLength(sobj) == 0) {
         addReply(c,shared.nullbulk);
     } else {
         robj *dobj = lookupKeyWrite(c->db,c->argv[2]);
-        robj *ele = listNodeValue(ln);
-        list *dstlist;
-
-        if (dobj && dobj->type != REDIS_LIST) {
-            addReply(c,shared.wrongtypeerr);
-            return;
-        }
+        if (dobj && checkType(c,dobj,REDIS_LIST)) return;
+        value = lPop(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],ele)) {
-            if (dobj == NULL) {
-                /* Create the list if the key does not exist */
-                dobj = createListObject();
+        if (!handleClientsWaitingListPush(c,c->argv[2],value)) {
+            /* Create the list if the key does not exist */
+            if (!dobj) {
+                dobj = createObject(REDIS_LIST,ziplistNew());
+                dobj->encoding = REDIS_ENCODING_ZIPLIST;
                 dictAdd(c->db->dict,c->argv[2],dobj);
                 incrRefCount(c->argv[2]);
             }
-            dstlist = dobj->ptr;
-            listAddNodeHead(dstlist,ele);
-            incrRefCount(ele);
+            lPush(dobj,value,REDIS_HEAD);
         }
 
         /* Send the element to the client as reply as well */
-        addReplyBulk(c,ele);
+        addReplyBulk(c,value);
+
+        /* lPop returns an object with its refcount incremented */
+        decrRefCount(value);
 
-        /* Finally remove the element from the source list */
-        listDelNode(srclist,ln);
-        if (listLength(srclist) == 0) deleteKey(c->db,c->argv[1]);
+        /* Delete the source list when it is empty */
+        if (lLength(sobj) == 0) deleteKey(c->db,c->argv[1]);
         server.dirty++;
     }
 }