refactor asyncCommand

Former-commit-id: 6af5775e01872f130bc18791fdb4c0b22507b37f

src/db.cpp

@@ -1184,7 +1184,7 @@ void scanGenericCommand(client *c, robj_roptr o, unsigned long cursor) {
     {
         // Do an async version
         if (c->asyncCommand(
-            [c, cursor, keys, pat, type, use_pattern, count] (const redisDbPersistentDataSnapshot * snapshot) {
+            [c, keys, pat, type, cursor, count, use_pattern] (const redisDbPersistentDataSnapshot *snapshot, std::vector<robj_sharedptr>) {
                 sds patCopy = pat ? sdsdup(pat) : nullptr;
                 sds typeCopy = type ? sdsdup(type) : nullptr;
                 auto cursorResult = snapshot->scan_threadsafe(cursor, count, typeCopy, keys);
@@ -1207,16 +1207,13 @@ void scanGenericCommand(client *c, robj_roptr o, unsigned long cursor) {
                     sdsfree(patCopy);
                 if (typeCopy != nullptr)
                     sdsfree(typeCopy);
-                return (void *)cursorResult;
-            },
-            [c, keys] (const redisDbPersistentDataSnapshot *, void *data) {
                 mstime_t timeScanFilter;
                 latencyStartMonitor(timeScanFilter);
-                scanFilterAndReply(c, keys, nullptr, nullptr, false, nullptr, (unsigned long)data);
+                scanFilterAndReply(c, keys, nullptr, nullptr, false, nullptr, cursorResult);
                 latencyEndMonitor(timeScanFilter);
                 latencyAddSampleIfNeeded("scan-async-filter", timeScanFilter);
             },
-            [keys] (const redisDbPersistentDataSnapshot *, void *) {
+            [keys] (const redisDbPersistentDataSnapshot *) {
                 listSetFreeMethod(keys,decrRefCountVoid);
                 listRelease(keys);
             }

src/server.cpp

@@ -4952,23 +4952,16 @@ bool client::postFunction(std::function<void(client *)> fn, bool fLock) {
     }, fLock) == AE_OK;
 }
 
-list *client::argsAsList() {
-    list *args = listCreate();
+std::vector<robj_sharedptr> client::args() {
+    std::vector<robj_sharedptr> args;
     for (int j = 1; j < this->argc; j++) {
-        incrRefCount(this->argv[j]);
-        listAddNodeTail(args, this->argv[j]);
+        args.push_back(robj_sharedptr(argv[j]));
     }
     return args;
 }
 
-void client::freeArgList(list* args) {
-    listSetFreeMethod(args,decrRefCountVoid);
-    listRelease(args);
-}
-
-bool client::asyncCommand(std::function<void *(const redisDbPersistentDataSnapshot *)> &&preFn, 
-                            std::function<void(const redisDbPersistentDataSnapshot *, void *)> &&mainFn, 
-                            std::function<void(const redisDbPersistentDataSnapshot *, void *)> &&postFn) 
+bool client::asyncCommand(std::function<void(const redisDbPersistentDataSnapshot *, std::vector<robj_sharedptr>)> &&mainFn, 
+                            std::function<void(const redisDbPersistentDataSnapshot *)> &&postFn) 
 {
     serverAssert(FCorrectThread(this));
     const redisDbPersistentDataSnapshot *snapshot = nullptr;
@@ -4979,18 +4972,19 @@ bool client::asyncCommand(std::function<void *(const redisDbPersistentDataSnapsh
     }
     aeEventLoop *el = serverTL->el;
     blockClient(this, BLOCKED_ASYNC);
-    g_pserver->asyncworkqueue->AddWorkFunction([el, this, preFn, mainFn, postFn, snapshot] {
-        void *preData = preFn(snapshot);
-        aePostFunction(el, [this, mainFn, postFn, snapshot, preData] {
+    g_pserver->asyncworkqueue->AddWorkFunction([el, this, mainFn, postFn, snapshot] {
+        std::vector<robj_sharedptr> args = this->args();
+        aePostFunction(el, [this, mainFn, postFn, snapshot, args] {
             aeReleaseLock();
             std::unique_lock<decltype(this->lock)> lock(this->lock);
             AeLocker locker;
             locker.arm(this);
             unblockClient(this);
-            mainFn(snapshot, preData);
+            mainFn(snapshot, args);
             locker.disarm();
             lock.unlock();
-            postFn(snapshot, preData);
+            if (postFn)
+                postFn(snapshot);
             this->db->endSnapshotAsync(snapshot);
             aeAcquireLock();
         });

src/server.h

@@ -1661,11 +1661,9 @@ struct client {
     // post a function from a non-client thread to run on its client thread
     bool postFunction(std::function<void(client *)> fn, bool fLock = true);
     size_t argv_len_sum() const;
-    list *argsAsList();
-    void freeArgList(list* args);
-    bool asyncCommand(std::function<void *(const redisDbPersistentDataSnapshot *)> &&preFn, 
-                        std::function<void(const redisDbPersistentDataSnapshot *, void *)> &&mainFn, 
-                        std::function<void(const redisDbPersistentDataSnapshot *, void *)> &&postFn);
+    std::vector<robj_sharedptr> args();
+    bool asyncCommand(std::function<void(const redisDbPersistentDataSnapshot *, std::vector<robj_sharedptr>)> &&mainFn, 
+                        std::function<void(const redisDbPersistentDataSnapshot *)> &&postFn = nullptr);
 };
 
 struct saveparam {

src/t_string.cpp

@@ -524,21 +524,19 @@ void getrangeCommand(client *c) {
     }
 }
 
-void mgetCore(client *c, list *keys, const redisDbPersistentDataSnapshot *snapshot = nullptr) {
-    addReplyArrayLen(c,listLength(keys));
-    listNode *ln = listFirst(keys);
-    while (ln != nullptr) {
+void mgetCore(client *c, robj **keys, int count, const redisDbPersistentDataSnapshot *snapshot = nullptr) {
+    addReplyArrayLen(c,count);
+    for (int i = 0; i < count; i++) {
         robj_roptr o;
         if (snapshot)
-            o = snapshot->find_cached_threadsafe(szFromObj((robj*)listNodeValue(ln))).val();
+            o = snapshot->find_cached_threadsafe(szFromObj(keys[i])).val();
         else
-            o = lookupKeyRead(c->db,(robj*)listNodeValue(ln));
+            o = lookupKeyRead(c->db,keys[i]);
         if (o == nullptr || o->type != OBJ_STRING) {
             addReplyNull(c);
         } else {
             addReplyBulk(c,o);
         }
-        ln = ln->next;
     }
 }
 
@@ -546,23 +544,15 @@ void mgetCommand(client *c) {
     // Do async version for large number of arguments
     if (c->argc > 100) {
         if (c->asyncCommand(
-                [c] (const redisDbPersistentDataSnapshot *) {
-                    return c->argsAsList();
-                }, 
-                [c] (const redisDbPersistentDataSnapshot *snapshot, void *keys) {
-                    mgetCore(c, (list *)keys, snapshot);
-                }, 
-                [c] (const redisDbPersistentDataSnapshot *, void *keys) {
-                    c->freeArgList((list *)keys);
+                [c] (const redisDbPersistentDataSnapshot *snapshot, std::vector<robj_sharedptr> keys) {
+                    mgetCore(c, (robj **)keys.data(), keys.size(), snapshot);
                 }
             )) {
             return;
         }
     }
 
-    list *keys = c->argsAsList();
-    mgetCore(c, keys);
-    c->freeArgList(keys);
+    mgetCore(c, c->argv + 1, c->argc - 1);
 }
 
 void msetGenericCommand(client *c, int nx) {