refactor: do some internal refactor.

source/libs/stream/src/stream.c

@@ -253,6 +253,25 @@ static int32_t streamTaskAppendInputBlocks(SStreamTask* pTask, const SStreamDisp
   return status;
 }
 
+static int32_t buildDispatchRsp(const SStreamTask* pTask, const SStreamDispatchReq* pReq, int32_t status, void** pBuf) {
+  *pBuf = rpcMallocCont(sizeof(SMsgHead) + sizeof(SStreamDispatchRsp));
+  if (*pBuf == NULL) {
+    return TSDB_CODE_OUT_OF_MEMORY;
+  }
+
+  ((SMsgHead*)(*pBuf))->vgId = htonl(pReq->upstreamNodeId);
+  SStreamDispatchRsp* pDispatchRsp = POINTER_SHIFT((*pBuf), sizeof(SMsgHead));
+
+  pDispatchRsp->inputStatus = status;
+  pDispatchRsp->streamId = htobe64(pReq->streamId);
+  pDispatchRsp->upstreamNodeId = htonl(pReq->upstreamNodeId);
+  pDispatchRsp->upstreamTaskId = htonl(pReq->upstreamTaskId);
+  pDispatchRsp->downstreamNodeId = htonl(pTask->info.nodeId);
+  pDispatchRsp->downstreamTaskId = htonl(pTask->id.taskId);
+
+  return TSDB_CODE_SUCCESS;
+}
+
 int32_t streamProcessDispatchMsg(SStreamTask* pTask, SStreamDispatchReq* pReq, SRpcMsg* pRsp, bool exec) {
   qDebug("s-task:%s receive dispatch msg from taskId:0x%x(vgId:%d), msgLen:%" PRId64, pTask->id.idStr,
          pReq->upstreamTaskId, pReq->upstreamNodeId, pReq->totalLen);