From 8aede75b9e5fa5c3df7c14bd9e6b1cc09623c092 Mon Sep 17 00:00:00 2001
From: Peter Romianowski <pero@flunder.io>
Date: Sat, 12 Oct 2019 17:06:08 +0200
Subject: [PATCH 1/2] Improved performance of Pipeline.exec

---
 lib/pipeline.ts | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/lib/pipeline.ts b/lib/pipeline.ts
index e5ea2a59..09e28ace 100644
--- a/lib/pipeline.ts
+++ b/lib/pipeline.ts
@@ -303,6 +303,7 @@ Pipeline.prototype.exec = function(callback: CallbackFunction) {
 
   function execPipeline() {
     let data: Buffer | string = "";
+    let buffers: Buffer[];
     let writePending: number = (_this.replyPending = _this._queue.length);
 
     let node;
@@ -319,16 +320,25 @@ Pipeline.prototype.exec = function(callback: CallbackFunction) {
           bufferMode = true;
         }
         if (bufferMode) {
-          data = Buffer.concat([
-            typeof data === "string" ? Buffer.from(data, "utf8") : data,
+          if (!buffers) {
+            buffers = [];
+          }
+          if (typeof data === "string") {
+            buffers.push(Buffer.from(data, "utf8"));
+            data = undefined;
+          }
+          buffers.push(
             typeof writable === "string"
               ? Buffer.from(writable, "utf8")
               : writable
-          ]);
+          );
         } else {
           data += writable;
         }
         if (!--writePending) {
+          if (buffers) {
+            data = Buffer.concat(buffers);
+          }
           if (_this.isCluster) {
             node.redis.stream.write(data);
           } else {

From 1abe7b3365f4a28ad79700a3c3a71a43cf5efea0 Mon Sep 17 00:00:00 2001
From: Peter Romianowski <pero@flunder.io>
Date: Sat, 12 Oct 2019 17:27:10 +0200
Subject: [PATCH 2/2] Reset buffers and made code more readable

---
 lib/pipeline.ts | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/lib/pipeline.ts b/lib/pipeline.ts
index 09e28ace..ca436959 100644
--- a/lib/pipeline.ts
+++ b/lib/pipeline.ts
@@ -302,7 +302,7 @@ Pipeline.prototype.exec = function(callback: CallbackFunction) {
     .then(execPipeline);
 
   function execPipeline() {
-    let data: Buffer | string = "";
+    let data = "";
     let buffers: Buffer[];
     let writePending: number = (_this.replyPending = _this._queue.length);
 
@@ -336,18 +336,22 @@ Pipeline.prototype.exec = function(callback: CallbackFunction) {
           data += writable;
         }
         if (!--writePending) {
+          let sendData: Buffer | string;
           if (buffers) {
-            data = Buffer.concat(buffers);
+            sendData = Buffer.concat(buffers);
+          } else {
+            sendData = data;
           }
           if (_this.isCluster) {
-            node.redis.stream.write(data);
+            node.redis.stream.write(sendData);
           } else {
-            _this.redis.stream.write(data);
+            _this.redis.stream.write(sendData);
           }
 
           // Reset writePending for resending
           writePending = _this._queue.length;
           data = "";
+          buffers = undefined;
           bufferMode = false;
         }
       }