From 89758cee2f7306d1a3471fe9f64d86f5c25aa8b4 Mon Sep 17 00:00:00 2001
From: regevbr <regevbr@gmail.com>
Date: Fri, 19 Jun 2020 03:39:06 +0300
Subject: [PATCH] fix: major performance issues with bytea performance #2240

---
 packages/pg-protocol/src/parser.ts | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/packages/pg-protocol/src/parser.ts b/packages/pg-protocol/src/parser.ts
index eabb1e3d7..56670fd75 100644
--- a/packages/pg-protocol/src/parser.ts
+++ b/packages/pg-protocol/src/parser.ts
@@ -150,14 +150,14 @@ export class Parser {
       this.remainingBufferLength = 0
       this.remainingBufferOffset = 0
     } else {
+      this.remainingBufferLength = fullLength - offset
       if (reuseRemainingBuffer) {
         // Adjust the cursors of remainingBuffer
-        this.remainingBufferLength = combinedBufferLength - offset
-        this.remainingBufferOffset += offset
+        this.remainingBufferOffset = offset
       } else {
-        // To avoid side effects, copy the remaining part of the new buffer to remainingBuffer
-        this.remainingBuffer = combinedBuffer.slice(offset)
-        this.remainingBufferLength = this.remainingBuffer.byteLength
+        // To avoid side effects, copy the remaining part of the new buffer to remainingBuffer with extra space for next buffer
+        this.remainingBuffer = Buffer.allocUnsafe(combinedBufferLength * 2)
+        combinedBuffer.copy(this.remainingBuffer, 0, offset)
         this.remainingBufferOffset = 0
       }
     }