From 252ea397055208436253a740aaf7aaae1edf5488 Mon Sep 17 00:00:00 2001
From: Ryan Lester <hacker@linux.com>
Date: Tue, 4 May 2021 20:00:21 -0400
Subject: [PATCH] encode/decode minor performance optimization

https://github.com/msgpack/msgpack-javascript/issues/172
---
 src/decode.ts | 31 +++++++++++++------------------
 src/encode.ts | 23 +++++++++++++----------
 2 files changed, 26 insertions(+), 28 deletions(-)

diff --git a/src/decode.ts b/src/decode.ts
index 267b7d92..4d8300fb 100644
--- a/src/decode.ts
+++ b/src/decode.ts
@@ -40,7 +40,18 @@ export type DecodeOptions<ContextType = undefined> = Readonly<
 > &
   ContextOf<ContextType>;
 
+const getDecoder = (options: any) => new Decoder(
+  options.extensionCodec,
+  (options as typeof options & { context: any }).context,
+  options.maxStrLength,
+  options.maxBinLength,
+  options.maxArrayLength,
+  options.maxMapLength,
+  options.maxExtLength,
+);
+
 export const defaultDecodeOptions: DecodeOptions = {};
+const defaultDecoder = getDecoder(defaultDecodeOptions);
 
 /**
  * It decodes a single MessagePack object in a buffer.
@@ -52,15 +63,7 @@ export function decode<ContextType = undefined>(
   buffer: ArrayLike<number> | BufferSource,
   options: DecodeOptions<SplitUndefined<ContextType>> = defaultDecodeOptions as any,
 ): unknown {
-  const decoder = new Decoder(
-    options.extensionCodec,
-    (options as typeof options & { context: any }).context,
-    options.maxStrLength,
-    options.maxBinLength,
-    options.maxArrayLength,
-    options.maxMapLength,
-    options.maxExtLength,
-  );
+  const decoder = options === defaultDecodeOptions ? defaultDecoder : getDecoder(options);
   return decoder.decode(buffer);
 }
 
@@ -72,14 +75,6 @@ export function decodeMulti<ContextType = undefined>(
   buffer: ArrayLike<number> | BufferSource,
   options: DecodeOptions<SplitUndefined<ContextType>> = defaultDecodeOptions as any,
 ): Generator<unknown, void, unknown> {
-  const decoder = new Decoder(
-    options.extensionCodec,
-    (options as typeof options & { context: any }).context,
-    options.maxStrLength,
-    options.maxBinLength,
-    options.maxArrayLength,
-    options.maxMapLength,
-    options.maxExtLength,
-  );
+  const decoder = options === defaultDecodeOptions ? defaultDecoder : getDecoder(options);
   return decoder.decodeMulti(buffer);
 }
diff --git a/src/encode.ts b/src/encode.ts
index 07d59ad9..32ebbdac 100644
--- a/src/encode.ts
+++ b/src/encode.ts
@@ -55,7 +55,19 @@ export type EncodeOptions<ContextType = undefined> = Partial<
 > &
   ContextOf<ContextType>;
 
+const getEncoder = (options: any) => new Encoder(
+  options.extensionCodec,
+  (options as typeof options & { context: any }).context,
+  options.maxDepth,
+  options.initialBufferSize,
+  options.sortKeys,
+  options.forceFloat32,
+  options.ignoreUndefined,
+  options.forceIntegerToFloat,
+);
+
 const defaultEncodeOptions: EncodeOptions = {};
+const defaultEncoder = getEncoder(defaultEncodeOptions);
 
 /**
  * It encodes `value` in the MessagePack format and
@@ -67,15 +79,6 @@ export function encode<ContextType = undefined>(
   value: unknown,
   options: EncodeOptions<SplitUndefined<ContextType>> = defaultEncodeOptions as any,
 ): Uint8Array {
-  const encoder = new Encoder(
-    options.extensionCodec,
-    (options as typeof options & { context: any }).context,
-    options.maxDepth,
-    options.initialBufferSize,
-    options.sortKeys,
-    options.forceFloat32,
-    options.ignoreUndefined,
-    options.forceIntegerToFloat,
-  );
+  const encoder = options === defaultEncodeOptions ? defaultEncoder : getEncoder(options);
   return encoder.encode(value);
 }