lib: use FastBuffer for empty buffer allocation

gurgunday · RafaelGSS · commit 1a0c3dddb9ec · 2026-01-13T10:04:02.000-03:00
PR-URL: #60558 Reviewed-By: Luigi Pinca <luigipinca@gmail.com> Reviewed-By: Juan José Arboleda <soyjuanarbol@gmail.com>
diff --git a/lib/buffer.js b/lib/buffer.js
@@ -352,13 +352,13 @@ Buffer.copyBytesFrom = function copyBytesFrom(view, offset, length) {
 
   const viewLength = TypedArrayPrototypeGetLength(view);
   if (viewLength === 0) {
-    return Buffer.alloc(0);
+    return new FastBuffer();
   }
 
   if (offset !== undefined || length !== undefined) {
     if (offset !== undefined) {
       validateInteger(offset, 'offset', 0);
-      if (offset >= viewLength) return Buffer.alloc(0);
+      if (offset >= viewLength) return new FastBuffer();
     } else {
       offset = 0;
     }
@@ -1262,7 +1262,7 @@ if (internalBinding('config').hasIntl) {
       throw new ERR_INVALID_ARG_TYPE('source',
                                      ['Buffer', 'Uint8Array'], source);
     }
-    if (source.length === 0) return Buffer.alloc(0);
+    if (source.length === 0) return new FastBuffer();
 
     fromEncoding = normalizeEncoding(fromEncoding) || fromEncoding;
     toEncoding = normalizeEncoding(toEncoding) || toEncoding;
diff --git a/lib/dgram.js b/lib/dgram.js
@@ -73,6 +73,7 @@ const {
   defaultTriggerAsyncIdScope,
   symbols: { async_id_symbol, owner_symbol },
 } = require('internal/async_hooks');
+const { FastBuffer } = require('internal/buffer');
 const { UV_UDP_REUSEADDR } = internalBinding('constants').os;
 
 const {
@@ -688,7 +689,7 @@ Socket.prototype.send = function(buffer,
     this.bind({ port: 0, exclusive: true }, null);
 
   if (list.length === 0)
-    ArrayPrototypePush(list, Buffer.alloc(0));
+    ArrayPrototypePush(list, new FastBuffer());
 
   // If the socket hasn't been bound yet, push the outbound packet onto the
   // send queue and send after binding is complete.
diff --git a/lib/internal/debugger/inspect_client.js b/lib/internal/debugger/inspect_client.js
@@ -16,6 +16,7 @@ const { ERR_DEBUGGER_ERROR } = require('internal/errors').codes;
 const { EventEmitter, once } = require('events');
 const http = require('http');
 const { URL } = require('internal/url');
+const { FastBuffer } = require('internal/buffer');
 
 const debuglog = require('internal/util/debuglog').debuglog('inspect');
 
@@ -79,7 +80,7 @@ function encodeFrameHybi17(payload) {
     additionalLength[0] = (dataLength & 0xFF00) >> 8;
     additionalLength[1] = dataLength & 0xFF;
   } else {
-    additionalLength = Buffer.alloc(0);
+    additionalLength = new FastBuffer();
     singleByteLength = dataLength;
   }
 
@@ -233,7 +234,7 @@ class Client extends EventEmitter {
     this._lastId = 0;
     this._socket = null;
     this._pending = {};
-    this._unprocessed = Buffer.alloc(0);
+    this._unprocessed = new FastBuffer();
   }
 
   callMethod(method, params) {
diff --git a/lib/internal/streams/readable.js b/lib/internal/streams/readable.js
@@ -1605,7 +1605,7 @@ function fromList(n, state) {
         buf[idx++] = null;
       }
     } else if (len - idx === 0) {
-      ret = Buffer.alloc(0);
+      ret = new FastBuffer();
     } else if (len - idx === 1) {
       ret = buf[idx];
       buf[idx++] = null;
diff --git a/lib/internal/test_runner/runner.js b/lib/internal/test_runner/runner.js
@@ -78,6 +78,7 @@ const {
   kTestTimeoutFailure,
   Test,
 } = require('internal/test_runner/test');
+const { FastBuffer } = require('internal/buffer');
 
 const {
   convertStringToRegExp,
@@ -324,7 +325,7 @@ class FileTest extends Test {
     // This method is called when it is known that there is at least one message
     let bufferHead = this.#rawBuffer[0];
     let headerIndex = bufferHead.indexOf(v8Header);
-    let nonSerialized = Buffer.alloc(0);
+    let nonSerialized = new FastBuffer();
 
     while (bufferHead && headerIndex !== 0) {
       const nonSerializedData = headerIndex === -1 ?
diff --git a/lib/zlib.js b/lib/zlib.js
@@ -70,6 +70,7 @@ const {
   validateUint32,
   validateFiniteNumber,
 } = require('internal/validators');
+const { FastBuffer } = require('internal/buffer');
 
 const kFlushFlag = Symbol('kFlushFlag');
 const kError = Symbol('kError');
@@ -150,7 +151,7 @@ function zlibBufferOnError(err) {
 function zlibBufferOnEnd() {
   let buf;
   if (this.nread === 0) {
-    buf = Buffer.alloc(0);
+    buf = new FastBuffer();
   } else {
     const bufs = this.buffers;
     buf = (bufs.length === 1 ? bufs[0] : Buffer.concat(bufs, this.nread));
@@ -301,7 +302,7 @@ ZlibBase.prototype.reset = function() {
  * @returns {void}
  */
 ZlibBase.prototype._flush = function(callback) {
-  this._transform(Buffer.alloc(0), '', callback);
+  this._transform(new FastBuffer(), '', callback);
 };
 
 /**
@@ -476,7 +477,7 @@ function processChunkSync(self, chunk, flushFlag) {
   _close(self);
 
   if (nread === 0)
-    return Buffer.alloc(0);
+    return new FastBuffer();
 
   return (buffers.length === 1 ? buffers[0] : Buffer.concat(buffers, nread));
 }

Original file line number	Diff line number	Diff line change
`@@ -1605,7 +1605,7 @@ function fromList(n, state) {`
`1605`	`1605`	`buf[idx++] = null;`
`1606`	`1606`	`}`
`1607`	`1607`	`} else if (len - idx === 0) {`
`1608`		`- ret = Buffer.alloc(0);`
	`1608`	`+ ret = new FastBuffer();`
`1609`	`1609`	`} else if (len - idx === 1) {`
`1610`	`1610`	`ret = buf[idx];`
`1611`	`1611`	`buf[idx++] = null;`