10x faster `new Buffer` (#1717)

Co-authored-by: Jarred Sumner <709451+Jarred-Sumner@users.noreply.github.com>

2 files changed, 46 insertions, 38 deletions

diff --git a/src/bun.js/builtins/js/JSBufferConstructor.js b/src/bun.js/builtins/js/JSBufferConstructor.js
index bfb122034..48342fe26 100644
--- a/src/bun.js/builtins/js/JSBufferConstructor.js
+++ b/src/bun.js/builtins/js/JSBufferConstructor.js
@@ -25,6 +25,14 @@
 
 // ^ that comment is required or the builtins generator will have a fit.
 
+function alloc(n) {
+    "use strict";
+    if (typeof n !== "number" || n < 0) {
+      @throwRangeError("n must be a positive integer less than 2^32");
+    }
+    
+    return new this(n);
+}
 
 function from(items) {
   "use strict";
@@ -64,5 +72,5 @@ function from(items) {
     // Don't pass the second argument because Node's Buffer.from doesn't accept
     // a function and Uint8Array.from requires it if it exists
     // That means we cannot use @tailCallFowrardArguments here, sadly
-    return this.toBuffer(@Uint8Array.from(arrayLike));
+    return new this(@Uint8Array.from(arrayLike).buffer);
 }
diff --git a/src/bun.js/builtins/js/JSBufferPrototype.js b/src/bun.js/builtins/js/JSBufferPrototype.js
index 689dc2dde..ef3332d88 100644
--- a/src/bun.js/builtins/js/JSBufferPrototype.js
+++ b/src/bun.js/builtins/js/JSBufferPrototype.js
@@ -31,176 +31,176 @@
 
 function setBigUint64(offset, value, le) {
   "use strict";
-  return this.dataView.setBigUint64(offset, value, le);
+  return (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setBigUint64(offset, value, le);
 }
 function readInt8(offset) {
   "use strict";
-  return this.dataView.getInt8(offset);
+  return (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getInt8(offset);
 }
 function readUInt8(offset) {
   "use strict";
-  return this.dataView.getUint8(offset);
+  return (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getUint8(offset);
 }
 function readInt16LE(offset) {
   "use strict";
-  return this.dataView.getInt16(offset, true);
+  return (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getInt16(offset, true);
 }
 function readInt16BE(offset) {
   "use strict";
-  return this.dataView.getInt16(offset, false);
+  return (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getInt16(offset, false);
 }
 function readUInt16LE(offset) {
   "use strict";
-  return this.dataView.getUint16(offset, true);
+  return (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getUint16(offset, true);
 }
 function readUInt16BE(offset) {
   "use strict";
-  return this.dataView.getUint16(offset, false);
+  return (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getUint16(offset, false);
 }
 function readInt32LE(offset) {
   "use strict";
-  return this.dataView.getInt32(offset, true);
+  return (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getInt32(offset, true);
 }
 function readInt32BE(offset) {
   "use strict";
-  return this.dataView.getInt32(offset, false);
+  return (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getInt32(offset, false);
 }
 function readUInt32LE(offset) {
   "use strict";
-  return this.dataView.getUint32(offset, true);
+  return (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getUint32(offset, true);
 }
 function readUInt32BE(offset) {
   "use strict";
-  return this.dataView.getUint32(offset, false);
+  return (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getUint32(offset, false);
 }
 function readFloatLE(offset) {
   "use strict";
-  return this.dataView.getFloat32(offset, true);
+  return (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getFloat32(offset, true);
 }
 function readFloatBE(offset) {
   "use strict";
-  return this.dataView.getFloat32(offset, false);
+  return (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getFloat32(offset, false);
 }
 function readDoubleLE(offset) {
   "use strict";
-  return this.dataView.getFloat64(offset, true);
+  return (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getFloat64(offset, true);
 }
 function readDoubleBE(offset) {
   "use strict";
-  return this.dataView.getFloat64(offset, false);
+  return (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getFloat64(offset, false);
 }
 function readBigInt64LE(offset) {
   "use strict";
-  return this.dataView.getBigInt64(offset, true);
+  return (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getBigInt64(offset, true);
 }
 function readBigInt64BE(offset) {
   "use strict";
-  return this.dataView.getBigInt64(offset, false);
+  return (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getBigInt64(offset, false);
 }
 function readBigUInt64LE(offset) {
   "use strict";
-  return this.dataView.getBigUint64(offset, true);
+  return (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getBigUint64(offset, true);
 }
 function readBigUInt64BE(offset) {
   "use strict";
-  return this.dataView.getBigUint64(offset, false);
+  return (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getBigUint64(offset, false);
 }
 function writeInt8(value, offset) {
   "use strict";
-  this.dataView.setInt8(offset, value);
+  (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setInt8(offset, value);
   return offset + 1;
 }
 function writeUInt8(value, offset) {
   "use strict";
-  this.dataView.setUint8(offset, value);
+  (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setUint8(offset, value);
   return offset + 1;
 }
 function writeInt16LE(value, offset) {
   "use strict";
-  this.dataView.setInt16(offset, value, true);
+  (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setInt16(offset, value, true);
   return offset + 2;
 }
 function writeInt16BE(value, offset) {
   "use strict";
-  this.dataView.setInt16(offset, value, false);
+  (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setInt16(offset, value, false);
   return offset + 2;
 }
 function writeUInt16LE(value, offset) {
   "use strict";
-  this.dataView.setUint16(offset, value, true);
+  (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setUint16(offset, value, true);
   return offset + 2;
 }
 function writeUInt16BE(value, offset) {
   "use strict";
-  this.dataView.setUint16(offset, value, false);
+  (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setUint16(offset, value, false);
   return offset + 2;
 }
 function writeInt32LE(value, offset) {
   "use strict";
-  this.dataView.setInt32(offset, value, true);
+  (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setInt32(offset, value, true);
   return offset + 4;
 }
 function writeInt32BE(value, offset) {
   "use strict";
-  this.dataView.setInt32(offset, value, false);
+  (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setInt32(offset, value, false);
   return offset + 4;
 }
 function writeUInt32LE(value, offset) {
   "use strict";
-  this.dataView.setUint32(offset, value, true);
+  (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setUint32(offset, value, true);
   return offset + 4;
 }
 function writeUInt32BE(value, offset) {
   "use strict";
-  this.dataView.setUint32(offset, value, false);
+  (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setUint32(offset, value, false);
   return offset + 4;
 }
 
 function writeFloatLE(value, offset) {
   "use strict";
-  this.dataView.setFloat32(offset, value, true);
+  (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setFloat32(offset, value, true);
   return offset + 4;
 }
 
 function writeFloatBE(value, offset) {
   "use strict";
-  this.dataView.setFloat32(offset, value, false);
+  (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setFloat32(offset, value, false);
   return offset + 4;
 }
 
 function writeDoubleLE(value, offset) {
   "use strict";
-  this.dataView.setFloat64(offset, value, true);
+  (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setFloat64(offset, value, true);
   return offset + 8;
 }
 
 function writeDoubleBE(value, offset) {
   "use strict";
-  this.dataView.setFloat64(offset, value, false);
+  (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setFloat64(offset, value, false);
   return offset + 8;
 }
 
 function writeBigInt64LE(value, offset) {
   "use strict";
-  this.dataView.setBigInt64(offset, value, true);
+  (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setBigInt64(offset, value, true);
   return offset + 8;
 }
 
 function writeBigInt64BE(value, offset) {
   "use strict";
-  this.dataView.setBigInt64(offset, value, false);
+  (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setBigInt64(offset, value, false);
   return offset + 8;
 }
 
 function writeBigUInt64LE(value, offset) {
   "use strict";
-  this.dataView.setBigUint64(offset, value, true);
+  (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setBigUint64(offset, value, true);
   return offset + 8;
 }
 
 function writeBigUInt64BE(value, offset) {
   "use strict";
-  this.dataView.setBigUint64(offset, value, false);
+  (this.@dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setBigUint64(offset, value, false);
   return offset + 8;
 }