From 38542f76a97e5c424aeada2e2dc8371797449335 Mon Sep 17 00:00:00 2001
From: Nathan Rajlich <nathan@tootallnate.net>
Date: Sun, 6 May 2012 12:47:25 -0700
Subject: [PATCH] buffer: make SlowBuffer inherit from Buffer

This frees us from manually having to copy over functions to SlowBuffer's
prototype (which has bitten us multiple times in the past).

As an added bonus, the `inspect()` function is now shared between Buffer
and SlowBuffer, removing some duplicate code.

Closes #3228.
---
 lib/buffer.js | 56 +++++++++------------------------------------------
 1 file changed, 9 insertions(+), 47 deletions(-)

diff --git a/lib/buffer.js b/lib/buffer.js
index de1efcb5ed6..70fefedad8a 100644
--- a/lib/buffer.js
+++ b/lib/buffer.js
@@ -33,6 +33,10 @@ function binaryWarn() {
 
 exports.INSPECT_MAX_BYTES = 50;
 
+// Make SlowBuffer inherit from Buffer.
+// This is an exception to the rule that __proto__ is not allowed in core.
+SlowBuffer.prototype.__proto__ = Buffer.prototype;
+
 
 function toHex(n) {
   if (n < 16) return '0' + n.toString(16);
@@ -40,20 +44,6 @@ function toHex(n) {
 }
 
 
-SlowBuffer.prototype.inspect = function() {
-  var out = [],
-      len = this.length;
-  for (var i = 0; i < len; i++) {
-    out[i] = toHex(this[i]);
-    if (i == exports.INSPECT_MAX_BYTES) {
-      out[i + 1] = '...';
-      break;
-    }
-  }
-  return '<SlowBuffer ' + out.join(' ') + '>';
-};
-
-
 SlowBuffer.prototype.hexSlice = function(start, end) {
   var len = this.length;
 
@@ -302,24 +292,25 @@ function allocPool() {
 
 // Static methods
 Buffer.isBuffer = function isBuffer(b) {
-  return b instanceof Buffer || b instanceof SlowBuffer;
+  return b instanceof Buffer;
 };
 
 
 // Inspect
 Buffer.prototype.inspect = function inspect() {
   var out = [],
-      len = this.length;
+      len = this.length,
+      name = this.constructor.name;
 
   for (var i = 0; i < len; i++) {
-    out[i] = toHex(this.parent[i + this.offset]);
+    out[i] = toHex(this[i]);
     if (i == exports.INSPECT_MAX_BYTES) {
       out[i + 1] = '...';
       break;
     }
   }
 
-  return '<Buffer ' + out.join(' ') + '>';
+  return '<' + name  + ' ' + out.join(' ') + '>';
 };
 
 
@@ -1143,32 +1134,3 @@ Buffer.prototype.writeDoubleLE = function(value, offset, noAssert) {
 Buffer.prototype.writeDoubleBE = function(value, offset, noAssert) {
   writeDouble(this, value, offset, true, noAssert);
 };
-
-SlowBuffer.prototype.readUInt8 = Buffer.prototype.readUInt8;
-SlowBuffer.prototype.readUInt16LE = Buffer.prototype.readUInt16LE;
-SlowBuffer.prototype.readUInt16BE = Buffer.prototype.readUInt16BE;
-SlowBuffer.prototype.readUInt32LE = Buffer.prototype.readUInt32LE;
-SlowBuffer.prototype.readUInt32BE = Buffer.prototype.readUInt32BE;
-SlowBuffer.prototype.readInt8 = Buffer.prototype.readInt8;
-SlowBuffer.prototype.readInt16LE = Buffer.prototype.readInt16LE;
-SlowBuffer.prototype.readInt16BE = Buffer.prototype.readInt16BE;
-SlowBuffer.prototype.readInt32LE = Buffer.prototype.readInt32LE;
-SlowBuffer.prototype.readInt32BE = Buffer.prototype.readInt32BE;
-SlowBuffer.prototype.readFloatLE = Buffer.prototype.readFloatLE;
-SlowBuffer.prototype.readFloatBE = Buffer.prototype.readFloatBE;
-SlowBuffer.prototype.readDoubleLE = Buffer.prototype.readDoubleLE;
-SlowBuffer.prototype.readDoubleBE = Buffer.prototype.readDoubleBE;
-SlowBuffer.prototype.writeUInt8 = Buffer.prototype.writeUInt8;
-SlowBuffer.prototype.writeUInt16LE = Buffer.prototype.writeUInt16LE;
-SlowBuffer.prototype.writeUInt16BE = Buffer.prototype.writeUInt16BE;
-SlowBuffer.prototype.writeUInt32LE = Buffer.prototype.writeUInt32LE;
-SlowBuffer.prototype.writeUInt32BE = Buffer.prototype.writeUInt32BE;
-SlowBuffer.prototype.writeInt8 = Buffer.prototype.writeInt8;
-SlowBuffer.prototype.writeInt16LE = Buffer.prototype.writeInt16LE;
-SlowBuffer.prototype.writeInt16BE = Buffer.prototype.writeInt16BE;
-SlowBuffer.prototype.writeInt32LE = Buffer.prototype.writeInt32LE;
-SlowBuffer.prototype.writeInt32BE = Buffer.prototype.writeInt32BE;
-SlowBuffer.prototype.writeFloatLE = Buffer.prototype.writeFloatLE;
-SlowBuffer.prototype.writeFloatBE = Buffer.prototype.writeFloatBE;
-SlowBuffer.prototype.writeDoubleLE = Buffer.prototype.writeDoubleLE;
-SlowBuffer.prototype.writeDoubleBE = Buffer.prototype.writeDoubleBE;