buffer: optimize Buffer.prototype.write(s, 'hex')

Move the implementation to C++ land. This is similar to commit 3f65916
but this time for the write() function and the Buffer(s, 'hex')
constructor.

Speeds up the benchmark below about 24x (2.6s vs 1:02m).

  var s = 'f';
  for (var i = 0; i < 26; ++i) s += s;  // 64 MB
  Buffer(s, 'hex');

1 files changed, 1 insertions, 0 deletions

diff --git a/src/node_buffer.h b/src/node_buffer.h
index 27991fcfc..5743f9b26 100644
--- a/src/node_buffer.h
+++ b/src/node_buffer.h
@@ -124,6 +124,7 @@ class NODE_EXTERN Buffer: public ObjectWrap {
   static v8::Handle<v8::Value> AsciiWrite(const v8::Arguments &args);
   static v8::Handle<v8::Value> Utf8Write(const v8::Arguments &args);
   static v8::Handle<v8::Value> Ucs2Write(const v8::Arguments &args);
+  static v8::Handle<v8::Value> HexWrite(const v8::Arguments &args);
   static v8::Handle<v8::Value> ReadFloatLE(const v8::Arguments &args);
   static v8::Handle<v8::Value> ReadFloatBE(const v8::Arguments &args);
   static v8::Handle<v8::Value> ReadDoubleLE(const v8::Arguments &args);