From 4b67f0be6d682845661662f43602b4c0245b02a0 Mon Sep 17 00:00:00 2001
From: isaacs <i@izs.me>
Date: Wed, 27 Feb 2013 19:32:19 -0800
Subject: [PATCH] stream: Add stream.unshift(chunk)

---
 lib/_stream_readable.js | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/lib/_stream_readable.js b/lib/_stream_readable.js
index 9193f4f27b9..9f384a409e9 100644
--- a/lib/_stream_readable.js
+++ b/lib/_stream_readable.js
@@ -106,10 +106,15 @@ function Readable(options) {
 // write() some more.
 Readable.prototype.push = function(chunk) {
   var state = this._readableState;
-  return readableAddChunk(this, state, chunk);
+  return readableAddChunk(this, state, chunk, false);
 };
 
-function readableAddChunk(stream, state, chunk) {
+Readable.prototype.unshift = function(chunk) {
+  var state = this._readableState;
+  return readableAddChunk(this, state, chunk, true);
+};
+
+function readableAddChunk(stream, state, chunk, addToFront) {
   state.reading = false;
 
   var er = chunkInvalid(state, chunk);
@@ -123,7 +128,10 @@ function readableAddChunk(stream, state, chunk) {
 
     // update the buffer info.
     state.length += state.objectMode ? 1 : chunk.length;
-    state.buffer.push(chunk);
+    if (addToFront)
+      state.buffer.unshift(chunk);
+    else
+      state.buffer.push(chunk);
 
     if (state.needReadable)
       emitReadable(stream);