From 812b73ffbcd41739c6a82a8a7b77310d23a4103a Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Wed, 27 Jul 2016 16:26:43 -0700
Subject: [PATCH] bip151: use reference slices initially for parsing.

---
 lib/bcoin/bip151.js  | 72 ++++++++++++++++++++++++++++----------
 lib/bcoin/workers.js | 83 ++++++++++++++++++++++++--------------------
 2 files changed, 100 insertions(+), 55 deletions(-)

diff --git a/lib/bcoin/bip151.js b/lib/bcoin/bip151.js
index 7ea88411..e63e0e00 100644
--- a/lib/bcoin/bip151.js
+++ b/lib/bcoin/bip151.js
@@ -273,32 +273,68 @@ BIP151Stream.prototype.verify = function verify(tag) {
  */
 
 BIP151Stream.prototype.feed = function feed(data) {
-  var chunk, off, len;
+  var chunk;
 
   this.total += data.length;
   this.pending.push(data);
 
   while (this.total >= this.waiting) {
-    chunk = new Buffer(this.waiting);
-    off = 0;
-    len = 0;
-
-    while (off < chunk.length) {
-      len = this.pending[0].copy(chunk, off);
-      if (len === this.pending[0].length)
-        this.pending.shift();
-      else
-        this.pending[0] = this.pending[0].slice(len);
-      off += len;
-    }
-
-    assert.equal(off, chunk.length);
-
-    this.total -= chunk.length;
+    chunk = this.read(this.waiting);
     this.parse(chunk);
   }
 };
 
+/**
+ * Read and consume a number of bytes
+ * from the buffered stream.
+ * @param {Number} size
+ * @returns {Buffer}
+ */
+
+BIP151Stream.prototype.read = function read(size) {
+  var pending, chunk, off, len;
+
+  assert(this.total >= size, 'Reading too much.');
+
+  if (size === 0)
+    return new Buffer(0);
+
+  pending = this.pending[0];
+
+  if (pending.length > size) {
+    chunk = pending.slice(0, size);
+    this.pending[0] = pending.slice(size);
+    this.total -= chunk.length;
+    return chunk;
+  }
+
+  if (pending.length === size) {
+    chunk = this.pending.shift();
+    this.total -= chunk.length;
+    return chunk;
+  }
+
+  chunk = new Buffer(size);
+  off = 0;
+  len = 0;
+
+  while (off < chunk.length) {
+    pending = this.pending[0];
+    len = pending.copy(chunk, off);
+    if (len === pending.length)
+      this.pending.shift();
+    else
+      this.pending[0] = pending.slice(len);
+    off += len;
+  }
+
+  assert.equal(off, chunk.length);
+
+  this.total -= chunk.length;
+
+  return chunk;
+};
+
 /**
  * Parse a ciphertext payload chunk.
  * Potentially emits a `packet` event.
@@ -350,7 +386,7 @@ BIP151Stream.prototype.parse = function parse(data) {
   this.decrypt(payload);
   this.sequence();
 
-  p = bcoin.reader(payload, true);
+  p = bcoin.reader(payload);
 
   while (p.left()) {
     try {
diff --git a/lib/bcoin/workers.js b/lib/bcoin/workers.js
index 14b68a62..5ac1f028 100644
--- a/lib/bcoin/workers.js
+++ b/lib/bcoin/workers.js
@@ -948,52 +948,61 @@ function Parser() {
 utils.inherits(Parser, EventEmitter);
 
 Parser.prototype.feed = function feed(data) {
-  var chunk, off, len;
+  var chunk;
 
   this.total += data.length;
   this.pending.push(data);
 
   while (this.total >= this.waiting) {
-    if (this.waiting === 0) {
-      this.parse(new Buffer(0));
-      continue;
-    }
-
-    if (this.pending[0].length > this.waiting) {
-      chunk = this.pending[0].slice(0, this.waiting);
-      this.pending[0] = this.pending[0].slice(this.waiting);
-      this.total -= chunk.length;
-      this.parse(chunk);
-      continue;
-    }
-
-    if (this.pending[0].length === this.waiting) {
-      chunk = this.pending.shift();
-      this.total -= chunk.length;
-      this.parse(chunk);
-      continue;
-    }
-
-    chunk = new Buffer(this.waiting);
-    off = 0;
-    len = 0;
-
-    while (off < chunk.length) {
-      len = this.pending[0].copy(chunk, off);
-      if (len === this.pending[0].length)
-        this.pending.shift();
-      else
-        this.pending[0] = this.pending[0].slice(len);
-      off += len;
-    }
-
-    assert.equal(off, chunk.length);
-
-    this.total -= chunk.length;
+    chunk = this.read(this.waiting);
     this.parse(chunk);
   }
 };
 
+Parser.prototype.read = function read(size) {
+  var pending, chunk, off, len;
+
+  assert(this.total >= size, 'Reading too much.');
+
+  if (size === 0)
+    return new Buffer(0);
+
+  pending = this.pending[0];
+
+  if (pending.length > size) {
+    chunk = pending.slice(0, size);
+    this.pending[0] = pending.slice(size);
+    this.total -= chunk.length;
+    return chunk;
+  }
+
+  if (pending.length === size) {
+    chunk = this.pending.shift();
+    this.total -= chunk.length;
+    return chunk;
+  }
+
+  chunk = new Buffer(size);
+  off = 0;
+  len = 0;
+
+  while (off < chunk.length) {
+    pending = this.pending[0];
+    len = pending.copy(chunk, off);
+    if (len === pending.length)
+      this.pending.shift();
+    else
+      this.pending[0] = pending.slice(len);
+    off += len;
+  }
+
+  assert.equal(off, chunk.length);
+
+  this.total -= chunk.length;
+
+  return chunk;
+};
+
 Parser.prototype.parse = function parse(data) {
   var packet;