From 559cb628895912179a88516537e62004a3a2408c Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Tue, 17 May 2016 15:17:39 -0700
Subject: [PATCH] varint. misc.

---
 lib/bcoin/reader.js | 10 +++-------
 lib/bcoin/utils.js  | 34 +++++++++++++++++-----------------
 lib/bcoin/writer.js |  2 ++
 3 files changed, 22 insertions(+), 24 deletions(-)

diff --git a/lib/bcoin/reader.js b/lib/bcoin/reader.js
index 42f84038..de089196 100644
--- a/lib/bcoin/reader.js
+++ b/lib/bcoin/reader.js
@@ -474,13 +474,9 @@ BufferReader.prototype.readDoubleBE = function readDoubleBE() {
  */
 
 BufferReader.prototype.readVarint = function readVarint(big) {
-  var result;
-  assert(this.offset + 1 <= this.data.length);
-  result = utils.readVarint(this.data, this.offset, big);
-  assert(result.off <= this.data.length);
-  assert(result.r >= 0);
-  this.offset = result.off;
-  return result.r;
+  var result = utils.readVarint(this.data, this.offset, big);
+  this.offset += result.size;
+  return result.value;
 };
 
 /**
diff --git a/lib/bcoin/utils.js b/lib/bcoin/utils.js
index 2aec0c82..15133ebe 100644
--- a/lib/bcoin/utils.js
+++ b/lib/bcoin/utils.js
@@ -2018,41 +2018,41 @@ utils.write64BE = function write64BE(dst, num, off) {
  */
 
 utils.readVarint = function readVarint(data, off, big) {
-  var r, bytes;
+  var value, size;
 
   off = off >>> 0;
 
   assert(off < data.length);
 
   if (data[off] < 0xfd) {
-    r = data[off];
+    size = 1;
+    value = data[off];
     if (big)
-      r = new bn(r);
-    bytes = 1;
+      value = new bn(value);
   } else if (data[off] === 0xfd) {
-    assert(off + 2 < data.length);
-    r = data[off + 1] | (data[off + 2] << 8);
+    size = 3;
+    assert(off + size <= data.length);
+    value = data[off + 1] | (data[off + 2] << 8);
     if (big)
-      r = new bn(r);
-    bytes = 3;
+      value = new bn(value);
   } else if (data[off] === 0xfe) {
-    assert(off + 4 < data.length);
-    r = utils.readU32(data, off + 1);
+    size = 5;
+    assert(off + size <= data.length);
+    value = utils.readU32(data, off + 1);
     if (big)
-      r = new bn(r);
-    bytes = 5;
+      value = new bn(value);
   } else if (data[off] === 0xff) {
-    assert(off + 8 < data.length);
+    size = 9;
+    assert(off + size <= data.length);
     if (big)
-      r = utils.readU64(data, off + 1);
+      value = utils.readU64(data, off + 1);
     else
-      r = utils.readU64N(data, off + 1);
-    bytes = 9;
+      value = utils.readU64N(data, off + 1);
   } else {
     assert(false, 'Malformed varint.');
   }
 
-  return { off: off + bytes, r: r };
+  return { size: size, value: value };
 };
 
 /**
diff --git a/lib/bcoin/writer.js b/lib/bcoin/writer.js
index 025f1237..b9538c8b 100644
--- a/lib/bcoin/writer.js
+++ b/lib/bcoin/writer.js
@@ -112,6 +112,8 @@ BufferWriter.prototype.render = function render(keep) {
     }
   }
 
+  assert(off === data.length);
+
   if (!keep)
     this.destroy();