util: minor changes to static writer.

lib/utils/staticwriter.js

@@ -11,18 +11,9 @@ var encoding = require('./encoding');
 var crypto = require('../crypto/crypto');
 
 /**
- * An object that allows writing of buffers in a
+ * Statically allocated buffer writer.
- * sane manner. This buffer writer is extremely
- * optimized since it does not actually write
- * anything until `render` is called. It makes
- * one allocation: at the end, once it knows the
- * size of the buffer to be allocated. Because
- * of this, it can also act as a size calculator
- * which is useful for guaging block size
- * without actually serializing any data.
- * @exports StaticWriter
  * @constructor
- * @param {(StaticWriter|Object)?} options
+ * @param {Number} size
  */
 
 function StaticWriter(size) {
@@ -320,7 +311,9 @@ StaticWriter.prototype.writeBytes = function writeBytes(value) {
   if (value.length === 0)
     return;
 
-  this.written += value.copy(this.data, this.written);
+  value.copy(this.data, this.written);
+
+  this.written += value.length;
 };
 
 /**
@@ -402,7 +395,8 @@ StaticWriter.prototype.writeNullString = function writeNullString(value, enc) {
 StaticWriter.prototype.writeChecksum = function writeChecksum() {
   var data = this.data.slice(0, this.written);
   var hash = crypto.hash256(data);
-  this.written += hash.copy(this.data, this.written, 0, 4);
+  hash.copy(this.data, this.written, 0, 4);
+  this.written += 4;
 };
 
 /**

lib/utils/writer.js

@@ -53,7 +53,6 @@ var FILL = 24;
  * without actually serializing any data.
  * @exports BufferWriter
  * @constructor
- * @param {(BufferWriter|Object)?} options
  */
 
 function BufferWriter() {