streams: refactor LazyTransform to internal/

This commit refactors LazyTransform from the crypto implementation
(lib/crypto.js) into an internal module (not publicy accessible) in
internal/streams/lazy_transform.js. This promotes a more modular core
design and removes code bloat in crypto, as LazyTransform didn't
specifically have anything to do with cryptography, but rather a fast
way to support two APIs on a stream.

PR-URL: https://github.com/nodejs/node/pull/2566
Reviewed-By: Fedor Indutny <fedor.indutny@gmail.com>

1 files changed, 1 insertions, 31 deletions

diff --git a/lib/crypto.js b/lib/crypto.js
index bfe7837cb4..b32d9aff90 100644
--- a/lib/crypto.js
+++ b/lib/crypto.js
@@ -20,6 +20,7 @@ const constants = require('constants');
 const stream = require('stream');
 const util = require('util');
 const internalUtil = require('internal/util');
+const LazyTransform = require('internal/streams/lazy_transform');
 
 const DH_GENERATOR = 2;
 
@@ -42,37 +43,6 @@ const assert = require('assert');
 const StringDecoder = require('string_decoder').StringDecoder;
 
 
-function LazyTransform(options) {
-  this._options = options;
-}
-util.inherits(LazyTransform, stream.Transform);
-
-[
-  '_readableState',
-  '_writableState',
-  '_transformState'
-].forEach(function(prop, i, props) {
-  Object.defineProperty(LazyTransform.prototype, prop, {
-    get: function() {
-      stream.Transform.call(this, this._options);
-      this._writableState.decodeStrings = false;
-      this._writableState.defaultEncoding = 'binary';
-      return this[prop];
-    },
-    set: function(val) {
-      Object.defineProperty(this, prop, {
-        value: val,
-        enumerable: true,
-        configurable: true,
-        writable: true
-      });
-    },
-    configurable: true,
-    enumerable: true
-  });
-});
-
-
 exports.createHash = exports.Hash = Hash;
 function Hash(algorithm, options) {
   if (!(this instanceof Hash))