crypto: initialize transform lazily

lib/crypto.js

@@ -150,15 +150,33 @@ exports.createCredentials = function(options, context) {
 };
 
 
+function LazyTransform(options) {
+  this._options = options;
+}
+util.inherits(LazyTransform, stream.Transform);
+
+['read', 'write', 'end'].forEach(function(action, i, actions) {
+  LazyTransform.prototype[action] = function() {
+    stream.Transform.call(this, this._options);
+
+    actions.forEach(function(action) {
+      this[action] = stream.Transform.prototype[action];
+    }, this);
+
+    return this[action].apply(this, arguments);
+  };
+});
+
+
 exports.createHash = exports.Hash = Hash;
 function Hash(algorithm, options) {
   if (!(this instanceof Hash))
     return new Hash(algorithm);
   this._binding = new binding.Hash(algorithm);
-  stream.Transform.call(this, options);
+  LazyTransform.call(this, options);
 }
 
-util.inherits(Hash, stream.Transform);
+util.inherits(Hash, LazyTransform);
 
 Hash.prototype._transform = function(chunk, encoding, callback) {
   this._binding.update(chunk, encoding);
@@ -194,10 +212,10 @@ function Hmac(hmac, key, options) {
     return new Hmac(hmac, key);
   this._binding = new binding.Hmac();
   this._binding.init(hmac, toBuf(key));
-  stream.Transform.call(this, options);
+  LazyTransform.call(this, options);
 }
 
-util.inherits(Hmac, stream.Transform);
+util.inherits(Hmac, LazyTransform);
 
 Hmac.prototype.update = Hash.prototype.update;
 Hmac.prototype.digest = Hash.prototype.digest;
@@ -221,10 +239,10 @@ function Cipher(cipher, password, options) {
   this._binding.init(cipher, toBuf(password));
   this._decoder = null;
 
-  stream.Transform.call(this, options);
+  LazyTransform.call(this, options);
 }
 
-util.inherits(Cipher, stream.Transform);
+util.inherits(Cipher, LazyTransform);
 
 Cipher.prototype._transform = function(chunk, encoding, callback) {
   this.push(this._binding.update(chunk, encoding));
@@ -280,10 +298,10 @@ function Cipheriv(cipher, key, iv, options) {
   this._binding.initiv(cipher, toBuf(key), toBuf(iv));
   this._decoder = null;
 
-  stream.Transform.call(this, options);
+  LazyTransform.call(this, options);
 }
 
-util.inherits(Cipheriv, stream.Transform);
+util.inherits(Cipheriv, LazyTransform);
 
 Cipheriv.prototype._transform = Cipher.prototype._transform;
 Cipheriv.prototype._flush = Cipher.prototype._flush;
@@ -302,10 +320,10 @@ function Decipher(cipher, password, options) {
   this._binding.init(cipher, toBuf(password));
   this._decoder = null;
 
-  stream.Transform.call(this, options);
+  LazyTransform.call(this, options);
 }
 
-util.inherits(Decipher, stream.Transform);
+util.inherits(Decipher, LazyTransform);
 
 Decipher.prototype._transform = Cipher.prototype._transform;
 Decipher.prototype._flush = Cipher.prototype._flush;
@@ -325,10 +343,10 @@ function Decipheriv(cipher, key, iv, options) {
   this._binding.initiv(cipher, toBuf(key), toBuf(iv));
   this._decoder = null;
 
-  stream.Transform.call(this, options);
+  LazyTransform.call(this, options);
 }
 
-util.inherits(Decipheriv, stream.Transform);
+util.inherits(Decipheriv, LazyTransform);
 
 Decipheriv.prototype._transform = Cipher.prototype._transform;
 Decipheriv.prototype._flush = Cipher.prototype._flush;