crypto: use on-stack storage in HashUpdate

Boosts speed up to 10% on primitive `createHash().update().digest()`
benchmark.

PR-URL: #664
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

Author: indutny

src/node_crypto.cc

@@ -2750,19 +2750,10 @@ void CipherBase::Update(const FunctionCallbackInfo<Value>& args) {
 
   // Only copy the data if we have to, because it's a string
   if (args[0]->IsString()) {
-    Local<String> string = args[0].As<String>();
-    enum encoding encoding = ParseEncoding(env->isolate(), args[1], BINARY);
-    if (!StringBytes::IsValidString(env->isolate(), string, encoding))
-      return env->ThrowTypeError("Bad input string");
-    size_t buflen = StringBytes::StorageSize(env->isolate(), string, encoding);
-    char* buf = new char[buflen];
-    size_t written = StringBytes::Write(env->isolate(),
-                                        buf,
-                                        buflen,
-                                        string,
-                                        encoding);
-    r = cipher->Update(buf, written, &out, &out_len);
-    delete[] buf;
+    StringBytes::InlineDecoder decoder;
+    if (!decoder.Decode(env, args[0].As<String>(), args[1], BINARY))
+      return;
+    r = cipher->Update(decoder.out(), decoder.size(), &out, &out_len);
   } else {
     char* buf = Buffer::Data(args[0]);
     size_t buflen = Buffer::Length(args[0]);
@@ -2929,19 +2920,10 @@ void Hmac::HmacUpdate(const FunctionCallbackInfo<Value>& args) {
   // Only copy the data if we have to, because it's a string
   bool r;
   if (args[0]->IsString()) {
-    Local<String> string = args[0].As<String>();
-    enum encoding encoding = ParseEncoding(env->isolate(), args[1], BINARY);
-    if (!StringBytes::IsValidString(env->isolate(), string, encoding))
-      return env->ThrowTypeError("Bad input string");
-    size_t buflen = StringBytes::StorageSize(env->isolate(), string, encoding);
-    char* buf = new char[buflen];
-    size_t written = StringBytes::Write(env->isolate(),
-                                        buf,
-                                        buflen,
-                                        string,
-                                        encoding);
-    r = hmac->HmacUpdate(buf, written);
-    delete[] buf;
+    StringBytes::InlineDecoder decoder;
+    if (!decoder.Decode(env, args[0].As<String>(), args[1], BINARY))
+      return;
+    r = hmac->HmacUpdate(decoder.out(), decoder.size());
   } else {
     char* buf = Buffer::Data(args[0]);
     size_t buflen = Buffer::Length(args[0]);
@@ -3053,19 +3035,10 @@ void Hash::HashUpdate(const FunctionCallbackInfo<Value>& args) {
   // Only copy the data if we have to, because it's a string
   bool r;
   if (args[0]->IsString()) {
-    Local<String> string = args[0].As<String>();
-    enum encoding encoding = ParseEncoding(env->isolate(), args[1], BINARY);
-    if (!StringBytes::IsValidString(env->isolate(), string, encoding))
-      return env->ThrowTypeError("Bad input string");
-    size_t buflen = StringBytes::StorageSize(env->isolate(), string, encoding);
-    char* buf = new char[buflen];
-    size_t written = StringBytes::Write(env->isolate(),
-                                        buf,
-                                        buflen,
-                                        string,
-                                        encoding);
-    r = hash->HashUpdate(buf, written);
-    delete[] buf;
+    StringBytes::InlineDecoder decoder;
+    if (!decoder.Decode(env, args[0].As<String>(), args[1], BINARY))
+      return;
+    r = hash->HashUpdate(decoder.out(), decoder.size());
   } else {
     char* buf = Buffer::Data(args[0]);
     size_t buflen = Buffer::Length(args[0]);
@@ -3214,19 +3187,10 @@ void Sign::SignUpdate(const FunctionCallbackInfo<Value>& args) {
   // Only copy the data if we have to, because it's a string
   Error err;
   if (args[0]->IsString()) {
-    Local<String> string = args[0].As<String>();
-    enum encoding encoding = ParseEncoding(env->isolate(), args[1], BINARY);
-    if (!StringBytes::IsValidString(env->isolate(), string, encoding))
-      return env->ThrowTypeError("Bad input string");
-    size_t buflen = StringBytes::StorageSize(env->isolate(), string, encoding);
-    char* buf = new char[buflen];
-    size_t written = StringBytes::Write(env->isolate(),
-                                        buf,
-                                        buflen,
-                                        string,
-                                        encoding);
-    err = sign->SignUpdate(buf, written);
-    delete[] buf;
+    StringBytes::InlineDecoder decoder;
+    if (!decoder.Decode(env, args[0].As<String>(), args[1], BINARY))
+      return;
+    err = sign->SignUpdate(decoder.out(), decoder.size());
   } else {
     char* buf = Buffer::Data(args[0]);
     size_t buflen = Buffer::Length(args[0]);
@@ -3395,19 +3359,10 @@ void Verify::VerifyUpdate(const FunctionCallbackInfo<Value>& args) {
   // Only copy the data if we have to, because it's a string
   Error err;
   if (args[0]->IsString()) {
-    Local<String> string = args[0].As<String>();
-    enum encoding encoding = ParseEncoding(env->isolate(), args[1], BINARY);
-    if (!StringBytes::IsValidString(env->isolate(), string, encoding))
-      return env->ThrowTypeError("Bad input string");
-    size_t buflen = StringBytes::StorageSize(env->isolate(), string, encoding);
-    char* buf = new char[buflen];
-    size_t written = StringBytes::Write(env->isolate(),
-                                        buf,
-                                        buflen,
-                                        string,
-                                        encoding);
-    err = verify->VerifyUpdate(buf, written);
-    delete[] buf;
+    StringBytes::InlineDecoder decoder;
+    if (!decoder.Decode(env, args[0].As<String>(), args[1], BINARY))
+      return;
+    err = verify->VerifyUpdate(decoder.out(), decoder.size());
   } else {
     char* buf = Buffer::Data(args[0]);
     size_t buflen = Buffer::Length(args[0]);