src: improve StreamBase read throughput

Improve performance by providing JS with the raw ingridients
for the read data, i.e. an `ArrayBuffer` + offset + length
fields, instead of creating `Buffer` instances in C++ land.

PR-URL: #23797
Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

Author: addaleax

Diff for: benchmark/net/tcp-raw-c2s.js

@@ -46,15 +46,15 @@ function main({ dur, len, type }) {
       process.exit(0);
     }, dur * 1000);
 
-    clientHandle.onread = function(nread, buffer) {
+    clientHandle.onread = function(buffer) {
       // we're not expecting to ever get an EOF from the client.
       // just lots of data forever.
-      if (nread < 0)
-        fail(nread, 'read');
+      if (!buffer)
+        fail('read');
 
       // don't slice the buffer.  the point of this is to isolate, not
       // simulate real traffic.
-      bytes += buffer.length;
+      bytes += buffer.byteLength;
     };
 
     clientHandle.readStart();

Diff for: benchmark/net/tcp-raw-pipe.js

@@ -43,15 +43,15 @@ function main({ dur, len, type }) {
     if (err)
       fail(err, 'connect');
 
-    clientHandle.onread = function(nread, buffer) {
+    clientHandle.onread = function(buffer) {
       // we're not expecting to ever get an EOF from the client.
       // just lots of data forever.
-      if (nread < 0)
-        fail(nread, 'read');
+      if (!buffer)
+        fail('read');
 
       const writeReq = new WriteWrap();
       writeReq.async = false;
-      err = clientHandle.writeBuffer(writeReq, buffer);
+      err = clientHandle.writeBuffer(writeReq, Buffer.from(buffer));
 
       if (err)
         fail(err, 'write');
@@ -89,11 +89,11 @@ function main({ dur, len, type }) {
   if (err)
     fail(err, 'connect');
 
-  clientHandle.onread = function(nread, buffer) {
-    if (nread < 0)
-      fail(nread, 'read');
+  clientHandle.onread = function(buffer) {
+    if (!buffer)
+      fail('read');
 
-    bytes += buffer.length;
+    bytes += buffer.byteLength;
   };
 
   connectReq.oncomplete = function(err) {

Diff for: benchmark/net/tcp-raw-s2c.js

@@ -109,15 +109,15 @@ function main({ dur, len, type }) {
 
     connectReq.oncomplete = function() {
       var bytes = 0;
-      clientHandle.onread = function(nread, buffer) {
+      clientHandle.onread = function(buffer) {
         // we're not expecting to ever get an EOF from the client.
         // just lots of data forever.
-        if (nread < 0)
-          fail(nread, 'read');
+        if (!buffer)
+          fail('read');
 
         // don't slice the buffer.  the point of this is to isolate, not
         // simulate real traffic.
-        bytes += buffer.length;
+        bytes += buffer.byteLength;
       };
 
       clientHandle.readStart();

Diff for: lib/internal/child_process.js

@@ -22,7 +22,12 @@ const util = require('util');
 const assert = require('assert');
 
 const { Process } = internalBinding('process_wrap');
-const { WriteWrap } = internalBinding('stream_wrap');
+const {
+  WriteWrap,
+  kReadBytesOrError,
+  kArrayBufferOffset,
+  streamBaseState
+} = internalBinding('stream_wrap');
 const { Pipe, constants: PipeConstants } = internalBinding('pipe_wrap');
 const { TCP } = internalBinding('tcp_wrap');
 const { TTY } = internalBinding('tty_wrap');
@@ -486,11 +491,13 @@ function setupChannel(target, channel) {
   var pendingHandle = null;
   channel.buffering = false;
   channel.pendingHandle = null;
-  channel.onread = function(nread, pool) {
+  channel.onread = function(arrayBuffer) {
     const recvHandle = channel.pendingHandle;
     channel.pendingHandle = null;
-    // TODO(bnoordhuis) Check that nread > 0.
-    if (pool) {
+    if (arrayBuffer) {
+      const nread = streamBaseState[kReadBytesOrError];
+      const offset = streamBaseState[kArrayBufferOffset];
+      const pool = new Uint8Array(arrayBuffer, offset, nread);
       if (recvHandle)
         pendingHandle = recvHandle;
 

Diff for: lib/internal/http2/core.js

@@ -120,7 +120,11 @@ const { isArrayBufferView } = require('internal/util/types');
 
 const { FileHandle } = process.binding('fs');
 const binding = internalBinding('http2');
-const { ShutdownWrap } = internalBinding('stream_wrap');
+const {
+  ShutdownWrap,
+  kReadBytesOrError,
+  streamBaseState
+} = internalBinding('stream_wrap');
 const { UV_EOF } = internalBinding('uv');
 
 const { StreamPipe } = internalBinding('stream_pipe');
@@ -2043,7 +2047,8 @@ function onFileUnpipe() {
 
 // This is only called once the pipe has returned back control, so
 // it only has to handle errors and End-of-File.
-function onPipedFileHandleRead(err) {
+function onPipedFileHandleRead() {
+  const err = streamBaseState[kReadBytesOrError];
   if (err < 0 && err !== UV_EOF) {
     this.stream.close(NGHTTP2_INTERNAL_ERROR);
   }

Diff for: lib/internal/stream_base_commons.js

@@ -1,7 +1,13 @@
 'use strict';
 
 const { Buffer } = require('buffer');
-const { WriteWrap } = internalBinding('stream_wrap');
+const { FastBuffer } = require('internal/buffer');
+const {
+  WriteWrap,
+  kReadBytesOrError,
+  kArrayBufferOffset,
+  streamBaseState
+} = internalBinding('stream_wrap');
 const { UV_EOF } = internalBinding('uv');
 const { errnoException } = require('internal/errors');
 const { owner_symbol } = require('internal/async_hooks').symbols;
@@ -84,13 +90,17 @@ function afterWriteDispatched(self, req, err, cb) {
   }
 }
 
-function onStreamRead(nread, buf) {
+function onStreamRead(arrayBuffer) {
+  const nread = streamBaseState[kReadBytesOrError];
+
   const handle = this;
   const stream = this[owner_symbol];
 
   stream[kUpdateTimer]();
 
   if (nread > 0 && !stream.destroyed) {
+    const offset = streamBaseState[kArrayBufferOffset];
+    const buf = new FastBuffer(arrayBuffer, offset, nread);
     if (!stream.push(buf)) {
       handle.reading = false;
       if (!stream.destroyed) {

Diff for: src/env-inl.h

@@ -446,6 +446,11 @@ Environment::trace_category_state() {
   return trace_category_state_;
 }
 
+inline AliasedBuffer<int32_t, v8::Int32Array>&
+Environment::stream_base_state() {
+  return stream_base_state_;
+}
+
 inline uint32_t Environment::get_next_module_id() {
   return module_id_counter_++;
 }

Diff for: src/env.cc

@@ -158,6 +158,7 @@ Environment::Environment(IsolateData* isolate_data,
       makecallback_cntr_(0),
       should_abort_on_uncaught_toggle_(isolate_, 1),
       trace_category_state_(isolate_, kTraceCategoryCount),
+      stream_base_state_(isolate_, StreamBase::kNumStreamBaseStateFields),
       http_parser_buffer_(nullptr),
       fs_stats_field_array_(isolate_, kFsStatsFieldsLength * 2),
       fs_stats_field_bigint_array_(isolate_, kFsStatsFieldsLength * 2),

Diff for: src/env.h

@@ -668,6 +668,7 @@ class Environment {
   should_abort_on_uncaught_toggle();
 
   inline AliasedBuffer<uint8_t, v8::Uint8Array>& trace_category_state();
+  inline AliasedBuffer<int32_t, v8::Int32Array>& stream_base_state();
 
   // The necessary API for async_hooks.
   inline double new_async_id();
@@ -951,6 +952,8 @@ class Environment {
   AliasedBuffer<uint8_t, v8::Uint8Array> trace_category_state_;
   std::unique_ptr<TrackingTraceStateObserver> trace_state_observer_;
 
+  AliasedBuffer<int32_t, v8::Int32Array> stream_base_state_;
+
   std::unique_ptr<performance::performance_state> performance_state_;
   std::unordered_map<std::string, uint64_t> performance_marks_;
 

Diff for: src/node_http2.cc

@@ -1256,10 +1256,7 @@ void Http2StreamListener::OnStreamRead(ssize_t nread, const uv_buf_t& buf) {
   CHECK_LE(offset, session->stream_buf_.len);
   CHECK_LE(offset + buf.len, session->stream_buf_.len);
 
-  Local<Object> buffer =
-      Buffer::New(env, session->stream_buf_ab_, offset, nread).ToLocalChecked();
-
-  stream->CallJSOnreadMethod(nread, buffer);
+  stream->CallJSOnreadMethod(nread, session->stream_buf_ab_, offset);
 }
 
 

Diff for: src/stream_base.cc

@@ -17,6 +17,7 @@
 namespace node {
 
 using v8::Array;
+using v8::ArrayBuffer;
 using v8::Boolean;
 using v8::Context;
 using v8::FunctionCallbackInfo;
@@ -303,17 +304,29 @@ int StreamBase::WriteString(const FunctionCallbackInfo<Value>& args) {
 }
 
 
-void StreamBase::CallJSOnreadMethod(ssize_t nread, Local<Object> buf) {
+void StreamBase::CallJSOnreadMethod(ssize_t nread,
+                                    Local<ArrayBuffer> ab,
+                                    size_t offset) {
   Environment* env = env_;
 
+#ifdef DEBUG
+  CHECK_EQ(static_cast<int32_t>(nread), nread);
+  CHECK_EQ(static_cast<int32_t>(offset), offset);
+
+  if (ab.IsEmpty()) {
+    CHECK_EQ(offset, 0);
+    CHECK_LE(nread, 0);
+  } else {
+    CHECK_GE(nread, 0);
+  }
+#endif
+  env->stream_base_state()[kReadBytesOrError] = nread;
+  env->stream_base_state()[kArrayBufferOffset] = offset;
+
   Local<Value> argv[] = {
-    Integer::New(env->isolate(), nread),
-    buf
+    ab.IsEmpty() ? Undefined(env->isolate()).As<Value>() : ab.As<Value>()
   };
 
-  if (argv[1].IsEmpty())
-    argv[1] = Undefined(env->isolate());
-
   AsyncWrap* wrap = GetAsyncWrap();
   CHECK_NOT_NULL(wrap);
   wrap->MakeCallback(env->onread_string(), arraysize(argv), argv);
@@ -366,14 +379,18 @@ void EmitToJSStreamListener::OnStreamRead(ssize_t nread, const uv_buf_t& buf) {
   if (nread <= 0)  {
     free(buf.base);
     if (nread < 0)
-      stream->CallJSOnreadMethod(nread, Local<Object>());
+      stream->CallJSOnreadMethod(nread, Local<ArrayBuffer>());
     return;
   }
 
   CHECK_LE(static_cast<size_t>(nread), buf.len);
   char* base = Realloc(buf.base, nread);
 
-  Local<Object> obj = Buffer::New(env, base, nread).ToLocalChecked();
+  Local<ArrayBuffer> obj = ArrayBuffer::New(
+      env->isolate(),
+      base,
+      nread,
+      v8::ArrayBufferCreationMode::kInternalized);  // Transfer ownership to V8.
   stream->CallJSOnreadMethod(nread, obj);
 }
 

Diff for: src/stream_base.h

@@ -264,7 +264,9 @@ class StreamBase : public StreamResource {
   virtual bool IsIPCPipe();
   virtual int GetFD();
 
-  void CallJSOnreadMethod(ssize_t nread, v8::Local<v8::Object> buf);
+  void CallJSOnreadMethod(ssize_t nread,
+                          v8::Local<v8::ArrayBuffer> ab,
+                          size_t offset = 0);
 
   // This is named `stream_env` to avoid name clashes, because a lot of
   // subclasses are also `BaseObject`s.
@@ -326,12 +328,20 @@ class StreamBase : public StreamResource {
       const v8::FunctionCallbackInfo<v8::Value>& args)>
   static void JSMethod(const v8::FunctionCallbackInfo<v8::Value>& args);
 
+  // Internal, used only in StreamBase methods + env.cc.
+  enum StreamBaseStateFields {
+    kReadBytesOrError,
+    kArrayBufferOffset,
+    kNumStreamBaseStateFields
+  };
+
  private:
   Environment* env_;
   EmitToJSStreamListener default_listener_;
 
   friend class WriteWrap;
   friend class ShutdownWrap;
+  friend class Environment;  // For kNumStreamBaseStateFields.
 };
 
 

Diff for: src/stream_wrap.cc

@@ -80,6 +80,11 @@ void LibuvStreamWrap::Initialize(Local<Object> target,
   target->Set(writeWrapString,
               ww->GetFunction(env->context()).ToLocalChecked());
   env->set_write_wrap_template(ww->InstanceTemplate());
+
+  NODE_DEFINE_CONSTANT(target, kReadBytesOrError);
+  NODE_DEFINE_CONSTANT(target, kArrayBufferOffset);
+  target->Set(context, FIXED_ONE_BYTE_STRING(env->isolate(), "streamBaseState"),
+              env->stream_base_state().GetJSArray()).FromJust();
 }
 
 

Diff for: test/parallel/test-net-end-close.js

@@ -6,11 +6,15 @@ const net = require('net');
 
 const { internalBinding } = require('internal/test/binding');
 const { UV_EOF } = internalBinding('uv');
+const { streamBaseState, kReadBytesOrError } = internalBinding('stream_wrap');
 
 const s = new net.Socket({
   handle: {
     readStart: function() {
-      setImmediate(() => this.onread(UV_EOF, null));
+      setImmediate(() => {
+        streamBaseState[kReadBytesOrError] = UV_EOF;
+        this.onread();
+      });
     },
     close: (cb) => setImmediate(cb)
   },

Diff for: test/parallel/test-process-wrap.js

@@ -44,11 +44,10 @@ p.onexit = function(exitCode, signal) {
   processExited = true;
 };
 
-pipe.onread = function(err, b, off, len) {
+pipe.onread = function(arrayBuffer) {
   assert.ok(processExited);
-  if (b) {
+  if (arrayBuffer) {
     gotPipeData = true;
-    console.log('read %d', len);
   } else {
     gotPipeEOF = true;
     pipe.close();

Diff for: test/parallel/test-tcp-wrap-listen.js

@@ -5,7 +5,12 @@ const assert = require('assert');
 
 const { internalBinding } = require('internal/test/binding');
 const { TCP, constants: TCPConstants } = internalBinding('tcp_wrap');
-const { WriteWrap } = internalBinding('stream_wrap');
+const {
+  WriteWrap,
+  kReadBytesOrError,
+  kArrayBufferOffset,
+  streamBaseState
+} = internalBinding('stream_wrap');
 
 const server = new TCP(TCPConstants.SOCKET);
 
@@ -30,8 +35,11 @@ server.onconnection = (err, client) => {
 
   client.readStart();
   client.pendingWrites = [];
-  client.onread = common.mustCall((err, buffer) => {
-    if (buffer) {
+  client.onread = common.mustCall((arrayBuffer) => {
+    if (arrayBuffer) {
+      const offset = streamBaseState[kArrayBufferOffset];
+      const nread = streamBaseState[kReadBytesOrError];
+      const buffer = Buffer.from(arrayBuffer, offset, nread);
       assert.ok(buffer.length > 0);
 
       assert.strictEqual(client.writeQueueSize, 0);