lts/src/stream_pipe.cc
#include "stream_pipe.h"
#include "stream_base-inl.h"
#include "node_buffer.h"
#include "util-inl.h"
using v8::Context;
using v8::Function;
using v8::FunctionCallbackInfo;
using v8::FunctionTemplate;
using v8::Local;
using v8::Object;
using v8::Value;
namespace node {
StreamPipe::StreamPipe(StreamBase* source,
StreamBase* sink,
Local<Object> obj)
: AsyncWrap(source->stream_env(), obj, AsyncWrap::PROVIDER_STREAMPIPE) {
MakeWeak();
CHECK_NOT_NULL(sink);
CHECK_NOT_NULL(source);
source->PushStreamListener(&readable_listener_);
sink->PushStreamListener(&writable_listener_);
uses_wants_write_ = sink->HasWantsWrite();
// Set up links between this object and the source/sink objects.
// In particular, this makes sure that they are garbage collected as a group,
// if that applies to the given streams (for example, Http2Streams use
// weak references).
obj->Set(env()->context(), env()->source_string(), source->GetObject())
.Check();
source->GetObject()->Set(env()->context(), env()->pipe_target_string(), obj)
.Check();
obj->Set(env()->context(), env()->sink_string(), sink->GetObject())
.Check();
sink->GetObject()->Set(env()->context(), env()->pipe_source_string(), obj)
.Check();
}
StreamPipe::~StreamPipe() {
Unpipe(true);
}
StreamBase* StreamPipe::source() {
return static_cast<StreamBase*>(readable_listener_.stream());
}
StreamBase* StreamPipe::sink() {
return static_cast<StreamBase*>(writable_listener_.stream());
}
void StreamPipe::Unpipe(bool is_in_deletion) {
if (is_closed_)
return;
// Note that we possibly cannot use virtual methods on `source` and `sink`
// here, because this function can be called from their destructors via
// `OnStreamDestroy()`.
if (!source_destroyed_)
source()->ReadStop();
is_closed_ = true;
is_reading_ = false;
source()->RemoveStreamListener(&readable_listener_);
if (pending_writes_ == 0)
sink()->RemoveStreamListener(&writable_listener_);
if (is_in_deletion) return;
// Delay the JS-facing part with SetImmediate, because this might be from
// inside the garbage collector, so we can’t run JS here.
HandleScope handle_scope(env()->isolate());
BaseObjectPtr<StreamPipe> strong_ref{this};
env()->SetImmediate([this, strong_ref](Environment* env) {
HandleScope handle_scope(env->isolate());
Context::Scope context_scope(env->context());
Local<Object> object = this->object();
Local<Value> onunpipe;
if (!object->Get(env->context(), env->onunpipe_string()).ToLocal(&onunpipe))
return;
if (onunpipe->IsFunction() &&
MakeCallback(onunpipe.As<Function>(), 0, nullptr).IsEmpty()) {
return;
}
// Set all the links established in the constructor to `null`.
Local<Value> null = Null(env->isolate());
Local<Value> source_v;
Local<Value> sink_v;
if (!object->Get(env->context(), env->source_string()).ToLocal(&source_v) ||
!object->Get(env->context(), env->sink_string()).ToLocal(&sink_v) ||
!source_v->IsObject() || !sink_v->IsObject()) {
return;
}
if (object->Set(env->context(), env->source_string(), null).IsNothing() ||
object->Set(env->context(), env->sink_string(), null).IsNothing() ||
source_v.As<Object>()
->Set(env->context(), env->pipe_target_string(), null)
.IsNothing() ||
sink_v.As<Object>()
->Set(env->context(), env->pipe_source_string(), null)
.IsNothing()) {
return;
}
});
}
uv_buf_t StreamPipe::ReadableListener::OnStreamAlloc(size_t suggested_size) {
StreamPipe* pipe = ContainerOf(&StreamPipe::readable_listener_, this);
size_t size = std::min(suggested_size, pipe->wanted_data_);
CHECK_GT(size, 0);
return pipe->env()->AllocateManaged(size).release();
}
void StreamPipe::ReadableListener::OnStreamRead(ssize_t nread,
const uv_buf_t& buf_) {
StreamPipe* pipe = ContainerOf(&StreamPipe::readable_listener_, this);
AllocatedBuffer buf(pipe->env(), buf_);
if (nread < 0) {
// EOF or error; stop reading and pass the error to the previous listener
// (which might end up in JS).
pipe->is_eof_ = true;
// Cache `sink()` here because the previous listener might do things
// that eventually lead to an `Unpipe()` call.
StreamBase* sink = pipe->sink();
stream()->ReadStop();
CHECK_NOT_NULL(previous_listener_);
previous_listener_->OnStreamRead(nread, uv_buf_init(nullptr, 0));
// If we’re not writing, close now. Otherwise, we’ll do that in
// `OnStreamAfterWrite()`.
if (pipe->pending_writes_ == 0) {
sink->Shutdown();
pipe->Unpipe();
}
return;
}
pipe->ProcessData(nread, std::move(buf));
}
void StreamPipe::ProcessData(size_t nread, AllocatedBuffer&& buf) {
CHECK(uses_wants_write_ || pending_writes_ == 0);
uv_buf_t buffer = uv_buf_init(buf.data(), nread);
StreamWriteResult res = sink()->Write(&buffer, 1);
pending_writes_++;
if (!res.async) {
writable_listener_.OnStreamAfterWrite(nullptr, res.err);
} else {
is_reading_ = false;
res.wrap->SetAllocatedStorage(std::move(buf));
if (source() != nullptr)
source()->ReadStop();
}
}
void StreamPipe::WritableListener::OnStreamAfterWrite(WriteWrap* w,
int status) {
StreamPipe* pipe = ContainerOf(&StreamPipe::writable_listener_, this);
pipe->pending_writes_--;
if (pipe->is_closed_) {
if (pipe->pending_writes_ == 0) {
Environment* env = pipe->env();
HandleScope handle_scope(env->isolate());
Context::Scope context_scope(env->context());
pipe->MakeCallback(env->oncomplete_string(), 0, nullptr).ToLocalChecked();
stream()->RemoveStreamListener(this);
}
return;
}
if (pipe->is_eof_) {
HandleScope handle_scope(pipe->env()->isolate());
InternalCallbackScope callback_scope(pipe,
InternalCallbackScope::kSkipTaskQueues);
pipe->sink()->Shutdown();
pipe->Unpipe();
return;
}
if (status != 0) {
CHECK_NOT_NULL(previous_listener_);
StreamListener* prev = previous_listener_;
pipe->Unpipe();
prev->OnStreamAfterWrite(w, status);
return;
}
if (!pipe->uses_wants_write_) {
OnStreamWantsWrite(65536);
}
}
void StreamPipe::WritableListener::OnStreamAfterShutdown(ShutdownWrap* w,
int status) {
StreamPipe* pipe = ContainerOf(&StreamPipe::writable_listener_, this);
CHECK_NOT_NULL(previous_listener_);
StreamListener* prev = previous_listener_;
pipe->Unpipe();
prev->OnStreamAfterShutdown(w, status);
}
void StreamPipe::ReadableListener::OnStreamDestroy() {
StreamPipe* pipe = ContainerOf(&StreamPipe::readable_listener_, this);
pipe->source_destroyed_ = true;
if (!pipe->is_eof_) {
OnStreamRead(UV_EPIPE, uv_buf_init(nullptr, 0));
}
}
void StreamPipe::WritableListener::OnStreamDestroy() {
StreamPipe* pipe = ContainerOf(&StreamPipe::writable_listener_, this);
pipe->sink_destroyed_ = true;
pipe->is_eof_ = true;
pipe->pending_writes_ = 0;
pipe->Unpipe();
}
void StreamPipe::WritableListener::OnStreamWantsWrite(size_t suggested_size) {
StreamPipe* pipe = ContainerOf(&StreamPipe::writable_listener_, this);
pipe->wanted_data_ = suggested_size;
if (pipe->is_reading_ || pipe->is_closed_)
return;
HandleScope handle_scope(pipe->env()->isolate());
InternalCallbackScope callback_scope(pipe,
InternalCallbackScope::kSkipTaskQueues);
pipe->is_reading_ = true;
pipe->source()->ReadStart();
}
uv_buf_t StreamPipe::WritableListener::OnStreamAlloc(size_t suggested_size) {
CHECK_NOT_NULL(previous_listener_);
return previous_listener_->OnStreamAlloc(suggested_size);
}
void StreamPipe::WritableListener::OnStreamRead(ssize_t nread,
const uv_buf_t& buf) {
CHECK_NOT_NULL(previous_listener_);
return previous_listener_->OnStreamRead(nread, buf);
}
void StreamPipe::New(const FunctionCallbackInfo<Value>& args) {
CHECK(args.IsConstructCall());
CHECK(args[0]->IsObject());
CHECK(args[1]->IsObject());
StreamBase* source = StreamBase::FromObject(args[0].As<Object>());
StreamBase* sink = StreamBase::FromObject(args[1].As<Object>());
new StreamPipe(source, sink, args.This());
}
void StreamPipe::Start(const FunctionCallbackInfo<Value>& args) {
StreamPipe* pipe;
ASSIGN_OR_RETURN_UNWRAP(&pipe, args.Holder());
pipe->is_closed_ = false;
pipe->writable_listener_.OnStreamWantsWrite(65536);
}
void StreamPipe::Unpipe(const FunctionCallbackInfo<Value>& args) {
StreamPipe* pipe;
ASSIGN_OR_RETURN_UNWRAP(&pipe, args.Holder());
pipe->Unpipe();
}
void StreamPipe::IsClosed(const FunctionCallbackInfo<Value>& args) {
StreamPipe* pipe;
ASSIGN_OR_RETURN_UNWRAP(&pipe, args.Holder());
args.GetReturnValue().Set(pipe->is_closed_);
}
void StreamPipe::PendingWrites(const FunctionCallbackInfo<Value>& args) {
StreamPipe* pipe;
ASSIGN_OR_RETURN_UNWRAP(&pipe, args.Holder());
args.GetReturnValue().Set(pipe->pending_writes_);
}
namespace {
void InitializeStreamPipe(Local<Object> target,
Local<Value> unused,
Local<Context> context,
void* priv) {
Environment* env = Environment::GetCurrent(context);
// Create FunctionTemplate for FileHandle::CloseReq
Local<FunctionTemplate> pipe = env->NewFunctionTemplate(StreamPipe::New);
Local<String> stream_pipe_string =
FIXED_ONE_BYTE_STRING(env->isolate(), "StreamPipe");
env->SetProtoMethod(pipe, "unpipe", StreamPipe::Unpipe);
env->SetProtoMethod(pipe, "start", StreamPipe::Start);
env->SetProtoMethod(pipe, "isClosed", StreamPipe::IsClosed);
env->SetProtoMethod(pipe, "pendingWrites", StreamPipe::PendingWrites);
pipe->Inherit(AsyncWrap::GetConstructorTemplate(env));
pipe->SetClassName(stream_pipe_string);
pipe->InstanceTemplate()->SetInternalFieldCount(
StreamPipe::kInternalFieldCount);
target
->Set(context, stream_pipe_string,
pipe->GetFunction(context).ToLocalChecked())
.Check();
}
} // anonymous namespace
} // namespace node
NODE_MODULE_CONTEXT_AWARE_INTERNAL(stream_pipe,
node::InitializeStreamPipe)