diff options
author | Anna Henningsen <anna@addaleax.net> | 2018-02-13 03:23:50 +0300 |
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committer | Anna Henningsen <anna@addaleax.net> | 2018-03-15 14:53:13 +0300 |
commit | 67f1d76956a8a5da9875b113371c8786ad579086 (patch) | |
tree | 220df0ab56ebc499c1edec20fe7b90449189d44b /src/stream_pipe.cc | |
parent | f7f1437d44f3e4b745e36540a752065cc58d993b (diff) |
src: introduce native-layer stream piping
Provide a way to create pipes between native `StreamBase` instances
that acts more directly than a `.pipe()` call would.
PR-URL: https://github.com/nodejs/node/pull/18936
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Diffstat (limited to 'src/stream_pipe.cc')
-rw-r--r-- | src/stream_pipe.cc | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/src/stream_pipe.cc b/src/stream_pipe.cc new file mode 100644 index 00000000000..8f0263cd9ae --- /dev/null +++ b/src/stream_pipe.cc @@ -0,0 +1,266 @@ +#include "stream_pipe.h" +#include "stream_base-inl.h" +#include "node_buffer.h" +#include "node_internals.h" + +using v8::Context; +using v8::External; +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(this); + + CHECK_NE(sink, nullptr); + CHECK_NE(source, nullptr); + + source->PushStreamListener(&readable_listener_); + sink->PushStreamListener(&writable_listener_); + + CHECK(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()) + .FromJust(); + source->GetObject()->Set(env()->context(), env()->pipe_target_string(), obj) + .FromJust(); + obj->Set(env()->context(), env()->sink_string(), sink->GetObject()) + .FromJust(); + sink->GetObject()->Set(env()->context(), env()->pipe_source_string(), obj) + .FromJust(); +} + +StreamPipe::~StreamPipe() { + CHECK(is_closed_); +} + +StreamBase* StreamPipe::source() { + return static_cast<StreamBase*>(readable_listener_.stream()); +} + +StreamBase* StreamPipe::sink() { + return static_cast<StreamBase*>(writable_listener_.stream()); +} + +void StreamPipe::Unpipe() { + if (is_closed_) + return; + + // Note that we cannot use virtual methods on `source` and `sink` here, + // because this function can be called from their destructors via + // `OnStreamDestroy()`. + + is_closed_ = true; + is_reading_ = false; + source()->RemoveStreamListener(&readable_listener_); + sink()->RemoveStreamListener(&writable_listener_); + + // 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()); + env()->SetImmediate([](Environment* env, void* data) { + StreamPipe* pipe = static_cast<StreamPipe*>(data); + + HandleScope handle_scope(env->isolate()); + Context::Scope context_scope(env->context()); + Local<Object> object = pipe->object(); + + if (object->Has(env->context(), env->onunpipe_string()).FromJust()) { + pipe->MakeCallback(env->onunpipe_string(), 0, nullptr).ToLocalChecked(); + } + + // Set all the links established in the constructor to `null`. + Local<Value> null = Null(env->isolate()); + + Local<Value> source_v; + Local<Value> sink_v; + source_v = object->Get(env->context(), env->source_string()) + .ToLocalChecked(); + sink_v = object->Get(env->context(), env->sink_string()) + .ToLocalChecked(); + CHECK(source_v->IsObject()); + CHECK(sink_v->IsObject()); + + object->Set(env->context(), env->source_string(), null).FromJust(); + object->Set(env->context(), env->sink_string(), null).FromJust(); + source_v.As<Object>()->Set(env->context(), + env->pipe_target_string(), + null).FromJust(); + sink_v.As<Object>()->Set(env->context(), + env->pipe_source_string(), + null).FromJust(); + }, static_cast<void*>(this), object()); +} + +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 uv_buf_init(Malloc(size), size); +} + +void StreamPipe::ReadableListener::OnStreamRead(ssize_t nread, + const uv_buf_t& buf) { + StreamPipe* pipe = ContainerOf(&StreamPipe::readable_listener_, this); + AsyncScope async_scope(pipe); + if (nread < 0) { + // EOF or error; stop reading and pass the error to the previous listener + // (which might end up in JS). + free(buf.base); + pipe->is_eof_ = true; + stream()->ReadStop(); + CHECK_NE(previous_listener_, nullptr); + 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->is_writing_) { + pipe->ShutdownWritable(); + pipe->Unpipe(); + } + return; + } + + pipe->ProcessData(nread, buf); +} + +void StreamPipe::ProcessData(size_t nread, const uv_buf_t& buf) { + uv_buf_t buffer = uv_buf_init(buf.base, nread); + StreamWriteResult res = sink()->Write(&buffer, 1); + if (!res.async) { + free(buf.base); + writable_listener_.OnStreamAfterWrite(nullptr, res.err); + } else { + is_writing_ = true; + is_reading_ = false; + res.wrap->SetAllocatedStorage(buf.base, buf.len); + source()->ReadStop(); + } +} + +void StreamPipe::ShutdownWritable() { + sink()->Shutdown(); +} + +void StreamPipe::WritableListener::OnStreamAfterWrite(WriteWrap* w, + int status) { + StreamPipe* pipe = ContainerOf(&StreamPipe::writable_listener_, this); + pipe->is_writing_ = false; + if (pipe->is_eof_) { + AsyncScope async_scope(pipe); + pipe->ShutdownWritable(); + pipe->Unpipe(); + return; + } + + if (status != 0) { + CHECK_NE(previous_listener_, nullptr); + StreamListener* prev = previous_listener_; + pipe->Unpipe(); + prev->OnStreamAfterWrite(w, status); + return; + } +} + +void StreamPipe::WritableListener::OnStreamAfterShutdown(ShutdownWrap* w, + int status) { + StreamPipe* pipe = ContainerOf(&StreamPipe::writable_listener_, this); + CHECK_NE(previous_listener_, nullptr); + StreamListener* prev = previous_listener_; + pipe->Unpipe(); + prev->OnStreamAfterShutdown(w, status); +} + +void StreamPipe::ReadableListener::OnStreamDestroy() { + StreamPipe* pipe = ContainerOf(&StreamPipe::readable_listener_, this); + if (!pipe->is_eof_) { + OnStreamRead(UV_EPIPE, uv_buf_init(nullptr, 0)); + } +} + +void StreamPipe::WritableListener::OnStreamDestroy() { + StreamPipe* pipe = ContainerOf(&StreamPipe::writable_listener_, this); + pipe->is_eof_ = true; + 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; + AsyncScope async_scope(pipe); + pipe->is_reading_ = true; + pipe->source()->ReadStart(); +} + +uv_buf_t StreamPipe::WritableListener::OnStreamAlloc(size_t suggested_size) { + CHECK_NE(previous_listener_, nullptr); + return previous_listener_->OnStreamAlloc(suggested_size); +} + +void StreamPipe::WritableListener::OnStreamRead(ssize_t nread, + const uv_buf_t& buf) { + CHECK_NE(previous_listener_, nullptr); + return previous_listener_->OnStreamRead(nread, buf); +} + +void StreamPipe::New(const FunctionCallbackInfo<Value>& args) { + CHECK(args.IsConstructCall()); + CHECK(args[0]->IsExternal()); + CHECK(args[1]->IsExternal()); + auto source = static_cast<StreamBase*>(args[0].As<External>()->Value()); + auto sink = static_cast<StreamBase*>(args[1].As<External>()->Value()); + + 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; + if (pipe->wanted_data_ > 0) + pipe->writable_listener_.OnStreamWantsWrite(pipe->wanted_data_); +} + +void StreamPipe::Unpipe(const FunctionCallbackInfo<Value>& args) { + StreamPipe* pipe; + ASSIGN_OR_RETURN_UNWRAP(&pipe, args.Holder()); + pipe->Unpipe(); +} + +namespace { + +void InitializeStreamPipe(Local<Object> target, + Local<Value> unused, + Local<Context> context) { + 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); + AsyncWrap::AddWrapMethods(env, pipe); + pipe->SetClassName(stream_pipe_string); + pipe->InstanceTemplate()->SetInternalFieldCount(1); + target->Set(context, stream_pipe_string, pipe->GetFunction()).FromJust(); +} + +} // anonymous namespace + +} // namespace node + +NODE_MODULE_CONTEXT_AWARE_INTERNAL(stream_pipe, + node::InitializeStreamPipe) |