refactor: rewrite the net module to simplify state tracking (#21244)

shell/browser/api/atom_api_url_loader.cc

@@ -0,0 +1,448 @@
+// Copyright (c) 2019 Slack Technologies, Inc.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#include "shell/browser/api/atom_api_url_loader.h"
+
+#include <algorithm>
+#include <map>
+#include <memory>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "base/containers/id_map.h"
+#include "gin/handle.h"
+#include "gin/object_template_builder.h"
+#include "gin/wrappable.h"
+#include "mojo/public/cpp/system/data_pipe_producer.h"
+#include "services/network/public/cpp/resource_request.h"
+#include "services/network/public/cpp/simple_url_loader.h"
+#include "services/network/public/mojom/chunked_data_pipe_getter.mojom.h"
+#include "services/network/public/mojom/url_loader_factory.mojom.h"
+#include "shell/browser/api/atom_api_session.h"
+#include "shell/browser/atom_browser_context.h"
+#include "shell/common/gin_converters/callback_converter.h"
+#include "shell/common/gin_converters/gurl_converter.h"
+#include "shell/common/gin_converters/net_converter.h"
+#include "shell/common/gin_helper/dictionary.h"
+#include "shell/common/gin_helper/object_template_builder.h"
+#include "shell/common/node_includes.h"
+
+class BufferDataSource : public mojo::DataPipeProducer::DataSource {
+ public:
+  explicit BufferDataSource(base::span<char> buffer) {
+    buffer_.resize(buffer.size());
+    memcpy(buffer_.data(), buffer.data(), buffer_.size());
+  }
+  ~BufferDataSource() override = default;
+
+ private:
+  // mojo::DataPipeProducer::DataSource:
+  uint64_t GetLength() const override { return buffer_.size(); }
+  ReadResult Read(uint64_t offset, base::span<char> buffer) override {
+    ReadResult result;
+    if (offset <= buffer_.size()) {
+      size_t readable_size = buffer_.size() - offset;
+      size_t writable_size = buffer.size();
+      size_t copyable_size = std::min(readable_size, writable_size);
+      memcpy(buffer.data(), &buffer_[offset], copyable_size);
+      result.bytes_read = copyable_size;
+    } else {
+      NOTREACHED();
+      result.result = MOJO_RESULT_OUT_OF_RANGE;
+    }
+    return result;
+  }
+
+  std::vector<char> buffer_;
+};
+
+class JSChunkedDataPipeGetter : public gin::Wrappable<JSChunkedDataPipeGetter>,
+                                public network::mojom::ChunkedDataPipeGetter {
+ public:
+  static gin::Handle<JSChunkedDataPipeGetter> Create(
+      v8::Isolate* isolate,
+      v8::Local<v8::Function> body_func,
+      mojo::PendingReceiver<network::mojom::ChunkedDataPipeGetter>
+          chunked_data_pipe_getter) {
+    return gin::CreateHandle(
+        isolate, new JSChunkedDataPipeGetter(
+                     isolate, body_func, std::move(chunked_data_pipe_getter)));
+  }
+
+  // gin::Wrappable
+  gin::ObjectTemplateBuilder GetObjectTemplateBuilder(
+      v8::Isolate* isolate) override {
+    return gin::Wrappable<JSChunkedDataPipeGetter>::GetObjectTemplateBuilder(
+               isolate)
+        .SetMethod("write", &JSChunkedDataPipeGetter::WriteChunk)
+        .SetMethod("done", &JSChunkedDataPipeGetter::Done);
+  }
+
+  static gin::WrapperInfo kWrapperInfo;
+  ~JSChunkedDataPipeGetter() override = default;
+
+ private:
+  JSChunkedDataPipeGetter(
+      v8::Isolate* isolate,
+      v8::Local<v8::Function> body_func,
+      mojo::PendingReceiver<network::mojom::ChunkedDataPipeGetter>
+          chunked_data_pipe_getter)
+      : isolate_(isolate), body_func_(isolate, body_func) {
+    receiver_.Bind(std::move(chunked_data_pipe_getter));
+  }
+
+  // network::mojom::ChunkedDataPipeGetter:
+  void GetSize(GetSizeCallback callback) override {
+    size_callback_ = std::move(callback);
+  }
+
+  void StartReading(mojo::ScopedDataPipeProducerHandle pipe) override {
+    DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+
+    if (body_func_.IsEmpty()) {
+      LOG(ERROR) << "Tried to read twice from a JSChunkedDataPipeGetter";
+      // Drop the handle on the floor.
+      return;
+    }
+    data_producer_ = std::make_unique<mojo::DataPipeProducer>(std::move(pipe));
+
+    v8::HandleScope handle_scope(isolate_);
+    v8::MicrotasksScope script_scope(isolate_,
+                                     v8::MicrotasksScope::kRunMicrotasks);
+    auto maybe_wrapper = GetWrapper(isolate_);
+    v8::Local<v8::Value> wrapper;
+    if (!maybe_wrapper.ToLocal(&wrapper)) {
+      return;
+    }
+    v8::Local<v8::Value> argv[] = {wrapper};
+    node::Environment* env = node::Environment::GetCurrent(isolate_);
+    auto global = env->context()->Global();
+    node::MakeCallback(isolate_, global, body_func_.Get(isolate_),
+                       node::arraysize(argv), argv, {0, 0});
+  }
+
+  v8::Local<v8::Promise> WriteChunk(v8::Local<v8::Value> buffer_val) {
+    gin_helper::Promise<void> promise(isolate_);
+    v8::Local<v8::Promise> handle = promise.GetHandle();
+    if (!buffer_val->IsArrayBufferView()) {
+      promise.RejectWithErrorMessage("Expected an ArrayBufferView");
+      return handle;
+    }
+    if (is_writing_) {
+      promise.RejectWithErrorMessage("Only one write can be pending at a time");
+      return handle;
+    }
+    if (!size_callback_) {
+      promise.RejectWithErrorMessage("Can't write after calling done()");
+      return handle;
+    }
+    auto buffer = buffer_val.As<v8::ArrayBufferView>();
+    is_writing_ = true;
+    bytes_written_ += buffer->ByteLength();
+    auto backing_store = buffer->Buffer()->GetBackingStore();
+    auto buffer_span = base::make_span(
+        static_cast<char*>(backing_store->Data()) + buffer->ByteOffset(),
+        buffer->ByteLength());
+    auto buffer_source = std::make_unique<BufferDataSource>(buffer_span);
+    data_producer_->Write(
+        std::move(buffer_source),
+        base::BindOnce(&JSChunkedDataPipeGetter::OnWriteChunkComplete,
+                       // We're OK to use Unretained here because we own
+                       // |data_producer_|.
+                       base::Unretained(this), std::move(promise)));
+    return handle;
+  }
+
+  void OnWriteChunkComplete(gin_helper::Promise<void> promise,
+                            MojoResult result) {
+    DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+    is_writing_ = false;
+    if (result == MOJO_RESULT_OK) {
+      promise.Resolve();
+    } else {
+      promise.RejectWithErrorMessage("mojo result not ok");
+      Finished();
+    }
+  }
+
+  // TODO(nornagon): accept a net error here to allow the data provider to
+  // cancel the request with an error.
+  void Done() {
+    if (size_callback_) {
+      std::move(size_callback_).Run(net::OK, bytes_written_);
+      Finished();
+    }
+  }
+
+  void Finished() {
+    size_callback_.Reset();
+    body_func_.Reset();
+    receiver_.reset();
+    data_producer_.reset();
+  }
+
+  GetSizeCallback size_callback_;
+  mojo::Receiver<network::mojom::ChunkedDataPipeGetter> receiver_{this};
+  std::unique_ptr<mojo::DataPipeProducer> data_producer_;
+  bool is_writing_ = false;
+  uint64_t bytes_written_ = 0;
+
+  v8::Isolate* isolate_;
+  v8::Global<v8::Function> body_func_;
+};
+
+gin::WrapperInfo JSChunkedDataPipeGetter::kWrapperInfo = {
+    gin::kEmbedderNativeGin};
+
+namespace electron {
+
+namespace api {
+
+namespace {
+
+const net::NetworkTrafficAnnotationTag kTrafficAnnotation =
+    net::DefineNetworkTrafficAnnotation("electron_net_module", R"(
+        semantics {
+          sender: "Electron Net module"
+          description:
+            "Issue HTTP/HTTPS requests using Chromium's native networking "
+            "library."
+          trigger: "Using the Net module"
+          data: "Anything the user wants to send."
+          destination: OTHER
+        }
+        policy {
+          cookies_allowed: YES
+          cookies_store: "user"
+          setting: "This feature cannot be disabled."
+        })");
+
+base::IDMap<SimpleURLLoaderWrapper*>& GetAllRequests() {
+  static base::NoDestructor<base::IDMap<SimpleURLLoaderWrapper*>>
+      s_all_requests;
+  return *s_all_requests;
+}
+
+}  // namespace
+
+SimpleURLLoaderWrapper::SimpleURLLoaderWrapper(
+    std::unique_ptr<network::ResourceRequest> request,
+    network::mojom::URLLoaderFactory* url_loader_factory)
+    : id_(GetAllRequests().Add(this)) {
+  // We slightly abuse the |render_frame_id| field in ResourceRequest so that
+  // we can correlate any authentication events that arrive with this request.
+  request->render_frame_id = id_;
+
+  // SimpleURLLoader wants to control the request body itself. We have other
+  // ideas.
+  auto request_body = std::move(request->request_body);
+  auto* request_ref = request.get();
+  loader_ =
+      network::SimpleURLLoader::Create(std::move(request), kTrafficAnnotation);
+  if (request_body) {
+    request_ref->request_body = std::move(request_body);
+  }
+
+  loader_->SetAllowHttpErrorResults(true);
+  loader_->SetOnResponseStartedCallback(base::BindOnce(
+      &SimpleURLLoaderWrapper::OnResponseStarted, base::Unretained(this)));
+  loader_->SetOnRedirectCallback(base::BindRepeating(
+      &SimpleURLLoaderWrapper::OnRedirect, base::Unretained(this)));
+  loader_->SetOnUploadProgressCallback(base::BindRepeating(
+      &SimpleURLLoaderWrapper::OnUploadProgress, base::Unretained(this)));
+  loader_->SetOnDownloadProgressCallback(base::BindRepeating(
+      &SimpleURLLoaderWrapper::OnDownloadProgress, base::Unretained(this)));
+
+  loader_->DownloadAsStream(url_loader_factory, this);
+}
+
+void SimpleURLLoaderWrapper::Pin() {
+  // Prevent ourselves from being GC'd until the request is complete.
+  // Must be called after InitWithArgs(), otherwise GetWrapper() isn't
+  // initialized.
+  pinned_wrapper_.Reset(isolate(), GetWrapper());
+}
+
+void SimpleURLLoaderWrapper::PinBodyGetter(v8::Local<v8::Value> body_getter) {
+  pinned_chunk_pipe_getter_.Reset(isolate(), body_getter);
+}
+
+SimpleURLLoaderWrapper::~SimpleURLLoaderWrapper() {
+  GetAllRequests().Remove(id_);
+}
+
+// static
+SimpleURLLoaderWrapper* SimpleURLLoaderWrapper::FromID(uint32_t id) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+  return GetAllRequests().Lookup(id);
+}
+
+void SimpleURLLoaderWrapper::OnAuthRequired(
+    const GURL& url,
+    bool first_auth_attempt,
+    net::AuthChallengeInfo auth_info,
+    network::mojom::URLResponseHeadPtr head,
+    mojo::PendingRemote<network::mojom::AuthChallengeResponder>
+        auth_challenge_responder) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+  mojo::Remote<network::mojom::AuthChallengeResponder> auth_responder(
+      std::move(auth_challenge_responder));
+  // WeakPtr because if we're Cancel()ed while waiting for auth, and the
+  // network service also decides to cancel at the same time and kill this
+  // pipe, we might end up trying to call Cancel again on dead memory.
+  auth_responder.set_disconnect_handler(base::BindOnce(
+      &SimpleURLLoaderWrapper::Cancel, weak_factory_.GetWeakPtr()));
+  auto cb = base::BindOnce(
+      [](mojo::Remote<network::mojom::AuthChallengeResponder> auth_responder,
+         gin::Arguments* args) {
+        base::string16 username_str, password_str;
+        if (!args->GetNext(&username_str) || !args->GetNext(&password_str)) {
+          auth_responder->OnAuthCredentials(base::nullopt);
+          return;
+        }
+        auth_responder->OnAuthCredentials(
+            net::AuthCredentials(username_str, password_str));
+      },
+      std::move(auth_responder));
+  Emit("login", auth_info, base::AdaptCallbackForRepeating(std::move(cb)));
+}
+
+void SimpleURLLoaderWrapper::Cancel() {
+  loader_.reset();
+  pinned_wrapper_.Reset();
+  pinned_chunk_pipe_getter_.Reset();
+  // This ensures that no further callbacks will be called, so there's no need
+  // for additional guards.
+}
+
+// static
+mate::WrappableBase* SimpleURLLoaderWrapper::New(gin::Arguments* args) {
+  gin_helper::Dictionary opts;
+  if (!args->GetNext(&opts)) {
+    args->ThrowTypeError("Expected a dictionary");
+    return nullptr;
+  }
+  auto request = std::make_unique<network::ResourceRequest>();
+  opts.Get("method", &request->method);
+  opts.Get("url", &request->url);
+  std::map<std::string, std::string> extra_headers;
+  if (opts.Get("extraHeaders", &extra_headers)) {
+    for (const auto& it : extra_headers) {
+      if (!net::HttpUtil::IsValidHeaderName(it.first) ||
+          !net::HttpUtil::IsValidHeaderValue(it.second)) {
+        args->ThrowTypeError("Invalid header name or value");
+        return nullptr;
+      }
+      request->headers.SetHeader(it.first, it.second);
+    }
+  }
+
+  v8::Local<v8::Value> body;
+  v8::Local<v8::Value> chunk_pipe_getter;
+  if (opts.Get("body", &body)) {
+    if (body->IsArrayBufferView()) {
+      auto buffer_body = body.As<v8::ArrayBufferView>();
+      auto backing_store = buffer_body->Buffer()->GetBackingStore();
+      request->request_body = network::ResourceRequestBody::CreateFromBytes(
+          static_cast<char*>(backing_store->Data()) + buffer_body->ByteOffset(),
+          buffer_body->ByteLength());
+    } else if (body->IsFunction()) {
+      auto body_func = body.As<v8::Function>();
+
+      mojo::PendingRemote<network::mojom::ChunkedDataPipeGetter>
+          data_pipe_getter;
+      chunk_pipe_getter = JSChunkedDataPipeGetter::Create(
+                              args->isolate(), body_func,
+                              data_pipe_getter.InitWithNewPipeAndPassReceiver())
+                              .ToV8();
+      request->request_body = new network::ResourceRequestBody();
+      request->request_body->SetToChunkedDataPipe(std::move(data_pipe_getter));
+    }
+  }
+
+  std::string partition;
+  gin::Handle<Session> session;
+  if (!opts.Get("session", &session)) {
+    if (opts.Get("partition", &partition))
+      session = Session::FromPartition(args->isolate(), partition);
+    else  // default session
+      session = Session::FromPartition(args->isolate(), "");
+  }
+
+  auto url_loader_factory = session->browser_context()->GetURLLoaderFactory();
+
+  auto* ret =
+      new SimpleURLLoaderWrapper(std::move(request), url_loader_factory.get());
+  ret->InitWithArgs(args);
+  ret->Pin();
+  if (!chunk_pipe_getter.IsEmpty()) {
+    ret->PinBodyGetter(chunk_pipe_getter);
+  }
+  return ret;
+}
+
+void SimpleURLLoaderWrapper::OnDataReceived(base::StringPiece string_piece,
+                                            base::OnceClosure resume) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+  v8::HandleScope handle_scope(isolate());
+  auto array_buffer = v8::ArrayBuffer::New(isolate(), string_piece.size());
+  auto backing_store = array_buffer->GetBackingStore();
+  memcpy(backing_store->Data(), string_piece.data(), string_piece.size());
+  Emit("data", array_buffer);
+  std::move(resume).Run();
+}
+
+void SimpleURLLoaderWrapper::OnComplete(bool success) {
+  if (success) {
+    Emit("complete");
+  } else {
+    Emit("error", net::ErrorToString(loader_->NetError()));
+  }
+  loader_.reset();
+  pinned_wrapper_.Reset();
+  pinned_chunk_pipe_getter_.Reset();
+}
+
+void SimpleURLLoaderWrapper::OnRetry(base::OnceClosure start_retry) {}
+
+void SimpleURLLoaderWrapper::OnResponseStarted(
+    const GURL& final_url,
+    const network::mojom::URLResponseHead& response_head) {
+  gin::Dictionary dict = gin::Dictionary::CreateEmpty(isolate());
+  dict.Set("statusCode", response_head.headers->response_code());
+  dict.Set("statusMessage", response_head.headers->GetStatusText());
+  dict.Set("headers", response_head.headers.get());
+  dict.Set("httpVersion", response_head.headers->GetHttpVersion());
+  Emit("response-started", final_url, dict);
+}
+
+void SimpleURLLoaderWrapper::OnRedirect(
+    const net::RedirectInfo& redirect_info,
+    const network::mojom::URLResponseHead& response_head,
+    std::vector<std::string>* removed_headers) {
+  Emit("redirect", redirect_info, response_head.headers.get());
+}
+
+void SimpleURLLoaderWrapper::OnUploadProgress(uint64_t position,
+                                              uint64_t total) {
+  Emit("upload-progress", position, total);
+}
+
+void SimpleURLLoaderWrapper::OnDownloadProgress(uint64_t current) {
+  Emit("download-progress", current);
+}
+
+// static
+void SimpleURLLoaderWrapper::BuildPrototype(
+    v8::Isolate* isolate,
+    v8::Local<v8::FunctionTemplate> prototype) {
+  prototype->SetClassName(gin::StringToV8(isolate, "SimpleURLLoaderWrapper"));
+  gin_helper::ObjectTemplateBuilder(isolate, prototype->PrototypeTemplate())
+      .SetMethod("cancel", &SimpleURLLoaderWrapper::Cancel);
+}
+
+}  // namespace api
+
+}  // namespace electron