fix: implement ses.getBlobData() for NetworkService (#20041)

* pass data pipe to JS

* implement reading buffer

* re-enable ses.getBlobData test

* remove AtomBlobReader

shell/browser/api/atom_api_data_pipe_holder.cc

@@ -0,0 +1,185 @@
+// Copyright (c) 2019 GitHub, 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_data_pipe_holder.h"
+
+#include <utility>
+#include <vector>
+
+#include "base/memory/weak_ptr.h"
+#include "base/strings/string_number_conversions.h"
+#include "mojo/public/cpp/system/data_pipe.h"
+#include "mojo/public/cpp/system/simple_watcher.h"
+#include "net/base/net_errors.h"
+#include "shell/common/key_weak_map.h"
+#include "shell/common/promise_util.h"
+
+#include "shell/common/node_includes.h"
+
+namespace electron {
+
+namespace api {
+
+namespace {
+
+// Incremental ID.
+int g_next_id = 0;
+
+// Map that manages all the DataPipeHolder objects.
+KeyWeakMap<std::string> g_weak_map;
+
+// Utility class to read from data pipe.
+class DataPipeReader {
+ public:
+  DataPipeReader(util::Promise<v8::Local<v8::Value>> promise,
+                 network::mojom::DataPipeGetterPtr data_pipe_getter)
+      : promise_(std::move(promise)),
+        data_pipe_getter_(std::move(data_pipe_getter)),
+        handle_watcher_(FROM_HERE,
+                        mojo::SimpleWatcher::ArmingPolicy::MANUAL,
+                        base::SequencedTaskRunnerHandle::Get()) {
+    // Get a new data pipe and start.
+    mojo::DataPipe data_pipe;
+    data_pipe_getter_->Read(std::move(data_pipe.producer_handle),
+                            base::BindOnce(&DataPipeReader::ReadCallback,
+                                           weak_factory_.GetWeakPtr()));
+    data_pipe_ = std::move(data_pipe.consumer_handle);
+    handle_watcher_.Watch(data_pipe_.get(), MOJO_HANDLE_SIGNAL_READABLE,
+                          base::BindRepeating(&DataPipeReader::OnHandleReadable,
+                                              weak_factory_.GetWeakPtr()));
+  }
+
+  ~DataPipeReader() = default;
+
+ private:
+  // Callback invoked by DataPipeGetter::Read.
+  void ReadCallback(int32_t status, uint64_t size) {
+    if (status != net::OK) {
+      OnFailure();
+      return;
+    }
+    buffer_.resize(size);
+    head_ = &buffer_.front();
+    remaining_size_ = size;
+    handle_watcher_.ArmOrNotify();
+  }
+
+  // Called by |handle_watcher_| when data is available or the pipe was closed,
+  // and there's a pending Read() call.
+  void OnHandleReadable(MojoResult result) {
+    if (result != MOJO_RESULT_OK) {
+      OnFailure();
+      return;
+    }
+
+    // Read.
+    uint32_t length = remaining_size_;
+    result = data_pipe_->ReadData(head_, &length, MOJO_READ_DATA_FLAG_NONE);
+    if (result == MOJO_RESULT_OK) {  // success
+      remaining_size_ -= length;
+      head_ += length;
+      if (remaining_size_ == 0)
+        OnSuccess();
+    } else if (result == MOJO_RESULT_SHOULD_WAIT) {  // IO pending
+      handle_watcher_.ArmOrNotify();
+    } else {  // error
+      OnFailure();
+    }
+  }
+
+  void OnFailure() {
+    promise_.RejectWithErrorMessage("Could not get blob data");
+    delete this;
+  }
+
+  void OnSuccess() {
+    // Pass the buffer to JS.
+    //
+    // Note that the lifetime of the native buffer belongs to us, and we will
+    // free memory when JS buffer gets garbage collected.
+    v8::Locker locker(promise_.isolate());
+    v8::HandleScope handle_scope(promise_.isolate());
+    v8::Local<v8::Value> buffer =
+        node::Buffer::New(promise_.isolate(), &buffer_.front(), buffer_.size(),
+                          &DataPipeReader::FreeBuffer, this)
+            .ToLocalChecked();
+    promise_.Resolve(buffer);
+
+    // Destroy data pipe.
+    handle_watcher_.Cancel();
+    data_pipe_.reset();
+    data_pipe_getter_ = nullptr;
+  }
+
+  static void FreeBuffer(char* data, void* self) {
+    delete static_cast<DataPipeReader*>(self);
+  }
+
+  util::Promise<v8::Local<v8::Value>> promise_;
+
+  network::mojom::DataPipeGetterPtr data_pipe_getter_;
+  mojo::ScopedDataPipeConsumerHandle data_pipe_;
+  mojo::SimpleWatcher handle_watcher_;
+
+  // Stores read data.
+  std::vector<char> buffer_;
+
+  // The head of buffer.
+  char* head_ = nullptr;
+
+  // Remaining data to read.
+  uint64_t remaining_size_ = 0;
+
+  base::WeakPtrFactory<DataPipeReader> weak_factory_{this};
+
+  DISALLOW_COPY_AND_ASSIGN(DataPipeReader);
+};
+
+}  // namespace
+
+gin::WrapperInfo DataPipeHolder::kWrapperInfo = {gin::kEmbedderNativeGin};
+
+DataPipeHolder::DataPipeHolder(const network::DataElement& element)
+    : id_(base::NumberToString(++g_next_id)),
+      data_pipe_(element.CloneDataPipeGetter()) {}
+
+DataPipeHolder::~DataPipeHolder() = default;
+
+v8::Local<v8::Promise> DataPipeHolder::ReadAll(v8::Isolate* isolate) {
+  util::Promise<v8::Local<v8::Value>> promise(isolate);
+  v8::Local<v8::Promise> handle = promise.GetHandle();
+  if (!data_pipe_) {
+    promise.RejectWithErrorMessage("Could not get blob data");
+    return handle;
+  }
+
+  new DataPipeReader(std::move(promise), std::move(data_pipe_));
+  return handle;
+}
+
+// static
+gin::Handle<DataPipeHolder> DataPipeHolder::Create(
+    v8::Isolate* isolate,
+    const network::DataElement& element) {
+  auto handle = gin::CreateHandle(isolate, new DataPipeHolder(element));
+  g_weak_map.Set(isolate, handle->id(),
+                 handle->GetWrapper(isolate).ToLocalChecked());
+  return handle;
+}
+
+// static
+gin::Handle<DataPipeHolder> DataPipeHolder::From(v8::Isolate* isolate,
+                                                 const std::string& id) {
+  v8::MaybeLocal<v8::Object> object = g_weak_map.Get(isolate, id);
+  if (!object.IsEmpty()) {
+    gin::Handle<DataPipeHolder> handle;
+    if (gin::ConvertFromV8(isolate, object.ToLocalChecked(), &handle))
+      return handle;
+  }
+  return gin::Handle<DataPipeHolder>();
+}
+
+}  // namespace api
+
+}  // namespace electron

shell/browser/api/atom_api_data_pipe_holder.h

@@ -0,0 +1,53 @@
+// Copyright (c) 2019 GitHub, Inc.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#ifndef SHELL_BROWSER_API_ATOM_API_DATA_PIPE_HOLDER_H_
+#define SHELL_BROWSER_API_ATOM_API_DATA_PIPE_HOLDER_H_
+
+#include <string>
+
+#include "gin/handle.h"
+#include "gin/wrappable.h"
+#include "services/network/public/cpp/data_element.h"
+#include "services/network/public/mojom/data_pipe_getter.mojom.h"
+
+namespace electron {
+
+namespace api {
+
+// Retains reference to the data pipe.
+class DataPipeHolder : public gin::Wrappable<DataPipeHolder> {
+ public:
+  static gin::WrapperInfo kWrapperInfo;
+
+  static gin::Handle<DataPipeHolder> Create(
+      v8::Isolate* isolate,
+      const network::DataElement& element);
+  static gin::Handle<DataPipeHolder> From(v8::Isolate* isolate,
+                                          const std::string& id);
+
+  // Read all data at once.
+  //
+  // TODO(zcbenz): This is apparently not suitable for really large data, but
+  // no one has complained about it yet.
+  v8::Local<v8::Promise> ReadAll(v8::Isolate* isolate);
+
+  // The unique ID that can be used to receive the object.
+  const std::string& id() const { return id_; }
+
+ private:
+  explicit DataPipeHolder(const network::DataElement& element);
+  ~DataPipeHolder() override;
+
+  std::string id_;
+  network::mojom::DataPipeGetterPtr data_pipe_;
+
+  DISALLOW_COPY_AND_ASSIGN(DataPipeHolder);
+};
+
+}  // namespace api
+
+}  // namespace electron
+
+#endif  // SHELL_BROWSER_API_ATOM_API_DATA_PIPE_HOLDER_H_

shell/browser/api/atom_api_session.cc

@@ -41,6 +41,7 @@
 #include "services/network/network_service.h"
 #include "services/network/public/cpp/features.h"
 #include "shell/browser/api/atom_api_cookies.h"
+#include "shell/browser/api/atom_api_data_pipe_holder.h"
 #include "shell/browser/api/atom_api_download_item.h"
 #include "shell/browser/api/atom_api_net_log.h"
 #include "shell/browser/api/atom_api_protocol_ns.h"
@@ -502,15 +503,14 @@ std::string Session::GetUserAgent() {
 
 v8::Local<v8::Promise> Session::GetBlobData(v8::Isolate* isolate,
                                             const std::string& uuid) {
-  util::Promise<v8::Local<v8::Value>> promise(isolate);
-  v8::Local<v8::Promise> handle = promise.GetHandle();
+  gin::Handle<DataPipeHolder> holder = DataPipeHolder::From(isolate, uuid);
+  if (holder.IsEmpty()) {
+    util::Promise<v8::Local<v8::Value>> promise(isolate);
+    promise.RejectWithErrorMessage("Could not get blob data handle");
+    return promise.GetHandle();
+  }
 
-  AtomBlobReader* blob_reader = browser_context()->GetBlobReader();
-  base::PostTaskWithTraits(
-      FROM_HERE, {BrowserThread::IO},
-      base::BindOnce(&AtomBlobReader::StartReading,
-                     base::Unretained(blob_reader), uuid, std::move(promise)));
-  return handle;
+  return holder->ReadAll(isolate);
 }
 
 void Session::DownloadURL(const GURL& url) {

shell/browser/api/atom_api_session.h

@@ -13,7 +13,6 @@
 #include "electron/buildflags/buildflags.h"
 #include "native_mate/handle.h"
 #include "shell/browser/api/trackable_object.h"
-#include "shell/browser/atom_blob_reader.h"
 #include "shell/browser/net/resolve_proxy_helper.h"
 #include "shell/common/promise_util.h"