services/network/url_loader_factory.h

// Copyright 2017 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef SERVICES_NETWORK_URL_LOADER_FACTORY_H_
#define SERVICES_NETWORK_URL_LOADER_FACTORY_H_

#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "mojo/public/cpp/bindings/pending_receiver.h"
#include "mojo/public/cpp/bindings/pending_remote.h"
#include "mojo/public/cpp/bindings/remote.h"
#include "net/traffic_annotation/network_traffic_annotation.h"
#include "services/network/public/mojom/cookie_access_observer.mojom.h"
#include "services/network/public/mojom/cross_origin_embedder_policy.mojom.h"
#include "services/network/public/mojom/network_context.mojom.h"
#include "services/network/public/mojom/url_loader_factory.mojom.h"

namespace network {

class NetworkContext;
class ResourceSchedulerClient;
class URLLoader;

namespace cors {
class CorsURLLoaderFactory;
}  // namespace cors

// This class is an implementation of mojom::URLLoaderFactory that
// creates a mojom::URLLoader.
// A URLLoaderFactory has a pointer to ResourceSchedulerClient. A
// ResourceSchedulerClient is associated with cloned
// NetworkServiceURLLoaderFactories. Roughly one URLLoaderFactory
// is created for one frame in render process, so it means ResourceScheduler
// works on each frame.
// A URLLoaderFactory can be created with null ResourceSchedulerClient, in which
// case requests constructed by the factory will not be throttled.
// Note that the CORS related part is implemented in CorsURLLoader[Factory]
// and NetworkContext::CreateURLLoaderFactory returns a CorsURLLoaderFactory,
// instead of a URLLoaderFactory.
class URLLoaderFactory : public mojom::URLLoaderFactory {
 public:
  // NOTE: |context| must outlive this instance.
  URLLoaderFactory(
      NetworkContext* context,
      mojom::URLLoaderFactoryParamsPtr params,
      scoped_refptr<ResourceSchedulerClient> resource_scheduler_client,
      cors::CorsURLLoaderFactory* cors_url_loader_factory);

  ~URLLoaderFactory() override;

  // mojom::URLLoaderFactory implementation.
  void CreateLoaderAndStart(mojo::PendingReceiver<mojom::URLLoader> receiver,
                            int32_t request_id,
                            uint32_t options,
                            const ResourceRequest& url_request,
                            mojo::PendingRemote<mojom::URLLoaderClient> client,
                            const net::MutableNetworkTrafficAnnotationTag&
                                traffic_annotation) override;
  void Clone(mojo::PendingReceiver<mojom::URLLoaderFactory> receiver) override;

  // Called by URLLoaders created by this factory each time before a request is
  // sent.
  void OnBeforeURLRequest();

  mojom::DevToolsObserver* GetDevToolsObserver() const;
  mojom::CookieAccessObserver* GetCookieAccessObserver() const;
  mojom::URLLoaderNetworkServiceObserver* GetURLLoaderNetworkServiceObserver()
      const;

  static constexpr int kMaxKeepaliveConnections = 2048;
  static constexpr int kMaxKeepaliveConnectionsPerTopLevelFrame = 256;
  static constexpr int kMaxTotalKeepaliveRequestSize = 512 * 1024;

 private:
  // Starts the timer to call
  // URLLoaderNetworkServiceObserver::OnLoadingStateUpdate(), if
  // needed.
  void MaybeStartUpdateLoadInfoTimer();

  // Invoked once the browser has acknowledged receiving the previous LoadInfo.
  // Sets |waiting_on_load_state_ack_| to false, and calls
  // MaybeStartUpdateLoadeInfoTimer.
  void AckUpdateLoadInfo();

  // Finds the most relevant URLLoader that is outstanding and asks it to
  // send an update.
  void UpdateLoadInfo();

  // The NetworkContext that indirectly owns |this|.
  NetworkContext* const context_;
  mojom::URLLoaderFactoryParamsPtr params_;
  scoped_refptr<ResourceSchedulerClient> resource_scheduler_client_;
  mojo::Remote<mojom::TrustedURLLoaderHeaderClient> header_client_;
  mojo::Remote<mojom::CrossOriginEmbedderPolicyReporter> coep_reporter_;

  // |cors_url_loader_factory_| owns this.
  cors::CorsURLLoaderFactory* cors_url_loader_factory_;

  mojo::Remote<mojom::CookieAccessObserver> cookie_observer_;
  mojo::Remote<mojom::URLLoaderNetworkServiceObserver>
      url_loader_network_service_observer_;
  mojo::Remote<mojom::DevToolsObserver> devtools_observer_;

  base::OneShotTimer update_load_info_timer_;
  bool waiting_on_load_state_ack_ = false;

  DISALLOW_COPY_AND_ASSIGN(URLLoaderFactory);
};

}  // namespace network

#endif  // SERVICES_NETWORK_URL_LOADER_FACTORY_H_