// Copyright (c) 2012 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.

// See http://dev.chromium.org/developers/design-documents/multi-process-resource-loading

#include "content/renderer/loader/resource_dispatcher.h"

#include <utility>

#include "base/atomic_sequence_num.h"
#include "base/bind.h"
#include "base/compiler_specific.h"
#include "base/debug/alias.h"
#include "base/debug/stack_trace.h"
#include "base/files/file_path.h"
#include "base/metrics/histogram_macros.h"
#include "base/rand_util.h"
#include "base/strings/string_util.h"
#include "base/synchronization/waitable_event.h"
#include "base/task/post_task.h"
#include "base/time/time.h"
#include "build/build_config.h"
#include "content/common/inter_process_time_ticks_converter.h"
#include "content/common/mime_sniffing_throttle.h"
#include "content/common/navigation_params.h"
#include "content/common/net/record_load_histograms.h"
#include "content/common/throttling_url_loader.h"
#include "content/public/common/browser_side_navigation_policy.h"
#include "content/public/common/resource_load_info.mojom.h"
#include "content/public/common/resource_type.h"
#include "content/public/common/url_utils.h"
#include "content/public/renderer/fixed_received_data.h"
#include "content/public/renderer/request_peer.h"
#include "content/public/renderer/resource_dispatcher_delegate.h"
#include "content/renderer/loader/request_extra_data.h"
#include "content/renderer/loader/sync_load_context.h"
#include "content/renderer/loader/sync_load_response.h"
#include "content/renderer/loader/url_loader_client_impl.h"
#include "content/renderer/render_frame_impl.h"
#include "content/renderer/render_thread_impl.h"
#include "net/base/load_flags.h"
#include "net/base/net_errors.h"
#include "net/base/request_priority.h"
#include "net/http/http_response_headers.h"
#include "services/network/public/cpp/features.h"
#include "services/network/public/cpp/resource_request.h"
#include "services/network/public/cpp/resource_response.h"
#include "services/network/public/cpp/url_loader_completion_status.h"
#include "third_party/blink/public/common/service_worker/service_worker_utils.h"

namespace content {

namespace {

// Converts |time| from a remote to local TimeTicks, overwriting the original
// value.
void RemoteToLocalTimeTicks(
    const InterProcessTimeTicksConverter& converter,
    base::TimeTicks* time) {
  RemoteTimeTicks remote_time = RemoteTimeTicks::FromTimeTicks(*time);
  *time = converter.ToLocalTimeTicks(remote_time).ToTimeTicks();
}

void CheckSchemeForReferrerPolicy(const network::ResourceRequest& request) {
  if ((request.referrer_policy == Referrer::GetDefaultReferrerPolicy() ||
       request.referrer_policy ==
           net::URLRequest::
               CLEAR_REFERRER_ON_TRANSITION_FROM_SECURE_TO_INSECURE) &&
      request.referrer.SchemeIsCryptographic() &&
      !request.url.SchemeIsCryptographic()) {
    LOG(FATAL) << "Trying to send secure referrer for insecure request "
               << "without an appropriate referrer policy.\n"
               << "URL = " << request.url << "\n"
               << "Referrer = " << request.referrer;
  }
}

void NotifySubresourceStarted(
    scoped_refptr<base::SingleThreadTaskRunner> thread_task_runner,
    int render_frame_id,
    const GURL& url,
    net::CertStatus cert_status) {
  if (!thread_task_runner)
    return;

  if (!thread_task_runner->BelongsToCurrentThread()) {
    thread_task_runner->PostTask(
        FROM_HERE, base::BindOnce(NotifySubresourceStarted, thread_task_runner,
                                  render_frame_id, url, cert_status));
    return;
  }

  RenderFrameImpl* render_frame =
      RenderFrameImpl::FromRoutingID(render_frame_id);
  if (!render_frame)
    return;

  render_frame->GetFrameHost()->SubresourceResponseStarted(url, cert_status);
}

void NotifyResourceLoadStarted(
    scoped_refptr<base::SingleThreadTaskRunner> thread_task_runner,
    int render_frame_id,
    int request_id,
    const network::ResourceResponseHead& response_head,
    content::ResourceType resource_type) {
  if (!thread_task_runner)
    return;

  if (!thread_task_runner->BelongsToCurrentThread()) {
    thread_task_runner->PostTask(
        FROM_HERE, base::BindOnce(NotifyResourceLoadStarted, thread_task_runner,
                                  render_frame_id, request_id, response_head,
                                  resource_type));
    return;
  }

  RenderFrameImpl* render_frame =
      RenderFrameImpl::FromRoutingID(render_frame_id);
  if (!render_frame)
    return;

  render_frame->DidStartResponse(request_id, response_head, resource_type);
}

void NotifyResourceLoadComplete(
    scoped_refptr<base::SingleThreadTaskRunner> thread_task_runner,
    int render_frame_id,
    mojom::ResourceLoadInfoPtr resource_load_info,
    const network::URLLoaderCompletionStatus& status) {
  if (!thread_task_runner)
    return;

  if (!thread_task_runner->BelongsToCurrentThread()) {
    thread_task_runner->PostTask(
        FROM_HERE,
        base::BindOnce(NotifyResourceLoadComplete, thread_task_runner,
                       render_frame_id, std::move(resource_load_info), status));
    return;
  }

  RenderFrameImpl* render_frame =
      RenderFrameImpl::FromRoutingID(render_frame_id);
  if (!render_frame)
    return;

  render_frame->DidCompleteResponse(resource_load_info->request_id, status);
  render_frame->GetFrameHost()->ResourceLoadComplete(
      std::move(resource_load_info));
}

void NotifyResourceLoadCancel(
    scoped_refptr<base::SingleThreadTaskRunner> thread_task_runner,
    int render_frame_id,
    int request_id) {
  if (!thread_task_runner)
    return;

  if (!thread_task_runner->BelongsToCurrentThread()) {
    thread_task_runner->PostTask(
        FROM_HERE, base::BindOnce(NotifyResourceLoadCancel, thread_task_runner,
                                  render_frame_id, request_id));
    return;
  }

  RenderFrameImpl* render_frame =
      RenderFrameImpl::FromRoutingID(render_frame_id);
  if (!render_frame)
    return;

  render_frame->DidCancelResponse(request_id);
}

void NotifyResourceTransferSizeUpdate(
    scoped_refptr<base::SingleThreadTaskRunner> thread_task_runner,
    int render_frame_id,
    int request_id,
    int transfer_size_diff) {
  if (!thread_task_runner)
    return;

  if (!thread_task_runner->BelongsToCurrentThread()) {
    thread_task_runner->PostTask(
        FROM_HERE,
        base::BindOnce(NotifyResourceTransferSizeUpdate, thread_task_runner,
                       render_frame_id, request_id, transfer_size_diff));
    return;
  }

  RenderFrameImpl* render_frame =
      RenderFrameImpl::FromRoutingID(render_frame_id);
  if (!render_frame)
    return;

  render_frame->DidReceiveTransferSizeUpdate(request_id, transfer_size_diff);
}

#if defined(OS_ANDROID)
void NotifyUpdateUserGestureCarryoverInfo(int render_frame_id) {
  scoped_refptr<base::SingleThreadTaskRunner> task_runner =
      RenderThreadImpl::DeprecatedGetMainTaskRunner();
  if (!task_runner->BelongsToCurrentThread()) {
    task_runner->PostTask(
        FROM_HERE,
        base::BindOnce(NotifyUpdateUserGestureCarryoverInfo, render_frame_id));
    return;
  }

  RenderFrameImpl* render_frame =
      RenderFrameImpl::FromRoutingID(render_frame_id);
  if (!render_frame)
    return;

  render_frame->GetFrameHost()->UpdateUserGestureCarryoverInfo();
}
#endif

// Returns true if the headers indicate that this resource should always be
// revalidated or not cached.
bool AlwaysAccessNetwork(
    const scoped_refptr<net::HttpResponseHeaders>& headers) {
  if (!headers)
    return false;

  // RFC 2616, section 14.9.
  return headers->HasHeaderValue("cache-control", "no-cache") ||
         headers->HasHeaderValue("cache-control", "no-store") ||
         headers->HasHeaderValue("pragma", "no-cache") ||
         headers->HasHeaderValue("vary", "*");
}

int GetInitialRequestID() {
  // Starting with a random number speculatively avoids RDH_INVALID_REQUEST_ID
  // which are assumed to have been caused by restarting RequestID at 0 when
  // restarting a renderer after a crash - this would cause collisions if
  // requests from the previously crashed renderer are still active.  See
  // https://crbug.com/614281#c61 for more details about this hypothesis.
  //
  // To avoid increasing the likelyhood of overflowing the range of available
  // RequestIDs, kMax is set to a relatively low value of 2^20 (rather than
  // to something higher like 2^31).
  const int kMin = 0;
  const int kMax = 1 << 20;
  return base::RandInt(kMin, kMax);
}

// Determines if the loader should be restarted on a redirect using
// ThrottlingURLLoader::FollowRedirectForcingRestart.
bool RedirectRequiresLoaderRestart(const GURL& original_url,
                                   const GURL& redirect_url) {
  if (!base::FeatureList::IsEnabled(network::features::kNetworkService))
    return false;

  // Restart is needed if the URL is no longer handled by network service.
  if (IsURLHandledByNetworkService(original_url))
    return !IsURLHandledByNetworkService(redirect_url);

  // If URL wasn't originally handled by network service, restart is needed if
  // schemes are different.
  return original_url.scheme_piece() != redirect_url.scheme_piece();
}

}  // namespace

// static
int ResourceDispatcher::MakeRequestID() {
  // NOTE: The resource_dispatcher_host also needs probably unique
  // request_ids, so they count down from -2 (-1 is a special "we're
  // screwed value"), while the renderer process counts up.
  static const int kInitialRequestID = GetInitialRequestID();
  static base::AtomicSequenceNumber sequence;
  return kInitialRequestID + sequence.GetNext();
}

ResourceDispatcher::ResourceDispatcher()
    : delegate_(nullptr), weak_factory_(this) {}

ResourceDispatcher::~ResourceDispatcher() {
}

ResourceDispatcher::PendingRequestInfo*
ResourceDispatcher::GetPendingRequestInfo(int request_id) {
  auto it = pending_requests_.find(request_id);
  if (it == pending_requests_.end())
    return nullptr;
  return it->second.get();
}

void ResourceDispatcher::OnUploadProgress(int request_id,
                                          int64_t position,
                                          int64_t size) {
  PendingRequestInfo* request_info = GetPendingRequestInfo(request_id);
  if (!request_info)
    return;

  request_info->peer->OnUploadProgress(position, size);
}

void ResourceDispatcher::OnReceivedResponse(
    int request_id,
    const network::ResourceResponseHead& initial_response_head) {
  TRACE_EVENT0("loader", "ResourceDispatcher::OnReceivedResponse");
  PendingRequestInfo* request_info = GetPendingRequestInfo(request_id);
  if (!request_info)
    return;
  request_info->local_response_start = base::TimeTicks::Now();
  request_info->remote_request_start =
      initial_response_head.load_timing.request_start;
  // Now that response_start has been set, we can properly set the TimeTicks in
  // the ResourceResponseInfo.
  network::ResourceResponseInfo renderer_response_info;
  ToResourceResponseInfo(*request_info, initial_response_head,
                         &renderer_response_info);
  request_info->load_timing_info = renderer_response_info.load_timing;

  if (renderer_response_info.network_accessed) {
    if (request_info->resource_type == RESOURCE_TYPE_MAIN_FRAME) {
      UMA_HISTOGRAM_ENUMERATION("Net.ConnectionInfo.MainFrame",
                                renderer_response_info.connection_info,
                                net::HttpResponseInfo::NUM_OF_CONNECTION_INFOS);
    } else {
      UMA_HISTOGRAM_ENUMERATION("Net.ConnectionInfo.SubResource",
                                renderer_response_info.connection_info,
                                net::HttpResponseInfo::NUM_OF_CONNECTION_INFOS);
    }
  }

  network::ResourceResponseHead response_head;
  std::unique_ptr<NavigationResponseOverrideParameters> response_override =
      std::move(request_info->navigation_response_override);
  if (response_override) {
    CHECK(IsBrowserSideNavigationEnabled());
    response_head = response_override->response;
  } else {
    response_head = initial_response_head;
  }

  request_info->mime_type = response_head.mime_type;
  request_info->network_accessed = response_head.network_accessed;
  request_info->always_access_network =
      AlwaysAccessNetwork(response_head.headers);
  if (delegate_) {
    std::unique_ptr<RequestPeer> new_peer = delegate_->OnReceivedResponse(
        std::move(request_info->peer), response_head.mime_type,
        request_info->url);
    DCHECK(new_peer);
    request_info->peer = std::move(new_peer);
  }
  request_info->host_port_pair = renderer_response_info.socket_address;
  if (!IsResourceTypeFrame(request_info->resource_type)) {
    NotifySubresourceStarted(RenderThreadImpl::DeprecatedGetMainTaskRunner(),
                             request_info->render_frame_id,
                             request_info->response_url,
                             response_head.cert_status);
  }

  request_info->peer->OnReceivedResponse(renderer_response_info);

  // Make a deep copy of ResourceResponseHead before passing it cross-thread.
  auto resource_response = base::MakeRefCounted<network::ResourceResponse>();
  resource_response->head = response_head;
  auto deep_copied_response = resource_response->DeepCopy();
  NotifyResourceLoadStarted(RenderThreadImpl::DeprecatedGetMainTaskRunner(),
                            request_info->render_frame_id, request_id,
                            deep_copied_response->head,
                            request_info->resource_type);
}

void ResourceDispatcher::OnReceivedCachedMetadata(
    int request_id,
    const std::vector<uint8_t>& data) {
  PendingRequestInfo* request_info = GetPendingRequestInfo(request_id);
  if (!request_info)
    return;

  if (data.size()) {
    request_info->peer->OnReceivedCachedMetadata(
        reinterpret_cast<const char*>(&data.front()), data.size());
  }
}

void ResourceDispatcher::OnStartLoadingResponseBody(
    int request_id,
    mojo::ScopedDataPipeConsumerHandle body) {
  PendingRequestInfo* request_info = GetPendingRequestInfo(request_id);
  if (!request_info)
    return;

  request_info->peer->OnStartLoadingResponseBody(std::move(body));
}

void ResourceDispatcher::OnReceivedRedirect(
    int request_id,
    const net::RedirectInfo& redirect_info,
    const network::ResourceResponseHead& response_head,
    scoped_refptr<base::SingleThreadTaskRunner> task_runner) {
  TRACE_EVENT0("loader", "ResourceDispatcher::OnReceivedRedirect");
  PendingRequestInfo* request_info = GetPendingRequestInfo(request_id);
  if (!request_info)
    return;
  if (!request_info->url_loader && request_info->should_follow_redirect) {
    // This is a redirect that synchronously came as the loader is being
    // constructed, due to a URLLoaderThrottle that changed the starting
    // URL. Handle this in a posted task, as we don't have the loader
    // pointer yet.
    base::ThreadTaskRunnerHandle::Get()->PostTask(
        FROM_HERE, base::BindOnce(&ResourceDispatcher::OnReceivedRedirect,
                                  weak_factory_.GetWeakPtr(), request_id,
                                  redirect_info, response_head, task_runner));
    return;
  }

  request_info->local_response_start = base::TimeTicks::Now();
  request_info->remote_request_start = response_head.load_timing.request_start;
  request_info->redirect_requires_loader_restart =
      RedirectRequiresLoaderRestart(request_info->response_url,
                                    redirect_info.new_url);

  network::ResourceResponseInfo renderer_response_info;
  ToResourceResponseInfo(*request_info, response_head, &renderer_response_info);
  if (request_info->peer->OnReceivedRedirect(redirect_info,
                                             renderer_response_info)) {
    // Double-check if the request is still around. The call above could
    // potentially remove it.
    request_info = GetPendingRequestInfo(request_id);
    if (!request_info)
      return;
    // We update the response_url here for tracking/stats use later.
    request_info->response_url = redirect_info.new_url;
    request_info->response_method = redirect_info.new_method;
    request_info->response_referrer = GURL(redirect_info.new_referrer);
    request_info->has_pending_redirect = true;
    mojom::RedirectInfoPtr net_redirect_info = mojom::RedirectInfo::New();
    net_redirect_info->url = redirect_info.new_url;
    net_redirect_info->network_info = mojom::CommonNetworkInfo::New();
    net_redirect_info->network_info->network_accessed =
        response_head.network_accessed;
    net_redirect_info->network_info->always_access_network =
        AlwaysAccessNetwork(response_head.headers);
    net_redirect_info->network_info->ip_port_pair =
        response_head.socket_address;
    request_info->redirect_info_chain.push_back(std::move(net_redirect_info));

    if (!request_info->is_deferred)
      FollowPendingRedirect(request_info);
  } else {
    Cancel(request_id, std::move(task_runner));
  }
}

void ResourceDispatcher::FollowPendingRedirect(
    PendingRequestInfo* request_info) {
  if (request_info->has_pending_redirect &&
      request_info->should_follow_redirect) {
    request_info->has_pending_redirect = false;
    // net::URLRequest clears its request_start on redirect, so should we.
    request_info->local_request_start = base::TimeTicks::Now();
    // Redirect URL may not be handled by the network service, so force a
    // restart in case another URLLoaderFactory should handle the URL.
    if (request_info->redirect_requires_loader_restart) {
      request_info->url_loader->FollowRedirectForcingRestart();
    } else {
      request_info->url_loader->FollowRedirect(base::nullopt);
    }
  }
}

void ResourceDispatcher::OnRequestComplete(
    int request_id,
    const network::URLLoaderCompletionStatus& status) {
  TRACE_EVENT0("loader", "ResourceDispatcher::OnRequestComplete");

  PendingRequestInfo* request_info = GetPendingRequestInfo(request_id);
  if (!request_info)
    return;
  request_info->buffer.reset();
  request_info->buffer_size = 0;
  request_info->net_error = status.error_code;

  auto resource_load_info = mojom::ResourceLoadInfo::New();
  resource_load_info->url = request_info->response_url;
  resource_load_info->original_url = request_info->url;
  resource_load_info->referrer = request_info->response_referrer;
  resource_load_info->method = request_info->response_method;
  resource_load_info->resource_type = request_info->resource_type;
  resource_load_info->request_id = request_id;
  resource_load_info->mime_type = request_info->mime_type;
  resource_load_info->network_info = mojom::CommonNetworkInfo::New();
  resource_load_info->network_info->network_accessed =
      request_info->network_accessed;
  resource_load_info->network_info->always_access_network =
      request_info->always_access_network;
  resource_load_info->network_info->ip_port_pair = request_info->host_port_pair;
  resource_load_info->load_timing_info = request_info->load_timing_info;
  resource_load_info->was_cached = status.exists_in_cache;
  resource_load_info->net_error = status.error_code;
  resource_load_info->redirect_info_chain =
      std::move(request_info->redirect_info_chain);
  resource_load_info->total_received_bytes = status.encoded_data_length;
  resource_load_info->raw_body_bytes = status.encoded_body_length;

  NotifyResourceLoadComplete(RenderThreadImpl::DeprecatedGetMainTaskRunner(),
                             request_info->render_frame_id,
                             std::move(resource_load_info), status);

  RequestPeer* peer = request_info->peer.get();

  if (delegate_) {
    std::unique_ptr<RequestPeer> new_peer = delegate_->OnRequestComplete(
        std::move(request_info->peer), request_info->resource_type,
        status.error_code);
    DCHECK(new_peer);
    request_info->peer = std::move(new_peer);
  }

  network::URLLoaderCompletionStatus renderer_status(status);
  // TODO(toyoshim): Consider to convert status.cors_preflight_timing_info here.
  if (status.completion_time.is_null()) {
    // No completion timestamp is provided, leave it as is.
  } else if (request_info->remote_request_start.is_null() ||
             request_info->load_timing_info.request_start.is_null()) {
    // We cannot convert the remote time to a local time, let's use the current
    // timestamp. This happens when
    //  - We get an error before OnReceivedRedirect or OnReceivedResponse is
    //    called, or
    //  - Somehow such a timestamp was missing in the LoadTimingInfo.
    renderer_status.completion_time = base::TimeTicks::Now();
  } else {
    // We have already converted the request start timestamp, let's use that
    // conversion information.
    // Note: We cannot create a InterProcessTimeTicksConverter with
    // (local_request_start, now, remote_request_start, remote_completion_time)
    // as that may result in inconsistent timestamps.
    renderer_status.completion_time =
        std::min(status.completion_time - request_info->remote_request_start +
                     request_info->load_timing_info.request_start,
                 base::TimeTicks::Now());
  }
  // The request ID will be removed from our pending list in the destructor.
  // Normally, dispatching this message causes the reference-counted request to
  // die immediately.
  // TODO(kinuko): Revisit here. This probably needs to call request_info->peer
  // but the past attempt to change it seems to have caused crashes.
  // (crbug.com/547047)
  peer->OnCompletedRequest(renderer_status);
}

bool ResourceDispatcher::RemovePendingRequest(
    int request_id,
    scoped_refptr<base::SingleThreadTaskRunner> task_runner) {
  auto it = pending_requests_.find(request_id);
  if (it == pending_requests_.end())
    return false;

  if (it->second->net_error == net::ERR_IO_PENDING) {
    it->second->net_error = net::ERR_ABORTED;
    NotifyResourceLoadCancel(RenderThreadImpl::DeprecatedGetMainTaskRunner(),
                             it->second->render_frame_id, request_id);
  }

  RecordLoadHistograms(it->second->response_url, it->second->resource_type,
                       it->second->net_error);

  // Cancel loading.
  it->second->url_loader = nullptr;
  // Clear URLLoaderClient to stop receiving further Mojo IPC from the browser
  // process.
  it->second->url_loader_client = nullptr;

  // Always delete the pending_request asyncly so that cancelling the request
  // doesn't delete the request context info while its response is still being
  // handled.
  task_runner->DeleteSoon(FROM_HERE, it->second.release());
  pending_requests_.erase(it);

  return true;
}

void ResourceDispatcher::Cancel(
    int request_id,
    scoped_refptr<base::SingleThreadTaskRunner> task_runner) {
  auto it = pending_requests_.find(request_id);
  if (it == pending_requests_.end()) {
    DLOG(ERROR) << "unknown request";
    return;
  }

  // Cancel the request if it didn't complete, and clean it up so the bridge
  // will receive no more messages.
  RemovePendingRequest(request_id, std::move(task_runner));
}

void ResourceDispatcher::SetDefersLoading(int request_id, bool value) {
  PendingRequestInfo* request_info = GetPendingRequestInfo(request_id);
  if (!request_info) {
    DLOG(ERROR) << "unknown request";
    return;
  }
  if (value) {
    request_info->is_deferred = value;
    request_info->url_loader_client->SetDefersLoading();
  } else if (request_info->is_deferred) {
    request_info->is_deferred = false;
    request_info->url_loader_client->UnsetDefersLoading();

    FollowPendingRedirect(request_info);
  }
}

void ResourceDispatcher::DidChangePriority(int request_id,
                                           net::RequestPriority new_priority,
                                           int intra_priority_value) {
  PendingRequestInfo* request_info = GetPendingRequestInfo(request_id);
  if (!request_info) {
    DLOG(ERROR) << "unknown request";
    return;
  }

  request_info->url_loader->SetPriority(new_priority, intra_priority_value);
}

void ResourceDispatcher::OnTransferSizeUpdated(int request_id,
                                               int32_t transfer_size_diff) {
  DCHECK_GT(transfer_size_diff, 0);
  PendingRequestInfo* request_info = GetPendingRequestInfo(request_id);
  if (!request_info)
    return;

  // TODO(yhirano): Consider using int64_t in
  // RequestPeer::OnTransferSizeUpdated.
  request_info->peer->OnTransferSizeUpdated(transfer_size_diff);

  NotifyResourceTransferSizeUpdate(
      RenderThreadImpl::DeprecatedGetMainTaskRunner(),
      request_info->render_frame_id, request_id, transfer_size_diff);
}

ResourceDispatcher::PendingRequestInfo::PendingRequestInfo(
    std::unique_ptr<RequestPeer> peer,
    ResourceType resource_type,
    int render_frame_id,
    const GURL& request_url,
    const std::string& method,
    const GURL& referrer,
    std::unique_ptr<NavigationResponseOverrideParameters>
        navigation_response_override_params)
    : peer(std::move(peer)),
      resource_type(resource_type),
      render_frame_id(render_frame_id),
      url(request_url),
      response_url(request_url),
      response_method(method),
      response_referrer(referrer),
      local_request_start(base::TimeTicks::Now()),
      buffer_size(0),
      navigation_response_override(
          std::move(navigation_response_override_params)) {}

ResourceDispatcher::PendingRequestInfo::~PendingRequestInfo() {
}

void ResourceDispatcher::StartSync(
    std::unique_ptr<network::ResourceRequest> request,
    int routing_id,
    const net::NetworkTrafficAnnotationTag& traffic_annotation,
    SyncLoadResponse* response,
    scoped_refptr<network::SharedURLLoaderFactory> url_loader_factory,
    std::vector<std::unique_ptr<URLLoaderThrottle>> throttles,
    base::TimeDelta timeout,
    blink::mojom::BlobRegistryPtrInfo download_to_blob_registry,
    std::unique_ptr<RequestPeer> peer) {
  CheckSchemeForReferrerPolicy(*request);

  std::unique_ptr<network::SharedURLLoaderFactoryInfo> factory_info =
      url_loader_factory->Clone();
  base::WaitableEvent redirect_or_response_event(
      base::WaitableEvent::ResetPolicy::MANUAL,
      base::WaitableEvent::InitialState::NOT_SIGNALED);

  // Prepare the configured throttles for use on a separate thread.
  for (const auto& throttle : throttles)
    throttle->DetachFromCurrentSequence();

  // A task is posted to a separate thread to execute the request so that
  // this thread may block on a waitable event. It is safe to pass raw
  // pointers to |sync_load_response| and |event| as this stack frame will
  // survive until the request is complete.
  scoped_refptr<base::SingleThreadTaskRunner> task_runner =
      base::CreateSingleThreadTaskRunnerWithTraits({});
  task_runner->PostTask(
      FROM_HERE,
      base::BindOnce(&SyncLoadContext::StartAsyncWithWaitableEvent,
                     std::move(request), routing_id, task_runner,
                     traffic_annotation, std::move(factory_info),
                     std::move(throttles), base::Unretained(response),
                     base::Unretained(&redirect_or_response_event),
                     base::Unretained(terminate_sync_load_event_), timeout,
                     std::move(download_to_blob_registry)));

  // redirect_or_response_event will signal when each redirect completes, and
  // when the final response is complete.
  redirect_or_response_event.Wait();

  while (response->context_for_redirect) {
    DCHECK(response->redirect_info);
    bool follow_redirect =
        peer->OnReceivedRedirect(*response->redirect_info, response->info);
    redirect_or_response_event.Reset();
    if (follow_redirect) {
      task_runner->PostTask(
          FROM_HERE,
          base::BindOnce(&SyncLoadContext::FollowRedirect,
                         base::Unretained(response->context_for_redirect)));
    } else {
      task_runner->PostTask(
          FROM_HERE,
          base::BindOnce(&SyncLoadContext::CancelRedirect,
                         base::Unretained(response->context_for_redirect)));
    }
    redirect_or_response_event.Wait();
  }
}

int ResourceDispatcher::StartAsync(
    std::unique_ptr<network::ResourceRequest> request,
    int routing_id,
    scoped_refptr<base::SingleThreadTaskRunner> loading_task_runner,
    const net::NetworkTrafficAnnotationTag& traffic_annotation,
    bool is_sync,
    bool pass_response_pipe_to_peer,
    std::unique_ptr<RequestPeer> peer,
    scoped_refptr<network::SharedURLLoaderFactory> url_loader_factory,
    std::vector<std::unique_ptr<URLLoaderThrottle>> throttles,
    std::unique_ptr<NavigationResponseOverrideParameters>
        response_override_params,
    base::OnceClosure* continue_navigation_function) {
  CheckSchemeForReferrerPolicy(*request);

#if defined(OS_ANDROID)
  if (request->resource_type != RESOURCE_TYPE_MAIN_FRAME &&
      request->has_user_gesture) {
    NotifyUpdateUserGestureCarryoverInfo(request->render_frame_id);
  }
#endif

  bool override_url_loader =
      !!response_override_params &&
      !!response_override_params->url_loader_client_endpoints;

  // Compute a unique request_id for this renderer process.
  int request_id = MakeRequestID();
  pending_requests_[request_id] = std::make_unique<PendingRequestInfo>(
      std::move(peer), static_cast<ResourceType>(request->resource_type),
      request->render_frame_id, request->url, request->method,
      request->referrer, std::move(response_override_params));

  if (override_url_loader) {
    // Redirect checks are handled by NavigationURLLoaderImpl, so it's safe to
    // pass true for |bypass_redirect_checks|.
    pending_requests_[request_id]->url_loader_client =
        std::make_unique<URLLoaderClientImpl>(
            request_id, this, loading_task_runner,
            true /* bypass_redirect_checks */, request->url);

    if (request->resource_type == RESOURCE_TYPE_SHARED_WORKER) {
      // For shared workers, immediately post a task for continuing loading
      // because shared workers don't have the concept of the navigation commit
      // and |continue_navigation_function| is never called.
      // TODO(nhiroki): Unify this case with the navigation case for code
      // health.
      loading_task_runner->PostTask(
          FROM_HERE, base::BindOnce(&ResourceDispatcher::ContinueForNavigation,
                                    weak_factory_.GetWeakPtr(), request_id));
    } else {
      // For navigations, |continue_navigation_function| is called after the
      // navigation commit.
      DCHECK(continue_navigation_function);
      *continue_navigation_function =
          base::BindOnce(&ResourceDispatcher::ContinueForNavigation,
                         weak_factory_.GetWeakPtr(), request_id);
    }
    return request_id;
  }

  std::unique_ptr<URLLoaderClientImpl> client(new URLLoaderClientImpl(
      request_id, this, loading_task_runner,
      url_loader_factory->BypassRedirectChecks(), request->url));

  if (pass_response_pipe_to_peer)
    client->SetPassResponsePipeToDispatcher(true);

  uint32_t options = network::mojom::kURLLoadOptionNone;
  // TODO(jam): use this flag for ResourceDispatcherHost code path once
  // MojoLoading is the only IPC code path.
  if (request->fetch_request_context_type !=
      static_cast<int>(blink::mojom::RequestContextType::FETCH)) {
    // MIME sniffing should be disabled for a request initiated by fetch().
    options |= network::mojom::kURLLoadOptionSniffMimeType;
    if (blink::ServiceWorkerUtils::IsServicificationEnabled())
      throttles.push_back(std::make_unique<MimeSniffingThrottle>());
  }
  if (is_sync) {
    options |= network::mojom::kURLLoadOptionSynchronous;
    request->load_flags |= net::LOAD_IGNORE_LIMITS;
  }

  std::unique_ptr<ThrottlingURLLoader> url_loader =
      ThrottlingURLLoader::CreateLoaderAndStart(
          std::move(url_loader_factory), std::move(throttles), routing_id,
          request_id, options, request.get(), client.get(), traffic_annotation,
          std::move(loading_task_runner));
  pending_requests_[request_id]->url_loader = std::move(url_loader);
  pending_requests_[request_id]->url_loader_client = std::move(client);

  return request_id;
}

void ResourceDispatcher::ToResourceResponseInfo(
    const PendingRequestInfo& request_info,
    const network::ResourceResponseHead& browser_info,
    network::ResourceResponseInfo* renderer_info) const {
  *renderer_info = browser_info;
  if (base::TimeTicks::IsConsistentAcrossProcesses() ||
      request_info.local_request_start.is_null() ||
      request_info.local_response_start.is_null() ||
      browser_info.request_start.is_null() ||
      browser_info.response_start.is_null() ||
      browser_info.load_timing.request_start.is_null()) {
    return;
  }
  InterProcessTimeTicksConverter converter(
      LocalTimeTicks::FromTimeTicks(request_info.local_request_start),
      LocalTimeTicks::FromTimeTicks(request_info.local_response_start),
      RemoteTimeTicks::FromTimeTicks(browser_info.request_start),
      RemoteTimeTicks::FromTimeTicks(browser_info.response_start));

  net::LoadTimingInfo* load_timing = &renderer_info->load_timing;
  RemoteToLocalTimeTicks(converter, &load_timing->request_start);
  RemoteToLocalTimeTicks(converter, &load_timing->proxy_resolve_start);
  RemoteToLocalTimeTicks(converter, &load_timing->proxy_resolve_end);
  RemoteToLocalTimeTicks(converter, &load_timing->connect_timing.dns_start);
  RemoteToLocalTimeTicks(converter, &load_timing->connect_timing.dns_end);
  RemoteToLocalTimeTicks(converter, &load_timing->connect_timing.connect_start);
  RemoteToLocalTimeTicks(converter, &load_timing->connect_timing.connect_end);
  RemoteToLocalTimeTicks(converter, &load_timing->connect_timing.ssl_start);
  RemoteToLocalTimeTicks(converter, &load_timing->connect_timing.ssl_end);
  RemoteToLocalTimeTicks(converter, &load_timing->send_start);
  RemoteToLocalTimeTicks(converter, &load_timing->send_end);
  RemoteToLocalTimeTicks(converter, &load_timing->receive_headers_end);
  RemoteToLocalTimeTicks(converter, &load_timing->push_start);
  RemoteToLocalTimeTicks(converter, &load_timing->push_end);
  RemoteToLocalTimeTicks(converter, &renderer_info->service_worker_start_time);
  RemoteToLocalTimeTicks(converter, &renderer_info->service_worker_ready_time);
}

void ResourceDispatcher::ContinueForNavigation(int request_id) {
  PendingRequestInfo* request_info = GetPendingRequestInfo(request_id);
  if (!request_info)
    return;

  std::unique_ptr<NavigationResponseOverrideParameters> response_override =
      std::move(request_info->navigation_response_override);
  DCHECK(response_override);

  // Mark the request so we do not attempt to follow the redirects, they already
  // happened.
  request_info->should_follow_redirect = false;

  URLLoaderClientImpl* client_ptr = request_info->url_loader_client.get();
  // PlzNavigate: during navigations, the ResourceResponse has already been
  // received on the browser side, and has been passed down to the renderer.
  // Replay the redirects that happened during navigation.
  DCHECK_EQ(response_override->redirect_responses.size(),
            response_override->redirect_infos.size());
  for (size_t i = 0; i < response_override->redirect_responses.size(); ++i) {
    client_ptr->OnReceiveRedirect(response_override->redirect_infos[i],
                                  response_override->redirect_responses[i]);
    // The request might have been cancelled while processing the redirect.
    if (!GetPendingRequestInfo(request_id))
      return;
  }

  client_ptr->OnReceiveResponse(response_override->response);

  // Abort if the request is cancelled.
  if (!GetPendingRequestInfo(request_id))
    return;

  DCHECK(response_override->url_loader_client_endpoints);
  client_ptr->Bind(std::move(response_override->url_loader_client_endpoints));
}

}  // namespace content