Index: content/browser/loader/async_revalidation_driver.cc |
diff --git a/content/browser/loader/async_revalidation_driver.cc b/content/browser/loader/async_revalidation_driver.cc |
new file mode 100644 |
index 0000000000000000000000000000000000000000..2ac88c361bb1bbad7197b2ed7fe0d4d9e3467242 |
--- /dev/null |
+++ b/content/browser/loader/async_revalidation_driver.cc |
@@ -0,0 +1,272 @@ |
+// Copyright 2015 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. |
+ |
+#include "content/browser/loader/async_revalidation_driver.h" |
+ |
+#include <utility> |
+ |
+#include "base/callback_helpers.h" |
+#include "base/location.h" |
+#include "base/logging.h" |
+#include "base/memory/ref_counted.h" |
+#include "base/metrics/user_metrics_action.h" |
+#include "base/single_thread_task_runner.h" |
+#include "base/thread_task_runner_handle.h" |
+#include "base/time/time.h" |
+#include "content/public/browser/user_metrics.h" |
+#include "net/base/net_errors.h" |
+#include "net/url_request/url_request_status.h" |
+ |
+namespace content { |
+ |
+namespace { |
+// This matches the maximum allocation size of AsyncResourceHandler. |
+const int kReadBufSize = 32 * 1024; |
+ |
+// The time to wait for a response. Since this includes the time taken to |
+// connect, this has been set to match the connect timeout |
+// kTransportConnectJobTimeoutInSeconds. |
+const int kResponseTimeoutInSeconds = 240; // 4 minutes. |
+ |
+// This value should not be too large, as this request may be tying up a socket |
+// that could be used for something better. However, if it is too small, the |
+// cache entry will be truncated for no good reason. |
+// TODO(ricea): Find a more scientific way to set this timeout. |
+const int kReadTimeoutInSeconds = 30; |
+} // namespace |
+ |
+// The use of base::Unretained() in the initialisation of read_timer_ is safe |
+// because base::Timer guarantees not to call the callback after being |
+// destroyed. |
kinuko
2015/11/27 08:50:01
nit: this comment seems obsolete now
Adam Rice
2015/11/27 14:45:13
Thanks. Removed.
|
+AsyncRevalidationDriver::AsyncRevalidationDriver( |
+ scoped_ptr<net::URLRequest> request, |
+ scoped_ptr<ResourceThrottle> throttle, |
+ const base::Closure& completion_callback) |
+ : request_(std::move(request)), |
+ throttle_(std::move(throttle)), |
+ completion_callback_(completion_callback), |
+ weak_ptr_factory_(this) { |
+ request_->set_delegate(this); |
+ throttle_->set_controller(this); |
+} |
+ |
+AsyncRevalidationDriver::~AsyncRevalidationDriver() {} |
+ |
+void AsyncRevalidationDriver::StartRequest() { |
+ RecordAction(base::UserMetricsAction("AsyncRevalidationCreated")); |
+ // Give the handler a chance to delay the URLRequest from being started. |
+ bool defer_start = false; |
+ throttle_->WillStartRequest(&defer_start); |
+ |
+ if (defer_start) { |
+ RecordDefer(); |
+ } else { |
+ StartRequestInternal(); |
+ } |
+} |
+ |
+void AsyncRevalidationDriver::CancelRequest() { |
+ CancelRequestInternal(net::ERR_ABORTED); |
+} |
+ |
+void AsyncRevalidationDriver::OnReceivedRedirect( |
+ net::URLRequest* request, |
+ const net::RedirectInfo& redirect_info, |
+ bool* defer) { |
+ DCHECK_EQ(request_.get(), request); |
+ |
+ // The async revalidation should not follow redirects, because caching is |
+ // a property of an individual HTTP resource. |
+ DVLOG(1) << "OnReceivedRedirect: " << request_->url().spec(); |
+ RecordAction(base::UserMetricsAction("AsyncRevalidationRedirected")); |
+ CancelRequest(); |
+} |
+ |
+void AsyncRevalidationDriver::OnAuthRequired( |
+ net::URLRequest* request, |
+ net::AuthChallengeInfo* auth_info) { |
+ DCHECK_EQ(request_.get(), request); |
+ // This error code doesn't have exactly the right semantics, but it should |
+ // be sufficient to narrow down the problem in net logs. |
+ request_->CancelWithError(net::ERR_ACCESS_DENIED); |
+} |
+ |
+void AsyncRevalidationDriver::OnBeforeNetworkStart(net::URLRequest* request, |
+ bool* defer) { |
+ DCHECK_EQ(request_.get(), request); |
+ |
+ // Verify that the ResourceScheduler does not defer here. |
+ throttle_->WillStartUsingNetwork(defer); |
+ DCHECK(!*defer); |
+ |
+ // Start the response timer. This use of base::Unretained() is guaranteed safe |
+ // by the semantics of base::OneShotTimer. |
+ timer_.Start( |
+ FROM_HERE, base::TimeDelta::FromSeconds(kResponseTimeoutInSeconds), |
+ base::Bind(&AsyncRevalidationDriver::OnTimeout, base::Unretained(this), |
+ "AsyncRevalidationResponseTimeout")); |
+} |
+ |
+void AsyncRevalidationDriver::OnResponseStarted(net::URLRequest* request) { |
+ DCHECK_EQ(request_.get(), request); |
+ |
+ DVLOG(1) << "OnResponseStarted: " << request_->url().spec(); |
+ |
+ // We have the response. No need to wait any longer. |
+ timer_.Stop(); |
+ |
+ if (!request_->status().is_success()) { |
+ ResponseCompleted(); |
+ return; |
+ } |
+ |
+ const net::HttpResponseInfo& response_info = request_->response_info(); |
+ if (!response_info.response_time.is_null() && response_info.was_cached) { |
+ // The cached entry was revalidated. No need to read it in. |
+ ResponseCompleted(); |
+ return; |
+ } |
+ |
+ bool defer = false; |
+ throttle_->WillProcessResponse(&defer); |
+ DCHECK(!defer); |
+ |
+ // Set up the timer for reading the body. This use of base::Unretained() is |
+ // guaranteed safe by the semantics of base::OneShotTimer. |
+ timer_.Start( |
+ FROM_HERE, base::TimeDelta::FromSeconds(kReadTimeoutInSeconds), |
+ base::Bind(&AsyncRevalidationDriver::OnTimeout, base::Unretained(this), |
+ "AsyncRevalidationReadTimeout")); |
+ StartReading(false); // Read the first chunk. |
+} |
+ |
+void AsyncRevalidationDriver::OnReadCompleted(net::URLRequest* request, |
+ int bytes_read) { |
+ DCHECK_EQ(request_.get(), request); |
+ DCHECK(!is_deferred_); |
+ DVLOG(1) << "OnReadCompleted: \"" << request_->url().spec() << "\"" |
+ << " bytes_read = " << bytes_read; |
+ |
+ // bytes_read == -1 is an error. |
+ // bytes_read == 0 is EOF. |
+ if (bytes_read == -1 || bytes_read == 0 || !request_->status().is_success()) { |
+ ResponseCompleted(); |
+ return; |
+ } |
+ |
+ DCHECK_GT(bytes_read, 0); |
+ StartReading(true); // Read the next chunk. |
+} |
+ |
+void AsyncRevalidationDriver::Resume() { |
+ DCHECK(is_deferred_); |
+ is_deferred_ = false; |
+ request_->LogUnblocked(); |
+ StartRequestInternal(); |
+} |
+ |
+void AsyncRevalidationDriver::Cancel() { |
+ NOTREACHED(); |
+} |
+ |
+void AsyncRevalidationDriver::CancelAndIgnore() { |
+ NOTREACHED(); |
+} |
+ |
+void AsyncRevalidationDriver::CancelWithError(int error_code) { |
+ NOTREACHED(); |
+} |
+ |
+void AsyncRevalidationDriver::StartRequestInternal() { |
+ DCHECK(!request_->is_pending()); |
+ |
+ // This can happen if Resume() is called after CancelRequest(). |
+ // Since CancelRequest() will have called ResponseCompleted() asynchronously, |
+ // it's not necessary to call it again. |
+ if (!request_->status().is_success()) |
+ return; |
+ |
+ request_->Start(); |
+} |
+ |
+void AsyncRevalidationDriver::CancelRequestInternal(int error) { |
+ DVLOG(1) << "CancelRequestInternal: " << request_->url().spec(); |
+ |
+ bool was_pending = request_->is_pending(); |
+ |
+ request_->CancelWithError(error); |
+ |
+ if (!was_pending) { |
+ // If the request isn't in flight, then we won't get an asynchronous |
+ // notification from the request, so we have to signal ourselves to finish |
+ // this request. |
+ scoped_refptr<base::SingleThreadTaskRunner> single_thread_task_runner = |
+ base::ThreadTaskRunnerHandle::Get(); |
+ single_thread_task_runner->PostTask( |
+ FROM_HERE, base::Bind(&AsyncRevalidationDriver::ResponseCompleted, |
+ weak_ptr_factory_.GetWeakPtr())); |
+ } |
+} |
+ |
+void AsyncRevalidationDriver::StartReading(bool is_continuation) { |
+ int bytes_read = 0; |
+ ReadMore(&bytes_read); |
+ |
+ // If IO is pending, wait for the URLRequest to call OnReadCompleted. |
+ if (request_->status().is_io_pending()) |
+ return; |
+ |
+ if (!is_continuation || bytes_read <= 0) { |
+ OnReadCompleted(request_.get(), bytes_read); |
+ } else { |
+ // Else, trigger OnReadCompleted asynchronously to avoid starving the IO |
+ // thread in case the URLRequest can provide data synchronously. |
+ scoped_refptr<base::SingleThreadTaskRunner> single_thread_task_runner = |
+ base::ThreadTaskRunnerHandle::Get(); |
+ single_thread_task_runner->PostTask( |
+ FROM_HERE, |
+ base::Bind(&AsyncRevalidationDriver::OnReadCompleted, |
+ weak_ptr_factory_.GetWeakPtr(), request_.get(), bytes_read)); |
+ } |
+} |
+ |
+void AsyncRevalidationDriver::ReadMore(int* bytes_read) { |
+ DCHECK(!is_deferred_); |
+ |
+ if (!read_buffer_) |
+ read_buffer_ = new net::IOBuffer(kReadBufSize); |
+ |
+ timer_.Reset(); |
+ request_->Read(read_buffer_.get(), kReadBufSize, bytes_read); |
+ |
+ // No need to check the return value here as we'll detect errors by |
+ // inspecting the URLRequest's status. |
+} |
+ |
+void AsyncRevalidationDriver::ResponseCompleted() { |
+ DVLOG(1) << "ResponseCompleted: " << request_->url().spec(); |
+ // When this class cancels a redirect, URLRequest calls both the |
+ // OnResponseStarted() and OnReadCompleted() callbacks. This class should not |
+ // run |completion_callback_| twice. |
+ // |
+ // TODO(ricea): Work out why URLRequest calls both methods on cancellation and |
+ // make it stop. |
+ if (completion_callback_.is_null()) |
+ return; |
+ base::ResetAndReturn(&completion_callback_).Run(); |
+ // |this| may be deleted after this point. |
+} |
+ |
+void AsyncRevalidationDriver::OnTimeout(const char* action_name) { |
+ RecordAction(base::UserMetricsAction(action_name)); |
+ CancelRequestInternal(net::ERR_TIMED_OUT); |
+} |
+ |
+void AsyncRevalidationDriver::RecordDefer() { |
+ request_->LogBlockedBy(throttle_->GetNameForLogging()); |
+ DCHECK(!is_deferred_); |
+ is_deferred_ = true; |
+} |
+ |
+} // namespace content |