| // 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/histogram_macros.h" |
| #include "base/metrics/sparse_histogram.h" |
| #include "base/single_thread_task_runner.h" |
| #include "base/threading/thread_task_runner_handle.h" |
| #include "base/time/time.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 |
| |
| AsyncRevalidationDriver::AsyncRevalidationDriver( |
| std::unique_ptr<net::URLRequest> request, |
| std::unique_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() { |
| // 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::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(); |
| CancelRequestInternal(net::ERR_ABORTED, RESULT_GOT_REDIRECT); |
| } |
| |
| 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. |
| CancelRequestInternal(net::ERR_ACCESS_DENIED, RESULT_AUTH_FAILED); |
| } |
| |
| 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()) { |
| UMA_HISTOGRAM_SPARSE_SLOWLY("Net.AsyncRevalidation.ResponseError", |
| -request_->status().ToNetError()); |
| ResponseCompleted(RESULT_NET_ERROR); |
| // |this| may be deleted after this point. |
| 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(RESULT_REVALIDATED); |
| // |this| may be deleted after this point. |
| 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), RESULT_BODY_TIMEOUT)); |
| StartReading(false); // Read the first chunk. |
| } |
| |
| void AsyncRevalidationDriver::OnReadCompleted(net::URLRequest* request, |
| int bytes_read) { |
| // request_ could be NULL if a timeout happened while OnReadCompleted() was |
| // queued to run asynchronously. |
| if (!request_) |
| return; |
| DCHECK_EQ(request_.get(), request); |
| DCHECK(!is_deferred_); |
| DVLOG(1) << "OnReadCompleted: \"" << request_->url().spec() << "\"" |
| << " bytes_read = " << bytes_read; |
| |
| // bytes_read == 0 is EOF. |
| if (bytes_read == 0) { |
| ResponseCompleted(RESULT_LOADED); |
| return; |
| } |
| // bytes_read == -1 is an error. |
| if (bytes_read == -1 || !request_->status().is_success()) { |
| UMA_HISTOGRAM_SPARSE_SLOWLY("Net.AsyncRevalidation.ReadError", |
| -request_->status().ToNetError()); |
| ResponseCompleted(RESULT_READ_ERROR); |
| // |this| may be deleted after this point. |
| return; |
| } |
| |
| DCHECK_GT(bytes_read, 0); |
| StartReading(true); // Read the next chunk. |
| } |
| |
| void AsyncRevalidationDriver::Resume() { |
| DCHECK(is_deferred_); |
| DCHECK(request_); |
| 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_); |
| DCHECK(!request_->is_pending()); |
| |
| // 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), RESULT_RESPONSE_TIMEOUT)); |
| request_->Start(); |
| } |
| |
| void AsyncRevalidationDriver::CancelRequestInternal( |
| int error, |
| AsyncRevalidationResult result) { |
| DVLOG(1) << "CancelRequestInternal: " << request_->url().spec(); |
| |
| // Set the error code since this will be reported to the NetworkDelegate and |
| // recorded in the NetLog. |
| request_->CancelWithError(error); |
| |
| // The ResourceScheduler needs to be able to examine the request when the |
| // ResourceThrottle is destroyed, so delete it first. |
| throttle_.reset(); |
| |
| // Destroy the request so that it doesn't try to send an asynchronous |
| // notification of completion. |
| request_.reset(); |
| |
| // Cancel timer to prevent OnTimeout() being called. |
| timer_.Stop(); |
| |
| ResponseCompleted(result); |
| // |this| may deleted after this point. |
| } |
| |
| 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( |
| AsyncRevalidationResult result) { |
| DVLOG(1) << "ResponseCompleted: " |
| << (request_ ? request_->url().spec() : "(request deleted)") |
| << "result = " << result; |
| UMA_HISTOGRAM_ENUMERATION("Net.AsyncRevalidation.Result", result, RESULT_MAX); |
| DCHECK(!completion_callback_.is_null()); |
| base::ResetAndReturn(&completion_callback_).Run(); |
| // |this| may be deleted after this point. |
| } |
| |
| void AsyncRevalidationDriver::OnTimeout(AsyncRevalidationResult result) { |
| CancelRequestInternal(net::ERR_TIMED_OUT, result); |
| } |
| |
| void AsyncRevalidationDriver::RecordDefer() { |
| request_->LogBlockedBy(throttle_->GetNameForLogging()); |
| DCHECK(!is_deferred_); |
| is_deferred_ = true; |
| } |
| |
| } // namespace content |