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1 // Copyright 2015 The Chromium Authors. All rights reserved. | |
2 // Use of this source code is governed by a BSD-style license that can be | |
3 // found in the LICENSE file. | |
4 | |
5 #include "content/browser/loader/async_revalidation_driver.h" | |
6 | |
7 #include <utility> | |
8 | |
9 #include "base/callback_helpers.h" | |
10 #include "base/location.h" | |
11 #include "base/logging.h" | |
12 #include "base/memory/ref_counted.h" | |
13 #include "base/metrics/user_metrics_action.h" | |
14 #include "base/single_thread_task_runner.h" | |
15 #include "base/thread_task_runner_handle.h" | |
16 #include "base/time/time.h" | |
17 #include "content/public/browser/user_metrics.h" | |
18 #include "net/base/net_errors.h" | |
19 #include "net/url_request/url_request_status.h" | |
20 | |
21 namespace content { | |
22 | |
23 namespace { | |
24 // This matches the maximum allocation size of AsyncResourceHandler. | |
25 const int kReadBufSize = 32 * 1024; | |
26 | |
27 // The time to wait for a response. Since this includes the time taken to | |
28 // connect, this has been set to match the connect timeout | |
29 // kTransportConnectJobTimeoutInSeconds. | |
30 const int kResponseTimeoutInSeconds = 240; // 4 minutes. | |
31 | |
32 // This value should not be too large, as this request may be tying up a socket | |
33 // that could be used for something better. However, if it is too small, the | |
34 // cache entry will be truncated for no good reason. | |
35 // TODO(ricea): Find a more scientific way to set this timeout. | |
36 const int kReadTimeoutInSeconds = 30; | |
37 } // namespace | |
38 | |
39 // The use of base::Unretained() in the initialisation of read_timer_ is safe | |
40 // because base::Timer guarantees not to call the callback after being | |
41 // destroyed. | |
kinuko
2015/11/27 08:50:01
nit: this comment seems obsolete now
Adam Rice
2015/11/27 14:45:13
Thanks. Removed.
| |
42 AsyncRevalidationDriver::AsyncRevalidationDriver( | |
43 scoped_ptr<net::URLRequest> request, | |
44 scoped_ptr<ResourceThrottle> throttle, | |
45 const base::Closure& completion_callback) | |
46 : request_(std::move(request)), | |
47 throttle_(std::move(throttle)), | |
48 completion_callback_(completion_callback), | |
49 weak_ptr_factory_(this) { | |
50 request_->set_delegate(this); | |
51 throttle_->set_controller(this); | |
52 } | |
53 | |
54 AsyncRevalidationDriver::~AsyncRevalidationDriver() {} | |
55 | |
56 void AsyncRevalidationDriver::StartRequest() { | |
57 RecordAction(base::UserMetricsAction("AsyncRevalidationCreated")); | |
58 // Give the handler a chance to delay the URLRequest from being started. | |
59 bool defer_start = false; | |
60 throttle_->WillStartRequest(&defer_start); | |
61 | |
62 if (defer_start) { | |
63 RecordDefer(); | |
64 } else { | |
65 StartRequestInternal(); | |
66 } | |
67 } | |
68 | |
69 void AsyncRevalidationDriver::CancelRequest() { | |
70 CancelRequestInternal(net::ERR_ABORTED); | |
71 } | |
72 | |
73 void AsyncRevalidationDriver::OnReceivedRedirect( | |
74 net::URLRequest* request, | |
75 const net::RedirectInfo& redirect_info, | |
76 bool* defer) { | |
77 DCHECK_EQ(request_.get(), request); | |
78 | |
79 // The async revalidation should not follow redirects, because caching is | |
80 // a property of an individual HTTP resource. | |
81 DVLOG(1) << "OnReceivedRedirect: " << request_->url().spec(); | |
82 RecordAction(base::UserMetricsAction("AsyncRevalidationRedirected")); | |
83 CancelRequest(); | |
84 } | |
85 | |
86 void AsyncRevalidationDriver::OnAuthRequired( | |
87 net::URLRequest* request, | |
88 net::AuthChallengeInfo* auth_info) { | |
89 DCHECK_EQ(request_.get(), request); | |
90 // This error code doesn't have exactly the right semantics, but it should | |
91 // be sufficient to narrow down the problem in net logs. | |
92 request_->CancelWithError(net::ERR_ACCESS_DENIED); | |
93 } | |
94 | |
95 void AsyncRevalidationDriver::OnBeforeNetworkStart(net::URLRequest* request, | |
96 bool* defer) { | |
97 DCHECK_EQ(request_.get(), request); | |
98 | |
99 // Verify that the ResourceScheduler does not defer here. | |
100 throttle_->WillStartUsingNetwork(defer); | |
101 DCHECK(!*defer); | |
102 | |
103 // Start the response timer. This use of base::Unretained() is guaranteed safe | |
104 // by the semantics of base::OneShotTimer. | |
105 timer_.Start( | |
106 FROM_HERE, base::TimeDelta::FromSeconds(kResponseTimeoutInSeconds), | |
107 base::Bind(&AsyncRevalidationDriver::OnTimeout, base::Unretained(this), | |
108 "AsyncRevalidationResponseTimeout")); | |
109 } | |
110 | |
111 void AsyncRevalidationDriver::OnResponseStarted(net::URLRequest* request) { | |
112 DCHECK_EQ(request_.get(), request); | |
113 | |
114 DVLOG(1) << "OnResponseStarted: " << request_->url().spec(); | |
115 | |
116 // We have the response. No need to wait any longer. | |
117 timer_.Stop(); | |
118 | |
119 if (!request_->status().is_success()) { | |
120 ResponseCompleted(); | |
121 return; | |
122 } | |
123 | |
124 const net::HttpResponseInfo& response_info = request_->response_info(); | |
125 if (!response_info.response_time.is_null() && response_info.was_cached) { | |
126 // The cached entry was revalidated. No need to read it in. | |
127 ResponseCompleted(); | |
128 return; | |
129 } | |
130 | |
131 bool defer = false; | |
132 throttle_->WillProcessResponse(&defer); | |
133 DCHECK(!defer); | |
134 | |
135 // Set up the timer for reading the body. This use of base::Unretained() is | |
136 // guaranteed safe by the semantics of base::OneShotTimer. | |
137 timer_.Start( | |
138 FROM_HERE, base::TimeDelta::FromSeconds(kReadTimeoutInSeconds), | |
139 base::Bind(&AsyncRevalidationDriver::OnTimeout, base::Unretained(this), | |
140 "AsyncRevalidationReadTimeout")); | |
141 StartReading(false); // Read the first chunk. | |
142 } | |
143 | |
144 void AsyncRevalidationDriver::OnReadCompleted(net::URLRequest* request, | |
145 int bytes_read) { | |
146 DCHECK_EQ(request_.get(), request); | |
147 DCHECK(!is_deferred_); | |
148 DVLOG(1) << "OnReadCompleted: \"" << request_->url().spec() << "\"" | |
149 << " bytes_read = " << bytes_read; | |
150 | |
151 // bytes_read == -1 is an error. | |
152 // bytes_read == 0 is EOF. | |
153 if (bytes_read == -1 || bytes_read == 0 || !request_->status().is_success()) { | |
154 ResponseCompleted(); | |
155 return; | |
156 } | |
157 | |
158 DCHECK_GT(bytes_read, 0); | |
159 StartReading(true); // Read the next chunk. | |
160 } | |
161 | |
162 void AsyncRevalidationDriver::Resume() { | |
163 DCHECK(is_deferred_); | |
164 is_deferred_ = false; | |
165 request_->LogUnblocked(); | |
166 StartRequestInternal(); | |
167 } | |
168 | |
169 void AsyncRevalidationDriver::Cancel() { | |
170 NOTREACHED(); | |
171 } | |
172 | |
173 void AsyncRevalidationDriver::CancelAndIgnore() { | |
174 NOTREACHED(); | |
175 } | |
176 | |
177 void AsyncRevalidationDriver::CancelWithError(int error_code) { | |
178 NOTREACHED(); | |
179 } | |
180 | |
181 void AsyncRevalidationDriver::StartRequestInternal() { | |
182 DCHECK(!request_->is_pending()); | |
183 | |
184 // This can happen if Resume() is called after CancelRequest(). | |
185 // Since CancelRequest() will have called ResponseCompleted() asynchronously, | |
186 // it's not necessary to call it again. | |
187 if (!request_->status().is_success()) | |
188 return; | |
189 | |
190 request_->Start(); | |
191 } | |
192 | |
193 void AsyncRevalidationDriver::CancelRequestInternal(int error) { | |
194 DVLOG(1) << "CancelRequestInternal: " << request_->url().spec(); | |
195 | |
196 bool was_pending = request_->is_pending(); | |
197 | |
198 request_->CancelWithError(error); | |
199 | |
200 if (!was_pending) { | |
201 // If the request isn't in flight, then we won't get an asynchronous | |
202 // notification from the request, so we have to signal ourselves to finish | |
203 // this request. | |
204 scoped_refptr<base::SingleThreadTaskRunner> single_thread_task_runner = | |
205 base::ThreadTaskRunnerHandle::Get(); | |
206 single_thread_task_runner->PostTask( | |
207 FROM_HERE, base::Bind(&AsyncRevalidationDriver::ResponseCompleted, | |
208 weak_ptr_factory_.GetWeakPtr())); | |
209 } | |
210 } | |
211 | |
212 void AsyncRevalidationDriver::StartReading(bool is_continuation) { | |
213 int bytes_read = 0; | |
214 ReadMore(&bytes_read); | |
215 | |
216 // If IO is pending, wait for the URLRequest to call OnReadCompleted. | |
217 if (request_->status().is_io_pending()) | |
218 return; | |
219 | |
220 if (!is_continuation || bytes_read <= 0) { | |
221 OnReadCompleted(request_.get(), bytes_read); | |
222 } else { | |
223 // Else, trigger OnReadCompleted asynchronously to avoid starving the IO | |
224 // thread in case the URLRequest can provide data synchronously. | |
225 scoped_refptr<base::SingleThreadTaskRunner> single_thread_task_runner = | |
226 base::ThreadTaskRunnerHandle::Get(); | |
227 single_thread_task_runner->PostTask( | |
228 FROM_HERE, | |
229 base::Bind(&AsyncRevalidationDriver::OnReadCompleted, | |
230 weak_ptr_factory_.GetWeakPtr(), request_.get(), bytes_read)); | |
231 } | |
232 } | |
233 | |
234 void AsyncRevalidationDriver::ReadMore(int* bytes_read) { | |
235 DCHECK(!is_deferred_); | |
236 | |
237 if (!read_buffer_) | |
238 read_buffer_ = new net::IOBuffer(kReadBufSize); | |
239 | |
240 timer_.Reset(); | |
241 request_->Read(read_buffer_.get(), kReadBufSize, bytes_read); | |
242 | |
243 // No need to check the return value here as we'll detect errors by | |
244 // inspecting the URLRequest's status. | |
245 } | |
246 | |
247 void AsyncRevalidationDriver::ResponseCompleted() { | |
248 DVLOG(1) << "ResponseCompleted: " << request_->url().spec(); | |
249 // When this class cancels a redirect, URLRequest calls both the | |
250 // OnResponseStarted() and OnReadCompleted() callbacks. This class should not | |
251 // run |completion_callback_| twice. | |
252 // | |
253 // TODO(ricea): Work out why URLRequest calls both methods on cancellation and | |
254 // make it stop. | |
255 if (completion_callback_.is_null()) | |
256 return; | |
257 base::ResetAndReturn(&completion_callback_).Run(); | |
258 // |this| may be deleted after this point. | |
259 } | |
260 | |
261 void AsyncRevalidationDriver::OnTimeout(const char* action_name) { | |
262 RecordAction(base::UserMetricsAction(action_name)); | |
263 CancelRequestInternal(net::ERR_TIMED_OUT); | |
264 } | |
265 | |
266 void AsyncRevalidationDriver::RecordDefer() { | |
267 request_->LogBlockedBy(throttle_->GetNameForLogging()); | |
268 DCHECK(!is_deferred_); | |
269 is_deferred_ = true; | |
270 } | |
271 | |
272 } // namespace content | |
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