| // Copyright 2014 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 "net/url_request/sdch_dictionary_fetcher.h" |
| |
| #include <stdint.h> |
| |
| #include "base/auto_reset.h" |
| #include "base/bind.h" |
| #include "base/compiler_specific.h" |
| #include "base/thread_task_runner_handle.h" |
| #include "net/base/load_flags.h" |
| #include "net/url_request/url_request_context.h" |
| #include "net/url_request/url_request_status.h" |
| #include "net/url_request/url_request_throttler_manager.h" |
| |
| namespace { |
| |
| const int kBufferSize = 4096; |
| |
| } // namespace |
| |
| namespace net { |
| |
| SdchDictionaryFetcher::SdchDictionaryFetcher( |
| URLRequestContext* context, |
| const OnDictionaryFetchedCallback& callback) |
| : next_state_(STATE_NONE), |
| in_loop_(false), |
| context_(context), |
| dictionary_fetched_callback_(callback), |
| weak_factory_(this) { |
| DCHECK(CalledOnValidThread()); |
| DCHECK(context); |
| } |
| |
| SdchDictionaryFetcher::~SdchDictionaryFetcher() { |
| DCHECK(CalledOnValidThread()); |
| } |
| |
| void SdchDictionaryFetcher::Schedule(const GURL& dictionary_url) { |
| DCHECK(CalledOnValidThread()); |
| |
| // Avoid pushing duplicate copy onto queue. We may fetch this url again later |
| // and get a different dictionary, but there is no reason to have it in the |
| // queue twice at one time. |
| if (!fetch_queue_.empty() && fetch_queue_.back() == dictionary_url) { |
| SdchManager::SdchErrorRecovery( |
| SdchManager::DICTIONARY_ALREADY_SCHEDULED_TO_DOWNLOAD); |
| return; |
| } |
| if (attempted_load_.find(dictionary_url) != attempted_load_.end()) { |
| SdchManager::SdchErrorRecovery( |
| SdchManager::DICTIONARY_ALREADY_TRIED_TO_DOWNLOAD); |
| return; |
| } |
| attempted_load_.insert(dictionary_url); |
| fetch_queue_.push(dictionary_url); |
| |
| next_state_ = STATE_IDLE; |
| |
| // There are no callbacks to user code from the dictionary fetcher, |
| // and Schedule() is only called from user code, so this call to DoLoop() |
| // does not require an |if (in_loop_) return;| guard. |
| DoLoop(OK); |
| } |
| |
| void SdchDictionaryFetcher::Cancel() { |
| DCHECK(CalledOnValidThread()); |
| |
| next_state_ = STATE_NONE; |
| |
| while (!fetch_queue_.empty()) |
| fetch_queue_.pop(); |
| attempted_load_.clear(); |
| weak_factory_.InvalidateWeakPtrs(); |
| current_request_.reset(NULL); |
| buffer_ = NULL; |
| dictionary_.clear(); |
| } |
| |
| void SdchDictionaryFetcher::OnResponseStarted(URLRequest* request) { |
| DCHECK(CalledOnValidThread()); |
| DCHECK_EQ(request, current_request_.get()); |
| DCHECK_EQ(next_state_, STATE_REQUEST_STARTED); |
| |
| // The response has started, so the stream can be read from. |
| next_state_ = STATE_REQUEST_READING; |
| |
| // If this function was synchronously called, the containing |
| // state machine loop will handle the state transition. Otherwise, |
| // restart the state machine loop. |
| if (in_loop_) |
| return; |
| |
| DoLoop(request->status().error()); |
| } |
| |
| void SdchDictionaryFetcher::OnReadCompleted(URLRequest* request, |
| int bytes_read) { |
| DCHECK(CalledOnValidThread()); |
| DCHECK_EQ(request, current_request_.get()); |
| DCHECK_EQ(next_state_, STATE_REQUEST_READING); |
| |
| // No state transition is required in this function; the |
| // completion of the request is detected in DoRead(). |
| |
| if (request->status().is_success()) |
| dictionary_.append(buffer_->data(), bytes_read); |
| |
| // If this function was synchronously called, the containing |
| // state machine loop will handle the state transition. Otherwise, |
| // restart the state machine loop. |
| if (in_loop_) |
| return; |
| |
| DoLoop(request->status().error()); |
| } |
| |
| int SdchDictionaryFetcher::DoLoop(int rv) { |
| DCHECK(!in_loop_); |
| base::AutoReset<bool> auto_reset_in_loop(&in_loop_, true); |
| |
| do { |
| State state = next_state_; |
| next_state_ = STATE_NONE; |
| switch (state) { |
| case STATE_IDLE: |
| rv = DoDispatchRequest(rv); |
| break; |
| case STATE_REQUEST_STARTED: |
| rv = DoRequestStarted(rv); |
| break; |
| case STATE_REQUEST_READING: |
| rv = DoRead(rv); |
| break; |
| case STATE_REQUEST_COMPLETE: |
| rv = DoCompleteRequest(rv); |
| break; |
| case STATE_NONE: |
| NOTREACHED(); |
| } |
| } while (rv != ERR_IO_PENDING && next_state_ != STATE_NONE); |
| |
| return rv; |
| } |
| |
| int SdchDictionaryFetcher::DoDispatchRequest(int rv) { |
| DCHECK(CalledOnValidThread()); |
| |
| // |rv| is ignored, as the result from the previous request doesn't |
| // affect the next request. |
| |
| if (fetch_queue_.empty() || current_request_.get()) { |
| next_state_ = STATE_NONE; |
| return OK; |
| } |
| |
| current_request_ = |
| context_->CreateRequest(fetch_queue_.front(), IDLE, this, NULL); |
| current_request_->SetLoadFlags(LOAD_DO_NOT_SEND_COOKIES | |
| LOAD_DO_NOT_SAVE_COOKIES); |
| buffer_ = new IOBuffer(kBufferSize); |
| fetch_queue_.pop(); |
| |
| next_state_ = STATE_REQUEST_STARTED; |
| current_request_->Start(); |
| |
| return OK; |
| } |
| |
| int SdchDictionaryFetcher::DoRequestStarted(int rv) { |
| DCHECK(CalledOnValidThread()); |
| DCHECK_EQ(rv, OK); // Can only come straight from above function. |
| |
| // The transition to STATE_REQUEST_READING occurs in the |
| // OnResponseStarted() callback triggered by URLRequest::Start() |
| // (called in DoDispatchRequest(), above). If that callback did not |
| // occur synchronously, this routine is executed; it returns ERR_IO_PENDING, |
| // indicating to the controlling loop that no further work should be done |
| // until the callback occurs (which will re-invoke DoLoop()). |
| next_state_ = STATE_REQUEST_STARTED; |
| return ERR_IO_PENDING; |
| } |
| |
| int SdchDictionaryFetcher::DoRead(int rv) { |
| DCHECK(CalledOnValidThread()); |
| |
| // If there's been an error, abort the current request. |
| if (rv != OK) { |
| current_request_.reset(); |
| buffer_ = NULL; |
| next_state_ = STATE_IDLE; |
| |
| return OK; |
| } |
| |
| next_state_ = STATE_REQUEST_READING; |
| int bytes_read = 0; |
| if (!current_request_->Read(buffer_.get(), kBufferSize, &bytes_read)) { |
| if (current_request_->status().is_io_pending()) |
| return ERR_IO_PENDING; |
| |
| if (current_request_->status().error() == OK) { |
| // This "should never happen", but if it does the result will be |
| // an infinite loop. It's not clear how to handle a read failure |
| // without a promise to invoke the callback at some point in the future, |
| // so the request is failed. |
| SdchManager::SdchErrorRecovery(SdchManager::DICTIONARY_FETCH_READ_FAILED); |
| DLOG(FATAL) |
| << "URLRequest::Read() returned false without IO pending or error!"; |
| return ERR_FAILED; |
| } |
| |
| return current_request_->status().error(); |
| } |
| |
| if (bytes_read != 0) |
| dictionary_.append(buffer_->data(), bytes_read); |
| else |
| next_state_ = STATE_REQUEST_COMPLETE; |
| |
| return OK; |
| } |
| |
| int SdchDictionaryFetcher::DoCompleteRequest(int rv) { |
| DCHECK(CalledOnValidThread()); |
| |
| // If the dictionary was successfully fetched, add it to the manager. |
| if (rv == OK) |
| dictionary_fetched_callback_.Run(dictionary_, current_request_->url()); |
| |
| current_request_.reset(); |
| buffer_ = NULL; |
| dictionary_.clear(); |
| |
| next_state_ = STATE_IDLE; |
| |
| return OK; |
| } |
| |
| } // namespace net |