1// Copyright (c) 2011 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 "chrome/browser/net/sdch_dictionary_fetcher.h"
6
7#include "base/compiler_specific.h"
8#include "chrome/browser/profiles/profile.h"
9#include "net/url_request/url_request_status.h"
10
11SdchDictionaryFetcher::SdchDictionaryFetcher()
12    : ALLOW_THIS_IN_INITIALIZER_LIST(method_factory_(this)),
13      task_is_pending_(false) {
14}
15
16SdchDictionaryFetcher::~SdchDictionaryFetcher() {
17}
18
19// static
20void SdchDictionaryFetcher::Shutdown() {
21  net::SdchManager::Shutdown();
22}
23
24void SdchDictionaryFetcher::Schedule(const GURL& dictionary_url) {
25  // Avoid pushing duplicate copy onto queue.  We may fetch this url again later
26  // and get a different dictionary, but there is no reason to have it in the
27  // queue twice at one time.
28  if (!fetch_queue_.empty() && fetch_queue_.back() == dictionary_url) {
29    net::SdchManager::SdchErrorRecovery(
30        net::SdchManager::DICTIONARY_ALREADY_SCHEDULED_TO_DOWNLOAD);
31    return;
32  }
33  if (attempted_load_.find(dictionary_url) != attempted_load_.end()) {
34    net::SdchManager::SdchErrorRecovery(
35        net::SdchManager::DICTIONARY_ALREADY_TRIED_TO_DOWNLOAD);
36    return;
37  }
38  attempted_load_.insert(dictionary_url);
39  fetch_queue_.push(dictionary_url);
40  ScheduleDelayedRun();
41}
42
43void SdchDictionaryFetcher::ScheduleDelayedRun() {
44  if (fetch_queue_.empty() || current_fetch_.get() || task_is_pending_)
45    return;
46  MessageLoop::current()->PostDelayedTask(FROM_HERE,
47      method_factory_.NewRunnableMethod(&SdchDictionaryFetcher::StartFetching),
48      kMsDelayFromRequestTillDownload);
49  task_is_pending_ = true;
50}
51
52void SdchDictionaryFetcher::StartFetching() {
53  DCHECK(task_is_pending_);
54  task_is_pending_ = false;
55
56  net::URLRequestContextGetter* context = Profile::GetDefaultRequestContext();
57  if (!context) {
58    // Shutdown in progress.
59    // Simulate handling of all dictionary requests by clearing queue.
60    while (!fetch_queue_.empty())
61      fetch_queue_.pop();
62    return;
63  }
64
65  current_fetch_.reset(new URLFetcher(fetch_queue_.front(), URLFetcher::GET,
66                                      this));
67  fetch_queue_.pop();
68  current_fetch_->set_request_context(context);
69  current_fetch_->Start();
70}
71
72void SdchDictionaryFetcher::OnURLFetchComplete(
73    const URLFetcher* source,
74    const GURL& url,
75    const net::URLRequestStatus& status,
76    int response_code,
77    const ResponseCookies& cookies,
78    const std::string& data) {
79  if ((200 == response_code) &&
80      (status.status() == net::URLRequestStatus::SUCCESS))
81    net::SdchManager::Global()->AddSdchDictionary(data, url);
82  current_fetch_.reset(NULL);
83  ScheduleDelayedRun();
84}
85