1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
|
// Copyright (c) 2012 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.
#ifndef CHROME_BROWSER_WEB_RESOURCE_WEB_RESOURCE_SERVICE_H_
#define CHROME_BROWSER_WEB_RESOURCE_WEB_RESOURCE_SERVICE_H_
#include <string>
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/weak_ptr.h"
#include "chrome/browser/web_resource/json_asynchronous_unpacker.h"
#include "chrome/browser/web_resource/resource_request_allowed_notifier.h"
#include "net/url_request/url_fetcher_delegate.h"
#include "url/gurl.h"
class PrefService;
namespace base {
class DictionaryValue;
}
namespace net {
class URLFetcher;
}
// A WebResourceService fetches JSON data from a web server and periodically
// refreshes it.
class WebResourceService
: public net::URLFetcherDelegate,
public JSONAsynchronousUnpackerDelegate,
public base::RefCountedThreadSafe<WebResourceService>,
public ResourceRequestAllowedNotifier::Observer {
public:
WebResourceService(PrefService* prefs,
const GURL& web_resource_server,
bool apply_locale_to_url_,
const char* last_update_time_pref_name,
int start_fetch_delay_ms,
int cache_update_delay_ms);
// Sleep until cache needs to be updated, but always for at least
// |start_fetch_delay_ms| so we don't interfere with startup.
// Then begin updating resources.
void StartAfterDelay();
// JSONAsynchronousUnpackerDelegate methods.
virtual void OnUnpackFinished(const DictionaryValue& parsed_json) OVERRIDE;
virtual void OnUnpackError(const std::string& error_message) OVERRIDE;
protected:
virtual ~WebResourceService();
// For the subclasses to process the result of a fetch.
virtual void Unpack(const base::DictionaryValue& parsed_json) = 0;
PrefService* prefs_;
private:
class UnpackerClient;
friend class base::RefCountedThreadSafe<WebResourceService>;
// net::URLFetcherDelegate implementation:
virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
// Schedules a fetch after |delay_ms| milliseconds.
void ScheduleFetch(int64 delay_ms);
// Starts fetching data from the server.
void StartFetch();
// Set |in_fetch_| to false, clean up temp directories (in the future).
void EndFetch();
// Implements ResourceRequestAllowedNotifier::Observer.
virtual void OnResourceRequestsAllowed() OVERRIDE;
// Helper class used to tell this service if it's allowed to make network
// resource requests.
ResourceRequestAllowedNotifier resource_request_allowed_notifier_;
// The tool that fetches the url data from the server.
scoped_ptr<net::URLFetcher> url_fetcher_;
// The tool that parses and transforms the json data. Weak reference as it
// deletes itself once the unpack is done.
JSONAsynchronousUnpacker* json_unpacker_;
// True if we are currently fetching or unpacking data. If we are asked to
// start a fetch when we are still fetching resource data, schedule another
// one in |cache_update_delay_ms_| time, and silently exit.
bool in_fetch_;
// URL that hosts the web resource.
GURL web_resource_server_;
// Indicates whether we should append locale to the web resource server URL.
bool apply_locale_to_url_;
// Pref name to store the last update's time.
const char* last_update_time_pref_name_;
// Delay on first fetch so we don't interfere with startup.
int start_fetch_delay_ms_;
// Delay between calls to update the web resource cache. This delay may be
// different for different builds of Chrome.
int cache_update_delay_ms_;
// So that we can delay our start so as not to affect start-up time; also,
// so that we can schedule future cache updates.
base::WeakPtrFactory<WebResourceService> weak_ptr_factory_;
DISALLOW_COPY_AND_ASSIGN(WebResourceService);
};
#endif // CHROME_BROWSER_WEB_RESOURCE_WEB_RESOURCE_SERVICE_H_
|
