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
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
|
// Copyright (c) 2006-2008 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.
// This file declares a HttpTransactionFactory implementation that can be
// layered on top of another HttpTransactionFactory to add HTTP caching. The
// caching logic follows RFC 2616 (any exceptions are called out in the code).
//
// The HttpCache takes a disk_cache::Backend as a parameter, and uses that for
// the cache storage.
//
// See HttpTransactionFactory and HttpTransaction for more details.
#ifndef NET_HTTP_HTTP_CACHE_H_
#define NET_HTTP_HTTP_CACHE_H_
#include <list>
#include <set>
#include "base/basictypes.h"
#include "base/hash_tables.h"
#include "base/task.h"
#include "net/http/http_transaction_factory.h"
namespace disk_cache {
class Backend;
class Entry;
}
namespace net {
class HttpNetworkSession;
class HttpRequestInfo;
class HttpResponseInfo;
class ProxyService;
class HttpCache : public HttpTransactionFactory {
public:
~HttpCache();
// The cache mode of operation.
enum Mode {
// Normal mode just behaves like a standard web cache.
NORMAL = 0,
// Record mode caches everything for purposes of offline playback.
RECORD,
// Playback mode replays from a cache without considering any
// standard invalidations.
PLAYBACK
};
// The type of an HttpCache object, essentially describe what an HttpCache
// object is for.
enum Type {
// An HttpCache object for common objects, e.g. html pages, images, fonts,
// css files, js files and other common web resources.
COMMON = 0,
// A cache system for media file, e.g. video and audio files. These files
// are huge and has special requirement for access.
MEDIA
};
// Initialize the cache from the directory where its data is stored. The
// disk cache is initialized lazily (by CreateTransaction) in this case. If
// |cache_size| is zero, a default value will be calculated automatically.
HttpCache(ProxyService* proxy_service,
const std::wstring& cache_dir,
int cache_size);
// Initialize the cache from the directory where its data is stored. The
// disk cache is initialized lazily (by CreateTransaction) in this case. If
// |cache_size| is zero, a default value will be calculated automatically.
// Provide an existing HttpNetworkSession, the cache can construct a
// network layer with a shared HttpNetworkSession in order for multiple
// network layers to share information (e.g. authenication data).
HttpCache(HttpNetworkSession* session, const std::wstring& cache_dir,
int cache_size);
// Initialize using an in-memory cache. The cache is initialized lazily
// (by CreateTransaction) in this case. If |cache_size| is zero, a default
// value will be calculated automatically.
HttpCache(ProxyService* proxy_service, int cache_size);
// Initialize the cache from its component parts, which is useful for
// testing. The lifetime of the network_layer and disk_cache are managed by
// the HttpCache and will be destroyed using |delete| when the HttpCache is
// destroyed.
HttpCache(HttpTransactionFactory* network_layer,
disk_cache::Backend* disk_cache);
HttpTransactionFactory* network_layer() { return network_layer_.get(); }
disk_cache::Backend* disk_cache() { return disk_cache_.get(); }
// HttpTransactionFactory implementation:
virtual HttpTransaction* CreateTransaction();
virtual HttpCache* GetCache();
virtual void Suspend(bool suspend);
// Helper function for reading response info from the disk cache.
static bool ReadResponseInfo(disk_cache::Entry* disk_entry,
HttpResponseInfo* response_info);
// Helper function for writing response info into the disk cache.
static bool WriteResponseInfo(disk_cache::Entry* disk_entry,
const HttpResponseInfo* response_info,
bool skip_transient_headers);
// Generate a key that can be used inside the cache.
std::string GenerateCacheKey(const HttpRequestInfo* request);
// Get/Set the cache's mode.
void set_mode(Mode value) { mode_ = value; }
Mode mode() { return mode_; }
void set_type(Type type) { type_ = type; }
Type type() { return type_; }
private:
// Types --------------------------------------------------------------------
class Transaction;
friend class Transaction;
typedef std::list<Transaction*> TransactionList;
struct ActiveEntry {
disk_cache::Entry* disk_entry;
Transaction* writer;
TransactionList readers;
TransactionList pending_queue;
bool will_process_pending_queue;
bool doomed;
explicit ActiveEntry(disk_cache::Entry*);
~ActiveEntry();
};
typedef base::hash_map<std::string, ActiveEntry*> ActiveEntriesMap;
typedef std::set<ActiveEntry*> ActiveEntriesSet;
// Methods ------------------------------------------------------------------
void DoomEntry(const std::string& key);
void FinalizeDoomedEntry(ActiveEntry* entry);
ActiveEntry* FindActiveEntry(const std::string& key);
ActiveEntry* ActivateEntry(const std::string& key, disk_cache::Entry*);
void DeactivateEntry(ActiveEntry* entry);
ActiveEntry* OpenEntry(const std::string& key);
ActiveEntry* CreateEntry(const std::string& cache_key);
void DestroyEntry(ActiveEntry* entry);
int AddTransactionToEntry(ActiveEntry* entry, Transaction* trans);
void DoneWithEntry(ActiveEntry* entry, Transaction* trans);
void DoneWritingToEntry(ActiveEntry* entry, bool success);
void DoneReadingFromEntry(ActiveEntry* entry, Transaction* trans);
void ConvertWriterToReader(ActiveEntry* entry);
void RemovePendingTransaction(Transaction* trans);
void ProcessPendingQueue(ActiveEntry* entry);
// Events (called via PostTask) ---------------------------------------------
void OnProcessPendingQueue(ActiveEntry* entry);
// Variables ----------------------------------------------------------------
// used when lazily constructing the disk_cache_
std::wstring disk_cache_dir_;
Mode mode_;
Type type_;
scoped_ptr<HttpTransactionFactory> network_layer_;
scoped_ptr<disk_cache::Backend> disk_cache_;
// The set of active entries indexed by cache key
ActiveEntriesMap active_entries_;
// The set of doomed entries
ActiveEntriesSet doomed_entries_;
ScopedRunnableMethodFactory<HttpCache> task_factory_;
bool in_memory_cache_;
int cache_size_;
typedef base::hash_map<std::string, int> PlaybackCacheMap;
scoped_ptr<PlaybackCacheMap> playback_cache_map_;
RevocableStore transactions_;
DISALLOW_COPY_AND_ASSIGN(HttpCache);
};
} // namespace net
#endif // NET_HTTP_HTTP_CACHE_H_
|
