1 // Copyright (c) 2012 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.
5 // This file declares a HttpTransactionFactory implementation that can be
6 // layered on top of another HttpTransactionFactory to add HTTP caching. The
7 // caching logic follows RFC 2616 (any exceptions are called out in the code).
9 // The HttpCache takes a disk_cache::Backend as a parameter, and uses that for
12 // See HttpTransactionFactory and HttpTransaction for more details.
14 #ifndef NET_HTTP_HTTP_CACHE_H_
15 #define NET_HTTP_HTTP_CACHE_H_
21 #include "base/basictypes.h"
22 #include "base/containers/hash_tables.h"
23 #include "base/files/file_path.h"
24 #include "base/memory/scoped_ptr.h"
25 #include "base/memory/weak_ptr.h"
26 #include "base/message_loop/message_loop_proxy.h"
27 #include "base/threading/non_thread_safe.h"
28 #include "base/time/time.h"
29 #include "net/base/cache_type.h"
30 #include "net/base/completion_callback.h"
31 #include "net/base/load_states.h"
32 #include "net/base/net_export.h"
33 #include "net/base/request_priority.h"
34 #include "net/http/http_network_session.h"
35 #include "net/http/http_transaction_factory.h"
39 namespace disk_cache {
48 class HttpAuthHandlerFactory;
49 class HttpNetworkSession;
50 class HttpResponseInfo;
51 class HttpServerProperties;
54 class NetworkDelegate;
55 class ServerBoundCertService;
57 class SSLConfigService;
58 class TransportSecurityState;
59 class ViewCacheHelper;
60 struct HttpRequestInfo;
62 class NET_EXPORT HttpCache : public HttpTransactionFactory,
63 public base::SupportsWeakPtr<HttpCache>,
64 NON_EXPORTED_BASE(public base::NonThreadSafe) {
66 // The cache mode of operation.
68 // Normal mode just behaves like a standard web cache.
70 // Record mode caches everything for purposes of offline playback.
72 // Playback mode replays from a cache without considering any
73 // standard invalidations.
75 // Disables reads and writes from the cache.
76 // Equivalent to setting LOAD_DISABLE_CACHE on every request.
80 // A BackendFactory creates a backend object to be used by the HttpCache.
81 class NET_EXPORT BackendFactory {
83 virtual ~BackendFactory() {}
85 // The actual method to build the backend. Returns a net error code. If
86 // ERR_IO_PENDING is returned, the |callback| will be notified when the
87 // operation completes, and |backend| must remain valid until the
88 // notification arrives.
89 // The implementation must not access the factory object after invoking the
90 // |callback| because the object can be deleted from within the callback.
91 virtual int CreateBackend(NetLog* net_log,
92 scoped_ptr<disk_cache::Backend>* backend,
93 const CompletionCallback& callback) = 0;
96 // A default backend factory for the common use cases.
97 class NET_EXPORT DefaultBackend : public BackendFactory {
99 // |path| is the destination for any files used by the backend, and
100 // |cache_thread| is the thread where disk operations should take place. If
101 // |max_bytes| is zero, a default value will be calculated automatically.
102 DefaultBackend(CacheType type, BackendType backend_type,
103 const base::FilePath& path, int max_bytes,
104 base::MessageLoopProxy* thread);
105 virtual ~DefaultBackend();
107 // Returns a factory for an in-memory cache.
108 static BackendFactory* InMemory(int max_bytes);
110 // BackendFactory implementation.
111 virtual int CreateBackend(NetLog* net_log,
112 scoped_ptr<disk_cache::Backend>* backend,
113 const CompletionCallback& callback) OVERRIDE;
117 BackendType backend_type_;
118 const base::FilePath path_;
120 scoped_refptr<base::MessageLoopProxy> thread_;
123 // The disk cache is initialized lazily (by CreateTransaction) in this case.
124 // The HttpCache takes ownership of the |backend_factory|.
125 HttpCache(const net::HttpNetworkSession::Params& params,
126 BackendFactory* backend_factory);
128 // The disk cache is initialized lazily (by CreateTransaction) in this case.
129 // Provide an existing HttpNetworkSession, the cache can construct a
130 // network layer with a shared HttpNetworkSession in order for multiple
131 // network layers to share information (e.g. authentication data). The
132 // HttpCache takes ownership of the |backend_factory|.
133 HttpCache(HttpNetworkSession* session, BackendFactory* backend_factory);
135 // Initialize the cache from its component parts, which is useful for
136 // testing. The lifetime of the network_layer and backend_factory are managed
137 // by the HttpCache and will be destroyed using |delete| when the HttpCache is
139 HttpCache(HttpTransactionFactory* network_layer,
141 BackendFactory* backend_factory);
143 virtual ~HttpCache();
145 HttpTransactionFactory* network_layer() { return network_layer_.get(); }
147 // Retrieves the cache backend for this HttpCache instance. If the backend
148 // is not initialized yet, this method will initialize it. The return value is
149 // a network error code, and it could be ERR_IO_PENDING, in which case the
150 // |callback| will be notified when the operation completes. The pointer that
151 // receives the |backend| must remain valid until the operation completes.
152 int GetBackend(disk_cache::Backend** backend,
153 const net::CompletionCallback& callback);
155 // Returns the current backend (can be NULL).
156 disk_cache::Backend* GetCurrentBackend() const;
158 // Given a header data blob, convert it to a response info object.
159 static bool ParseResponseInfo(const char* data, int len,
160 HttpResponseInfo* response_info,
161 bool* response_truncated);
163 // Writes |buf_len| bytes of metadata stored in |buf| to the cache entry
164 // referenced by |url|, as long as the entry's |expected_response_time| has
165 // not changed. This method returns without blocking, and the operation will
166 // be performed asynchronously without any completion notification.
167 void WriteMetadata(const GURL& url,
168 RequestPriority priority,
169 base::Time expected_response_time,
173 // Get/Set the cache's mode.
174 void set_mode(Mode value) { mode_ = value; }
175 Mode mode() { return mode_; }
177 // Close currently active sockets so that fresh page loads will not use any
178 // recycled connections. For sockets currently in use, they may not close
179 // immediately, but they will not be reusable. This is for debugging.
180 void CloseAllConnections();
182 // Close all idle connections. Will close all sockets not in active use.
183 void CloseIdleConnections();
185 // Called whenever an external cache in the system reuses the resource
186 // referred to by |url| and |http_method|.
187 void OnExternalCacheHit(const GURL& url, const std::string& http_method);
189 // Initializes the Infinite Cache, if selected by the field trial.
190 void InitializeInfiniteCache(const base::FilePath& path);
192 // HttpTransactionFactory implementation:
193 virtual int CreateTransaction(RequestPriority priority,
194 scoped_ptr<HttpTransaction>* trans) OVERRIDE;
195 virtual HttpCache* GetCache() OVERRIDE;
196 virtual HttpNetworkSession* GetSession() OVERRIDE;
198 // Resets the network layer to allow for tests that probe
199 // network changes (e.g. host unreachable). The old network layer is
200 // returned to allow for filter patterns that only intercept
201 // some creation requests. Note ownership exchange.
202 scoped_ptr<HttpTransactionFactory>
203 SetHttpNetworkTransactionFactoryForTesting(
204 scoped_ptr<HttpTransactionFactory> new_network_layer);
207 // Disk cache entry data indices.
209 kResponseInfoIndex = 0,
210 kResponseContentIndex,
213 // Must remain at the end of the enum.
214 kNumCacheEntryDataIndices
216 friend class ViewCacheHelper;
219 // Types --------------------------------------------------------------------
221 class MetadataWriter;
222 class QuicServerInfoFactoryAdaptor;
225 friend class Transaction;
226 struct PendingOp; // Info for an entry under construction.
228 typedef std::list<Transaction*> TransactionList;
229 typedef std::list<WorkItem*> WorkItemList;
232 explicit ActiveEntry(disk_cache::Entry* entry);
235 disk_cache::Entry* disk_entry;
237 TransactionList readers;
238 TransactionList pending_queue;
239 bool will_process_pending_queue;
243 typedef base::hash_map<std::string, ActiveEntry*> ActiveEntriesMap;
244 typedef base::hash_map<std::string, PendingOp*> PendingOpsMap;
245 typedef std::set<ActiveEntry*> ActiveEntriesSet;
246 typedef base::hash_map<std::string, int> PlaybackCacheMap;
248 // Methods ------------------------------------------------------------------
250 // Creates the |backend| object and notifies the |callback| when the operation
251 // completes. Returns an error code.
252 int CreateBackend(disk_cache::Backend** backend,
253 const net::CompletionCallback& callback);
255 // Makes sure that the backend creation is complete before allowing the
256 // provided transaction to use the object. Returns an error code. |trans|
257 // will be notified via its IO callback if this method returns ERR_IO_PENDING.
258 // The transaction is free to use the backend directly at any time after
259 // receiving the notification.
260 int GetBackendForTransaction(Transaction* trans);
262 // Generates the cache key for this request.
263 std::string GenerateCacheKey(const HttpRequestInfo*);
265 // Dooms the entry selected by |key|, if it is currently in the list of active
267 void DoomActiveEntry(const std::string& key);
269 // Dooms the entry selected by |key|. |trans| will be notified via its IO
270 // callback if this method returns ERR_IO_PENDING. The entry can be
271 // currently in use or not.
272 int DoomEntry(const std::string& key, Transaction* trans);
274 // Dooms the entry selected by |key|. |trans| will be notified via its IO
275 // callback if this method returns ERR_IO_PENDING. The entry should not
276 // be currently in use.
277 int AsyncDoomEntry(const std::string& key, Transaction* trans);
279 // Dooms the entry associated with a GET for a given |url|.
280 void DoomMainEntryForUrl(const GURL& url);
282 // Closes a previously doomed entry.
283 void FinalizeDoomedEntry(ActiveEntry* entry);
285 // Returns an entry that is currently in use and not doomed, or NULL.
286 ActiveEntry* FindActiveEntry(const std::string& key);
288 // Creates a new ActiveEntry and starts tracking it. |disk_entry| is the disk
290 ActiveEntry* ActivateEntry(disk_cache::Entry* disk_entry);
292 // Deletes an ActiveEntry.
293 void DeactivateEntry(ActiveEntry* entry);
295 // Deletes an ActiveEntry using an exhaustive search.
296 void SlowDeactivateEntry(ActiveEntry* entry);
298 // Returns the PendingOp for the desired |key|. If an entry is not under
299 // construction already, a new PendingOp structure is created.
300 PendingOp* GetPendingOp(const std::string& key);
302 // Deletes a PendingOp.
303 void DeletePendingOp(PendingOp* pending_op);
305 // Opens the disk cache entry associated with |key|, returning an ActiveEntry
306 // in |*entry|. |trans| will be notified via its IO callback if this method
307 // returns ERR_IO_PENDING.
308 int OpenEntry(const std::string& key, ActiveEntry** entry,
311 // Creates the disk cache entry associated with |key|, returning an
312 // ActiveEntry in |*entry|. |trans| will be notified via its IO callback if
313 // this method returns ERR_IO_PENDING.
314 int CreateEntry(const std::string& key, ActiveEntry** entry,
317 // Destroys an ActiveEntry (active or doomed).
318 void DestroyEntry(ActiveEntry* entry);
320 // Adds a transaction to an ActiveEntry. If this method returns ERR_IO_PENDING
321 // the transaction will be notified about completion via its IO callback. This
322 // method returns ERR_CACHE_RACE to signal the transaction that it cannot be
323 // added to the provided entry, and it should retry the process with another
324 // one (in this case, the entry is no longer valid).
325 int AddTransactionToEntry(ActiveEntry* entry, Transaction* trans);
327 // Called when the transaction has finished working with this entry. |cancel|
328 // is true if the operation was cancelled by the caller instead of running
330 void DoneWithEntry(ActiveEntry* entry, Transaction* trans, bool cancel);
332 // Called when the transaction has finished writing to this entry. |success|
333 // is false if the cache entry should be deleted.
334 void DoneWritingToEntry(ActiveEntry* entry, bool success);
336 // Called when the transaction has finished reading from this entry.
337 void DoneReadingFromEntry(ActiveEntry* entry, Transaction* trans);
339 // Converts the active writer transaction to a reader so that other
340 // transactions can start reading from this entry.
341 void ConvertWriterToReader(ActiveEntry* entry);
343 // Returns the LoadState of the provided pending transaction.
344 LoadState GetLoadStateForPendingTransaction(const Transaction* trans);
346 // Removes the transaction |trans|, from the pending list of an entry
347 // (PendingOp, active or doomed entry).
348 void RemovePendingTransaction(Transaction* trans);
350 // Removes the transaction |trans|, from the pending list of |entry|.
351 bool RemovePendingTransactionFromEntry(ActiveEntry* entry,
354 // Removes the transaction |trans|, from the pending list of |pending_op|.
355 bool RemovePendingTransactionFromPendingOp(PendingOp* pending_op,
358 // Resumes processing the pending list of |entry|.
359 void ProcessPendingQueue(ActiveEntry* entry);
361 // Events (called via PostTask) ---------------------------------------------
363 void OnProcessPendingQueue(ActiveEntry* entry);
365 // Callbacks ----------------------------------------------------------------
367 // Processes BackendCallback notifications.
368 void OnIOComplete(int result, PendingOp* entry);
370 // Helper to conditionally delete |pending_op| if the HttpCache object it
371 // is meant for has been deleted.
373 // TODO(ajwong): The PendingOp lifetime management is very tricky. It might
374 // be possible to simplify it using either base::Owned() or base::Passed()
375 // with the callback.
376 static void OnPendingOpComplete(const base::WeakPtr<HttpCache>& cache,
377 PendingOp* pending_op,
380 // Processes the backend creation notification.
381 void OnBackendCreated(int result, PendingOp* pending_op);
383 // Variables ----------------------------------------------------------------
387 // Used when lazily constructing the disk_cache_.
388 scoped_ptr<BackendFactory> backend_factory_;
389 bool building_backend_;
393 const scoped_ptr<QuicServerInfoFactoryAdaptor> quic_server_info_factory_;
395 scoped_ptr<HttpTransactionFactory> network_layer_;
397 scoped_ptr<disk_cache::Backend> disk_cache_;
399 // The set of active entries indexed by cache key.
400 ActiveEntriesMap active_entries_;
402 // The set of doomed entries.
403 ActiveEntriesSet doomed_entries_;
405 // The set of entries "under construction".
406 PendingOpsMap pending_ops_;
408 scoped_ptr<PlaybackCacheMap> playback_cache_map_;
410 DISALLOW_COPY_AND_ASSIGN(HttpCache);
415 #endif // NET_HTTP_HTTP_CACHE_H_