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 HttpCache::Transaction, a private class of HttpCache so
6 // it should only be included by http_cache.cc
8 #ifndef NET_HTTP_HTTP_CACHE_TRANSACTION_H_
9 #define NET_HTTP_HTTP_CACHE_TRANSACTION_H_
13 #include "base/time/time.h"
14 #include "net/base/completion_callback.h"
15 #include "net/base/net_log.h"
16 #include "net/base/request_priority.h"
17 #include "net/http/http_cache.h"
18 #include "net/http/http_request_headers.h"
19 #include "net/http/http_response_info.h"
20 #include "net/http/http_transaction.h"
25 struct HttpRequestInfo
;
26 struct LoadTimingInfo
;
28 // This is the transaction that is returned by the HttpCache transaction
30 class HttpCache::Transaction
: public HttpTransaction
{
32 // The transaction has the following modes, which apply to how it may access
35 // o If the mode of the transaction is NONE, then it is in "pass through"
36 // mode and all methods just forward to the inner network transaction.
38 // o If the mode of the transaction is only READ, then it may only read from
41 // o If the mode of the transaction is only WRITE, then it may only write to
44 // o If the mode of the transaction is READ_WRITE, then the transaction may
45 // optionally modify the cache entry (e.g., possibly corresponding to
48 // o If the mode of the transaction is UPDATE, then the transaction may
49 // update existing cache entries, but will never create a new entry or
50 // respond using the entry read from the cache.
55 READ
= READ_META
| READ_DATA
,
57 READ_WRITE
= READ
| WRITE
,
58 UPDATE
= READ_META
| WRITE
, // READ_WRITE & ~READ_DATA
61 Transaction(RequestPriority priority
,
63 virtual ~Transaction();
65 Mode
mode() const { return mode_
; }
67 const std::string
& key() const { return cache_key_
; }
69 // Writes |buf_len| bytes of meta-data from the provided buffer |buf|. to the
70 // HTTP cache entry that backs this transaction (if any).
71 // Returns the number of bytes actually written, or a net error code. If the
72 // operation cannot complete immediately, returns ERR_IO_PENDING, grabs a
73 // reference to the buffer (until completion), and notifies the caller using
74 // the provided |callback| when the operation finishes.
76 // The first time this method is called for a given transaction, previous
77 // meta-data will be overwritten with the provided data, and subsequent
78 // invocations will keep appending to the cached entry.
80 // In order to guarantee that the metadata is set to the correct entry, the
81 // response (or response info) must be evaluated by the caller, for instance
82 // to make sure that the response_time is as expected, before calling this
84 int WriteMetadata(IOBuffer
* buf
,
86 const CompletionCallback
& callback
);
88 // This transaction is being deleted and we are not done writing to the cache.
89 // We need to indicate that the response data was truncated. Returns true on
90 // success. Keep in mind that this operation may have side effects, such as
91 // deleting the active entry.
92 bool AddTruncatedFlag();
94 HttpCache::ActiveEntry
* entry() { return entry_
; }
96 // Returns the LoadState of the writer transaction of a given ActiveEntry. In
97 // other words, returns the LoadState of this transaction without asking the
98 // http cache, because this transaction should be the one currently writing
99 // to the cache entry.
100 LoadState
GetWriterLoadState() const;
102 const CompletionCallback
& io_callback() { return io_callback_
; }
104 const BoundNetLog
& net_log() const;
106 // Bypasses the cache lock whenever there is lock contention.
107 void BypassLockForTest() {
108 bypass_lock_for_test_
= true;
111 // HttpTransaction methods:
112 virtual int Start(const HttpRequestInfo
* request_info
,
113 const CompletionCallback
& callback
,
114 const BoundNetLog
& net_log
) OVERRIDE
;
115 virtual int RestartIgnoringLastError(
116 const CompletionCallback
& callback
) OVERRIDE
;
117 virtual int RestartWithCertificate(
118 X509Certificate
* client_cert
,
119 const CompletionCallback
& callback
) OVERRIDE
;
120 virtual int RestartWithAuth(const AuthCredentials
& credentials
,
121 const CompletionCallback
& callback
) OVERRIDE
;
122 virtual bool IsReadyToRestartForAuth() OVERRIDE
;
123 virtual int Read(IOBuffer
* buf
,
125 const CompletionCallback
& callback
) OVERRIDE
;
126 virtual void StopCaching() OVERRIDE
;
127 virtual bool GetFullRequestHeaders(
128 HttpRequestHeaders
* headers
) const OVERRIDE
;
129 virtual int64
GetTotalReceivedBytes() const OVERRIDE
;
130 virtual void DoneReading() OVERRIDE
;
131 virtual const HttpResponseInfo
* GetResponseInfo() const OVERRIDE
;
132 virtual LoadState
GetLoadState() const OVERRIDE
;
133 virtual UploadProgress
GetUploadProgress(void) const OVERRIDE
;
134 virtual void SetQuicServerInfo(QuicServerInfo
* quic_server_info
) OVERRIDE
;
135 virtual bool GetLoadTimingInfo(
136 LoadTimingInfo
* load_timing_info
) const OVERRIDE
;
137 virtual void SetPriority(RequestPriority priority
) OVERRIDE
;
138 virtual void SetWebSocketHandshakeStreamCreateHelper(
139 net::WebSocketHandshakeStreamBase::CreateHelper
* create_helper
) OVERRIDE
;
140 virtual void SetBeforeNetworkStartCallback(
141 const BeforeNetworkStartCallback
& callback
) OVERRIDE
;
142 virtual void SetBeforeProxyHeadersSentCallback(
143 const BeforeProxyHeadersSentCallback
& callback
) OVERRIDE
;
144 virtual int ResumeNetworkStart() OVERRIDE
;
147 static const size_t kNumValidationHeaders
= 2;
148 // Helper struct to pair a header name with its value, for
149 // headers used to validate cache entries.
150 struct ValidationHeaders
{
151 ValidationHeaders() : initialized(false) {}
153 std::string values
[kNumValidationHeaders
];
160 STATE_GET_BACKEND_COMPLETE
,
162 STATE_SEND_REQUEST_COMPLETE
,
163 STATE_SUCCESSFUL_SEND_REQUEST
,
165 STATE_NETWORK_READ_COMPLETE
,
168 STATE_OPEN_ENTRY_COMPLETE
,
170 STATE_CREATE_ENTRY_COMPLETE
,
172 STATE_DOOM_ENTRY_COMPLETE
,
174 STATE_ADD_TO_ENTRY_COMPLETE
,
175 STATE_START_PARTIAL_CACHE_VALIDATION
,
176 STATE_COMPLETE_PARTIAL_CACHE_VALIDATION
,
177 STATE_UPDATE_CACHED_RESPONSE
,
178 STATE_UPDATE_CACHED_RESPONSE_COMPLETE
,
179 STATE_OVERWRITE_CACHED_RESPONSE
,
180 STATE_TRUNCATE_CACHED_DATA
,
181 STATE_TRUNCATE_CACHED_DATA_COMPLETE
,
182 STATE_TRUNCATE_CACHED_METADATA
,
183 STATE_TRUNCATE_CACHED_METADATA_COMPLETE
,
184 STATE_PARTIAL_HEADERS_RECEIVED
,
185 STATE_CACHE_READ_RESPONSE
,
186 STATE_CACHE_READ_RESPONSE_COMPLETE
,
187 STATE_CACHE_WRITE_RESPONSE
,
188 STATE_CACHE_WRITE_TRUNCATED_RESPONSE
,
189 STATE_CACHE_WRITE_RESPONSE_COMPLETE
,
190 STATE_CACHE_READ_METADATA
,
191 STATE_CACHE_READ_METADATA_COMPLETE
,
192 STATE_CACHE_QUERY_DATA
,
193 STATE_CACHE_QUERY_DATA_COMPLETE
,
194 STATE_CACHE_READ_DATA
,
195 STATE_CACHE_READ_DATA_COMPLETE
,
196 STATE_CACHE_WRITE_DATA
,
197 STATE_CACHE_WRITE_DATA_COMPLETE
200 // Used for categorizing transactions for reporting in histograms. Patterns
201 // cover relatively common use cases being measured and considered for
202 // optimization. Many use cases that are more complex or uncommon are binned
203 // as PATTERN_NOT_COVERED, and details are not reported.
204 // NOTE: This enumeration is used in histograms, so please do not add entries
206 enum TransactionPattern
{
209 PATTERN_ENTRY_NOT_CACHED
,
211 PATTERN_ENTRY_VALIDATED
,
212 PATTERN_ENTRY_UPDATED
,
213 PATTERN_ENTRY_CANT_CONDITIONALIZE
,
217 // This is a helper function used to trigger a completion callback. It may
218 // only be called if callback_ is non-null.
219 void DoCallback(int rv
);
221 // This will trigger the completion callback if appropriate.
222 int HandleResult(int rv
);
224 // Runs the state transition loop.
225 int DoLoop(int result
);
227 // Each of these methods corresponds to a State value. If there is an
228 // argument, the value corresponds to the return of the previous state or
229 // corresponding callback.
231 int DoGetBackendComplete(int result
);
233 int DoSendRequestComplete(int result
);
234 int DoSuccessfulSendRequest();
236 int DoNetworkReadComplete(int result
);
239 int DoOpenEntryComplete(int result
);
241 int DoCreateEntryComplete(int result
);
243 int DoDoomEntryComplete(int result
);
245 int DoAddToEntryComplete(int result
);
246 int DoStartPartialCacheValidation();
247 int DoCompletePartialCacheValidation(int result
);
248 int DoUpdateCachedResponse();
249 int DoUpdateCachedResponseComplete(int result
);
250 int DoOverwriteCachedResponse();
251 int DoTruncateCachedData();
252 int DoTruncateCachedDataComplete(int result
);
253 int DoTruncateCachedMetadata();
254 int DoTruncateCachedMetadataComplete(int result
);
255 int DoPartialHeadersReceived();
256 int DoCacheReadResponse();
257 int DoCacheReadResponseComplete(int result
);
258 int DoCacheWriteResponse();
259 int DoCacheWriteTruncatedResponse();
260 int DoCacheWriteResponseComplete(int result
);
261 int DoCacheReadMetadata();
262 int DoCacheReadMetadataComplete(int result
);
263 int DoCacheQueryData();
264 int DoCacheQueryDataComplete(int result
);
265 int DoCacheReadData();
266 int DoCacheReadDataComplete(int result
);
267 int DoCacheWriteData(int num_bytes
);
268 int DoCacheWriteDataComplete(int result
);
270 // These functions are involved in a field trial testing storing certificates
271 // in seperate entries from the HttpResponseInfo.
272 void ReadCertChain();
273 void WriteCertChain();
275 // Sets request_ and fields derived from it.
276 void SetRequest(const BoundNetLog
& net_log
, const HttpRequestInfo
* request
);
278 // Returns true if the request should be handled exclusively by the network
279 // layer (skipping the cache entirely).
280 bool ShouldPassThrough();
282 // Called to begin reading from the cache. Returns network error code.
283 int BeginCacheRead();
285 // Called to begin validating the cache entry. Returns network error code.
286 int BeginCacheValidation();
288 // Called to begin validating an entry that stores partial content. Returns
289 // a network error code.
290 int BeginPartialCacheValidation();
292 // Validates the entry headers against the requested range and continues with
293 // the validation of the rest of the entry. Returns a network error code.
294 int ValidateEntryHeadersAndContinue();
296 // Called to start requests which were given an "if-modified-since" or
297 // "if-none-match" validation header by the caller (NOT when the request was
298 // conditionalized internally in response to LOAD_VALIDATE_CACHE).
299 // Returns a network error code.
300 int BeginExternallyConditionalizedRequest();
302 // Called to restart a network transaction after an error. Returns network
304 int RestartNetworkRequest();
306 // Called to restart a network transaction with a client certificate.
307 // Returns network error code.
308 int RestartNetworkRequestWithCertificate(X509Certificate
* client_cert
);
310 // Called to restart a network transaction with authentication credentials.
311 // Returns network error code.
312 int RestartNetworkRequestWithAuth(const AuthCredentials
& credentials
);
314 // Called to determine if we need to validate the cache entry before using it.
315 bool RequiresValidation();
317 // Called to make the request conditional (to ask the server if the cached
318 // copy is valid). Returns true if able to make the request conditional.
319 bool ConditionalizeRequest();
321 // Makes sure that a 206 response is expected. Returns true on success.
322 // On success, handling_206_ will be set to true if we are processing a
324 bool ValidatePartialResponse();
326 // Handles a response validation error by bypassing the cache.
327 void IgnoreRangeRequest();
329 // Changes the response code of a range request to be 416 (Requested range not
331 void FailRangeRequest();
333 // Setups the transaction for reading from the cache entry.
334 int SetupEntryForRead();
336 // Reads data from the network.
337 int ReadFromNetwork(IOBuffer
* data
, int data_len
);
339 // Reads data from the cache entry.
340 int ReadFromEntry(IOBuffer
* data
, int data_len
);
342 // Called to write data to the cache entry. If the write fails, then the
343 // cache entry is destroyed. Future calls to this function will just do
344 // nothing without side-effect. Returns a network error code.
345 int WriteToEntry(int index
, int offset
, IOBuffer
* data
, int data_len
,
346 const CompletionCallback
& callback
);
348 // Called to write response_ to the cache entry. |truncated| indicates if the
349 // entry should be marked as incomplete.
350 int WriteResponseInfoToEntry(bool truncated
);
352 // Called to append response data to the cache entry. Returns a network error
354 int AppendResponseDataToEntry(IOBuffer
* data
, int data_len
,
355 const CompletionCallback
& callback
);
357 // Called when we are done writing to the cache entry.
358 void DoneWritingToEntry(bool success
);
360 // Returns an error to signal the caller that the current read failed. The
361 // current operation |result| is also logged. If |restart| is true, the
362 // transaction should be restarted.
363 int OnCacheReadError(int result
, bool restart
);
365 // Called when the cache lock timeout fires.
366 void OnAddToEntryTimeout(base::TimeTicks start_time
);
368 // Deletes the current partial cache entry (sparse), and optionally removes
369 // the control object (partial_).
370 void DoomPartialEntry(bool delete_object
);
372 // Performs the needed work after receiving data from the network, when
373 // working with range requests.
374 int DoPartialNetworkReadCompleted(int result
);
376 // Performs the needed work after receiving data from the cache, when
377 // working with range requests.
378 int DoPartialCacheReadCompleted(int result
);
380 // Restarts this transaction after deleting the cached data. It is meant to
381 // be used when the current request cannot be fulfilled due to conflicts
382 // between the byte range request and the cached entry.
383 int DoRestartPartialRequest();
385 // Resets |network_trans_|, which must be non-NULL. Also updates
386 // |old_network_trans_load_timing_|, which must be NULL when this is called.
387 void ResetNetworkTransaction();
389 // Returns true if we should bother attempting to resume this request if it
390 // is aborted while in progress. If |has_data| is true, the size of the stored
391 // data is considered for the result.
392 bool CanResume(bool has_data
);
394 void UpdateTransactionPattern(TransactionPattern new_transaction_pattern
);
395 void RecordHistograms();
397 // Called to signal completion of asynchronous IO.
398 void OnIOComplete(int result
);
401 const HttpRequestInfo
* request_
;
402 RequestPriority priority_
;
403 BoundNetLog net_log_
;
404 scoped_ptr
<HttpRequestInfo
> custom_request_
;
405 HttpRequestHeaders request_headers_copy_
;
406 // If extra_headers specified a "if-modified-since" or "if-none-match",
407 // |external_validation_| contains the value of those headers.
408 ValidationHeaders external_validation_
;
409 base::WeakPtr
<HttpCache
> cache_
;
410 HttpCache::ActiveEntry
* entry_
;
411 HttpCache::ActiveEntry
* new_entry_
;
412 scoped_ptr
<HttpTransaction
> network_trans_
;
413 CompletionCallback callback_
; // Consumer's callback.
414 HttpResponseInfo response_
;
415 HttpResponseInfo auth_response_
;
416 const HttpResponseInfo
* new_response_
;
417 std::string cache_key_
;
420 bool reading_
; // We are already reading. Never reverts to false once set.
421 bool invalid_range_
; // We may bypass the cache for this request.
422 bool truncated_
; // We don't have all the response data.
423 bool is_sparse_
; // The data is stored in sparse byte ranges.
424 bool range_requested_
; // The user requested a byte range.
425 bool handling_206_
; // We must deal with this 206 response.
426 bool cache_pending_
; // We are waiting for the HttpCache.
427 bool done_reading_
; // All available data was read.
428 bool vary_mismatch_
; // The request doesn't match the stored vary data.
429 bool couldnt_conditionalize_request_
;
430 bool bypass_lock_for_test_
; // A test is exercising the cache lock.
431 scoped_refptr
<IOBuffer
> read_buf_
;
434 int effective_load_flags_
;
436 scoped_ptr
<PartialData
> partial_
; // We are dealing with range requests.
437 UploadProgress final_upload_progress_
;
438 base::WeakPtrFactory
<Transaction
> weak_factory_
;
439 CompletionCallback io_callback_
;
441 // Members used to track data for histograms.
442 TransactionPattern transaction_pattern_
;
443 base::TimeTicks entry_lock_waiting_since_
;
444 base::TimeTicks first_cache_access_since_
;
445 base::TimeTicks send_request_since_
;
447 int64 total_received_bytes_
;
449 // Load timing information for the last network request, if any. Set in the
450 // 304 and 206 response cases, as the network transaction may be destroyed
451 // before the caller requests load timing information.
452 scoped_ptr
<LoadTimingInfo
> old_network_trans_load_timing_
;
454 // The helper object to use to create WebSocketHandshakeStreamBase
455 // objects. Only relevant when establishing a WebSocket connection.
456 // This is passed to the underlying network transaction. It is stored here in
457 // case the transaction does not exist yet.
458 WebSocketHandshakeStreamBase::CreateHelper
*
459 websocket_handshake_stream_base_create_helper_
;
461 BeforeNetworkStartCallback before_network_start_callback_
;
462 BeforeProxyHeadersSentCallback before_proxy_headers_sent_callback_
;
464 DISALLOW_COPY_AND_ASSIGN(Transaction
);
469 #endif // NET_HTTP_HTTP_CACHE_TRANSACTION_H_