3 * SQUID Web Proxy Cache http://www.squid-cache.org/
4 * ----------------------------------------------------------
6 * Squid is the result of efforts by numerous individuals from
7 * the Internet community; see the CONTRIBUTORS file for full
8 * details. Many organizations have provided support for Squid's
9 * development; see the SPONSORS file for full details. Squid is
10 * Copyrighted (C) 2001 by the Regents of the University of
11 * California; see the COPYRIGHT file for full details. Squid
12 * incorporates software developed and/or copyrighted by other
13 * sources; see the CREDITS file for full details.
15 * This program is free software; you can redistribute it and/or modify
16 * it under the terms of the GNU General Public License as published by
17 * the Free Software Foundation; either version 2 of the License, or
18 * (at your option) any later version.
20 * This program is distributed in the hope that it will be useful,
21 * but WITHOUT ANY WARRANTY; without even the implied warranty of
22 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
23 * GNU General Public License for more details.
25 * You should have received a copy of the GNU General Public License
26 * along with this program; if not, write to the Free Software
27 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
34 \defgroup StoreAPI Store API
38 #include "base/RefCount.h"
39 #include "comm/forward.h"
42 #include "http/forward.h"
43 #include "http/RequestMethod.h"
44 #include "HttpReply.h"
45 #include "MemObject.h"
47 #include "RemovalPolicy.h"
48 #include "StoreIOBuffer.h"
49 #include "StoreStats.h"
52 #include "esi/Element.h"
65 extern StoreIoStats store_io_stats
;
67 /// maximum number of entries per cache_dir
68 enum { SwapFilenMax
= 0xFFFFFF }; // keep in sync with StoreEntry::swap_filen
73 class StoreEntry
: public hash_link
77 static DeferredRead::DeferrableRead DeferReader
;
78 bool checkDeferRead(int fd
) const;
80 virtual const char *getMD5Text() const;
82 virtual ~StoreEntry();
84 virtual HttpReply
const *getReply() const;
85 virtual void write (StoreIOBuffer
);
87 /** Check if the Store entry is emtpty
88 * \retval true Store contains 0 bytes of data.
89 * \retval false Store contains 1 or more bytes of data.
90 * \retval false Store contains negative content !!!!!!
92 virtual bool isEmpty() const {
94 return mem_obj
->endOffset() == 0;
96 virtual bool isAccepting() const;
97 virtual size_t bytesWanted(Range
<size_t> const aRange
, bool ignoreDelayPool
= false) const;
98 virtual void complete();
99 virtual store_client_t
storeClientType() const;
100 virtual char const *getSerialisedMetaData();
101 void replaceHttpReply(HttpReply
*, bool andStartWriting
= true);
102 void startWriting(); ///< pack and write reply headers and, maybe, body
103 /// whether we may start writing to disk (now or in the future)
104 virtual bool mayStartSwapOut();
105 virtual void trimMemory(const bool preserveSwappable
);
111 void setPrivateKey();
113 void releaseRequest();
114 void negativeCache();
115 void cacheNegatively(); /** \todo argh, why both? */
116 void invokeHandlers();
118 void cacheInMemory(); ///< start or continue storing in memory cache
120 /// whether we are in the process of writing this entry to disk
121 bool swappingOut() const { return swap_status
== SWAPOUT_WRITING
; }
122 void swapOutFileClose(int how
);
123 const char *url() const;
125 int checkNegativeHit() const;
127 int validToSend() const;
128 bool memoryCachable() const; ///< may be cached in memory
130 /// if needed, initialize mem_obj member w/o URI-related information
131 MemObject
*makeMemObject();
133 /// initialize mem_obj member (if needed) and supply URI-related info
134 void createMemObject(const char *storeId
, const char *logUri
, const HttpRequestMethod
&aMethod
);
136 void dump(int debug_lvl
) const;
138 void hashInsert(const cache_key
*);
139 void registerAbort(STABH
* cb
, void *);
141 void setMemStatus(mem_status_t
);
142 void timestampsSet();
143 void unregisterAbort();
144 void destroyMemObject();
147 void delayAwareRead(const Comm::ConnectionPointer
&conn
, char *buf
, int len
, AsyncCall::Pointer callback
);
149 void setNoDelay (bool const);
150 bool modifiedSince(HttpRequest
* request
) const;
151 /// has ETag matching at least one of the If-Match etags
152 bool hasIfMatchEtag(const HttpRequest
&request
) const;
153 /// has ETag matching at least one of the If-None-Match etags
154 bool hasIfNoneMatchEtag(const HttpRequest
&request
) const;
155 /// whether this entry has an ETag; if yes, puts ETag value into parameter
156 bool hasEtag(ETag
&etag
) const;
158 /** What store does this entry belong too ? */
159 virtual RefCount
<SwapDir
> store() const;
162 RemovalPolicyNode repl
;
163 /* START OF ON-DISK STORE_META_STD TLV field */
168 uint64_t swap_file_sz
;
171 /* END OF ON-DISK STORE_META_STD */
173 /// unique ID inside a cache_dir for swapped out entries; -1 for others
174 sfileno swap_filen
:25; // keep in sync with SwapFilenMax
178 mem_status_t mem_status
:3;
180 ping_status_t ping_status
:3;
182 store_status_t store_status
:3;
184 swap_status_t swap_status
:3;
187 static size_t inUseCount();
188 static void getPublicByRequestMethod(StoreClient
* aClient
, HttpRequest
* request
, const HttpRequestMethod
& method
);
189 static void getPublicByRequest(StoreClient
* aClient
, HttpRequest
* request
);
190 static void getPublic(StoreClient
* aClient
, const char *uri
, const HttpRequestMethod
& method
);
192 virtual bool isNull() {
196 void *operator new(size_t byteCount
);
197 void operator delete(void *address
);
198 void setReleaseFlag();
201 ESIElement::Pointer cachedESITree
;
203 /** append bytes to the buffer */
204 virtual void append(char const *, int len
);
205 /** disable sending content to the clients */
206 virtual void buffer();
207 /** flush any buffered content */
208 virtual void flush();
209 virtual int64_t objectLen() const;
210 virtual int64_t contentLen() const;
212 /// claim shared ownership of this entry (for use in a given context)
213 /// matching lock() and unlock() contexts eases leak triage but is optional
214 void lock(const char *context
);
216 /// disclaim shared ownership; may remove entry from store and delete it
217 /// returns remaning lock level (zero for unlocked and possibly gone entry)
218 int unlock(const char *context
);
220 /// returns a local concurrent use counter, for debugging
221 int locks() const { return static_cast<int>(lock_count
); }
223 /// update last reference timestamp and related Store metadata
226 virtual void release();
229 /// call back producer when more buffer space is available
230 void deferProducer(const AsyncCall::Pointer
&producer
);
231 /// calls back producer registered with deferProducer
236 static MemAllocator
*pool
;
238 unsigned short lock_count
; /* Assume < 65536! */
241 /// producer callback registered with deferProducer
242 AsyncCall::Pointer deferredProducer
;
245 bool validLength() const;
246 bool hasOneOfEtags(const String
&reqETags
, const bool allowWeakMatch
) const;
249 std::ostream
&operator <<(std::ostream
&os
, const StoreEntry
&e
);
251 /// \ingroup StoreAPI
252 class NullStoreEntry
:public StoreEntry
256 static NullStoreEntry
*getInstance();
261 const char *getMD5Text() const;
262 HttpReply
const *getReply() const { return NULL
; }
263 void write (StoreIOBuffer
) {}
265 bool isEmpty () const {return true;}
267 virtual size_t bytesWanted(Range
<size_t> const aRange
, bool ignoreDelayPool
= false) const { return aRange
.end
; }
269 void operator delete(void *address
);
273 store_client_t
storeClientType() const {return STORE_MEM_CLIENT
;}
275 char const *getSerialisedMetaData();
276 bool mayStartSwapout() {return false;}
278 void trimMemory(const bool preserveSwappable
) {}
280 static NullStoreEntry _instance
;
283 /// \ingroup StoreAPI
284 typedef void (*STOREGETCLIENT
) (StoreEntry
*, void *cbdata
);
288 * Abstract base class that will replace the whole store and swapdir interface.
290 class Store
: public RefCountable
294 /** The root store */
295 static Store
&Root() {
296 if (CurrentRoot
== NULL
)
297 fatal("No Store Root has been set");
300 static void Root(Store
*);
301 static void Root(RefCount
<Store
>);
302 static void Stats(StoreEntry
* output
);
303 static void Maintain(void *unused
);
307 /** Handle pending callbacks - called by the event loop. */
308 virtual int callback() = 0;
310 /** create the resources needed for this store to operate */
311 virtual void create();
314 * Notify this store that its disk is full.
315 \todo XXX move into a protected api call between store files and their stores, rather than a top level api call
317 virtual void diskFull();
319 /** Retrieve a store entry from the store */
320 virtual StoreEntry
* get(const cache_key
*) = 0;
322 /** \todo imeplement the async version */
323 virtual void get(String
const key
, STOREGETCLIENT callback
, void *cbdata
) = 0;
325 /* prepare the store for use. The store need not be usable immediately,
326 * it should respond to readable() and writable() with true as soon
327 * as it can provide those services
329 virtual void init() = 0;
332 * The maximum size the store will support in normal use. Inaccuracy is permitted,
333 * but may throw estimates for memory etc out of whack.
335 virtual uint64_t maxSize() const = 0;
337 /** The minimum size the store will shrink to via normal housekeeping */
338 virtual uint64_t minSize() const = 0;
340 /** current store size */
341 virtual uint64_t currentSize() const = 0;
343 /** the total number of objects stored */
344 virtual uint64_t currentCount() const = 0;
346 /** the maximum object size that can be stored, -1 if unlimited */
347 virtual int64_t maxObjectSize() const = 0;
349 /// collect cache storage-related statistics
350 virtual void getStats(StoreInfoStats
&stats
) const = 0;
353 * Output stats to the provided store entry.
354 \todo make these calls asynchronous
356 virtual void stat(StoreEntry
&) const = 0;
358 /** Sync the store prior to shutdown */
361 /** remove a Store entry from the store */
362 virtual void unlink (StoreEntry
&);
364 /* search in the store */
365 virtual StoreSearch
*search(String
const url
, HttpRequest
*) = 0;
367 /* pulled up from SwapDir for migration.... probably do not belong here */
368 virtual void reference(StoreEntry
&) = 0; /* Reference this object */
370 /// Undo reference(), returning false iff idle e should be destroyed
371 virtual bool dereference(StoreEntry
&e
, bool wantsLocalMemory
) = 0;
373 virtual void maintain() = 0; /* perform regular maintenance should be private and self registered ... */
375 // XXX: This method belongs to Store::Root/StoreController, but it is here
376 // to avoid casting Root() to StoreController until Root() API is fixed.
377 /// informs stores that this entry will be eventually unlinked
378 virtual void markForUnlink(StoreEntry
&e
) {}
380 // XXX: This method belongs to Store::Root/StoreController, but it is here
381 // because test cases use non-StoreController derivatives as Root
382 /// called when the entry is no longer needed by any transaction
383 virtual void handleIdleEntry(StoreEntry
&e
) {}
385 // XXX: This method belongs to Store::Root/StoreController, but it is here
386 // because test cases use non-StoreController derivatives as Root
387 /// called to get rid of no longer needed entry data in RAM, if any
388 virtual void memoryOut(StoreEntry
&e
, const bool preserveSwappable
) {}
390 // XXX: This method belongs to Store::Root/StoreController, but it is here
391 // to avoid casting Root() to StoreController until Root() API is fixed.
392 /// makes the entry available for collapsing future requests
393 virtual void allowCollapsing(StoreEntry
*e
, const RequestFlags
&reqFlags
, const HttpRequestMethod
&reqMethod
) {}
395 // XXX: This method belongs to Store::Root/StoreController, but it is here
396 // to avoid casting Root() to StoreController until Root() API is fixed.
397 /// marks the entry completed for collapsed requests
398 virtual void transientsCompleteWriting(StoreEntry
&e
) {}
400 // XXX: This method belongs to Store::Root/StoreController, but it is here
401 // to avoid casting Root() to StoreController until Root() API is fixed.
402 /// Update local intransit entry after changes made by appending worker.
403 virtual void syncCollapsed(const sfileno xitIndex
) {}
405 // XXX: This method belongs to Store::Root/StoreController, but it is here
406 // to avoid casting Root() to StoreController until Root() API is fixed.
407 /// calls Root().transients->abandon() if transients are tracked
408 virtual void transientsAbandon(StoreEntry
&e
) {}
410 // XXX: This method belongs to Store::Root/StoreController, but it is here
411 // to avoid casting Root() to StoreController until Root() API is fixed.
412 /// number of the transient entry readers some time ago
413 virtual int transientReaders(const StoreEntry
&e
) const { return 0; }
415 // XXX: This method belongs to Store::Root/StoreController, but it is here
416 // to avoid casting Root() to StoreController until Root() API is fixed.
417 /// disassociates the entry from the intransit table
418 virtual void transientsDisconnect(MemObject
&mem_obj
) {}
420 // XXX: This method belongs to Store::Root/StoreController, but it is here
421 // to avoid casting Root() to StoreController until Root() API is fixed.
422 /// removes the entry from the memory cache
423 virtual void memoryUnlink(StoreEntry
&e
) {}
425 // XXX: This method belongs to Store::Root/StoreController, but it is here
426 // to avoid casting Root() to StoreController until Root() API is fixed.
427 /// disassociates the entry from the memory cache, preserving cached data
428 virtual void memoryDisconnect(StoreEntry
&e
) {}
430 /// If the entry is not found, return false. Otherwise, return true after
431 /// tying the entry to this cache and setting inSync to updateCollapsed().
432 virtual bool anchorCollapsed(StoreEntry
&collapsed
, bool &inSync
) { return false; }
434 /// update a local collapsed entry with fresh info from this cache (if any)
435 virtual bool updateCollapsed(StoreEntry
&collapsed
) { return false; }
438 static RefCount
<Store
> CurrentRoot
;
441 /// \ingroup StoreAPI
442 typedef RefCount
<Store
> StorePointer
;
444 /// \ingroup StoreAPI
445 size_t storeEntryInUse();
447 /// \ingroup StoreAPI
448 const char *storeEntryFlags(const StoreEntry
*);
450 /// \ingroup StoreAPI
451 void storeEntryReplaceObject(StoreEntry
*, HttpReply
*);
453 /// \ingroup StoreAPI
454 StoreEntry
*storeGetPublic(const char *uri
, const HttpRequestMethod
& method
);
456 /// \ingroup StoreAPI
457 StoreEntry
*storeGetPublicByRequest(HttpRequest
* request
);
459 /// \ingroup StoreAPI
460 StoreEntry
*storeGetPublicByRequestMethod(HttpRequest
* request
, const HttpRequestMethod
& method
);
462 /// \ingroup StoreAPI
463 /// Like storeCreatePureEntry(), but also locks the entry and sets entry key.
464 StoreEntry
*storeCreateEntry(const char *, const char *, const RequestFlags
&, const HttpRequestMethod
&);
466 /// \ingroup StoreAPI
467 /// Creates a new StoreEntry with mem_obj and sets initial flags/states.
468 StoreEntry
*storeCreatePureEntry(const char *storeId
, const char *logUrl
, const RequestFlags
&, const HttpRequestMethod
&);
470 /// \ingroup StoreAPI
471 void storeInit(void);
473 /// \ingroup StoreAPI
474 void storeConfigure(void);
476 /// \ingroup StoreAPI
477 void storeFreeMemory(void);
479 /// \ingroup StoreAPI
480 int expiresMoreThan(time_t, time_t);
482 /// \ingroup StoreAPI
483 void storeAppendPrintf(StoreEntry
*, const char *,...) PRINTF_FORMAT_ARG2
;
485 /// \ingroup StoreAPI
486 void storeAppendVPrintf(StoreEntry
*, const char *, va_list ap
);
488 /// \ingroup StoreAPI
489 int storeTooManyDiskFilesOpen(void);
492 /// \ingroup StoreAPI
493 void storeHeapPositionUpdate(StoreEntry
*, SwapDir
*);
495 /// \ingroup StoreAPI
496 void storeSwapFileNumberSet(StoreEntry
* e
, sfileno filn
);
498 /// \ingroup StoreAPI
499 void storeFsInit(void);
501 /// \ingroup StoreAPI
502 void storeFsDone(void);
504 /// \ingroup StoreAPI
505 void storeReplAdd(const char *, REMOVALPOLICYCREATE
*);
507 /// \ingroup StoreAPI
508 extern FREE destroyStoreEntry
;
512 \todo should be a subclass of Packer perhaps ?
514 void packerToStoreInit(Packer
* p
, StoreEntry
* e
);
516 /// \ingroup StoreAPI
517 void storeGetMemSpace(int size
);
519 #endif /* SQUID_STORE_H */