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 "HttpReply.h"
43 #include "HttpRequestMethod.h"
45 #include "RemovalPolicy.h"
46 #include "StoreIOBuffer.h"
47 #include "StoreStats.h"
50 #include "esi/Element.h"
66 extern StoreIoStats store_io_stats
;
68 /// maximum number of entries per cache_dir
69 enum { SwapFilenMax
= 0xFFFFFF }; // keep in sync with StoreEntry::swap_filen
74 class StoreEntry
: public hash_link
78 static DeferredRead::DeferrableRead DeferReader
;
79 bool checkDeferRead(int fd
) const;
81 virtual const char *getMD5Text() const;
83 virtual ~StoreEntry();
85 virtual HttpReply
const *getReply() const;
86 virtual void write (StoreIOBuffer
);
87 virtual _SQUID_INLINE_
bool isEmpty() const;
88 virtual bool isAccepting() const;
89 virtual size_t bytesWanted(Range
<size_t> const aRange
, bool ignoreDelayPool
= false) const;
90 virtual void complete();
91 virtual store_client_t
storeClientType() const;
92 virtual char const *getSerialisedMetaData();
93 void replaceHttpReply(HttpReply
*, bool andStartWriting
= true);
94 void startWriting(); ///< pack and write reply headers and, maybe, body
95 /// whether we may start writing to disk (now or in the future)
96 virtual bool mayStartSwapOut();
97 virtual void trimMemory(const bool preserveSwappable
);
103 void setPrivateKey();
105 void releaseRequest();
106 void negativeCache();
107 void cacheNegatively(); /** \todo argh, why both? */
108 void invokeHandlers();
110 void cacheInMemory(); ///< start or continue storing in memory cache
112 /// whether we are in the process of writing this entry to disk
113 bool swappingOut() const { return swap_status
== SWAPOUT_WRITING
; }
114 void swapOutFileClose(int how
);
115 const char *url() const;
117 int checkNegativeHit() const;
119 int validToSend() const;
120 bool memoryCachable() const; ///< may be cached in memory
122 /// if needed, initialize mem_obj member w/o URI-related information
123 MemObject
*makeMemObject();
125 /// initialize mem_obj member (if needed) and supply URI-related info
126 void createMemObject(const char *storeId
, const char *logUri
, const HttpRequestMethod
&aMethod
);
128 void dump(int debug_lvl
) const;
130 void hashInsert(const cache_key
*);
131 void registerAbort(STABH
* cb
, void *);
133 void setMemStatus(mem_status_t
);
134 void timestampsSet();
135 void unregisterAbort();
136 void destroyMemObject();
139 void delayAwareRead(const Comm::ConnectionPointer
&conn
, char *buf
, int len
, AsyncCall::Pointer callback
);
141 void setNoDelay (bool const);
142 bool modifiedSince(HttpRequest
* request
) const;
143 /// has ETag matching at least one of the If-Match etags
144 bool hasIfMatchEtag(const HttpRequest
&request
) const;
145 /// has ETag matching at least one of the If-None-Match etags
146 bool hasIfNoneMatchEtag(const HttpRequest
&request
) const;
147 /// whether this entry has an ETag; if yes, puts ETag value into parameter
148 bool hasEtag(ETag
&etag
) const;
150 /** What store does this entry belong too ? */
151 virtual RefCount
<SwapDir
> store() const;
154 RemovalPolicyNode repl
;
155 /* START OF ON-DISK STORE_META_STD TLV field */
160 uint64_t swap_file_sz
;
163 /* END OF ON-DISK STORE_META_STD */
165 /// unique ID inside a cache_dir for swapped out entries; -1 for others
166 sfileno swap_filen
:25; // keep in sync with SwapFilenMax
170 mem_status_t mem_status
:3;
172 ping_status_t ping_status
:3;
174 store_status_t store_status
:3;
176 swap_status_t swap_status
:3;
179 static size_t inUseCount();
180 static void getPublicByRequestMethod(StoreClient
* aClient
, HttpRequest
* request
, const HttpRequestMethod
& method
);
181 static void getPublicByRequest(StoreClient
* aClient
, HttpRequest
* request
);
182 static void getPublic(StoreClient
* aClient
, const char *uri
, const HttpRequestMethod
& method
);
184 virtual bool isNull() {
188 void *operator new(size_t byteCount
);
189 void operator delete(void *address
);
190 void setReleaseFlag();
193 ESIElement::Pointer cachedESITree
;
195 /** append bytes to the buffer */
196 virtual void append(char const *, int len
);
197 /** disable sending content to the clients */
198 virtual void buffer();
199 /** flush any buffered content */
200 virtual void flush();
201 virtual int64_t objectLen() const;
202 virtual int64_t contentLen() const;
204 /// claim shared ownership of this entry (for use in a given context)
205 /// matching lock() and unlock() contexts eases leak triage but is optional
206 void lock(const char *context
);
208 /// disclaim shared ownership; may remove entry from store and delete it
209 /// returns remaning lock level (zero for unlocked and possibly gone entry)
210 int unlock(const char *context
);
212 /// returns a local concurrent use counter, for debugging
213 int locks() const { return static_cast<int>(lock_count
); }
215 /// update last reference timestamp and related Store metadata
218 virtual void release();
221 /// call back producer when more buffer space is available
222 void deferProducer(const AsyncCall::Pointer
&producer
);
223 /// calls back producer registered with deferProducer
228 static MemAllocator
*pool
;
230 unsigned short lock_count
; /* Assume < 65536! */
233 /// producer callback registered with deferProducer
234 AsyncCall::Pointer deferredProducer
;
237 bool validLength() const;
238 bool hasOneOfEtags(const String
&reqETags
, const bool allowWeakMatch
) const;
241 std::ostream
&operator <<(std::ostream
&os
, const StoreEntry
&e
);
243 /// \ingroup StoreAPI
244 class NullStoreEntry
:public StoreEntry
248 static NullStoreEntry
*getInstance();
253 const char *getMD5Text() const;
254 _SQUID_INLINE_ HttpReply
const *getReply() const;
255 void write (StoreIOBuffer
) {}
257 bool isEmpty () const {return true;}
259 virtual size_t bytesWanted(Range
<size_t> const aRange
, bool ignoreDelayPool
= false) const { return aRange
.end
; }
261 void operator delete(void *address
);
265 store_client_t
storeClientType() const {return STORE_MEM_CLIENT
;}
267 char const *getSerialisedMetaData();
268 bool mayStartSwapout() {return false;}
270 void trimMemory(const bool preserveSwappable
) {}
272 static NullStoreEntry _instance
;
275 /// \ingroup StoreAPI
276 typedef void (*STOREGETCLIENT
) (StoreEntry
*, void *cbdata
);
280 * Abstract base class that will replace the whole store and swapdir interface.
282 class Store
: public RefCountable
286 /** The root store */
287 static _SQUID_INLINE_ Store
&Root();
288 static void Root(Store
*);
289 static void Root(RefCount
<Store
>);
290 static void Stats(StoreEntry
* output
);
291 static void Maintain(void *unused
);
295 /** Handle pending callbacks - called by the event loop. */
296 virtual int callback() = 0;
298 /** create the resources needed for this store to operate */
299 virtual void create();
302 * Notify this store that its disk is full.
303 \todo XXX move into a protected api call between store files and their stores, rather than a top level api call
305 virtual void diskFull();
307 /** Retrieve a store entry from the store */
308 virtual StoreEntry
* get(const cache_key
*) = 0;
310 /** \todo imeplement the async version */
311 virtual void get(String
const key
, STOREGETCLIENT callback
, void *cbdata
) = 0;
313 /* prepare the store for use. The store need not be usable immediately,
314 * it should respond to readable() and writable() with true as soon
315 * as it can provide those services
317 virtual void init() = 0;
320 * The maximum size the store will support in normal use. Inaccuracy is permitted,
321 * but may throw estimates for memory etc out of whack.
323 virtual uint64_t maxSize() const = 0;
325 /** The minimum size the store will shrink to via normal housekeeping */
326 virtual uint64_t minSize() const = 0;
328 /** current store size */
329 virtual uint64_t currentSize() const = 0;
331 /** the total number of objects stored */
332 virtual uint64_t currentCount() const = 0;
334 /** the maximum object size that can be stored, -1 if unlimited */
335 virtual int64_t maxObjectSize() const = 0;
337 /// collect cache storage-related statistics
338 virtual void getStats(StoreInfoStats
&stats
) const = 0;
341 * Output stats to the provided store entry.
342 \todo make these calls asynchronous
344 virtual void stat(StoreEntry
&) const = 0;
346 /** Sync the store prior to shutdown */
349 /** remove a Store entry from the store */
350 virtual void unlink (StoreEntry
&);
352 /* search in the store */
353 virtual StoreSearch
*search(String
const url
, HttpRequest
*) = 0;
355 /* pulled up from SwapDir for migration.... probably do not belong here */
356 virtual void reference(StoreEntry
&) = 0; /* Reference this object */
358 /// Undo reference(), returning false iff idle e should be destroyed
359 virtual bool dereference(StoreEntry
&e
, bool wantsLocalMemory
) = 0;
361 virtual void maintain() = 0; /* perform regular maintenance should be private and self registered ... */
363 // XXX: This method belongs to Store::Root/StoreController, but it is here
364 // to avoid casting Root() to StoreController until Root() API is fixed.
365 /// informs stores that this entry will be eventually unlinked
366 virtual void markForUnlink(StoreEntry
&e
) {}
368 // XXX: This method belongs to Store::Root/StoreController, but it is here
369 // because test cases use non-StoreController derivatives as Root
370 /// called when the entry is no longer needed by any transaction
371 virtual void handleIdleEntry(StoreEntry
&e
) {}
373 // XXX: This method belongs to Store::Root/StoreController, but it is here
374 // because test cases use non-StoreController derivatives as Root
375 /// called to get rid of no longer needed entry data in RAM, if any
376 virtual void memoryOut(StoreEntry
&e
, const bool preserveSwappable
) {}
378 // XXX: This method belongs to Store::Root/StoreController, but it is here
379 // to avoid casting Root() to StoreController until Root() API is fixed.
380 /// makes the entry available for collapsing future requests
381 virtual void allowCollapsing(StoreEntry
*e
, const RequestFlags
&reqFlags
, const HttpRequestMethod
&reqMethod
) {}
383 // XXX: This method belongs to Store::Root/StoreController, but it is here
384 // to avoid casting Root() to StoreController until Root() API is fixed.
385 /// marks the entry completed for collapsed requests
386 virtual void transientsCompleteWriting(StoreEntry
&e
) {}
388 // XXX: This method belongs to Store::Root/StoreController, but it is here
389 // to avoid casting Root() to StoreController until Root() API is fixed.
390 /// Update local intransit entry after changes made by appending worker.
391 virtual void syncCollapsed(const sfileno xitIndex
) {}
393 // XXX: This method belongs to Store::Root/StoreController, but it is here
394 // to avoid casting Root() to StoreController until Root() API is fixed.
395 /// calls Root().transients->abandon() if transients are tracked
396 virtual void transientsAbandon(StoreEntry
&e
) {}
398 // XXX: This method belongs to Store::Root/StoreController, but it is here
399 // to avoid casting Root() to StoreController until Root() API is fixed.
400 /// number of the transient entry readers some time ago
401 virtual int transientReaders(const StoreEntry
&e
) const { return 0; }
403 // XXX: This method belongs to Store::Root/StoreController, but it is here
404 // to avoid casting Root() to StoreController until Root() API is fixed.
405 /// disassociates the entry from the intransit table
406 virtual void transientsDisconnect(MemObject
&mem_obj
) {}
408 // XXX: This method belongs to Store::Root/StoreController, but it is here
409 // to avoid casting Root() to StoreController until Root() API is fixed.
410 /// removes the entry from the memory cache
411 virtual void memoryUnlink(StoreEntry
&e
) {}
413 // XXX: This method belongs to Store::Root/StoreController, but it is here
414 // to avoid casting Root() to StoreController until Root() API is fixed.
415 /// disassociates the entry from the memory cache, preserving cached data
416 virtual void memoryDisconnect(StoreEntry
&e
) {}
418 /// If the entry is not found, return false. Otherwise, return true after
419 /// tying the entry to this cache and setting inSync to updateCollapsed().
420 virtual bool anchorCollapsed(StoreEntry
&collapsed
, bool &inSync
) { return false; }
422 /// update a local collapsed entry with fresh info from this cache (if any)
423 virtual bool updateCollapsed(StoreEntry
&collapsed
) { return false; }
426 static RefCount
<Store
> CurrentRoot
;
429 /// \ingroup StoreAPI
430 typedef RefCount
<Store
> StorePointer
;
432 /// \ingroup StoreAPI
433 size_t storeEntryInUse();
435 /// \ingroup StoreAPI
436 const char *storeEntryFlags(const StoreEntry
*);
438 /// \ingroup StoreAPI
439 void storeEntryReplaceObject(StoreEntry
*, HttpReply
*);
441 /// \ingroup StoreAPI
442 StoreEntry
*storeGetPublic(const char *uri
, const HttpRequestMethod
& method
);
444 /// \ingroup StoreAPI
445 StoreEntry
*storeGetPublicByRequest(HttpRequest
* request
);
447 /// \ingroup StoreAPI
448 StoreEntry
*storeGetPublicByRequestMethod(HttpRequest
* request
, const HttpRequestMethod
& method
);
450 /// \ingroup StoreAPI
451 /// Like storeCreatePureEntry(), but also locks the entry and sets entry key.
452 StoreEntry
*storeCreateEntry(const char *, const char *, const RequestFlags
&, const HttpRequestMethod
&);
454 /// \ingroup StoreAPI
455 /// Creates a new StoreEntry with mem_obj and sets initial flags/states.
456 StoreEntry
*storeCreatePureEntry(const char *storeId
, const char *logUrl
, const RequestFlags
&, const HttpRequestMethod
&);
458 /// \ingroup StoreAPI
459 void storeInit(void);
461 /// \ingroup StoreAPI
462 void storeConfigure(void);
464 /// \ingroup StoreAPI
465 void storeFreeMemory(void);
467 /// \ingroup StoreAPI
468 int expiresMoreThan(time_t, time_t);
470 /// \ingroup StoreAPI
471 void storeAppendPrintf(StoreEntry
*, const char *,...) PRINTF_FORMAT_ARG2
;
473 /// \ingroup StoreAPI
474 void storeAppendVPrintf(StoreEntry
*, const char *, va_list ap
);
476 /// \ingroup StoreAPI
477 int storeTooManyDiskFilesOpen(void);
480 /// \ingroup StoreAPI
481 void storeHeapPositionUpdate(StoreEntry
*, SwapDir
*);
483 /// \ingroup StoreAPI
484 void storeSwapFileNumberSet(StoreEntry
* e
, sfileno filn
);
486 /// \ingroup StoreAPI
487 void storeFsInit(void);
489 /// \ingroup StoreAPI
490 void storeFsDone(void);
492 /// \ingroup StoreAPI
493 void storeReplAdd(const char *, REMOVALPOLICYCREATE
*);
495 /// \ingroup StoreAPI
496 extern FREE destroyStoreEntry
;
500 \todo should be a subclass of Packer perhaps ?
502 void packerToStoreInit(Packer
* p
, StoreEntry
* e
);
504 /// \ingroup StoreAPI
505 void storeGetMemSpace(int size
);
511 #endif /* SQUID_STORE_H */