src/Store.h

   1 /*
   2  * $Id$
   3  *
   4  *
   5  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   6  * ----------------------------------------------------------
   7  *
   8  *  Squid is the result of efforts by numerous individuals from
   9  *  the Internet community; see the CONTRIBUTORS file for full
  10  *  details.   Many organizations have provided support for Squid's
  11  *  development; see the SPONSORS file for full details.  Squid is
  12  *  Copyrighted (C) 2001 by the Regents of the University of
  13  *  California; see the COPYRIGHT file for full details.  Squid
  14  *  incorporates software developed and/or copyrighted by other
  15  *  sources; see the CREDITS file for full details.
  16  *
  17  *  This program is free software; you can redistribute it and/or modify
  18  *  it under the terms of the GNU General Public License as published by
  19  *  the Free Software Foundation; either version 2 of the License, or
  20  *  (at your option) any later version.
  21  *
  22  *  This program is distributed in the hope that it will be useful,
  23  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  *  GNU General Public License for more details.
  26  *
  27  *  You should have received a copy of the GNU General Public License
  28  *  along with this program; if not, write to the Free Software
  29  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  30  *
  31  */
  32 #ifndef SQUID_STORE_H
  33 #define SQUID_STORE_H
  34
  35 /**
  36  \defgroup StoreAPI  Store API
  37  \ingroup FileSystems
  38  */
  39
  40 #include "squid.h"
  41 #include "StoreIOBuffer.h"
  42 #include "Range.h"
  43 #include "RefCount.h"
  44 #include "CommRead.h"
  45 #include "Packer.h"
  46 #include "RemovalPolicy.h"
  47
  48 #if USE_SQUID_ESI
  49 #include "esi/Element.h"
  50 #endif
  51
  52 #if HAVE_OSTREAM
  53 #include <ostream>
  54 #endif
  55
  56
  57 class AsyncCall;
  58 class StoreClient;
  59 class MemObject;
  60 class Store;
  61 class StoreSearch;
  62
  63 typedef unsigned int ping_status_t;
  64
  65 /**
  66  \ingroup StoreAPI
  67  */
  68 class StoreEntry : public hash_link
  69 {
  70
  71 public:
  72     static DeferredRead::DeferrableRead DeferReader;
  73     bool checkDeferRead(int fd) const;
  74
  75     virtual const char *getMD5Text() const;
  76     StoreEntry();
  77     StoreEntry(const char *url, const char *log_url);
  78     virtual ~StoreEntry() {}
  79
  80     virtual HttpReply const *getReply() const;
  81     virtual void write (StoreIOBuffer);
  82     virtual _SQUID_INLINE_ bool isEmpty() const;
  83     virtual bool isAccepting() const;
  84     virtual size_t bytesWanted(Range<size_t> const) const;
  85     virtual void complete();
  86     virtual store_client_t storeClientType() const;
  87     virtual char const *getSerialisedMetaData();
  88     virtual void replaceHttpReply(HttpReply *);
  89     virtual bool swapoutPossible();
  90     virtual void trimMemory();
  91     void abort();
  92     void unlink();
  93     void makePublic();
  94     void makePrivate();
  95     void setPublicKey();
  96     void setPrivateKey();
  97     void expireNow();
  98     void releaseRequest();
  99     void negativeCache();
 100     void cacheNegatively();             /** \todo argh, why both? */
 101     void invokeHandlers();
 102     void purgeMem();
 103     void swapOut();
 104     bool swapOutAble() const;
 105     void swapOutFileClose();
 106     const char *url() const;
 107     int checkCachable();
 108     int checkNegativeHit() const;
 109     int locked() const;
 110     int validToSend() const;
 111     int keepInMemory() const;
 112     void createMemObject(const char *, const char *);
 113     void dump(int debug_lvl) const;
 114     void hashDelete();
 115     void hashInsert(const cache_key *);
 116     void registerAbort(STABH * cb, void *);
 117     void reset();
 118     void setMemStatus(mem_status_t);
 119     void timestampsSet();
 120     void unregisterAbort();
 121     void destroyMemObject();
 122     int checkTooSmall();
 123
 124     void delayAwareRead(int fd, char *buf, int len, AsyncCall::Pointer callback);
 125
 126     void setNoDelay (bool const);
 127     bool modifiedSince(HttpRequest * request) const;
 128
 129     /** What store does this entry belong too ? */
 130     virtual RefCount<Store> store() const;
 131
 132     MemObject *mem_obj;
 133     RemovalPolicyNode repl;
 134     /* START OF ON-DISK STORE_META_STD TLV field */
 135     time_t timestamp;
 136     time_t lastref;
 137     time_t expires;
 138     time_t lastmod;
 139     uint64_t swap_file_sz;
 140     u_short refcount;
 141     u_short flags;
 142     /* END OF ON-DISK STORE_META_STD */
 143
 144 sfileno swap_filen:
 145     25;
 146
 147 sdirno swap_dirn:
 148     7;
 149     u_short lock_count;         /* Assume < 65536! */
 150
 151 mem_status_t mem_status:
 152     3;
 153
 154 ping_status_t ping_status:
 155     3;
 156
 157 store_status_t store_status:
 158     3;
 159
 160 swap_status_t swap_status:
 161     3;
 162
 163 public:
 164     static size_t inUseCount();
 165     static void getPublicByRequestMethod(StoreClient * aClient, HttpRequest * request, const HttpRequestMethod& method);
 166     static void getPublicByRequest(StoreClient * aClient, HttpRequest * request);
 167     static void getPublic(StoreClient * aClient, const char *uri, const HttpRequestMethod& method);
 168
 169     virtual bool isNull() {
 170         return false;
 171     };
 172
 173     void *operator new(size_t byteCount);
 174     void operator delete(void *address);
 175     void setReleaseFlag();
 176 #if USE_SQUID_ESI
 177
 178     ESIElement::Pointer cachedESITree;
 179 #endif
 180     /** append bytes to the buffer */
 181     virtual void append(char const *, int len);
 182     /** disable sending content to the clients */
 183     virtual void buffer();
 184     /** flush any buffered content */
 185     virtual void flush();
 186     /** reduce the memory lock count on the entry */
 187     virtual int unlock();
 188     /** increate the memory lock count on the entry */
 189     virtual int64_t objectLen() const;
 190     virtual int64_t contentLen() const;
 191
 192     virtual void lock();
 193     virtual void release();
 194
 195 private:
 196     static MemAllocator *pool;
 197
 198     bool validLength() const;
 199 };
 200
 201 /// \ingroup StoreAPI
 202 class NullStoreEntry:public StoreEntry
 203 {
 204
 205 public:
 206     static NullStoreEntry *getInstance();
 207     bool isNull() {
 208         return true;
 209     }
 210
 211     const char *getMD5Text() const;
 212     _SQUID_INLINE_ HttpReply const *getReply() const;
 213     void write (StoreIOBuffer) {}
 214
 215     bool isEmpty () const {return true;}
 216
 217     virtual size_t bytesWanted(Range<size_t> const aRange) const { assert (aRange.size());return aRange.end - 1;}
 218
 219     void operator delete(void *address);
 220     void complete() {}
 221
 222 private:
 223     store_client_t storeClientType() const {return STORE_MEM_CLIENT;}
 224
 225     char const *getSerialisedMetaData();
 226     bool swapoutPossible() {return false;}
 227
 228     void trimMemory() {}
 229
 230
 231     static NullStoreEntry _instance;
 232 };
 233
 234 /// \ingroup StoreAPI
 235 typedef void (*STOREGETCLIENT) (StoreEntry *, void *cbdata);
 236
 237
 238 /**
 239  \ingroup StoreAPI
 240  * Abstract base class that will replace the whole store and swapdir interface.
 241  */
 242 class Store : public RefCountable
 243 {
 244
 245 public:
 246     /** The root store */
 247     static _SQUID_INLINE_ Store &Root();
 248     static void Root(Store *);
 249     static void Root(RefCount<Store>);
 250     static void Stats(StoreEntry * output);
 251     static void Maintain(void *unused);
 252
 253     virtual ~Store() {}
 254
 255     /** Handle pending callbacks - called by the event loop. */
 256     virtual int callback() = 0;
 257
 258     /** create the resources needed for this store to operate */
 259     virtual void create();
 260
 261     /**
 262      * Notify this store that its disk is full.
 263      \todo XXX move into a protected api call between store files and their stores, rather than a top level api call
 264      */
 265     virtual void diskFull();
 266
 267     /** Retrieve a store entry from the store */
 268     virtual StoreEntry * get(const cache_key *) = 0;
 269
 270     /** \todo imeplement the async version */
 271     virtual void get(String const key , STOREGETCLIENT callback, void *cbdata) = 0;
 272
 273     /* prepare the store for use. The store need not be usable immediately,
 274      * it should respond to readable() and writable() with true as soon
 275      * as it can provide those services
 276      */
 277     virtual void init() = 0;
 278
 279     /**
 280      * The maximum size the store will support in normal use. Inaccuracy is permitted,
 281      * but may throw estimates for memory etc out of whack.
 282      */
 283     virtual size_t maxSize() const = 0;
 284
 285     /** The minimum size the store will shrink to via normal housekeeping */
 286     virtual size_t minSize() const = 0;
 287
 288     /**
 289      * Output stats to the provided store entry.
 290      \todo make these calls asynchronous
 291      */
 292     virtual void stat(StoreEntry &) const = 0;
 293
 294     /** Sync the store prior to shutdown */
 295     virtual void sync();
 296
 297     /** remove a Store entry from the store */
 298     virtual void unlink (StoreEntry &);
 299
 300     /* search in the store */
 301     virtual StoreSearch *search(String const url, HttpRequest *) = 0;
 302
 303     /* pulled up from SwapDir for migration.... probably do not belong here */
 304     virtual void reference(StoreEntry &) = 0;   /* Reference this object */
 305
 306     virtual void dereference(StoreEntry &) = 0; /* Unreference this object */
 307
 308     virtual void maintain() = 0; /* perform regular maintenance should be private and self registered ... */
 309
 310     /* These should really be private */
 311     virtual void updateSize(int64_t size, int sign) = 0;
 312
 313 private:
 314     static RefCount<Store> CurrentRoot;
 315 };
 316
 317 /// \ingroup StoreAPI
 318 typedef RefCount<Store> StorePointer;
 319
 320 /// \ingroup StoreAPI
 321 SQUIDCEXTERN size_t storeEntryInUse();
 322
 323 /// \ingroup StoreAPI
 324 SQUIDCEXTERN const char *storeEntryFlags(const StoreEntry *);
 325
 326 /// \ingroup StoreAPI
 327 extern void storeEntryReplaceObject(StoreEntry *, HttpReply *);
 328
 329 /// \ingroup StoreAPI
 330 SQUIDCEXTERN StoreEntry *storeGetPublic(const char *uri, const HttpRequestMethod& method);
 331
 332 /// \ingroup StoreAPI
 333 SQUIDCEXTERN StoreEntry *storeGetPublicByRequest(HttpRequest * request);
 334
 335 /// \ingroup StoreAPI
 336 SQUIDCEXTERN StoreEntry *storeGetPublicByRequestMethod(HttpRequest * request, const HttpRequestMethod& method);
 337
 338 /// \ingroup StoreAPI
 339 SQUIDCEXTERN StoreEntry *storeCreateEntry(const char *, const char *, request_flags, const HttpRequestMethod&);
 340
 341 /// \ingroup StoreAPI
 342 SQUIDCEXTERN void storeInit(void);
 343
 344 /// \ingroup StoreAPI
 345 SQUIDCEXTERN void storeConfigure(void);
 346
 347 /// \ingroup StoreAPI
 348 SQUIDCEXTERN void storeFreeMemory(void);
 349
 350 /// \ingroup StoreAPI
 351 SQUIDCEXTERN int expiresMoreThan(time_t, time_t);
 352
 353 /// \ingroup StoreAPI
 354 SQUIDCEXTERN void storeAppendPrintf(StoreEntry *, const char *,...) PRINTF_FORMAT_ARG2;
 355
 356 /// \ingroup StoreAPI
 357 SQUIDCEXTERN void storeAppendVPrintf(StoreEntry *, const char *, va_list ap);
 358
 359 /// \ingroup StoreAPI
 360 SQUIDCEXTERN int storeTooManyDiskFilesOpen(void);
 361
 362 class SwapDir;
 363 /// \ingroup StoreAPI
 364 SQUIDCEXTERN void storeHeapPositionUpdate(StoreEntry *, SwapDir *);
 365
 366 /// \ingroup StoreAPI
 367 SQUIDCEXTERN void storeSwapFileNumberSet(StoreEntry * e, sfileno filn);
 368
 369 /// \ingroup StoreAPI
 370 SQUIDCEXTERN void storeFsInit(void);
 371
 372 /// \ingroup StoreAPI
 373 SQUIDCEXTERN void storeFsDone(void);
 374
 375 /// \ingroup StoreAPI
 376 SQUIDCEXTERN void storeReplAdd(const char *, REMOVALPOLICYCREATE *);
 377
 378 /// \ingroup StoreAPI
 379 extern FREE destroyStoreEntry;
 380
 381 /**
 382  \ingroup StoreAPI
 383  \todo should be a subclass of Packer perhaps ?
 384  */
 385 SQUIDCEXTERN void packerToStoreInit(Packer * p, StoreEntry * e);
 386
 387 #ifdef _USE_INLINE_
 388 #include "Store.cci"
 389 #endif
 390
 391 #endif /* SQUID_STORE_H */