src/Store.h

   1 /*
   2  * $Id: Store.h,v 1.44 2008/02/26 21:49:34 amosjeffries Exp $
   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
  42 /// \todo protect the 'ostream' file includes via configure file tests as per squid conventions.
  43 #include <ostream>
  44
  45 #include "StoreIOBuffer.h"
  46 #include "Range.h"
  47 #include "RefCount.h"
  48 #include "CommRead.h"
  49 #include "Packer.h"
  50 #include "RemovalPolicy.h"
  51
  52 #if USE_SQUID_ESI
  53 #include "ESIElement.h"
  54 #endif
  55
  56 class AsyncCall;
  57 class StoreClient;
  58 class MemObject;
  59 class Store;
  60 class StoreSearch;
  61
  62 typedef unsigned int ping_status_t;
  63
  64 /**
  65  \ingroup StoreAPI
  66  */
  67 class StoreEntry : public hash_link
  68 {
  69
  70 public:
  71     static DeferredRead::DeferrableRead DeferReader;
  72     bool checkDeferRead(int fd) const;
  73
  74     virtual const char *getMD5Text() const;
  75     StoreEntry();
  76     StoreEntry(const char *url, const char *log_url);
  77     virtual ~StoreEntry(){}
  78
  79     virtual HttpReply const *getReply() const;
  80     virtual void write (StoreIOBuffer);
  81     virtual _SQUID_INLINE_ bool isEmpty() const;
  82     virtual bool isAccepting() const;
  83     virtual size_t bytesWanted(Range<size_t> const) const;
  84     virtual void complete();
  85     virtual store_client_t storeClientType() const;
  86     virtual char const *getSerialisedMetaData();
  87     virtual void replaceHttpReply(HttpReply *);
  88     virtual bool swapoutPossible();
  89     virtual void trimMemory();
  90     void abort();
  91     void unlink();
  92     void makePublic();
  93     void makePrivate();
  94     void setPublicKey();
  95     void setPrivateKey();
  96     void expireNow();
  97     void releaseRequest();
  98     void negativeCache();
  99     void cacheNegatively();             /** \todo argh, why both? */
 100     void invokeHandlers();
 101     void purgeMem();
 102     void swapOut();
 103     bool swapOutAble() const;
 104     void swapOutFileClose();
 105     const char *url() const;
 106     int checkCachable();
 107     int checkNegativeHit() const;
 108     int locked() const;
 109     int validToSend() const;
 110     int keepInMemory() const;
 111     void createMemObject(const char *, const char *);
 112     void dump(int debug_lvl) const;
 113     void hashDelete();
 114     void hashInsert(const cache_key *);
 115     void registerAbort(STABH * cb, void *);
 116     void reset();
 117     void setMemStatus(mem_status_t);
 118     void timestampsSet();
 119     void unregisterAbort();
 120     void destroyMemObject();
 121     int checkTooSmall();
 122
 123     void delayAwareRead(int fd, char *buf, int len, AsyncCall::Pointer callback);
 124
 125     void setNoDelay (bool const);
 126     bool modifiedSince(HttpRequest * request) const;
 127
 128     /** What store does this entry belong too ? */
 129     virtual RefCount<Store> store() const;
 130
 131     MemObject *mem_obj;
 132     RemovalPolicyNode repl;
 133     /* START OF ON-DISK STORE_META_STD TLV field */
 134     time_t timestamp;
 135     time_t lastref;
 136     time_t expires;
 137     time_t lastmod;
 138     uint64_t swap_file_sz;
 139     u_short refcount;
 140     u_short flags;
 141     /* END OF ON-DISK STORE_META_STD */
 142
 143     sfileno swap_filen:25;
 144
 145     sdirno swap_dirn:7;
 146     u_short lock_count;         /* Assume < 65536! */
 147
 148     mem_status_t mem_status:3;
 149
 150     ping_status_t ping_status:3;
 151
 152     store_status_t store_status:3;
 153
 154     swap_status_t swap_status:3;
 155
 156 public:
 157     static size_t inUseCount();
 158     static void getPublicByRequestMethod(StoreClient * aClient, HttpRequest * request, const HttpRequestMethod& method);
 159     static void getPublicByRequest(StoreClient * aClient, HttpRequest * request);
 160     static void getPublic(StoreClient * aClient, const char *uri, const HttpRequestMethod& method);
 161
 162     virtual bool isNull()
 163     {
 164         return false;
 165     };
 166
 167     void *operator new(size_t byteCount);
 168     void operator delete(void *address);
 169     void setReleaseFlag();
 170 #if USE_SQUID_ESI
 171
 172     ESIElement::Pointer cachedESITree;
 173 #endif
 174     /** append bytes to the buffer */
 175     virtual void append(char const *, int len);
 176     /** disable sending content to the clients */
 177     virtual void buffer();
 178     /** flush any buffered content */
 179     virtual void flush();
 180     /** reduce the memory lock count on the entry */
 181     virtual int unlock();
 182     /** increate the memory lock count on the entry */
 183     virtual int64_t objectLen() const;
 184     virtual int64_t contentLen() const;
 185
 186     virtual void lock();
 187     virtual void release();
 188
 189 private:
 190     static MemAllocator *pool;
 191
 192     bool validLength() const;
 193 };
 194
 195 /// \ingroup StoreAPI
 196 class NullStoreEntry:public StoreEntry
 197 {
 198
 199 public:
 200     static NullStoreEntry *getInstance();
 201     bool isNull()
 202     {
 203         return true;
 204     }
 205
 206     const char *getMD5Text() const;
 207     _SQUID_INLINE_ HttpReply const *getReply() const;
 208     void write (StoreIOBuffer){}
 209
 210     bool isEmpty () const {return true;}
 211
 212     virtual size_t bytesWanted(Range<size_t> const aRange) const { assert (aRange.size());return aRange.end - 1;}
 213
 214     void operator delete(void *address);
 215     void complete(){}
 216
 217 private:
 218     store_client_t storeClientType() const{return STORE_MEM_CLIENT;}
 219
 220     char const *getSerialisedMetaData();
 221     bool swapoutPossible() {return false;}
 222
 223     void trimMemory() {}
 224
 225
 226     static NullStoreEntry _instance;
 227 };
 228
 229 /// \ingroup StoreAPI
 230 typedef void (*STOREGETCLIENT) (StoreEntry *, void *cbdata);
 231
 232
 233 /**
 234  \ingroup StoreAPI
 235  * Abstract base class that will replace the whole store and swapdir interface.
 236  */
 237 class Store : public RefCountable
 238 {
 239
 240 public:
 241     /** The root store */
 242     static _SQUID_INLINE_ Store &Root();
 243     static void Root(Store *);
 244     static void Root(RefCount<Store>);
 245     static void Stats(StoreEntry * output);
 246     static void Maintain(void *unused);
 247
 248     virtual ~Store() {}
 249
 250     /** Handle pending callbacks - called by the event loop. */
 251     virtual int callback() = 0;
 252
 253     /** create the resources needed for this store to operate */
 254     virtual void create();
 255
 256     /**
 257      * Notify this store that its disk is full.
 258      \todo XXX move into a protected api call between store files and their stores, rather than a top level api call
 259      */
 260     virtual void diskFull();
 261
 262     /** Retrieve a store entry from the store */
 263     virtual StoreEntry * get
 264         (const cache_key *) = 0;
 265
 266     /** \todo imeplement the async version */
 267     virtual void get
 268         (String const key , STOREGETCLIENT callback, void *cbdata) = 0;
 269
 270     /* prepare the store for use. The store need not be usable immediately,
 271      * it should respond to readable() and writable() with true as soon
 272      * as it can provide those services
 273      */
 274     virtual void init() = 0;
 275
 276     /**
 277      * The maximum size the store will support in normal use. Inaccuracy is permitted,
 278      * but may throw estimates for memory etc out of whack.
 279      */
 280     virtual size_t maxSize() const = 0;
 281
 282     /** The minimum size the store will shrink to via normal housekeeping */
 283     virtual size_t minSize() const = 0;
 284
 285     /**
 286      * Output stats to the provided store entry.
 287      \todo make these calls asynchronous
 288      */
 289     virtual void stat(StoreEntry &) const = 0;
 290
 291     /** Sync the store prior to shutdown */
 292     virtual void sync();
 293
 294     /** remove a Store entry from the store */
 295     virtual void unlink (StoreEntry &);
 296
 297     /* search in the store */
 298     virtual StoreSearch *search(String const url, HttpRequest *) = 0;
 299
 300     /* pulled up from SwapDir for migration.... probably do not belong here */
 301     virtual void reference(StoreEntry &) = 0;   /* Reference this object */
 302
 303     virtual void dereference(StoreEntry &) = 0; /* Unreference this object */
 304
 305     virtual void maintain() = 0; /* perform regular maintenance should be private and self registered ... */
 306
 307     /* These should really be private */
 308     virtual void updateSize(int64_t size, int sign) = 0;
 309
 310 private:
 311     static RefCount<Store> CurrentRoot;
 312 };
 313
 314 /// \ingroup StoreAPI
 315 typedef RefCount<Store> StorePointer;
 316
 317 /// \ingroup StoreAPI
 318 SQUIDCEXTERN size_t storeEntryInUse();
 319
 320 /// \ingroup StoreAPI
 321 SQUIDCEXTERN const char *storeEntryFlags(const StoreEntry *);
 322
 323 /// \ingroup StoreAPI
 324 extern void storeEntryReplaceObject(StoreEntry *, HttpReply *);
 325
 326 /// \ingroup StoreAPI
 327 SQUIDCEXTERN StoreEntry *storeGetPublic(const char *uri, const HttpRequestMethod& method);
 328
 329 /// \ingroup StoreAPI
 330 SQUIDCEXTERN StoreEntry *storeGetPublicByRequest(HttpRequest * request);
 331
 332 /// \ingroup StoreAPI
 333 SQUIDCEXTERN StoreEntry *storeGetPublicByRequestMethod(HttpRequest * request, const HttpRequestMethod& method);
 334
 335 /// \ingroup StoreAPI
 336 SQUIDCEXTERN StoreEntry *storeCreateEntry(const char *, const char *, request_flags, const HttpRequestMethod&);
 337
 338 /// \ingroup StoreAPI
 339 SQUIDCEXTERN void storeInit(void);
 340
 341 /// \ingroup StoreAPI
 342 SQUIDCEXTERN void storeConfigure(void);
 343
 344 /// \ingroup StoreAPI
 345 SQUIDCEXTERN void storeFreeMemory(void);
 346
 347 /// \ingroup StoreAPI
 348 SQUIDCEXTERN int expiresMoreThan(time_t, time_t);
 349
 350 #if STDC_HEADERS
 351 /// \ingroup StoreAPI
 352 SQUIDCEXTERN void storeAppendPrintf(StoreEntry *, const char *,...) PRINTF_FORMAT_ARG2;
 353 #else
 354 /// \ingroup StoreAPI
 355 SQUIDCEXTERN void storeAppendPrintf();
 356 #endif
 357
 358 /// \ingroup StoreAPI
 359 SQUIDCEXTERN void storeAppendVPrintf(StoreEntry *, const char *, va_list ap);
 360
 361 /// \ingroup StoreAPI
 362 SQUIDCEXTERN int storeTooManyDiskFilesOpen(void);
 363
 364 class SwapDir;
 365 /// \ingroup StoreAPI
 366 SQUIDCEXTERN void storeHeapPositionUpdate(StoreEntry *, SwapDir *);
 367
 368 /// \ingroup StoreAPI
 369 SQUIDCEXTERN void storeSwapFileNumberSet(StoreEntry * e, sfileno filn);
 370
 371 /// \ingroup StoreAPI
 372 SQUIDCEXTERN void storeFsInit(void);
 373
 374 /// \ingroup StoreAPI
 375 SQUIDCEXTERN void storeFsDone(void);
 376
 377 /// \ingroup StoreAPI
 378 SQUIDCEXTERN void storeReplAdd(const char *, REMOVALPOLICYCREATE *);
 379
 380 /// \ingroup StoreAPI
 381 extern FREE destroyStoreEntry;
 382
 383 /**
 384  \ingroup StoreAPI
 385  \todo should be a subclass of Packer perhaps ?
 386  */
 387 SQUIDCEXTERN void packerToStoreInit(Packer * p, StoreEntry * e);
 388
 389 #ifdef _USE_INLINE_
 390 #include "Store.cci"
 391 #endif
 392
 393 #endif /* SQUID_STORE_H */