src/store.cc

   1
   2 /*
   3  * DEBUG: section 20    Storage Manager
   4  * AUTHOR: Harvest Derived
   5  *
   6  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   7  * ----------------------------------------------------------
   8  *
   9  *  Squid is the result of efforts by numerous individuals from
  10  *  the Internet community; see the CONTRIBUTORS file for full
  11  *  details.   Many organizations have provided support for Squid's
  12  *  development; see the SPONSORS file for full details.  Squid is
  13  *  Copyrighted (C) 2001 by the Regents of the University of
  14  *  California; see the COPYRIGHT file for full details.  Squid
  15  *  incorporates software developed and/or copyrighted by other
  16  *  sources; see the CREDITS file for full details.
  17  *
  18  *  This program is free software; you can redistribute it and/or modify
  19  *  it under the terms of the GNU General Public License as published by
  20  *  the Free Software Foundation; either version 2 of the License, or
  21  *  (at your option) any later version.
  22  *
  23  *  This program is distributed in the hope that it will be useful,
  24  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  25  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  26  *  GNU General Public License for more details.
  27  *
  28  *  You should have received a copy of the GNU General Public License
  29  *  along with this program; if not, write to the Free Software
  30  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  31  *
  32  */
  33
  34 #include "squid.h"
  35 #include "CacheDigest.h"
  36 #include "CacheManager.h"
  37 #include "comm/Connection.h"
  38 #include "ETag.h"
  39 #include "event.h"
  40 #include "fde.h"
  41 #include "globals.h"
  42 #include "http.h"
  43 #include "HttpReply.h"
  44 #include "HttpRequest.h"
  45 #include "mem_node.h"
  46 #include "MemObject.h"
  47 #include "mgr/Registration.h"
  48 #include "mgr/StoreIoAction.h"
  49 #include "profiler/Profiler.h"
  50 #include "repl_modules.h"
  51 #include "RequestFlags.h"
  52 #include "SquidConfig.h"
  53 #include "SquidTime.h"
  54 #include "Stack.h"
  55 #include "StatCounters.h"
  56 #include "stmem.h"
  57 #include "store_digest.h"
  58 #include "store_key_md5.h"
  59 #include "store_key_md5.h"
  60 #include "store_log.h"
  61 #include "store_rebuild.h"
  62 #include "Store.h"
  63 #include "StoreClient.h"
  64 #include "StoreIOState.h"
  65 #include "StoreMeta.h"
  66 #include "StrList.h"
  67 #include "swap_log_op.h"
  68 #include "SwapDir.h"
  69 #include "tools.h"
  70 #if USE_DELAY_POOLS
  71 #include "DelayPools.h"
  72 #endif
  73 #if HAVE_LIMITS_H
  74 #include <limits.h>
  75 #endif
  76
  77 static STMCB storeWriteComplete;
  78
  79 #define REBUILD_TIMESTAMP_DELTA_MAX 2
  80
  81 #define STORE_IN_MEM_BUCKETS            (229)
  82
  83 /** \todo Convert these string constants to enum string-arrays generated */
  84
  85 const char *memStatusStr[] = {
  86     "NOT_IN_MEMORY",
  87     "IN_MEMORY"
  88 };
  89
  90 const char *pingStatusStr[] = {
  91     "PING_NONE",
  92     "PING_WAITING",
  93     "PING_DONE"
  94 };
  95
  96 const char *storeStatusStr[] = {
  97     "STORE_OK",
  98     "STORE_PENDING"
  99 };
 100
 101 const char *swapStatusStr[] = {
 102     "SWAPOUT_NONE",
 103     "SWAPOUT_WRITING",
 104     "SWAPOUT_DONE"
 105 };
 106
 107 /*
 108  * This defines an repl type
 109  */
 110
 111 typedef struct _storerepl_entry storerepl_entry_t;
 112
 113 struct _storerepl_entry {
 114     const char *typestr;
 115     REMOVALPOLICYCREATE *create;
 116 };
 117
 118 static storerepl_entry_t *storerepl_list = NULL;
 119
 120 /*
 121  * local function prototypes
 122  */
 123 static int getKeyCounter(void);
 124 static OBJH storeCheckCachableStats;
 125 static EVH storeLateRelease;
 126
 127 /*
 128  * local variables
 129  */
 130 static Stack<StoreEntry*> LateReleaseStack;
 131 MemAllocator *StoreEntry::pool = NULL;
 132
 133 StorePointer Store::CurrentRoot = NULL;
 134
 135 void
 136 Store::Root(Store * aRoot)
 137 {
 138     CurrentRoot = aRoot;
 139 }
 140
 141 void
 142 Store::Root(StorePointer aRoot)
 143 {
 144     Root(aRoot.getRaw());
 145 }
 146
 147 void
 148 Store::Stats(StoreEntry * output)
 149 {
 150     assert (output);
 151     Root().stat(*output);
 152 }
 153
 154 void
 155 Store::create()
 156 {}
 157
 158 void
 159 Store::diskFull()
 160 {}
 161
 162 void
 163 Store::sync()
 164 {}
 165
 166 void
 167 Store::unlink (StoreEntry &anEntry)
 168 {
 169     fatal("Store::unlink on invalid Store\n");
 170 }
 171
 172 void *
 173 StoreEntry::operator new (size_t bytecount)
 174 {
 175     assert (bytecount == sizeof (StoreEntry));
 176
 177     if (!pool) {
 178         pool = memPoolCreate ("StoreEntry", bytecount);
 179         pool->setChunkSize(2048 * 1024);
 180     }
 181
 182     return pool->alloc();
 183 }
 184
 185 void
 186 StoreEntry::operator delete (void *address)
 187 {
 188     pool->freeOne(address);
 189 }
 190
 191 void
 192 StoreEntry::makePublic()
 193 {
 194     /* This object can be cached for a long time */
 195
 196     if (EBIT_TEST(flags, ENTRY_CACHABLE))
 197         setPublicKey();
 198 }
 199
 200 void
 201 StoreEntry::makePrivate()
 202 {
 203     /* This object should never be cached at all */
 204     expireNow();
 205     releaseRequest(); /* delete object when not used */
 206     /* releaseRequest clears ENTRY_CACHABLE flag */
 207 }
 208
 209 void
 210 StoreEntry::cacheNegatively()
 211 {
 212     /* This object may be negatively cached */
 213     negativeCache();
 214
 215     if (EBIT_TEST(flags, ENTRY_CACHABLE))
 216         setPublicKey();
 217 }
 218
 219 size_t
 220 StoreEntry::inUseCount()
 221 {
 222     if (!pool)
 223         return 0;
 224     return pool->getInUseCount();
 225 }
 226
 227 const char *
 228 StoreEntry::getMD5Text() const
 229 {
 230     return storeKeyText((const cache_key *)key);
 231 }
 232
 233 #include "comm.h"
 234
 235 void
 236 StoreEntry::DeferReader(void *theContext, CommRead const &aRead)
 237 {
 238     StoreEntry *anEntry = (StoreEntry *)theContext;
 239     anEntry->delayAwareRead(aRead.conn,
 240                             aRead.buf,
 241                             aRead.len,
 242                             aRead.callback);
 243 }
 244
 245 void
 246 StoreEntry::delayAwareRead(const Comm::ConnectionPointer &conn, char *buf, int len, AsyncCall::Pointer callback)
 247 {
 248     size_t amountToRead = bytesWanted(Range<size_t>(0, len));
 249     /* sketch: readdeferer* = getdeferer.
 250      * ->deferRead (fd, buf, len, callback, DelayAwareRead, this)
 251      */
 252
 253     if (amountToRead == 0) {
 254         assert (mem_obj);
 255         /* read ahead limit */
 256         /* Perhaps these two calls should both live in MemObject */
 257 #if USE_DELAY_POOLS
 258         if (!mem_obj->readAheadPolicyCanRead()) {
 259 #endif
 260             mem_obj->delayRead(DeferredRead(DeferReader, this, CommRead(conn, buf, len, callback)));
 261             return;
 262 #if USE_DELAY_POOLS
 263         }
 264
 265         /* delay id limit */
 266         mem_obj->mostBytesAllowed().delayRead(DeferredRead(DeferReader, this, CommRead(conn, buf, len, callback)));
 267         return;
 268
 269 #endif
 270
 271     }
 272
 273     if (fd_table[conn->fd].closing()) {
 274         // Readers must have closing callbacks if they want to be notified. No
 275         // readers appeared to care around 2009/12/14 as they skipped reading
 276         // for other reasons. Closing may already be true at the delyaAwareRead
 277         // call time or may happen while we wait after delayRead() above.
 278         debugs(20, 3, HERE << "wont read from closing " << conn << " for " <<
 279                callback);
 280         return; // the read callback will never be called
 281     }
 282
 283     comm_read(conn, buf, amountToRead, callback);
 284 }
 285
 286 size_t
 287 StoreEntry::bytesWanted (Range<size_t> const aRange, bool ignoreDelayPools) const
 288 {
 289     if (mem_obj == NULL)
 290         return aRange.end;
 291
 292 #if URL_CHECKSUM_DEBUG
 293
 294     mem_obj->checkUrlChecksum();
 295
 296 #endif
 297
 298     if (!mem_obj->readAheadPolicyCanRead())
 299         return 0;
 300
 301     return mem_obj->mostBytesWanted(aRange.end, ignoreDelayPools);
 302 }
 303
 304 bool
 305 StoreEntry::checkDeferRead(int fd) const
 306 {
 307     return (bytesWanted(Range<size_t>(0,INT_MAX)) == 0);
 308 }
 309
 310 void
 311 StoreEntry::setNoDelay (bool const newValue)
 312 {
 313     if (mem_obj)
 314         mem_obj->setNoDelay(newValue);
 315 }
 316
 317 store_client_t
 318 StoreEntry::storeClientType() const
 319 {
 320     /* The needed offset isn't in memory
 321      * XXX TODO: this is wrong for range requests
 322      * as the needed offset may *not* be 0, AND
 323      * offset 0 in the memory object is the HTTP headers.
 324      */
 325
 326     if (mem_status == IN_MEMORY && Config.memShared && IamWorkerProcess()) {
 327         // clients of an object cached in shared memory are memory clients
 328         return STORE_MEM_CLIENT;
 329     }
 330
 331     assert(mem_obj);
 332
 333     if (mem_obj->inmem_lo)
 334         return STORE_DISK_CLIENT;
 335
 336     if (EBIT_TEST(flags, ENTRY_ABORTED)) {
 337         /* I don't think we should be adding clients to aborted entries */
 338         debugs(20, DBG_IMPORTANT, "storeClientType: adding to ENTRY_ABORTED entry");
 339         return STORE_MEM_CLIENT;
 340     }
 341
 342     if (store_status == STORE_OK) {
 343         /* the object has completed. */
 344
 345         if (mem_obj->inmem_lo == 0 && !isEmpty()) {
 346             if (swap_status == SWAPOUT_DONE) {
 347                 debugs(20,7, HERE << mem_obj << " lo: " << mem_obj->inmem_lo << " hi: " << mem_obj->endOffset() << " size: " << mem_obj->object_sz);
 348                 if (mem_obj->endOffset() == mem_obj->object_sz) {
 349                     /* hot object fully swapped in */
 350                     return STORE_MEM_CLIENT;
 351                 }
 352             } else {
 353                 /* Memory-only, or currently being swapped out */
 354                 return STORE_MEM_CLIENT;
 355             }
 356         }
 357         return STORE_DISK_CLIENT;
 358     }
 359
 360     /* here and past, entry is STORE_PENDING */
 361     /*
 362      * If this is the first client, let it be the mem client
 363      */
 364     if (mem_obj->nclients == 1)
 365         return STORE_MEM_CLIENT;
 366
 367     /*
 368      * If there is no disk file to open yet, we must make this a
 369      * mem client.  If we can't open the swapin file before writing
 370      * to the client, there is no guarantee that we will be able
 371      * to open it later when we really need it.
 372      */
 373     if (swap_status == SWAPOUT_NONE)
 374         return STORE_MEM_CLIENT;
 375
 376     /*
 377      * otherwise, make subsequent clients read from disk so they
 378      * can not delay the first, and vice-versa.
 379      */
 380     return STORE_DISK_CLIENT;
 381 }
 382
 383 StoreEntry::StoreEntry() :
 384         mem_obj(NULL),
 385         hidden_mem_obj(NULL),
 386         timestamp(-1),
 387         lastref(-1),
 388         expires(-1),
 389         lastmod(-1),
 390         swap_file_sz(0),
 391         refcount(0),
 392         flags(0),
 393         swap_filen(-1),
 394         swap_dirn(-1),
 395         lock_count(0),
 396         mem_status(NOT_IN_MEMORY),
 397         ping_status(PING_NONE),
 398         store_status(STORE_PENDING),
 399         swap_status(SWAPOUT_NONE)
 400 {
 401     debugs(20, 3, HERE << "new StoreEntry " << this);
 402 }
 403
 404 StoreEntry::StoreEntry(const char *aUrl, const char *aLogUrl) :
 405         mem_obj(NULL),
 406         hidden_mem_obj(NULL),
 407         timestamp(-1),
 408         lastref(-1),
 409         expires(-1),
 410         lastmod(-1),
 411         swap_file_sz(0),
 412         refcount(0),
 413         flags(0),
 414         swap_filen(-1),
 415         swap_dirn(-1),
 416         lock_count(0),
 417         mem_status(NOT_IN_MEMORY),
 418         ping_status(PING_NONE),
 419         store_status(STORE_PENDING),
 420         swap_status(SWAPOUT_NONE)
 421 {
 422     debugs(20, 3, HERE << "new StoreEntry " << this);
 423     mem_obj = new MemObject(aUrl, aLogUrl);
 424 }
 425
 426 StoreEntry::~StoreEntry()
 427 {
 428     if (swap_filen >= 0) {
 429         SwapDir &sd = dynamic_cast<SwapDir&>(*store());
 430         sd.disconnect(*this);
 431     }
 432     delete hidden_mem_obj;
 433 }
 434
 435 #if USE_ADAPTATION
 436 void
 437 StoreEntry::deferProducer(const AsyncCall::Pointer &producer)
 438 {
 439     if (!deferredProducer)
 440         deferredProducer = producer;
 441     else
 442         debugs(20, 5, HERE << "Deferred producer call is allready set to: " <<
 443                *deferredProducer << ", requested call: " << *producer);
 444 }
 445
 446 void
 447 StoreEntry::kickProducer()
 448 {
 449     if (deferredProducer != NULL) {
 450         ScheduleCallHere(deferredProducer);
 451         deferredProducer = NULL;
 452     }
 453 }
 454 #endif
 455
 456 void
 457 StoreEntry::destroyMemObject()
 458 {
 459     debugs(20, 3, HERE << "destroyMemObject " << mem_obj);
 460     setMemStatus(NOT_IN_MEMORY);
 461     MemObject *mem = mem_obj;
 462     mem_obj = NULL;
 463     delete mem;
 464     delete hidden_mem_obj;
 465     hidden_mem_obj = NULL;
 466 }
 467
 468 void
 469 StoreEntry::hideMemObject()
 470 {
 471     debugs(20, 3, HERE << "hiding " << mem_obj);
 472     assert(mem_obj);
 473     assert(!hidden_mem_obj);
 474     hidden_mem_obj = mem_obj;
 475     mem_obj = NULL;
 476 }
 477
 478 void
 479 destroyStoreEntry(void *data)
 480 {
 481     debugs(20, 3, HERE << "destroyStoreEntry: destroying " <<  data);
 482     StoreEntry *e = static_cast<StoreEntry *>(static_cast<hash_link *>(data));
 483     assert(e != NULL);
 484
 485     if (e == NullStoreEntry::getInstance())
 486         return;
 487
 488     e->destroyMemObject();
 489
 490     e->hashDelete();
 491
 492     assert(e->key == NULL);
 493
 494     delete e;
 495 }
 496
 497 /* ----- INTERFACE BETWEEN STORAGE MANAGER AND HASH TABLE FUNCTIONS --------- */
 498
 499 void
 500 StoreEntry::hashInsert(const cache_key * someKey)
 501 {
 502     debugs(20, 3, "StoreEntry::hashInsert: Inserting Entry " << this << " key '" << storeKeyText(someKey) << "'");
 503     key = storeKeyDup(someKey);
 504     hash_join(store_table, this);
 505 }
 506
 507 void
 508 StoreEntry::hashDelete()
 509 {
 510     hash_remove_link(store_table, this);
 511     storeKeyFree((const cache_key *)key);
 512     key = NULL;
 513 }
 514
 515 /* -------------------------------------------------------------------------- */
 516
 517 /* get rid of memory copy of the object */
 518 void
 519 StoreEntry::purgeMem()
 520 {
 521     if (mem_obj == NULL)
 522         return;
 523
 524     debugs(20, 3, "StoreEntry::purgeMem: Freeing memory-copy of " << getMD5Text());
 525
 526     destroyMemObject();
 527
 528     if (swap_status != SWAPOUT_DONE)
 529         release();
 530 }
 531
 532 /* RBC 20050104 this is wrong- memory ref counting
 533  * is not at all equivalent to the store 'usage' concept
 534  * which the replacement policies should be acting upon.
 535  * specifically, object iteration within stores needs
 536  * memory ref counting to prevent race conditions,
 537  * but this should not influence store replacement.
 538  */
 539 void
 540
 541 StoreEntry::lock()
 542 {
 543     ++lock_count;
 544     debugs(20, 3, "StoreEntry::lock: key '" << getMD5Text() <<"' count=" <<
 545            lock_count  );
 546     lastref = squid_curtime;
 547     Store::Root().reference(*this);
 548 }
 549
 550 void
 551 StoreEntry::setReleaseFlag()
 552 {
 553     if (EBIT_TEST(flags, RELEASE_REQUEST))
 554         return;
 555
 556     debugs(20, 3, "StoreEntry::setReleaseFlag: '" << getMD5Text() << "'");
 557
 558     EBIT_SET(flags, RELEASE_REQUEST);
 559 }
 560
 561 void
 562 StoreEntry::releaseRequest()
 563 {
 564     if (EBIT_TEST(flags, RELEASE_REQUEST))
 565         return;
 566
 567     setReleaseFlag();
 568
 569     /*
 570      * Clear cachable flag here because we might get called before
 571      * anyone else even looks at the cachability flag.  Also, this
 572      * prevents httpMakePublic from really setting a public key.
 573      */
 574     EBIT_CLR(flags, ENTRY_CACHABLE);
 575
 576     setPrivateKey();
 577 }
 578
 579 /* unlock object, return -1 if object get released after unlock
 580  * otherwise lock_count */
 581 int
 582 StoreEntry::unlock()
 583 {
 584     --lock_count;
 585     debugs(20, 3, "StoreEntry::unlock: key '" << getMD5Text() << "' count=" << lock_count);
 586
 587     if (lock_count)
 588         return (int) lock_count;
 589
 590     if (store_status == STORE_PENDING)
 591         setReleaseFlag();
 592
 593     assert(storePendingNClients(this) == 0);
 594
 595     if (EBIT_TEST(flags, RELEASE_REQUEST)) {
 596         this->release();
 597         return 0;
 598     }
 599
 600     if (EBIT_TEST(flags, KEY_PRIVATE))
 601         debugs(20, DBG_IMPORTANT, "WARNING: " << __FILE__ << ":" << __LINE__ << ": found KEY_PRIVATE");
 602
 603     Store::Root().handleIdleEntry(*this); // may delete us
 604     return 0;
 605 }
 606
 607 void
 608 StoreEntry::getPublicByRequestMethod  (StoreClient *aClient, HttpRequest * request, const HttpRequestMethod& method)
 609 {
 610     assert (aClient);
 611     StoreEntry *result = storeGetPublicByRequestMethod( request, method);
 612
 613     if (!result)
 614         aClient->created (NullStoreEntry::getInstance());
 615     else
 616         aClient->created (result);
 617 }
 618
 619 void
 620 StoreEntry::getPublicByRequest (StoreClient *aClient, HttpRequest * request)
 621 {
 622     assert (aClient);
 623     StoreEntry *result = storeGetPublicByRequest (request);
 624
 625     if (!result)
 626         result = NullStoreEntry::getInstance();
 627
 628     aClient->created (result);
 629 }
 630
 631 void
 632 StoreEntry::getPublic (StoreClient *aClient, const char *uri, const HttpRequestMethod& method)
 633 {
 634     assert (aClient);
 635     StoreEntry *result = storeGetPublic (uri, method);
 636
 637     if (!result)
 638         result = NullStoreEntry::getInstance();
 639
 640     aClient->created (result);
 641 }
 642
 643 StoreEntry *
 644 storeGetPublic(const char *uri, const HttpRequestMethod& method)
 645 {
 646     return Store::Root().get(storeKeyPublic(uri, method));
 647 }
 648
 649 StoreEntry *
 650 storeGetPublicByRequestMethod(HttpRequest * req, const HttpRequestMethod& method)
 651 {
 652     return Store::Root().get(storeKeyPublicByRequestMethod(req, method));
 653 }
 654
 655 StoreEntry *
 656 storeGetPublicByRequest(HttpRequest * req)
 657 {
 658     StoreEntry *e = storeGetPublicByRequestMethod(req, req->method);
 659
 660     if (e == NULL && req->method == Http::METHOD_HEAD)
 661         /* We can generate a HEAD reply from a cached GET object */
 662         e = storeGetPublicByRequestMethod(req, Http::METHOD_GET);
 663
 664     return e;
 665 }
 666
 667 static int
 668 getKeyCounter(void)
 669 {
 670     static int key_counter = 0;
 671
 672     if (++key_counter < 0)
 673         key_counter = 1;
 674
 675     return key_counter;
 676 }
 677
 678 /* RBC 20050104 AFAICT this should become simpler:
 679  * rather than reinserting with a special key it should be marked
 680  * as 'released' and then cleaned up when refcounting indicates.
 681  * the StoreHashIndex could well implement its 'released' in the
 682  * current manner.
 683  * Also, clean log writing should skip over ia,t
 684  * Otherwise, we need a 'remove from the index but not the store
 685  * concept'.
 686  */
 687 void
 688 StoreEntry::setPrivateKey()
 689 {
 690     const cache_key *newkey;
 691
 692     if (key && EBIT_TEST(flags, KEY_PRIVATE))
 693         return;                 /* is already private */
 694
 695     if (key) {
 696         if (swap_filen > -1)
 697             storeDirSwapLog(this, SWAP_LOG_DEL);
 698
 699         hashDelete();
 700     }
 701
 702     if (mem_obj != NULL) {
 703         mem_obj->id = getKeyCounter();
 704         newkey = storeKeyPrivate(mem_obj->url, mem_obj->method, mem_obj->id);
 705     } else {
 706         newkey = storeKeyPrivate("JUNK", Http::METHOD_NONE, getKeyCounter());
 707     }
 708
 709     assert(hash_lookup(store_table, newkey) == NULL);
 710     EBIT_SET(flags, KEY_PRIVATE);
 711     hashInsert(newkey);
 712 }
 713
 714 void
 715 StoreEntry::setPublicKey()
 716 {
 717     StoreEntry *e2 = NULL;
 718     const cache_key *newkey;
 719
 720     if (key && !EBIT_TEST(flags, KEY_PRIVATE))
 721         return;                 /* is already public */
 722
 723     assert(mem_obj);
 724
 725     /*
 726      * We can't make RELEASE_REQUEST objects public.  Depending on
 727      * when RELEASE_REQUEST gets set, we might not be swapping out
 728      * the object.  If we're not swapping out, then subsequent
 729      * store clients won't be able to access object data which has
 730      * been freed from memory.
 731      *
 732      * If RELEASE_REQUEST is set, then ENTRY_CACHABLE should not
 733      * be set, and StoreEntry::setPublicKey() should not be called.
 734      */
 735 #if MORE_DEBUG_OUTPUT
 736
 737     if (EBIT_TEST(flags, RELEASE_REQUEST))
 738         debugs(20, DBG_IMPORTANT, "assertion failed: RELEASE key " << key << ", url " << mem_obj->url);
 739
 740 #endif
 741
 742     assert(!EBIT_TEST(flags, RELEASE_REQUEST));
 743
 744     if (mem_obj->request) {
 745         HttpRequest *request = mem_obj->request;
 746
 747         if (!mem_obj->vary_headers) {
 748             /* First handle the case where the object no longer varies */
 749             safe_free(request->vary_headers);
 750         } else {
 751             if (request->vary_headers && strcmp(request->vary_headers, mem_obj->vary_headers) != 0) {
 752                 /* Oops.. the variance has changed. Kill the base object
 753                  * to record the new variance key
 754                  */
 755                 safe_free(request->vary_headers);       /* free old "bad" variance key */
 756                 StoreEntry *pe = storeGetPublic(mem_obj->url, mem_obj->method);
 757
 758                 if (pe)
 759                     pe->release();
 760             }
 761
 762             /* Make sure the request knows the variance status */
 763             if (!request->vary_headers) {
 764                 const char *vary = httpMakeVaryMark(request, mem_obj->getReply());
 765
 766                 if (vary)
 767                     request->vary_headers = xstrdup(vary);
 768             }
 769         }
 770
 771         // TODO: storeGetPublic() calls below may create unlocked entries.
 772         // We should add/use storeHas() API or lock/unlock those entries.
 773         if (mem_obj->vary_headers && !storeGetPublic(mem_obj->url, mem_obj->method)) {
 774             /* Create "vary" base object */
 775             String vary;
 776             StoreEntry *pe = storeCreateEntry(mem_obj->url, mem_obj->log_url, request->flags, request->method);
 777             /* We are allowed to do this typecast */
 778             HttpReply *rep = new HttpReply;
 779             rep->setHeaders(HTTP_OK, "Internal marker object", "x-squid-internal/vary", -1, -1, squid_curtime + 100000);
 780             vary = mem_obj->getReply()->header.getList(HDR_VARY);
 781
 782             if (vary.size()) {
 783                 /* Again, we own this structure layout */
 784                 rep->header.putStr(HDR_VARY, vary.termedBuf());
 785                 vary.clean();
 786             }
 787
 788 #if X_ACCELERATOR_VARY
 789             vary = mem_obj->getReply()->header.getList(HDR_X_ACCELERATOR_VARY);
 790
 791             if (vary.defined()) {
 792                 /* Again, we own this structure layout */
 793                 rep->header.putStr(HDR_X_ACCELERATOR_VARY, vary.termedBuf());
 794                 vary.clean();
 795             }
 796
 797 #endif
 798             pe->replaceHttpReply(rep);
 799
 800             pe->timestampsSet();
 801
 802             pe->makePublic();
 803
 804             pe->complete();
 805
 806             pe->unlock();
 807         }
 808
 809         newkey = storeKeyPublicByRequest(mem_obj->request);
 810     } else
 811         newkey = storeKeyPublic(mem_obj->url, mem_obj->method);
 812
 813     if ((e2 = (StoreEntry *) hash_lookup(store_table, newkey))) {
 814         debugs(20, 3, "StoreEntry::setPublicKey: Making old '" << mem_obj->url << "' private.");
 815         e2->setPrivateKey();
 816         e2->release();
 817
 818         if (mem_obj->request)
 819             newkey = storeKeyPublicByRequest(mem_obj->request);
 820         else
 821             newkey = storeKeyPublic(mem_obj->url, mem_obj->method);
 822     }
 823
 824     if (key)
 825         hashDelete();
 826
 827     EBIT_CLR(flags, KEY_PRIVATE);
 828
 829     hashInsert(newkey);
 830
 831     if (swap_filen > -1)
 832         storeDirSwapLog(this, SWAP_LOG_ADD);
 833 }
 834
 835 StoreEntry *
 836 storeCreateEntry(const char *url, const char *log_url, const RequestFlags &flags, const HttpRequestMethod& method)
 837 {
 838     StoreEntry *e = NULL;
 839     MemObject *mem = NULL;
 840     debugs(20, 3, "storeCreateEntry: '" << url << "'");
 841
 842     e = new StoreEntry(url, log_url);
 843     e->lock_count = 1;          /* Note lock here w/o calling storeLock() */
 844     mem = e->mem_obj;
 845     mem->method = method;
 846
 847     if (neighbors_do_private_keys || !flags.hierarchical)
 848         e->setPrivateKey();
 849     else
 850         e->setPublicKey();
 851
 852     if (flags.cachable) {
 853         EBIT_SET(e->flags, ENTRY_CACHABLE);
 854         EBIT_CLR(e->flags, RELEASE_REQUEST);
 855     } else {
 856         /* StoreEntry::releaseRequest() clears ENTRY_CACHABLE */
 857         e->releaseRequest();
 858     }
 859
 860     e->store_status = STORE_PENDING;
 861     e->setMemStatus(NOT_IN_MEMORY);
 862     e->refcount = 0;
 863     e->lastref = squid_curtime;
 864     e->timestamp = -1;          /* set in StoreEntry::timestampsSet() */
 865     e->ping_status = PING_NONE;
 866     EBIT_SET(e->flags, ENTRY_VALIDATED);
 867     return e;
 868 }
 869
 870 /* Mark object as expired */
 871 void
 872 StoreEntry::expireNow()
 873 {
 874     debugs(20, 3, "StoreEntry::expireNow: '" << getMD5Text() << "'");
 875     expires = squid_curtime;
 876 }
 877
 878 void
 879 storeWriteComplete (void *data, StoreIOBuffer wroteBuffer)
 880 {
 881     PROF_start(storeWriteComplete);
 882     StoreEntry *e = (StoreEntry *)data;
 883
 884     if (EBIT_TEST(e->flags, DELAY_SENDING)) {
 885         PROF_stop(storeWriteComplete);
 886         return;
 887     }
 888
 889     e->invokeHandlers();
 890     PROF_stop(storeWriteComplete);
 891 }
 892
 893 void
 894 StoreEntry::write (StoreIOBuffer writeBuffer)
 895 {
 896     assert(mem_obj != NULL);
 897     /* This assert will change when we teach the store to update */
 898     PROF_start(StoreEntry_write);
 899     assert(store_status == STORE_PENDING);
 900
 901     debugs(20, 5, "storeWrite: writing " << writeBuffer.length << " bytes for '" << getMD5Text() << "'");
 902     PROF_stop(StoreEntry_write);
 903     storeGetMemSpace(writeBuffer.length);
 904     mem_obj->write (writeBuffer, storeWriteComplete, this);
 905 }
 906
 907 /* Append incoming data from a primary server to an entry. */
 908 void
 909 StoreEntry::append(char const *buf, int len)
 910 {
 911     assert(mem_obj != NULL);
 912     assert(len >= 0);
 913     assert(store_status == STORE_PENDING);
 914
 915     StoreIOBuffer tempBuffer;
 916     tempBuffer.data = (char *)buf;
 917     tempBuffer.length = len;
 918     /*
 919      * XXX sigh, offset might be < 0 here, but it gets "corrected"
 920      * later.  This offset crap is such a mess.
 921      */
 922     tempBuffer.offset = mem_obj->endOffset() - (getReply() ? getReply()->hdr_sz : 0);
 923     write(tempBuffer);
 924 }
 925
 926 void
 927 storeAppendPrintf(StoreEntry * e, const char *fmt,...)
 928 {
 929     va_list args;
 930     va_start(args, fmt);
 931
 932     storeAppendVPrintf(e, fmt, args);
 933     va_end(args);
 934 }
 935
 936 /* used be storeAppendPrintf and Packer */
 937 void
 938 storeAppendVPrintf(StoreEntry * e, const char *fmt, va_list vargs)
 939 {
 940     LOCAL_ARRAY(char, buf, 4096);
 941     buf[0] = '\0';
 942     vsnprintf(buf, 4096, fmt, vargs);
 943     e->append(buf, strlen(buf));
 944 }
 945
 946 struct _store_check_cachable_hist {
 947
 948     struct {
 949         int non_get;
 950         int not_entry_cachable;
 951         int wrong_content_length;
 952         int negative_cached;
 953         int too_big;
 954         int too_small;
 955         int private_key;
 956         int too_many_open_files;
 957         int too_many_open_fds;
 958     } no;
 959
 960     struct {
 961         int Default;
 962     } yes;
 963 } store_check_cachable_hist;
 964
 965 int
 966 storeTooManyDiskFilesOpen(void)
 967 {
 968     if (Config.max_open_disk_fds == 0)
 969         return 0;
 970
 971     if (store_open_disk_fd > Config.max_open_disk_fds)
 972         return 1;
 973
 974     return 0;
 975 }
 976
 977 int
 978 StoreEntry::checkTooSmall()
 979 {
 980     if (EBIT_TEST(flags, ENTRY_SPECIAL))
 981         return 0;
 982
 983     if (STORE_OK == store_status)
 984         if (mem_obj->object_sz < 0 ||
 985                 mem_obj->object_sz < Config.Store.minObjectSize)
 986             return 1;
 987     if (getReply()->content_length > -1)
 988         if (getReply()->content_length < Config.Store.minObjectSize)
 989             return 1;
 990     return 0;
 991 }
 992
 993 // TODO: remove checks already performed by swapoutPossible()
 994 // TODO: move "too many open..." checks outside -- we are called too early/late
 995 int
 996 StoreEntry::checkCachable()
 997 {
 998 #if CACHE_ALL_METHODS
 999
1000     if (mem_obj->method != Http::METHOD_GET) {
1001         debugs(20, 2, "StoreEntry::checkCachable: NO: non-GET method");
1002         ++store_check_cachable_hist.no.non_get;
1003     } else
1004 #endif
1005         if (store_status == STORE_OK && EBIT_TEST(flags, ENTRY_BAD_LENGTH)) {
1006             debugs(20, 2, "StoreEntry::checkCachable: NO: wrong content-length");
1007             ++store_check_cachable_hist.no.wrong_content_length;
1008         } else if (!EBIT_TEST(flags, ENTRY_CACHABLE)) {
1009             debugs(20, 2, "StoreEntry::checkCachable: NO: not cachable");
1010             ++store_check_cachable_hist.no.not_entry_cachable;
1011         } else if (EBIT_TEST(flags, ENTRY_NEGCACHED)) {
1012             debugs(20, 3, "StoreEntry::checkCachable: NO: negative cached");
1013             ++store_check_cachable_hist.no.negative_cached;
1014             return 0;           /* avoid release call below */
1015         } else if ((getReply()->content_length > 0 &&
1016                     getReply()->content_length
1017                     > Config.Store.maxObjectSize) ||
1018                    mem_obj->endOffset() > Config.Store.maxObjectSize) {
1019             debugs(20, 2, "StoreEntry::checkCachable: NO: too big");
1020             ++store_check_cachable_hist.no.too_big;
1021         } else if (checkTooSmall()) {
1022             debugs(20, 2, "StoreEntry::checkCachable: NO: too small");
1023             ++store_check_cachable_hist.no.too_small;
1024         } else if (EBIT_TEST(flags, KEY_PRIVATE)) {
1025             debugs(20, 3, "StoreEntry::checkCachable: NO: private key");
1026             ++store_check_cachable_hist.no.private_key;
1027         } else if (swap_status != SWAPOUT_NONE) {
1028             /*
1029              * here we checked the swap_status because the remaining
1030              * cases are only relevant only if we haven't started swapping
1031              * out the object yet.
1032              */
1033             return 1;
1034         } else if (storeTooManyDiskFilesOpen()) {
1035             debugs(20, 2, "StoreEntry::checkCachable: NO: too many disk files open");
1036             ++store_check_cachable_hist.no.too_many_open_files;
1037         } else if (fdNFree() < RESERVED_FD) {
1038             debugs(20, 2, "StoreEntry::checkCachable: NO: too many FD's open");
1039             ++store_check_cachable_hist.no.too_many_open_fds;
1040         } else {
1041             ++store_check_cachable_hist.yes.Default;
1042             return 1;
1043         }
1044
1045     releaseRequest();
1046     /* StoreEntry::releaseRequest() cleared ENTRY_CACHABLE */
1047     return 0;
1048 }
1049
1050 void
1051 storeCheckCachableStats(StoreEntry *sentry)
1052 {
1053     storeAppendPrintf(sentry, "Category\t Count\n");
1054
1055 #if CACHE_ALL_METHODS
1056
1057     storeAppendPrintf(sentry, "no.non_get\t%d\n",
1058                       store_check_cachable_hist.no.non_get);
1059 #endif
1060
1061     storeAppendPrintf(sentry, "no.not_entry_cachable\t%d\n",
1062                       store_check_cachable_hist.no.not_entry_cachable);
1063     storeAppendPrintf(sentry, "no.wrong_content_length\t%d\n",
1064                       store_check_cachable_hist.no.wrong_content_length);
1065     storeAppendPrintf(sentry, "no.negative_cached\t%d\n",
1066                       store_check_cachable_hist.no.negative_cached);
1067     storeAppendPrintf(sentry, "no.too_big\t%d\n",
1068                       store_check_cachable_hist.no.too_big);
1069     storeAppendPrintf(sentry, "no.too_small\t%d\n",
1070                       store_check_cachable_hist.no.too_small);
1071     storeAppendPrintf(sentry, "no.private_key\t%d\n",
1072                       store_check_cachable_hist.no.private_key);
1073     storeAppendPrintf(sentry, "no.too_many_open_files\t%d\n",
1074                       store_check_cachable_hist.no.too_many_open_files);
1075     storeAppendPrintf(sentry, "no.too_many_open_fds\t%d\n",
1076                       store_check_cachable_hist.no.too_many_open_fds);
1077     storeAppendPrintf(sentry, "yes.default\t%d\n",
1078                       store_check_cachable_hist.yes.Default);
1079 }
1080
1081 void
1082 StoreEntry::complete()
1083 {
1084     debugs(20, 3, "storeComplete: '" << getMD5Text() << "'");
1085
1086     if (store_status != STORE_PENDING) {
1087         /*
1088          * if we're not STORE_PENDING, then probably we got aborted
1089          * and there should be NO clients on this entry
1090          */
1091         assert(EBIT_TEST(flags, ENTRY_ABORTED));
1092         assert(mem_obj->nclients == 0);
1093         return;
1094     }
1095
1096     /* This is suspect: mem obj offsets include the headers. do we adjust for that
1097      * in use of object_sz?
1098      */
1099     mem_obj->object_sz = mem_obj->endOffset();
1100
1101     store_status = STORE_OK;
1102
1103     assert(mem_status == NOT_IN_MEMORY);
1104
1105     if (!validLength()) {
1106         EBIT_SET(flags, ENTRY_BAD_LENGTH);
1107         releaseRequest();
1108     }
1109
1110 #if USE_CACHE_DIGESTS
1111     if (mem_obj->request)
1112         mem_obj->request->hier.store_complete_stop = current_time;
1113
1114 #endif
1115     /*
1116      * We used to call invokeHandlers, then storeSwapOut.  However,
1117      * Madhukar Reddy <myreddy@persistence.com> reported that
1118      * responses without content length would sometimes get released
1119      * in client_side, thinking that the response is incomplete.
1120      */
1121     invokeHandlers();
1122 }
1123
1124 /*
1125  * Someone wants to abort this transfer.  Set the reason in the
1126  * request structure, call the server-side callback and mark the
1127  * entry for releasing
1128  */
1129 void
1130 StoreEntry::abort()
1131 {
1132     ++statCounter.aborted_requests;
1133     assert(store_status == STORE_PENDING);
1134     assert(mem_obj != NULL);
1135     debugs(20, 6, "storeAbort: " << getMD5Text());
1136
1137     lock();         /* lock while aborting */
1138     negativeCache();
1139
1140     releaseRequest();
1141
1142     EBIT_SET(flags, ENTRY_ABORTED);
1143
1144     setMemStatus(NOT_IN_MEMORY);
1145
1146     store_status = STORE_OK;
1147
1148     /* Notify the server side */
1149
1150     /*
1151      * DPW 2007-05-07
1152      * Should we check abort.data for validity?
1153      */
1154     if (mem_obj->abort.callback) {
1155         if (!cbdataReferenceValid(mem_obj->abort.data))
1156             debugs(20, DBG_IMPORTANT,HERE << "queueing event when abort.data is not valid");
1157         eventAdd("mem_obj->abort.callback",
1158                  mem_obj->abort.callback,
1159                  mem_obj->abort.data,
1160                  0.0,
1161                  true);
1162         unregisterAbort();
1163     }
1164
1165     /* XXX Should we reverse these two, so that there is no
1166      * unneeded disk swapping triggered?
1167      */
1168     /* Notify the client side */
1169     invokeHandlers();
1170
1171     // abort swap out, invalidating what was created so far (release follows)
1172     swapOutFileClose(StoreIOState::writerGone);
1173
1174     unlock();       /* unlock */
1175 }
1176
1177 /**
1178  * Clear Memory storage to accommodate the given object len
1179  */
1180 void
1181 storeGetMemSpace(int size)
1182 {
1183     PROF_start(storeGetMemSpace);
1184     StoreEntry *e = NULL;
1185     int released = 0;
1186     static time_t last_check = 0;
1187     size_t pages_needed;
1188     RemovalPurgeWalker *walker;
1189
1190     if (squid_curtime == last_check) {
1191         PROF_stop(storeGetMemSpace);
1192         return;
1193     }
1194
1195     last_check = squid_curtime;
1196
1197     pages_needed = (size + SM_PAGE_SIZE-1) / SM_PAGE_SIZE;
1198
1199     if (mem_node::InUseCount() + pages_needed < store_pages_max) {
1200         PROF_stop(storeGetMemSpace);
1201         return;
1202     }
1203
1204     debugs(20, 2, "storeGetMemSpace: Starting, need " << pages_needed <<
1205            " pages");
1206
1207     /* XXX what to set as max_scan here? */
1208     walker = mem_policy->PurgeInit(mem_policy, 100000);
1209
1210     while ((e = walker->Next(walker))) {
1211         e->purgeMem();
1212         ++released;
1213
1214         if (mem_node::InUseCount() + pages_needed < store_pages_max)
1215             break;
1216     }
1217
1218     walker->Done(walker);
1219     debugs(20, 3, "storeGetMemSpace stats:");
1220     debugs(20, 3, "  " << std::setw(6) << hot_obj_count  << " HOT objects");
1221     debugs(20, 3, "  " << std::setw(6) << released  << " were released");
1222     PROF_stop(storeGetMemSpace);
1223 }
1224
1225 /* thunk through to Store::Root().maintain(). Note that this would be better still
1226  * if registered against the root store itself, but that requires more complex
1227  * update logic - bigger fish to fry first. Long term each store when
1228  * it becomes active will self register
1229  */
1230 void
1231 Store::Maintain(void *notused)
1232 {
1233     Store::Root().maintain();
1234
1235     /* Reregister a maintain event .. */
1236     eventAdd("MaintainSwapSpace", Maintain, NULL, 1.0, 1);
1237
1238 }
1239
1240 /* The maximum objects to scan for maintain storage space */
1241 #define MAINTAIN_MAX_SCAN       1024
1242 #define MAINTAIN_MAX_REMOVE     64
1243
1244 /*
1245  * This routine is to be called by main loop in main.c.
1246  * It removes expired objects on only one bucket for each time called.
1247  *
1248  * This should get called 1/s from main().
1249  */
1250 void
1251 StoreController::maintain()
1252 {
1253     static time_t last_warn_time = 0;
1254
1255     PROF_start(storeMaintainSwapSpace);
1256     swapDir->maintain();
1257
1258     /* this should be emitted by the oversize dir, not globally */
1259
1260     if (Store::Root().currentSize() > Store::Root().maxSize()) {
1261         if (squid_curtime - last_warn_time > 10) {
1262             debugs(20, DBG_CRITICAL, "WARNING: Disk space over limit: "
1263                    << Store::Root().currentSize() / 1024.0 << " KB > "
1264                    << (Store::Root().maxSize() >> 10) << " KB");
1265             last_warn_time = squid_curtime;
1266         }
1267     }
1268
1269     PROF_stop(storeMaintainSwapSpace);
1270 }
1271
1272 /* release an object from a cache */
1273 void
1274 StoreEntry::release()
1275 {
1276     PROF_start(storeRelease);
1277     debugs(20, 3, "storeRelease: Releasing: '" << getMD5Text() << "'");
1278     /* If, for any reason we can't discard this object because of an
1279      * outstanding request, mark it for pending release */
1280
1281     if (locked()) {
1282         expireNow();
1283         debugs(20, 3, "storeRelease: Only setting RELEASE_REQUEST bit");
1284         releaseRequest();
1285         PROF_stop(storeRelease);
1286         return;
1287     }
1288
1289     if (StoreController::store_dirs_rebuilding && swap_filen > -1) {
1290         setPrivateKey();
1291
1292         if (mem_obj)
1293             destroyMemObject();
1294
1295         if (swap_filen > -1) {
1296             /*
1297              * Fake a call to StoreEntry->lock()  When rebuilding is done,
1298              * we'll just call StoreEntry->unlock() on these.
1299              */
1300             ++lock_count;
1301             setReleaseFlag();
1302             LateReleaseStack.push_back(this);
1303         } else {
1304             destroyStoreEntry(static_cast<hash_link *>(this));
1305             // "this" is no longer valid
1306         }
1307
1308         PROF_stop(storeRelease);
1309         return;
1310     }
1311
1312     storeLog(STORE_LOG_RELEASE, this);
1313
1314     if (swap_filen > -1) {
1315         // log before unlink() below clears swap_filen
1316         if (!EBIT_TEST(flags, KEY_PRIVATE))
1317             storeDirSwapLog(this, SWAP_LOG_DEL);
1318
1319         unlink();
1320     }
1321
1322     setMemStatus(NOT_IN_MEMORY);
1323     destroyStoreEntry(static_cast<hash_link *>(this));
1324     PROF_stop(storeRelease);
1325 }
1326
1327 static void
1328 storeLateRelease(void *unused)
1329 {
1330     StoreEntry *e;
1331     int i;
1332     static int n = 0;
1333
1334     if (StoreController::store_dirs_rebuilding) {
1335         eventAdd("storeLateRelease", storeLateRelease, NULL, 1.0, 1);
1336         return;
1337     }
1338
1339     for (i = 0; i < 10; ++i) {
1340         e = LateReleaseStack.count ? LateReleaseStack.pop() : NULL;
1341
1342         if (e == NULL) {
1343             /* done! */
1344             debugs(20, DBG_IMPORTANT, "storeLateRelease: released " << n << " objects");
1345             return;
1346         }
1347
1348         e->unlock();
1349         ++n;
1350     }
1351
1352     eventAdd("storeLateRelease", storeLateRelease, NULL, 0.0, 1);
1353 }
1354
1355 /* return 1 if a store entry is locked */
1356 int
1357 StoreEntry::locked() const
1358 {
1359     if (lock_count)
1360         return 1;
1361
1362     if (swap_status == SWAPOUT_WRITING)
1363         return 1;
1364
1365     if (store_status == STORE_PENDING)
1366         return 1;
1367
1368     /*
1369      * SPECIAL, PUBLIC entries should be "locked"
1370      */
1371     if (EBIT_TEST(flags, ENTRY_SPECIAL))
1372         if (!EBIT_TEST(flags, KEY_PRIVATE))
1373             return 1;
1374
1375     return 0;
1376 }
1377
1378 bool
1379 StoreEntry::validLength() const
1380 {
1381     int64_t diff;
1382     const HttpReply *reply;
1383     assert(mem_obj != NULL);
1384     reply = getReply();
1385     debugs(20, 3, "storeEntryValidLength: Checking '" << getMD5Text() << "'");
1386     debugs(20, 5, "storeEntryValidLength:     object_len = " <<
1387            objectLen());
1388     debugs(20, 5, "storeEntryValidLength:         hdr_sz = " << reply->hdr_sz);
1389     debugs(20, 5, "storeEntryValidLength: content_length = " << reply->content_length);
1390
1391     if (reply->content_length < 0) {
1392         debugs(20, 5, "storeEntryValidLength: Unspecified content length: " << getMD5Text());
1393         return 1;
1394     }
1395
1396     if (reply->hdr_sz == 0) {
1397         debugs(20, 5, "storeEntryValidLength: Zero header size: " << getMD5Text());
1398         return 1;
1399     }
1400
1401     if (mem_obj->method == Http::METHOD_HEAD) {
1402         debugs(20, 5, "storeEntryValidLength: HEAD request: " << getMD5Text());
1403         return 1;
1404     }
1405
1406     if (reply->sline.status == HTTP_NOT_MODIFIED)
1407         return 1;
1408
1409     if (reply->sline.status == HTTP_NO_CONTENT)
1410         return 1;
1411
1412     diff = reply->hdr_sz + reply->content_length - objectLen();
1413
1414     if (diff == 0)
1415         return 1;
1416
1417     debugs(20, 3, "storeEntryValidLength: " << (diff < 0 ? -diff : diff)  << " bytes too " << (diff < 0 ? "big" : "small") <<"; '" << getMD5Text() << "'" );
1418
1419     return 0;
1420 }
1421
1422 static void
1423 storeRegisterWithCacheManager(void)
1424 {
1425     Mgr::RegisterAction("storedir", "Store Directory Stats", Store::Stats, 0, 1);
1426     Mgr::RegisterAction("store_io", "Store IO Interface Stats", &Mgr::StoreIoAction::Create, 0, 1);
1427     Mgr::RegisterAction("store_check_cachable_stats", "storeCheckCachable() Stats",
1428                         storeCheckCachableStats, 0, 1);
1429 }
1430
1431 void
1432 storeInit(void)
1433 {
1434     storeKeyInit();
1435     mem_policy = createRemovalPolicy(Config.memPolicy);
1436     storeDigestInit();
1437     storeLogOpen();
1438     eventAdd("storeLateRelease", storeLateRelease, NULL, 1.0, 1);
1439     Store::Root().init();
1440     storeRebuildStart();
1441
1442     storeRegisterWithCacheManager();
1443 }
1444
1445 void
1446 storeConfigure(void)
1447 {
1448     store_swap_high = (long) (((float) Store::Root().maxSize() *
1449                                (float) Config.Swap.highWaterMark) / (float) 100);
1450     store_swap_low = (long) (((float) Store::Root().maxSize() *
1451                               (float) Config.Swap.lowWaterMark) / (float) 100);
1452     store_pages_max = Config.memMaxSize / sizeof(mem_node);
1453 }
1454
1455 bool
1456 StoreEntry::memoryCachable() const
1457 {
1458     if (mem_obj == NULL)
1459         return 0;
1460
1461     if (mem_obj->data_hdr.size() == 0)
1462         return 0;
1463
1464     if (mem_obj->inmem_lo != 0)
1465         return 0;
1466
1467     if (!Config.onoff.memory_cache_first && swap_status == SWAPOUT_DONE && refcount == 1)
1468         return 0;
1469
1470     return 1;
1471 }
1472
1473 int
1474 StoreEntry::checkNegativeHit() const
1475 {
1476     if (!EBIT_TEST(flags, ENTRY_NEGCACHED))
1477         return 0;
1478
1479     if (expires <= squid_curtime)
1480         return 0;
1481
1482     if (store_status != STORE_OK)
1483         return 0;
1484
1485     return 1;
1486 }
1487
1488 /**
1489  * Set object for negative caching.
1490  * Preserves any expiry information given by the server.
1491  * In absence of proper expiry info it will set to expire immediately,
1492  * or with HTTP-violations enabled the configured negative-TTL is observed
1493  */
1494 void
1495 StoreEntry::negativeCache()
1496 {
1497     // XXX: should make the default for expires 0 instead of -1
1498     //      so we can distinguish "Expires: -1" from nothing.
1499     if (expires <= 0)
1500 #if USE_HTTP_VIOLATIONS
1501         expires = squid_curtime + Config.negativeTtl;
1502 #else
1503         expires = squid_curtime;
1504 #endif
1505     EBIT_SET(flags, ENTRY_NEGCACHED);
1506 }
1507
1508 void
1509 storeFreeMemory(void)
1510 {
1511     Store::Root(NULL);
1512 #if USE_CACHE_DIGESTS
1513
1514     if (store_digest)
1515         cacheDigestDestroy(store_digest);
1516
1517 #endif
1518
1519     store_digest = NULL;
1520 }
1521
1522 int
1523 expiresMoreThan(time_t expires, time_t when)
1524 {
1525     if (expires < 0)            /* No Expires given */
1526         return 1;
1527
1528     return (expires > (squid_curtime + when));
1529 }
1530
1531 int
1532 StoreEntry::validToSend() const
1533 {
1534     if (EBIT_TEST(flags, RELEASE_REQUEST))
1535         return 0;
1536
1537     if (EBIT_TEST(flags, ENTRY_NEGCACHED))
1538         if (expires <= squid_curtime)
1539             return 0;
1540
1541     if (EBIT_TEST(flags, ENTRY_ABORTED))
1542         return 0;
1543
1544     return 1;
1545 }
1546
1547 void
1548 StoreEntry::timestampsSet()
1549 {
1550     const HttpReply *reply = getReply();
1551     time_t served_date = reply->date;
1552     int age = reply->header.getInt(HDR_AGE);
1553     /* Compute the timestamp, mimicking RFC2616 section 13.2.3. */
1554     /* make sure that 0 <= served_date <= squid_curtime */
1555
1556     if (served_date < 0 || served_date > squid_curtime)
1557         served_date = squid_curtime;
1558
1559     /* Bug 1791:
1560      * If the returned Date: is more than 24 hours older than
1561      * the squid_curtime, then one of us needs to use NTP to set our
1562      * clock.  We'll pretend that our clock is right.
1563      */
1564     else if (served_date < (squid_curtime - 24 * 60 * 60) )
1565         served_date = squid_curtime;
1566
1567     /*
1568      * Compensate with Age header if origin server clock is ahead
1569      * of us and there is a cache in between us and the origin
1570      * server.  But DONT compensate if the age value is larger than
1571      * squid_curtime because it results in a negative served_date.
1572      */
1573     if (age > squid_curtime - served_date)
1574         if (squid_curtime > age)
1575             served_date = squid_curtime - age;
1576
1577     // compensate for Squid-to-server and server-to-Squid delays
1578     if (mem_obj && mem_obj->request) {
1579         const time_t request_sent =
1580             mem_obj->request->hier.peer_http_request_sent.tv_sec;
1581         if (0 < request_sent && request_sent < squid_curtime)
1582             served_date -= (squid_curtime - request_sent);
1583     }
1584
1585     if (reply->expires > 0 && reply->date > -1)
1586         expires = served_date + (reply->expires - reply->date);
1587     else
1588         expires = reply->expires;
1589
1590     lastmod = reply->last_modified;
1591
1592     timestamp = served_date;
1593 }
1594
1595 void
1596 StoreEntry::registerAbort(STABH * cb, void *data)
1597 {
1598     assert(mem_obj);
1599     assert(mem_obj->abort.callback == NULL);
1600     mem_obj->abort.callback = cb;
1601     mem_obj->abort.data = cbdataReference(data);
1602 }
1603
1604 void
1605 StoreEntry::unregisterAbort()
1606 {
1607     assert(mem_obj);
1608     if (mem_obj->abort.callback) {
1609         mem_obj->abort.callback = NULL;
1610         cbdataReferenceDone(mem_obj->abort.data);
1611     }
1612 }
1613
1614 void
1615 StoreEntry::dump(int l) const
1616 {
1617     debugs(20, l, "StoreEntry->key: " << getMD5Text());
1618     debugs(20, l, "StoreEntry->next: " << next);
1619     debugs(20, l, "StoreEntry->mem_obj: " << mem_obj);
1620     debugs(20, l, "StoreEntry->timestamp: " << timestamp);
1621     debugs(20, l, "StoreEntry->lastref: " << lastref);
1622     debugs(20, l, "StoreEntry->expires: " << expires);
1623     debugs(20, l, "StoreEntry->lastmod: " << lastmod);
1624     debugs(20, l, "StoreEntry->swap_file_sz: " << swap_file_sz);
1625     debugs(20, l, "StoreEntry->refcount: " << refcount);
1626     debugs(20, l, "StoreEntry->flags: " << storeEntryFlags(this));
1627     debugs(20, l, "StoreEntry->swap_dirn: " << swap_dirn);
1628     debugs(20, l, "StoreEntry->swap_filen: " << swap_filen);
1629     debugs(20, l, "StoreEntry->lock_count: " << lock_count);
1630     debugs(20, l, "StoreEntry->mem_status: " << mem_status);
1631     debugs(20, l, "StoreEntry->ping_status: " << ping_status);
1632     debugs(20, l, "StoreEntry->store_status: " << store_status);
1633     debugs(20, l, "StoreEntry->swap_status: " << swap_status);
1634 }
1635
1636 /*
1637  * NOTE, this function assumes only two mem states
1638  */
1639 void
1640 StoreEntry::setMemStatus(mem_status_t new_status)
1641 {
1642     if (new_status == mem_status)
1643         return;
1644
1645     // are we using a shared memory cache?
1646     if (Config.memShared && IamWorkerProcess()) {
1647         // enumerate calling cases if shared memory is enabled
1648         assert(new_status != IN_MEMORY || EBIT_TEST(flags, ENTRY_SPECIAL));
1649         // This method was designed to update replacement policy, not to
1650         // actually purge something from the memory cache (TODO: rename?).
1651         // Shared memory cache does not have a policy that needs updates.
1652         mem_status = new_status;
1653         return;
1654     }
1655
1656     assert(mem_obj != NULL);
1657
1658     if (new_status == IN_MEMORY) {
1659         assert(mem_obj->inmem_lo == 0);
1660
1661         if (EBIT_TEST(flags, ENTRY_SPECIAL)) {
1662             debugs(20, 4, "StoreEntry::setMemStatus: not inserting special " << mem_obj->url << " into policy");
1663         } else {
1664             mem_policy->Add(mem_policy, this, &mem_obj->repl);
1665             debugs(20, 4, "StoreEntry::setMemStatus: inserted mem node " << mem_obj->url << " key: " << getMD5Text());
1666         }
1667
1668         ++hot_obj_count; // TODO: maintain for the shared hot cache as well
1669     } else {
1670         if (EBIT_TEST(flags, ENTRY_SPECIAL)) {
1671             debugs(20, 4, "StoreEntry::setMemStatus: special entry " << mem_obj->url);
1672         } else {
1673             mem_policy->Remove(mem_policy, this, &mem_obj->repl);
1674             debugs(20, 4, "StoreEntry::setMemStatus: removed mem node " << mem_obj->url);
1675         }
1676
1677         --hot_obj_count;
1678     }
1679
1680     mem_status = new_status;
1681 }
1682
1683 const char *
1684 StoreEntry::url() const
1685 {
1686     if (this == NULL)
1687         return "[null_entry]";
1688     else if (mem_obj == NULL)
1689         return "[null_mem_obj]";
1690     else
1691         return mem_obj->url;
1692 }
1693
1694 void
1695 StoreEntry::createMemObject(const char *aUrl, const char *aLogUrl)
1696 {
1697     debugs(20, 3, "A mem_obj create attempted using : " << aUrl);
1698
1699     if (mem_obj)
1700         return;
1701
1702     if (hidden_mem_obj) {
1703         debugs(20, 3, HERE << "restoring " << hidden_mem_obj);
1704         mem_obj = hidden_mem_obj;
1705         hidden_mem_obj = NULL;
1706         mem_obj->resetUrls(aUrl, aLogUrl);
1707         return;
1708     }
1709
1710     mem_obj = new MemObject(aUrl, aLogUrl);
1711 }
1712
1713 /* this just sets DELAY_SENDING */
1714 void
1715 StoreEntry::buffer()
1716 {
1717     EBIT_SET(flags, DELAY_SENDING);
1718 }
1719
1720 /* this just clears DELAY_SENDING and Invokes the handlers */
1721 void
1722 StoreEntry::flush()
1723 {
1724     if (EBIT_TEST(flags, DELAY_SENDING)) {
1725         EBIT_CLR(flags, DELAY_SENDING);
1726         invokeHandlers();
1727     }
1728 }
1729
1730 int64_t
1731 StoreEntry::objectLen() const
1732 {
1733     assert(mem_obj != NULL);
1734     return mem_obj->object_sz;
1735 }
1736
1737 int64_t
1738 StoreEntry::contentLen() const
1739 {
1740     assert(mem_obj != NULL);
1741     assert(getReply() != NULL);
1742     return objectLen() - getReply()->hdr_sz;
1743 }
1744
1745 HttpReply const *
1746 StoreEntry::getReply () const
1747 {
1748     if (NULL == mem_obj)
1749         return NULL;
1750
1751     return mem_obj->getReply();
1752 }
1753
1754 void
1755 StoreEntry::reset()
1756 {
1757     assert (mem_obj);
1758     debugs(20, 3, "StoreEntry::reset: " << url());
1759     mem_obj->reset();
1760     HttpReply *rep = (HttpReply *) getReply();       // bypass const
1761     rep->reset();
1762     expires = lastmod = timestamp = -1;
1763 }
1764
1765 /*
1766  * storeFsInit
1767  *
1768  * This routine calls the SETUP routine for each fs type.
1769  * I don't know where the best place for this is, and I'm not going to shuffle
1770  * around large chunks of code right now (that can be done once its working.)
1771  */
1772 void
1773 storeFsInit(void)
1774 {
1775     storeReplSetup();
1776 }
1777
1778 /*
1779  * called to add another store removal policy module
1780  */
1781 void
1782 storeReplAdd(const char *type, REMOVALPOLICYCREATE * create)
1783 {
1784     int i;
1785
1786     /* find the number of currently known repl types */
1787     for (i = 0; storerepl_list && storerepl_list[i].typestr; ++i) {
1788         if (strcmp(storerepl_list[i].typestr, type) == 0) {
1789             debugs(20, DBG_IMPORTANT, "WARNING: Trying to load store replacement policy " << type << " twice.");
1790             return;
1791         }
1792     }
1793
1794     /* add the new type */
1795     storerepl_list = static_cast<storerepl_entry_t *>(xrealloc(storerepl_list, (i + 2) * sizeof(storerepl_entry_t)));
1796
1797     memset(&storerepl_list[i + 1], 0, sizeof(storerepl_entry_t));
1798
1799     storerepl_list[i].typestr = type;
1800
1801     storerepl_list[i].create = create;
1802 }
1803
1804 /*
1805  * Create a removal policy instance
1806  */
1807 RemovalPolicy *
1808 createRemovalPolicy(RemovalPolicySettings * settings)
1809 {
1810     storerepl_entry_t *r;
1811
1812     for (r = storerepl_list; r && r->typestr; ++r) {
1813         if (strcmp(r->typestr, settings->type) == 0)
1814             return r->create(settings->args);
1815     }
1816
1817     debugs(20, DBG_IMPORTANT, "ERROR: Unknown policy " << settings->type);
1818     debugs(20, DBG_IMPORTANT, "ERROR: Be sure to have set cache_replacement_policy");
1819     debugs(20, DBG_IMPORTANT, "ERROR:   and memory_replacement_policy in squid.conf!");
1820     fatalf("ERROR: Unknown policy %s\n", settings->type);
1821     return NULL;                /* NOTREACHED */
1822 }
1823
1824 #if 0
1825 void
1826 storeSwapFileNumberSet(StoreEntry * e, sfileno filn)
1827 {
1828     if (e->swap_file_number == filn)
1829         return;
1830
1831     if (filn < 0) {
1832         assert(-1 == filn);
1833         storeDirMapBitReset(e->swap_file_number);
1834         storeDirLRUDelete(e);
1835         e->swap_file_number = -1;
1836     } else {
1837         assert(-1 == e->swap_file_number);
1838         storeDirMapBitSet(e->swap_file_number = filn);
1839         storeDirLRUAdd(e);
1840     }
1841 }
1842
1843 #endif
1844
1845 /*
1846  * Replace a store entry with
1847  * a new reply. This eats the reply.
1848  */
1849 void
1850 StoreEntry::replaceHttpReply(HttpReply *rep, bool andStartWriting)
1851 {
1852     debugs(20, 3, "StoreEntry::replaceHttpReply: " << url());
1853
1854     if (!mem_obj) {
1855         debugs(20, DBG_CRITICAL, "Attempt to replace object with no in-memory representation");
1856         return;
1857     }
1858
1859     mem_obj->replaceHttpReply(rep);
1860
1861     if (andStartWriting)
1862         startWriting();
1863 }
1864
1865 void
1866 StoreEntry::startWriting()
1867 {
1868     Packer p;
1869
1870     /* TODO: when we store headers serparately remove the header portion */
1871     /* TODO: mark the length of the headers ? */
1872     /* We ONLY want the headers */
1873     packerToStoreInit(&p, this);
1874
1875     assert (isEmpty());
1876     assert(mem_obj);
1877
1878     const HttpReply *rep = getReply();
1879     assert(rep);
1880
1881     rep->packHeadersInto(&p);
1882     mem_obj->markEndOfReplyHeaders();
1883
1884     rep->body.packInto(&p);
1885
1886     packerClean(&p);
1887 }
1888
1889 char const *
1890 StoreEntry::getSerialisedMetaData()
1891 {
1892     StoreMeta *tlv_list = storeSwapMetaBuild(this);
1893     int swap_hdr_sz;
1894     char *result = storeSwapMetaPack(tlv_list, &swap_hdr_sz);
1895     storeSwapTLVFree(tlv_list);
1896     assert (swap_hdr_sz >= 0);
1897     mem_obj->swap_hdr_sz = (size_t) swap_hdr_sz;
1898     return result;
1899 }
1900
1901 void
1902 StoreEntry::trimMemory(const bool preserveSwappable)
1903 {
1904     /*
1905      * DPW 2007-05-09
1906      * Bug #1943.  We must not let go any data for IN_MEMORY
1907      * objects.  We have to wait until the mem_status changes.
1908      */
1909     if (mem_status == IN_MEMORY)
1910         return;
1911
1912     if (EBIT_TEST(flags, ENTRY_SPECIAL))
1913         return; // cannot trim because we do not load them again
1914
1915     if (!preserveSwappable) {
1916         if (mem_obj->policyLowestOffsetToKeep(0) == 0) {
1917             /* Nothing to do */
1918             return;
1919         }
1920         /*
1921          * Its not swap-able, and we're about to delete a chunk,
1922          * so we must make it PRIVATE.  This is tricky/ugly because
1923          * for the most part, we treat swapable == cachable here.
1924          */
1925         releaseRequest();
1926         mem_obj->trimUnSwappable ();
1927     } else {
1928         mem_obj->trimSwappable ();
1929     }
1930 }
1931
1932 bool
1933 StoreEntry::modifiedSince(HttpRequest * request) const
1934 {
1935     int object_length;
1936     time_t mod_time = lastmod;
1937
1938     if (mod_time < 0)
1939         mod_time = timestamp;
1940
1941     debugs(88, 3, "modifiedSince: '" << url() << "'");
1942
1943     debugs(88, 3, "modifiedSince: mod_time = " << mod_time);
1944
1945     if (mod_time < 0)
1946         return true;
1947
1948     /* Find size of the object */
1949     object_length = getReply()->content_length;
1950
1951     if (object_length < 0)
1952         object_length = contentLen();
1953
1954     if (mod_time > request->ims) {
1955         debugs(88, 3, "--> YES: entry newer than client");
1956         return true;
1957     } else if (mod_time < request->ims) {
1958         debugs(88, 3, "-->  NO: entry older than client");
1959         return false;
1960     } else if (request->imslen < 0) {
1961         debugs(88, 3, "-->  NO: same LMT, no client length");
1962         return false;
1963     } else if (request->imslen == object_length) {
1964         debugs(88, 3, "-->  NO: same LMT, same length");
1965         return false;
1966     } else {
1967         debugs(88, 3, "--> YES: same LMT, different length");
1968         return true;
1969     }
1970 }
1971
1972 bool
1973 StoreEntry::hasIfMatchEtag(const HttpRequest &request) const
1974 {
1975     const String reqETags = request.header.getList(HDR_IF_MATCH);
1976     return hasOneOfEtags(reqETags, false);
1977 }
1978
1979 bool
1980 StoreEntry::hasIfNoneMatchEtag(const HttpRequest &request) const
1981 {
1982     const String reqETags = request.header.getList(HDR_IF_NONE_MATCH);
1983     // weak comparison is allowed only for HEAD or full-body GET requests
1984     const bool allowWeakMatch = !request.flags.isRanged &&
1985                                 (request.method == Http::METHOD_GET || request.method == Http::METHOD_HEAD);
1986     return hasOneOfEtags(reqETags, allowWeakMatch);
1987 }
1988
1989 /// whether at least one of the request ETags matches entity ETag
1990 bool
1991 StoreEntry::hasOneOfEtags(const String &reqETags, const bool allowWeakMatch) const
1992 {
1993     const ETag repETag = getReply()->header.getETag(HDR_ETAG);
1994     if (!repETag.str)
1995         return strListIsMember(&reqETags, "*", ',');
1996
1997     bool matched = false;
1998     const char *pos = NULL;
1999     const char *item;
2000     int ilen;
2001     while (!matched && strListGetItem(&reqETags, ',', &item, &ilen, &pos)) {
2002         if (!strncmp(item, "*", ilen))
2003             matched = true;
2004         else {
2005             String str;
2006             str.append(item, ilen);
2007             ETag reqETag;
2008             if (etagParseInit(&reqETag, str.termedBuf())) {
2009                 matched = allowWeakMatch ? etagIsWeakEqual(repETag, reqETag) :
2010                           etagIsStrongEqual(repETag, reqETag);
2011             }
2012         }
2013     }
2014     return matched;
2015 }
2016
2017 SwapDir::Pointer
2018 StoreEntry::store() const
2019 {
2020     assert(0 <= swap_dirn && swap_dirn < Config.cacheSwap.n_configured);
2021     return INDEXSD(swap_dirn);
2022 }
2023
2024 void
2025 StoreEntry::unlink()
2026 {
2027     store()->unlink(*this); // implies disconnect()
2028     swap_filen = -1;
2029     swap_dirn = -1;
2030     swap_status = SWAPOUT_NONE;
2031 }
2032
2033 /*
2034  * return true if the entry is in a state where
2035  * it can accept more data (ie with write() method)
2036  */
2037 bool
2038 StoreEntry::isAccepting() const
2039 {
2040     if (STORE_PENDING != store_status)
2041         return false;
2042
2043     if (EBIT_TEST(flags, ENTRY_ABORTED))
2044         return false;
2045
2046     return true;
2047 }
2048
2049 std::ostream &operator <<(std::ostream &os, const StoreEntry &e)
2050 {
2051     return os << e.swap_filen << '@' << e.swap_dirn << '=' <<
2052            e.mem_status << '/' << e.ping_status << '/' << e.store_status << '/' <<
2053            e.swap_status;
2054 }
2055
2056 /* NullStoreEntry */
2057
2058 NullStoreEntry NullStoreEntry::_instance;
2059
2060 NullStoreEntry *
2061 NullStoreEntry::getInstance()
2062 {
2063     return &_instance;
2064 }
2065
2066 char const *
2067 NullStoreEntry::getMD5Text() const
2068 {
2069     return "N/A";
2070 }
2071
2072 void
2073 NullStoreEntry::operator delete(void*)
2074 {
2075     fatal ("Attempt to delete NullStoreEntry\n");
2076 }
2077
2078 char const *
2079 NullStoreEntry::getSerialisedMetaData()
2080 {
2081     return NULL;
2082 }
2083
2084 #if !_USE_INLINE_
2085 #include "Store.cci"
2086 #endif