src/store.cc

   1
   2 /*
   3  * $Id$
   4  *
   5  * DEBUG: section 20    Storage Manager
   6  * AUTHOR: Harvest Derived
   7  *
   8  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   9  * ----------------------------------------------------------
  10  *
  11  *  Squid is the result of efforts by numerous individuals from
  12  *  the Internet community; see the CONTRIBUTORS file for full
  13  *  details.   Many organizations have provided support for Squid's
  14  *  development; see the SPONSORS file for full details.  Squid is
  15  *  Copyrighted (C) 2001 by the Regents of the University of
  16  *  California; see the COPYRIGHT file for full details.  Squid
  17  *  incorporates software developed and/or copyrighted by other
  18  *  sources; see the CREDITS file for full details.
  19  *
  20  *  This program is free software; you can redistribute it and/or modify
  21  *  it under the terms of the GNU General Public License as published by
  22  *  the Free Software Foundation; either version 2 of the License, or
  23  *  (at your option) any later version.
  24  *
  25  *  This program is distributed in the hope that it will be useful,
  26  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  27  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  28  *  GNU General Public License for more details.
  29  *
  30  *  You should have received a copy of the GNU General Public License
  31  *  along with this program; if not, write to the Free Software
  32  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  33  *
  34  */
  35
  36 #include "squid.h"
  37 #include "CacheManager.h"
  38 #include "comm/Connection.h"
  39 #include "ETag.h"
  40 #include "event.h"
  41 #include "fde.h"
  42 #include "Store.h"
  43 #include "mgr/Registration.h"
  44 #include "StoreClient.h"
  45 #include "stmem.h"
  46 #include "HttpReply.h"
  47 #include "HttpRequest.h"
  48 #include "MemObject.h"
  49 #include "mem_node.h"
  50 #include "StoreMeta.h"
  51 #include "SwapDir.h"
  52 #include "StoreIOState.h"
  53 #if USE_DELAY_POOLS
  54 #include "DelayPools.h"
  55 #endif
  56 #include "Stack.h"
  57 #include "SquidTime.h"
  58 #include "swap_log_op.h"
  59 #include "mgr/StoreIoAction.h"
  60
  61 static STMCB storeWriteComplete;
  62
  63 #define REBUILD_TIMESTAMP_DELTA_MAX 2
  64
  65 #define STORE_IN_MEM_BUCKETS            (229)
  66
  67
  68 /** \todo Convert these string constants to enum string-arrays generated */
  69
  70 const char *memStatusStr[] = {
  71     "NOT_IN_MEMORY",
  72     "IN_MEMORY"
  73 };
  74
  75 const char *pingStatusStr[] = {
  76     "PING_NONE",
  77     "PING_WAITING",
  78     "PING_DONE"
  79 };
  80
  81 const char *storeStatusStr[] = {
  82     "STORE_OK",
  83     "STORE_PENDING"
  84 };
  85
  86 const char *swapStatusStr[] = {
  87     "SWAPOUT_NONE",
  88     "SWAPOUT_WRITING",
  89     "SWAPOUT_DONE"
  90 };
  91
  92
  93 /*
  94  * This defines an repl type
  95  */
  96
  97 typedef struct _storerepl_entry storerepl_entry_t;
  98
  99 struct _storerepl_entry {
 100     const char *typestr;
 101     REMOVALPOLICYCREATE *create;
 102 };
 103
 104 static storerepl_entry_t *storerepl_list = NULL;
 105
 106
 107 /*
 108  * local function prototypes
 109  */
 110 static int getKeyCounter(void);
 111 static OBJH storeCheckCachableStats;
 112 static EVH storeLateRelease;
 113
 114 /*
 115  * local variables
 116  */
 117 static Stack<StoreEntry*> LateReleaseStack;
 118 MemAllocator *StoreEntry::pool = NULL;
 119
 120 StorePointer Store::CurrentRoot = NULL;
 121
 122 void
 123 Store::Root(Store * aRoot)
 124 {
 125     CurrentRoot = aRoot;
 126 }
 127
 128 void
 129 Store::Root(StorePointer aRoot)
 130 {
 131     Root(aRoot.getRaw());
 132 }
 133
 134 void
 135 Store::Stats(StoreEntry * output)
 136 {
 137     assert (output);
 138     Root().stat(*output);
 139 }
 140
 141 void
 142 Store::create()
 143 {}
 144
 145 void
 146 Store::diskFull()
 147 {}
 148
 149 void
 150 Store::sync()
 151 {}
 152
 153 void
 154 Store::unlink (StoreEntry &anEntry)
 155 {
 156     fatal("Store::unlink on invalid Store\n");
 157 }
 158
 159 void *
 160 StoreEntry::operator new (size_t bytecount)
 161 {
 162     assert (bytecount == sizeof (StoreEntry));
 163
 164     if (!pool) {
 165         pool = memPoolCreate ("StoreEntry", bytecount);
 166         pool->setChunkSize(2048 * 1024);
 167     }
 168
 169     return pool->alloc();
 170 }
 171
 172 void
 173 StoreEntry::operator delete (void *address)
 174 {
 175     pool->freeOne(address);
 176 }
 177
 178 void
 179 StoreEntry::makePublic()
 180 {
 181     /* This object can be cached for a long time */
 182
 183     if (EBIT_TEST(flags, ENTRY_CACHABLE))
 184         setPublicKey();
 185 }
 186
 187 void
 188 StoreEntry::makePrivate()
 189 {
 190     /* This object should never be cached at all */
 191     expireNow();
 192     releaseRequest(); /* delete object when not used */
 193     /* releaseRequest clears ENTRY_CACHABLE flag */
 194 }
 195
 196 void
 197 StoreEntry::cacheNegatively()
 198 {
 199     /* This object may be negatively cached */
 200     negativeCache();
 201
 202     if (EBIT_TEST(flags, ENTRY_CACHABLE))
 203         setPublicKey();
 204 }
 205
 206 size_t
 207 StoreEntry::inUseCount()
 208 {
 209     if (!pool)
 210         return 0;
 211     return pool->getInUseCount();
 212 }
 213
 214 const char *
 215 StoreEntry::getMD5Text() const
 216 {
 217     return storeKeyText((const cache_key *)key);
 218 }
 219
 220 #include "comm.h"
 221
 222 void
 223 StoreEntry::DeferReader(void *theContext, CommRead const &aRead)
 224 {
 225     StoreEntry *anEntry = (StoreEntry *)theContext;
 226     anEntry->delayAwareRead(aRead.conn,
 227                             aRead.buf,
 228                             aRead.len,
 229                             aRead.callback);
 230 }
 231
 232 void
 233 StoreEntry::delayAwareRead(const Comm::ConnectionPointer &conn, char *buf, int len, AsyncCall::Pointer callback)
 234 {
 235     size_t amountToRead = bytesWanted(Range<size_t>(0, len));
 236     /* sketch: readdeferer* = getdeferer.
 237      * ->deferRead (fd, buf, len, callback, DelayAwareRead, this)
 238      */
 239
 240     if (amountToRead == 0) {
 241         assert (mem_obj);
 242         /* read ahead limit */
 243         /* Perhaps these two calls should both live in MemObject */
 244 #if USE_DELAY_POOLS
 245         if (!mem_obj->readAheadPolicyCanRead()) {
 246 #endif
 247             mem_obj->delayRead(DeferredRead(DeferReader, this, CommRead(conn, buf, len, callback)));
 248             return;
 249 #if USE_DELAY_POOLS
 250         }
 251
 252         /* delay id limit */
 253         mem_obj->mostBytesAllowed().delayRead(DeferredRead(DeferReader, this, CommRead(conn, buf, len, callback)));
 254         return;
 255
 256 #endif
 257
 258     }
 259
 260     if (fd_table[conn->fd].closing()) {
 261         // Readers must have closing callbacks if they want to be notified. No
 262         // readers appeared to care around 2009/12/14 as they skipped reading
 263         // for other reasons. Closing may already be true at the delyaAwareRead
 264         // call time or may happen while we wait after delayRead() above.
 265         debugs(20, 3, HERE << "wont read from closing " << conn << " for " <<
 266                callback);
 267         return; // the read callback will never be called
 268     }
 269
 270     comm_read(conn, buf, amountToRead, callback);
 271 }
 272
 273 size_t
 274 StoreEntry::bytesWanted (Range<size_t> const aRange) const
 275 {
 276     assert (aRange.size());
 277
 278     if (mem_obj == NULL)
 279         return aRange.end - 1;
 280
 281 #if URL_CHECKSUM_DEBUG
 282
 283     mem_obj->checkUrlChecksum();
 284
 285 #endif
 286
 287     /* Always read *something* here - we haven't got the header yet */
 288     if (EBIT_TEST(flags, ENTRY_FWD_HDR_WAIT))
 289         return aRange.end - 1;
 290
 291     if (!mem_obj->readAheadPolicyCanRead())
 292         return 0;
 293
 294     return mem_obj->mostBytesWanted(aRange.end - 1);
 295 }
 296
 297 bool
 298 StoreEntry::checkDeferRead(int fd) const
 299 {
 300     return (bytesWanted(Range<size_t>(0,INT_MAX)) == 0);
 301 }
 302
 303 void
 304 StoreEntry::setNoDelay (bool const newValue)
 305 {
 306     if (mem_obj)
 307         mem_obj->setNoDelay(newValue);
 308 }
 309
 310 store_client_t
 311 StoreEntry::storeClientType() const
 312 {
 313     /* The needed offset isn't in memory
 314      * XXX TODO: this is wrong for range requests
 315      * as the needed offset may *not* be 0, AND
 316      * offset 0 in the memory object is the HTTP headers.
 317      */
 318
 319     if (mem_status == IN_MEMORY && UsingSmp()) {
 320         // clients of an object cached in shared memory are memory clients
 321         return STORE_MEM_CLIENT;
 322     }
 323
 324     assert(mem_obj);
 325
 326     if (mem_obj->inmem_lo)
 327         return STORE_DISK_CLIENT;
 328
 329     if (EBIT_TEST(flags, ENTRY_ABORTED)) {
 330         /* I don't think we should be adding clients to aborted entries */
 331         debugs(20, 1, "storeClientType: adding to ENTRY_ABORTED entry");
 332         return STORE_MEM_CLIENT;
 333     }
 334
 335     if (store_status == STORE_OK) {
 336         /* the object has completed. */
 337
 338         if (mem_obj->inmem_lo == 0 && !isEmpty()) {
 339             if (swap_status == SWAPOUT_DONE) {
 340                 debugs(20,7, HERE << mem_obj << " lo: " << mem_obj->inmem_lo << " hi: " << mem_obj->endOffset() << " size: " << mem_obj->object_sz);
 341                 if (mem_obj->endOffset() == mem_obj->object_sz) {
 342                     /* hot object fully swapped in */
 343                     return STORE_MEM_CLIENT;
 344                 }
 345             } else {
 346                 /* Memory-only, or currently being swapped out */
 347                 return STORE_MEM_CLIENT;
 348             }
 349         }
 350         return STORE_DISK_CLIENT;
 351     }
 352
 353     /* here and past, entry is STORE_PENDING */
 354     /*
 355      * If this is the first client, let it be the mem client
 356      */
 357     if (mem_obj->nclients == 1)
 358         return STORE_MEM_CLIENT;
 359
 360     /*
 361      * If there is no disk file to open yet, we must make this a
 362      * mem client.  If we can't open the swapin file before writing
 363      * to the client, there is no guarantee that we will be able
 364      * to open it later when we really need it.
 365      */
 366     if (swap_status == SWAPOUT_NONE)
 367         return STORE_MEM_CLIENT;
 368
 369     /*
 370      * otherwise, make subsequent clients read from disk so they
 371      * can not delay the first, and vice-versa.
 372      */
 373     return STORE_DISK_CLIENT;
 374 }
 375
 376 StoreEntry::StoreEntry():
 377         hidden_mem_obj(NULL),
 378         swap_file_sz(0)
 379 {
 380     debugs(20, 3, HERE << "new StoreEntry " << this);
 381     mem_obj = NULL;
 382
 383     expires = lastmod = lastref = timestamp = -1;
 384
 385     swap_status = SWAPOUT_NONE;
 386     swap_filen = -1;
 387     swap_dirn = -1;
 388 }
 389
 390 StoreEntry::StoreEntry(const char *aUrl, const char *aLogUrl):
 391         hidden_mem_obj(NULL),
 392         swap_file_sz(0)
 393 {
 394     debugs(20, 3, HERE << "new StoreEntry " << this);
 395     mem_obj = new MemObject(aUrl, aLogUrl);
 396
 397     expires = lastmod = lastref = timestamp = -1;
 398
 399     swap_status = SWAPOUT_NONE;
 400     swap_filen = -1;
 401     swap_dirn = -1;
 402 }
 403
 404 StoreEntry::~StoreEntry()
 405 {
 406     if (swap_filen >= 0) {
 407         SwapDir &sd = dynamic_cast<SwapDir&>(*store());
 408         sd.disconnect(*this);
 409     }
 410     delete hidden_mem_obj;
 411 }
 412
 413 void
 414 StoreEntry::destroyMemObject()
 415 {
 416     debugs(20, 3, HERE << "destroyMemObject " << mem_obj);
 417     setMemStatus(NOT_IN_MEMORY);
 418     MemObject *mem = mem_obj;
 419     mem_obj = NULL;
 420     delete mem;
 421     delete hidden_mem_obj;
 422     hidden_mem_obj = NULL;
 423 }
 424
 425 void
 426 StoreEntry::hideMemObject()
 427 {
 428     debugs(20, 3, HERE << "hiding " << mem_obj);
 429     assert(mem_obj);
 430     assert(!hidden_mem_obj);
 431     hidden_mem_obj = mem_obj;
 432     mem_obj = NULL;
 433 }
 434
 435 void
 436 destroyStoreEntry(void *data)
 437 {
 438     debugs(20, 3, HERE << "destroyStoreEntry: destroying " <<  data);
 439     StoreEntry *e = static_cast<StoreEntry *>(static_cast<hash_link *>(data));
 440     assert(e != NULL);
 441
 442     if (e == NullStoreEntry::getInstance())
 443         return;
 444
 445     e->destroyMemObject();
 446
 447     e->hashDelete();
 448
 449     assert(e->key == NULL);
 450
 451     delete e;
 452 }
 453
 454 /* ----- INTERFACE BETWEEN STORAGE MANAGER AND HASH TABLE FUNCTIONS --------- */
 455
 456 void
 457 StoreEntry::hashInsert(const cache_key * someKey)
 458 {
 459     debugs(20, 3, "StoreEntry::hashInsert: Inserting Entry " << this << " key '" << storeKeyText(someKey) << "'");
 460     key = storeKeyDup(someKey);
 461     hash_join(store_table, this);
 462 }
 463
 464 void
 465 StoreEntry::hashDelete()
 466 {
 467     hash_remove_link(store_table, this);
 468     storeKeyFree((const cache_key *)key);
 469     key = NULL;
 470 }
 471
 472 /* -------------------------------------------------------------------------- */
 473
 474
 475 /* get rid of memory copy of the object */
 476 void
 477 StoreEntry::purgeMem()
 478 {
 479     if (mem_obj == NULL)
 480         return;
 481
 482     debugs(20, 3, "StoreEntry::purgeMem: Freeing memory-copy of " << getMD5Text());
 483
 484     destroyMemObject();
 485
 486     if (swap_status != SWAPOUT_DONE)
 487         release();
 488 }
 489
 490 /* RBC 20050104 this is wrong- memory ref counting
 491  * is not at all equivalent to the store 'usage' concept
 492  * which the replacement policies should be acting upon.
 493  * specifically, object iteration within stores needs
 494  * memory ref counting to prevent race conditions,
 495  * but this should not influence store replacement.
 496  */
 497 void
 498
 499 StoreEntry::lock()
 500 {
 501     lock_count++;
 502     debugs(20, 3, "StoreEntry::lock: key '" << getMD5Text() <<"' count=" <<
 503            lock_count  );
 504     lastref = squid_curtime;
 505     Store::Root().reference(*this);
 506 }
 507
 508 void
 509 StoreEntry::setReleaseFlag()
 510 {
 511     if (EBIT_TEST(flags, RELEASE_REQUEST))
 512         return;
 513
 514     debugs(20, 3, "StoreEntry::setReleaseFlag: '" << getMD5Text() << "'");
 515
 516     EBIT_SET(flags, RELEASE_REQUEST);
 517 }
 518
 519 void
 520 StoreEntry::releaseRequest()
 521 {
 522     if (EBIT_TEST(flags, RELEASE_REQUEST))
 523         return;
 524
 525     setReleaseFlag();
 526
 527     /*
 528      * Clear cachable flag here because we might get called before
 529      * anyone else even looks at the cachability flag.  Also, this
 530      * prevents httpMakePublic from really setting a public key.
 531      */
 532     EBIT_CLR(flags, ENTRY_CACHABLE);
 533
 534     setPrivateKey();
 535 }
 536
 537 /* unlock object, return -1 if object get released after unlock
 538  * otherwise lock_count */
 539 int
 540 StoreEntry::unlock()
 541 {
 542     lock_count--;
 543     debugs(20, 3, "StoreEntry::unlock: key '" << getMD5Text() << "' count=" << lock_count);
 544
 545     if (lock_count)
 546         return (int) lock_count;
 547
 548     if (store_status == STORE_PENDING)
 549         setReleaseFlag();
 550
 551     assert(storePendingNClients(this) == 0);
 552
 553     if (EBIT_TEST(flags, RELEASE_REQUEST))
 554     {
 555         this->release();
 556         return 0;
 557     }
 558
 559     if (EBIT_TEST(flags, KEY_PRIVATE))
 560         debugs(20, 1, "WARNING: " << __FILE__ << ":" << __LINE__ << ": found KEY_PRIVATE");
 561
 562     Store::Root().handleIdleEntry(*this); // may delete us
 563     return 0;
 564 }
 565
 566 void
 567 StoreEntry::getPublicByRequestMethod  (StoreClient *aClient, HttpRequest * request, const HttpRequestMethod& method)
 568 {
 569     assert (aClient);
 570     StoreEntry *result = storeGetPublicByRequestMethod( request, method);
 571
 572     if (!result)
 573         aClient->created (NullStoreEntry::getInstance());
 574     else
 575         aClient->created (result);
 576 }
 577
 578 void
 579 StoreEntry::getPublicByRequest (StoreClient *aClient, HttpRequest * request)
 580 {
 581     assert (aClient);
 582     StoreEntry *result = storeGetPublicByRequest (request);
 583
 584     if (!result)
 585         result = NullStoreEntry::getInstance();
 586
 587     aClient->created (result);
 588 }
 589
 590 void
 591 StoreEntry::getPublic (StoreClient *aClient, const char *uri, const HttpRequestMethod& method)
 592 {
 593     assert (aClient);
 594     StoreEntry *result = storeGetPublic (uri, method);
 595
 596     if (!result)
 597         result = NullStoreEntry::getInstance();
 598
 599     aClient->created (result);
 600 }
 601
 602 StoreEntry *
 603 storeGetPublic(const char *uri, const HttpRequestMethod& method)
 604 {
 605     return Store::Root().get(storeKeyPublic(uri, method));
 606 }
 607
 608 StoreEntry *
 609 storeGetPublicByRequestMethod(HttpRequest * req, const HttpRequestMethod& method)
 610 {
 611     return Store::Root().get(storeKeyPublicByRequestMethod(req, method));
 612 }
 613
 614 StoreEntry *
 615 storeGetPublicByRequest(HttpRequest * req)
 616 {
 617     StoreEntry *e = storeGetPublicByRequestMethod(req, req->method);
 618
 619     if (e == NULL && req->method == METHOD_HEAD)
 620         /* We can generate a HEAD reply from a cached GET object */
 621         e = storeGetPublicByRequestMethod(req, METHOD_GET);
 622
 623     return e;
 624 }
 625
 626 static int
 627 getKeyCounter(void)
 628 {
 629     static int key_counter = 0;
 630
 631     if (++key_counter < 0)
 632         key_counter = 1;
 633
 634     return key_counter;
 635 }
 636
 637 /* RBC 20050104 AFAICT this should become simpler:
 638  * rather than reinserting with a special key it should be marked
 639  * as 'released' and then cleaned up when refcounting indicates.
 640  * the StoreHashIndex could well implement its 'released' in the
 641  * current manner.
 642  * Also, clean log writing should skip over ia,t
 643  * Otherwise, we need a 'remove from the index but not the store
 644  * concept'.
 645  */
 646 void
 647 StoreEntry::setPrivateKey()
 648 {
 649     const cache_key *newkey;
 650
 651     if (key && EBIT_TEST(flags, KEY_PRIVATE))
 652         return;                 /* is already private */
 653
 654     if (key) {
 655         if (swap_filen > -1)
 656             storeDirSwapLog(this, SWAP_LOG_DEL);
 657
 658         hashDelete();
 659     }
 660
 661     if (mem_obj != NULL) {
 662         mem_obj->id = getKeyCounter();
 663         newkey = storeKeyPrivate(mem_obj->url, mem_obj->method, mem_obj->id);
 664     } else {
 665         newkey = storeKeyPrivate("JUNK", METHOD_NONE, getKeyCounter());
 666     }
 667
 668     assert(hash_lookup(store_table, newkey) == NULL);
 669     EBIT_SET(flags, KEY_PRIVATE);
 670     hashInsert(newkey);
 671 }
 672
 673 void
 674 StoreEntry::setPublicKey()
 675 {
 676     StoreEntry *e2 = NULL;
 677     const cache_key *newkey;
 678
 679     if (key && !EBIT_TEST(flags, KEY_PRIVATE))
 680         return;                 /* is already public */
 681
 682     assert(mem_obj);
 683
 684     /*
 685      * We can't make RELEASE_REQUEST objects public.  Depending on
 686      * when RELEASE_REQUEST gets set, we might not be swapping out
 687      * the object.  If we're not swapping out, then subsequent
 688      * store clients won't be able to access object data which has
 689      * been freed from memory.
 690      *
 691      * If RELEASE_REQUEST is set, then ENTRY_CACHABLE should not
 692      * be set, and StoreEntry::setPublicKey() should not be called.
 693      */
 694 #if MORE_DEBUG_OUTPUT
 695
 696     if (EBIT_TEST(flags, RELEASE_REQUEST))
 697         debugs(20, 1, "assertion failed: RELEASE key " << key << ", url " << mem_obj->url);
 698
 699 #endif
 700
 701     assert(!EBIT_TEST(flags, RELEASE_REQUEST));
 702
 703     if (mem_obj->request) {
 704         HttpRequest *request = mem_obj->request;
 705
 706         if (!mem_obj->vary_headers) {
 707             /* First handle the case where the object no longer varies */
 708             safe_free(request->vary_headers);
 709         } else {
 710             if (request->vary_headers && strcmp(request->vary_headers, mem_obj->vary_headers) != 0) {
 711                 /* Oops.. the variance has changed. Kill the base object
 712                  * to record the new variance key
 713                  */
 714                 safe_free(request->vary_headers);       /* free old "bad" variance key */
 715                 StoreEntry *pe = storeGetPublic(mem_obj->url, mem_obj->method);
 716
 717                 if (pe)
 718                     pe->release();
 719             }
 720
 721             /* Make sure the request knows the variance status */
 722             if (!request->vary_headers) {
 723                 const char *vary = httpMakeVaryMark(request, mem_obj->getReply());
 724
 725                 if (vary)
 726                     request->vary_headers = xstrdup(vary);
 727             }
 728         }
 729
 730         // TODO: storeGetPublic() calls below may create unlocked entries.
 731         // We should add/use storeHas() API or lock/unlock those entries.
 732         if (mem_obj->vary_headers && !storeGetPublic(mem_obj->url, mem_obj->method)) {
 733             /* Create "vary" base object */
 734             String vary;
 735             StoreEntry *pe = storeCreateEntry(mem_obj->url, mem_obj->log_url, request->flags, request->method);
 736             /* We are allowed to do this typecast */
 737             HttpReply *rep = new HttpReply;
 738             rep->setHeaders(HTTP_OK, "Internal marker object", "x-squid-internal/vary", -1, -1, squid_curtime + 100000);
 739             vary = mem_obj->getReply()->header.getList(HDR_VARY);
 740
 741             if (vary.size()) {
 742                 /* Again, we own this structure layout */
 743                 rep->header.putStr(HDR_VARY, vary.termedBuf());
 744                 vary.clean();
 745             }
 746
 747 #if X_ACCELERATOR_VARY
 748             vary = mem_obj->getReply()->header.getList(HDR_X_ACCELERATOR_VARY);
 749
 750             if (vary.defined()) {
 751                 /* Again, we own this structure layout */
 752                 rep->header.putStr(HDR_X_ACCELERATOR_VARY, vary.termedBuf());
 753                 vary.clean();
 754             }
 755
 756 #endif
 757             pe->replaceHttpReply(rep);
 758
 759             pe->timestampsSet();
 760
 761             pe->makePublic();
 762
 763             pe->complete();
 764
 765             pe->unlock();
 766         }
 767
 768         newkey = storeKeyPublicByRequest(mem_obj->request);
 769     } else
 770         newkey = storeKeyPublic(mem_obj->url, mem_obj->method);
 771
 772     if ((e2 = (StoreEntry *) hash_lookup(store_table, newkey))) {
 773         debugs(20, 3, "StoreEntry::setPublicKey: Making old '" << mem_obj->url << "' private.");
 774         e2->setPrivateKey();
 775         e2->release();
 776
 777         if (mem_obj->request)
 778             newkey = storeKeyPublicByRequest(mem_obj->request);
 779         else
 780             newkey = storeKeyPublic(mem_obj->url, mem_obj->method);
 781     }
 782
 783     if (key)
 784         hashDelete();
 785
 786     EBIT_CLR(flags, KEY_PRIVATE);
 787
 788     hashInsert(newkey);
 789
 790     if (swap_filen > -1)
 791         storeDirSwapLog(this, SWAP_LOG_ADD);
 792 }
 793
 794 StoreEntry *
 795 storeCreateEntry(const char *url, const char *log_url, request_flags flags, const HttpRequestMethod& method)
 796 {
 797     StoreEntry *e = NULL;
 798     MemObject *mem = NULL;
 799     debugs(20, 3, "storeCreateEntry: '" << url << "'");
 800
 801     e = new StoreEntry(url, log_url);
 802     e->lock_count = 1;          /* Note lock here w/o calling storeLock() */
 803     mem = e->mem_obj;
 804     mem->method = method;
 805
 806     if (neighbors_do_private_keys || !flags.hierarchical)
 807         e->setPrivateKey();
 808     else
 809         e->setPublicKey();
 810
 811     if (flags.cachable) {
 812         EBIT_SET(e->flags, ENTRY_CACHABLE);
 813         EBIT_CLR(e->flags, RELEASE_REQUEST);
 814     } else {
 815         /* StoreEntry::releaseRequest() clears ENTRY_CACHABLE */
 816         e->releaseRequest();
 817     }
 818
 819     e->store_status = STORE_PENDING;
 820     e->setMemStatus(NOT_IN_MEMORY);
 821     e->refcount = 0;
 822     e->lastref = squid_curtime;
 823     e->timestamp = -1;          /* set in StoreEntry::timestampsSet() */
 824     e->ping_status = PING_NONE;
 825     EBIT_SET(e->flags, ENTRY_VALIDATED);
 826     return e;
 827 }
 828
 829 /* Mark object as expired */
 830 void
 831 StoreEntry::expireNow()
 832 {
 833     debugs(20, 3, "StoreEntry::expireNow: '" << getMD5Text() << "'");
 834     expires = squid_curtime;
 835 }
 836
 837 void
 838 storeWriteComplete (void *data, StoreIOBuffer wroteBuffer)
 839 {
 840     PROF_start(storeWriteComplete);
 841     StoreEntry *e = (StoreEntry *)data;
 842
 843     if (EBIT_TEST(e->flags, DELAY_SENDING)) {
 844         PROF_stop(storeWriteComplete);
 845         return;
 846     }
 847
 848     e->invokeHandlers();
 849     PROF_stop(storeWriteComplete);
 850 }
 851
 852 void
 853 StoreEntry::write (StoreIOBuffer writeBuffer)
 854 {
 855     assert(mem_obj != NULL);
 856     /* This assert will change when we teach the store to update */
 857     PROF_start(StoreEntry_write);
 858     assert(store_status == STORE_PENDING);
 859
 860     if (!writeBuffer.length) {
 861         /* the headers are received already, but we have not received
 862          * any body data. There are BROKEN abuses of HTTP which require
 863          * the headers to be passed along before any body data - see
 864          * http://developer.apple.com/documentation/QuickTime/QTSS/Concepts/chapter_2_section_14.html
 865          * for an example of such bad behaviour. To accomodate this, if
 866          * we have a empty write arrive, we flush to our clients.
 867          * -RBC 20060903
 868          */
 869         PROF_stop(StoreEntry_write);
 870         invokeHandlers();
 871         return;
 872     }
 873
 874     debugs(20, 5, "storeWrite: writing " << writeBuffer.length << " bytes for '" << getMD5Text() << "'");
 875     PROF_stop(StoreEntry_write);
 876     storeGetMemSpace(writeBuffer.length);
 877     mem_obj->write (writeBuffer, storeWriteComplete, this);
 878 }
 879
 880 /* Append incoming data from a primary server to an entry. */
 881 void
 882 StoreEntry::append(char const *buf, int len)
 883 {
 884     assert(mem_obj != NULL);
 885     assert(len >= 0);
 886     assert(store_status == STORE_PENDING);
 887
 888     StoreIOBuffer tempBuffer;
 889     tempBuffer.data = (char *)buf;
 890     tempBuffer.length = len;
 891     /*
 892      * XXX sigh, offset might be < 0 here, but it gets "corrected"
 893      * later.  This offset crap is such a mess.
 894      */
 895     tempBuffer.offset = mem_obj->endOffset() - (getReply() ? getReply()->hdr_sz : 0);
 896     write(tempBuffer);
 897 }
 898
 899
 900 void
 901 storeAppendPrintf(StoreEntry * e, const char *fmt,...)
 902 {
 903     va_list args;
 904     va_start(args, fmt);
 905
 906     storeAppendVPrintf(e, fmt, args);
 907     va_end(args);
 908 }
 909
 910 /* used be storeAppendPrintf and Packer */
 911 void
 912 storeAppendVPrintf(StoreEntry * e, const char *fmt, va_list vargs)
 913 {
 914     LOCAL_ARRAY(char, buf, 4096);
 915     buf[0] = '\0';
 916     vsnprintf(buf, 4096, fmt, vargs);
 917     e->append(buf, strlen(buf));
 918 }
 919
 920 struct _store_check_cachable_hist {
 921
 922     struct {
 923         int non_get;
 924         int not_entry_cachable;
 925         int wrong_content_length;
 926         int negative_cached;
 927         int too_big;
 928         int too_small;
 929         int private_key;
 930         int too_many_open_files;
 931         int too_many_open_fds;
 932     } no;
 933
 934     struct {
 935         int Default;
 936     } yes;
 937 } store_check_cachable_hist;
 938
 939 int
 940 storeTooManyDiskFilesOpen(void)
 941 {
 942     if (Config.max_open_disk_fds == 0)
 943         return 0;
 944
 945     if (store_open_disk_fd > Config.max_open_disk_fds)
 946         return 1;
 947
 948     return 0;
 949 }
 950
 951 int
 952 StoreEntry::checkTooSmall()
 953 {
 954     if (EBIT_TEST(flags, ENTRY_SPECIAL))
 955         return 0;
 956
 957     if (STORE_OK == store_status)
 958         if (mem_obj->object_sz < 0 ||
 959                 mem_obj->object_sz < Config.Store.minObjectSize)
 960             return 1;
 961     if (getReply()->content_length > -1)
 962         if (getReply()->content_length < Config.Store.minObjectSize)
 963             return 1;
 964     return 0;
 965 }
 966
 967 // TODO: remove checks already performed by swapoutPossible()
 968 // TODO: move "too many open..." checks outside -- we are called too early/late
 969 int
 970 StoreEntry::checkCachable()
 971 {
 972 #if CACHE_ALL_METHODS
 973
 974     if (mem_obj->method != METHOD_GET) {
 975         debugs(20, 2, "StoreEntry::checkCachable: NO: non-GET method");
 976         store_check_cachable_hist.no.non_get++;
 977     } else
 978 #endif
 979         if (store_status == STORE_OK && EBIT_TEST(flags, ENTRY_BAD_LENGTH)) {
 980             debugs(20, 2, "StoreEntry::checkCachable: NO: wrong content-length");
 981             store_check_cachable_hist.no.wrong_content_length++;
 982         } else if (!EBIT_TEST(flags, ENTRY_CACHABLE)) {
 983             debugs(20, 2, "StoreEntry::checkCachable: NO: not cachable");
 984             store_check_cachable_hist.no.not_entry_cachable++;
 985         } else if (EBIT_TEST(flags, ENTRY_NEGCACHED)) {
 986             debugs(20, 3, "StoreEntry::checkCachable: NO: negative cached");
 987             store_check_cachable_hist.no.negative_cached++;
 988             return 0;           /* avoid release call below */
 989         } else if ((getReply()->content_length > 0 &&
 990                     getReply()->content_length
 991                     > Config.Store.maxObjectSize) ||
 992                    mem_obj->endOffset() > Config.Store.maxObjectSize) {
 993             debugs(20, 2, "StoreEntry::checkCachable: NO: too big");
 994             store_check_cachable_hist.no.too_big++;
 995         } else if (getReply()->content_length > Config.Store.maxObjectSize) {
 996             debugs(20, 2, "StoreEntry::checkCachable: NO: too big");
 997             store_check_cachable_hist.no.too_big++;
 998         } else if (checkTooSmall()) {
 999             debugs(20, 2, "StoreEntry::checkCachable: NO: too small");
1000             store_check_cachable_hist.no.too_small++;
1001         } else if (EBIT_TEST(flags, KEY_PRIVATE)) {
1002             debugs(20, 3, "StoreEntry::checkCachable: NO: private key");
1003             store_check_cachable_hist.no.private_key++;
1004         } else if (swap_status != SWAPOUT_NONE) {
1005             /*
1006              * here we checked the swap_status because the remaining
1007              * cases are only relevant only if we haven't started swapping
1008              * out the object yet.
1009              */
1010             return 1;
1011         } else if (storeTooManyDiskFilesOpen()) {
1012             debugs(20, 2, "StoreEntry::checkCachable: NO: too many disk files open");
1013             store_check_cachable_hist.no.too_many_open_files++;
1014         } else if (fdNFree() < RESERVED_FD) {
1015             debugs(20, 2, "StoreEntry::checkCachable: NO: too many FD's open");
1016             store_check_cachable_hist.no.too_many_open_fds++;
1017         } else {
1018             store_check_cachable_hist.yes.Default++;
1019             return 1;
1020         }
1021
1022     releaseRequest();
1023     /* StoreEntry::releaseRequest() cleared ENTRY_CACHABLE */
1024     return 0;
1025 }
1026
1027 void
1028 storeCheckCachableStats(StoreEntry *sentry)
1029 {
1030     storeAppendPrintf(sentry, "Category\t Count\n");
1031
1032 #if CACHE_ALL_METHODS
1033
1034     storeAppendPrintf(sentry, "no.non_get\t%d\n",
1035                       store_check_cachable_hist.no.non_get);
1036 #endif
1037
1038     storeAppendPrintf(sentry, "no.not_entry_cachable\t%d\n",
1039                       store_check_cachable_hist.no.not_entry_cachable);
1040     storeAppendPrintf(sentry, "no.wrong_content_length\t%d\n",
1041                       store_check_cachable_hist.no.wrong_content_length);
1042     storeAppendPrintf(sentry, "no.negative_cached\t%d\n",
1043                       store_check_cachable_hist.no.negative_cached);
1044     storeAppendPrintf(sentry, "no.too_big\t%d\n",
1045                       store_check_cachable_hist.no.too_big);
1046     storeAppendPrintf(sentry, "no.too_small\t%d\n",
1047                       store_check_cachable_hist.no.too_small);
1048     storeAppendPrintf(sentry, "no.private_key\t%d\n",
1049                       store_check_cachable_hist.no.private_key);
1050     storeAppendPrintf(sentry, "no.too_many_open_files\t%d\n",
1051                       store_check_cachable_hist.no.too_many_open_files);
1052     storeAppendPrintf(sentry, "no.too_many_open_fds\t%d\n",
1053                       store_check_cachable_hist.no.too_many_open_fds);
1054     storeAppendPrintf(sentry, "yes.default\t%d\n",
1055                       store_check_cachable_hist.yes.Default);
1056 }
1057
1058 void
1059 StoreEntry::complete()
1060 {
1061     debugs(20, 3, "storeComplete: '" << getMD5Text() << "'");
1062
1063     if (store_status != STORE_PENDING) {
1064         /*
1065          * if we're not STORE_PENDING, then probably we got aborted
1066          * and there should be NO clients on this entry
1067          */
1068         assert(EBIT_TEST(flags, ENTRY_ABORTED));
1069         assert(mem_obj->nclients == 0);
1070         return;
1071     }
1072
1073     /* This is suspect: mem obj offsets include the headers. do we adjust for that
1074      * in use of object_sz?
1075      */
1076     mem_obj->object_sz = mem_obj->endOffset();
1077
1078     store_status = STORE_OK;
1079
1080     assert(mem_status == NOT_IN_MEMORY);
1081
1082     if (!validLength()) {
1083         EBIT_SET(flags, ENTRY_BAD_LENGTH);
1084         releaseRequest();
1085     }
1086
1087 #if USE_CACHE_DIGESTS
1088     if (mem_obj->request)
1089         mem_obj->request->hier.store_complete_stop = current_time;
1090
1091 #endif
1092     /*
1093      * We used to call invokeHandlers, then storeSwapOut.  However,
1094      * Madhukar Reddy <myreddy@persistence.com> reported that
1095      * responses without content length would sometimes get released
1096      * in client_side, thinking that the response is incomplete.
1097      */
1098     invokeHandlers();
1099 }
1100
1101 /*
1102  * Someone wants to abort this transfer.  Set the reason in the
1103  * request structure, call the server-side callback and mark the
1104  * entry for releasing
1105  */
1106 void
1107 StoreEntry::abort()
1108 {
1109     statCounter.aborted_requests++;
1110     assert(store_status == STORE_PENDING);
1111     assert(mem_obj != NULL);
1112     debugs(20, 6, "storeAbort: " << getMD5Text());
1113
1114     lock();         /* lock while aborting */
1115     negativeCache();
1116
1117     releaseRequest();
1118
1119     EBIT_SET(flags, ENTRY_ABORTED);
1120
1121     setMemStatus(NOT_IN_MEMORY);
1122
1123     store_status = STORE_OK;
1124
1125     /* Notify the server side */
1126
1127     /*
1128      * DPW 2007-05-07
1129      * Should we check abort.data for validity?
1130      */
1131     if (mem_obj->abort.callback) {
1132         if (!cbdataReferenceValid(mem_obj->abort.data))
1133             debugs(20,1,HERE << "queueing event when abort.data is not valid");
1134         eventAdd("mem_obj->abort.callback",
1135                  mem_obj->abort.callback,
1136                  mem_obj->abort.data,
1137                  0.0,
1138                  true);
1139         unregisterAbort();
1140     }
1141
1142     /* XXX Should we reverse these two, so that there is no
1143      * unneeded disk swapping triggered?
1144      */
1145     /* Notify the client side */
1146     invokeHandlers();
1147
1148     // abort swap out, invalidating what was created so far (release follows)
1149     swapOutFileClose(StoreIOState::writerGone);
1150
1151     unlock();       /* unlock */
1152 }
1153
1154 /**
1155  * Clear Memory storage to accommodate the given object len
1156  */
1157 void
1158 storeGetMemSpace(int size)
1159 {
1160     PROF_start(storeGetMemSpace);
1161     StoreEntry *e = NULL;
1162     int released = 0;
1163     static time_t last_check = 0;
1164     size_t pages_needed;
1165     RemovalPurgeWalker *walker;
1166
1167     if (squid_curtime == last_check) {
1168         PROF_stop(storeGetMemSpace);
1169         return;
1170     }
1171
1172     last_check = squid_curtime;
1173
1174     pages_needed = (size / SM_PAGE_SIZE) + 1;
1175
1176     if (mem_node::InUseCount() + pages_needed < store_pages_max) {
1177         PROF_stop(storeGetMemSpace);
1178         return;
1179     }
1180
1181     debugs(20, 2, "storeGetMemSpace: Starting, need " << pages_needed <<
1182            " pages");
1183
1184     /* XXX what to set as max_scan here? */
1185     walker = mem_policy->PurgeInit(mem_policy, 100000);
1186
1187     while ((e = walker->Next(walker))) {
1188         e->purgeMem();
1189         released++;
1190
1191         if (mem_node::InUseCount() + pages_needed < store_pages_max)
1192             break;
1193     }
1194
1195     walker->Done(walker);
1196     debugs(20, 3, "storeGetMemSpace stats:");
1197     debugs(20, 3, "  " << std::setw(6) << hot_obj_count  << " HOT objects");
1198     debugs(20, 3, "  " << std::setw(6) << released  << " were released");
1199     PROF_stop(storeGetMemSpace);
1200 }
1201
1202
1203 /* thunk through to Store::Root().maintain(). Note that this would be better still
1204  * if registered against the root store itself, but that requires more complex
1205  * update logic - bigger fish to fry first. Long term each store when
1206  * it becomes active will self register
1207  */
1208 void
1209 Store::Maintain(void *notused)
1210 {
1211     Store::Root().maintain();
1212
1213     /* Reregister a maintain event .. */
1214     eventAdd("MaintainSwapSpace", Maintain, NULL, 1.0, 1);
1215
1216 }
1217
1218 /* The maximum objects to scan for maintain storage space */
1219 #define MAINTAIN_MAX_SCAN       1024
1220 #define MAINTAIN_MAX_REMOVE     64
1221
1222 /*
1223  * This routine is to be called by main loop in main.c.
1224  * It removes expired objects on only one bucket for each time called.
1225  *
1226  * This should get called 1/s from main().
1227  */
1228 void
1229 StoreController::maintain()
1230 {
1231     static time_t last_warn_time = 0;
1232
1233     PROF_start(storeMaintainSwapSpace);
1234     swapDir->maintain();
1235
1236     /* this should be emitted by the oversize dir, not globally */
1237
1238     if (Store::Root().currentSize() > Store::Root().maxSize()) {
1239         if (squid_curtime - last_warn_time > 10) {
1240             debugs(20, 0, "WARNING: Disk space over limit: "
1241                    << Store::Root().currentSize() / 1024.0 << " KB > "
1242                    << (Store::Root().maxSize() >> 10) << " KB");
1243             last_warn_time = squid_curtime;
1244         }
1245     }
1246
1247     PROF_stop(storeMaintainSwapSpace);
1248 }
1249
1250 /* release an object from a cache */
1251 void
1252 StoreEntry::release()
1253 {
1254     PROF_start(storeRelease);
1255     debugs(20, 3, "storeRelease: Releasing: '" << getMD5Text() << "'");
1256     /* If, for any reason we can't discard this object because of an
1257      * outstanding request, mark it for pending release */
1258
1259     if (locked()) {
1260         expireNow();
1261         debugs(20, 3, "storeRelease: Only setting RELEASE_REQUEST bit");
1262         releaseRequest();
1263         PROF_stop(storeRelease);
1264         return;
1265     }
1266
1267     if (StoreController::store_dirs_rebuilding && swap_filen > -1) {
1268         setPrivateKey();
1269
1270         if (mem_obj)
1271             destroyMemObject();
1272
1273         if (swap_filen > -1) {
1274             /*
1275              * Fake a call to StoreEntry->lock()  When rebuilding is done,
1276              * we'll just call StoreEntry->unlock() on these.
1277              */
1278             lock_count++;
1279             setReleaseFlag();
1280             LateReleaseStack.push_back(this);
1281         } else {
1282             destroyStoreEntry(static_cast<hash_link *>(this));
1283             // "this" is no longer valid
1284         }
1285
1286         PROF_stop(storeRelease);
1287         return;
1288     }
1289
1290     storeLog(STORE_LOG_RELEASE, this);
1291
1292     if (swap_filen > -1) {
1293         // log before unlink() below clears swap_filen
1294         if (!EBIT_TEST(flags, KEY_PRIVATE))
1295             storeDirSwapLog(this, SWAP_LOG_DEL);
1296
1297         unlink();
1298     }
1299
1300     setMemStatus(NOT_IN_MEMORY);
1301     destroyStoreEntry(static_cast<hash_link *>(this));
1302     PROF_stop(storeRelease);
1303 }
1304
1305 static void
1306 storeLateRelease(void *unused)
1307 {
1308     StoreEntry *e;
1309     int i;
1310     static int n = 0;
1311
1312     if (StoreController::store_dirs_rebuilding) {
1313         eventAdd("storeLateRelease", storeLateRelease, NULL, 1.0, 1);
1314         return;
1315     }
1316
1317     for (i = 0; i < 10; i++) {
1318         e = LateReleaseStack.count ? LateReleaseStack.pop() : NULL;
1319
1320         if (e == NULL) {
1321             /* done! */
1322             debugs(20, 1, "storeLateRelease: released " << n << " objects");
1323             return;
1324         }
1325
1326         e->unlock();
1327         n++;
1328     }
1329
1330     eventAdd("storeLateRelease", storeLateRelease, NULL, 0.0, 1);
1331 }
1332
1333 /* return 1 if a store entry is locked */
1334 int
1335 StoreEntry::locked() const
1336 {
1337     if (lock_count)
1338         return 1;
1339
1340     if (swap_status == SWAPOUT_WRITING)
1341         return 1;
1342
1343     if (store_status == STORE_PENDING)
1344         return 1;
1345
1346     /*
1347      * SPECIAL, PUBLIC entries should be "locked"
1348      */
1349     if (EBIT_TEST(flags, ENTRY_SPECIAL))
1350         if (!EBIT_TEST(flags, KEY_PRIVATE))
1351             return 1;
1352
1353     return 0;
1354 }
1355
1356 bool
1357 StoreEntry::validLength() const
1358 {
1359     int64_t diff;
1360     const HttpReply *reply;
1361     assert(mem_obj != NULL);
1362     reply = getReply();
1363     debugs(20, 3, "storeEntryValidLength: Checking '" << getMD5Text() << "'");
1364     debugs(20, 5, "storeEntryValidLength:     object_len = " <<
1365            objectLen());
1366     debugs(20, 5, "storeEntryValidLength:         hdr_sz = " << reply->hdr_sz);
1367     debugs(20, 5, "storeEntryValidLength: content_length = " << reply->content_length);
1368
1369     if (reply->content_length < 0) {
1370         debugs(20, 5, "storeEntryValidLength: Unspecified content length: " << getMD5Text());
1371         return 1;
1372     }
1373
1374     if (reply->hdr_sz == 0) {
1375         debugs(20, 5, "storeEntryValidLength: Zero header size: " << getMD5Text());
1376         return 1;
1377     }
1378
1379     if (mem_obj->method == METHOD_HEAD) {
1380         debugs(20, 5, "storeEntryValidLength: HEAD request: " << getMD5Text());
1381         return 1;
1382     }
1383
1384     if (reply->sline.status == HTTP_NOT_MODIFIED)
1385         return 1;
1386
1387     if (reply->sline.status == HTTP_NO_CONTENT)
1388         return 1;
1389
1390     diff = reply->hdr_sz + reply->content_length - objectLen();
1391
1392     if (diff == 0)
1393         return 1;
1394
1395     debugs(20, 3, "storeEntryValidLength: " << (diff < 0 ? -diff : diff)  << " bytes too " << (diff < 0 ? "big" : "small") <<"; '" << getMD5Text() << "'" );
1396
1397     return 0;
1398 }
1399
1400 static void
1401 storeRegisterWithCacheManager(void)
1402 {
1403     Mgr::RegisterAction("storedir", "Store Directory Stats", Store::Stats, 0, 1);
1404     Mgr::RegisterAction("store_io", "Store IO Interface Stats", &Mgr::StoreIoAction::Create, 0, 1);
1405     Mgr::RegisterAction("store_check_cachable_stats", "storeCheckCachable() Stats",
1406                         storeCheckCachableStats, 0, 1);
1407 }
1408
1409 void
1410 storeInit(void)
1411 {
1412     storeKeyInit();
1413     mem_policy = createRemovalPolicy(Config.memPolicy);
1414     storeDigestInit();
1415     storeLogOpen();
1416     eventAdd("storeLateRelease", storeLateRelease, NULL, 1.0, 1);
1417     Store::Root().init();
1418     storeRebuildStart();
1419
1420     storeRegisterWithCacheManager();
1421 }
1422
1423 void
1424 storeConfigure(void)
1425 {
1426     store_swap_high = (long) (((float) Store::Root().maxSize() *
1427                                (float) Config.Swap.highWaterMark) / (float) 100);
1428     store_swap_low = (long) (((float) Store::Root().maxSize() *
1429                               (float) Config.Swap.lowWaterMark) / (float) 100);
1430     store_pages_max = Config.memMaxSize / sizeof(mem_node);
1431 }
1432
1433 bool
1434 StoreEntry::memoryCachable() const
1435 {
1436     if (mem_obj == NULL)
1437         return 0;
1438
1439     if (mem_obj->data_hdr.size() == 0)
1440         return 0;
1441
1442     if (mem_obj->inmem_lo != 0)
1443         return 0;
1444
1445     if (!Config.onoff.memory_cache_first && swap_status == SWAPOUT_DONE && refcount == 1)
1446         return 0;
1447
1448     if (UsingSmp()) {
1449         const int64_t expectedSize = mem_obj->expectedReplySize();
1450         // objects of unknown size are not allowed into memory cache, for now
1451         if (expectedSize < 0 ||
1452             expectedSize > static_cast<int64_t>(Config.Store.maxInMemObjSize))
1453             return 0;
1454     }
1455
1456     return 1;
1457 }
1458
1459 int
1460 StoreEntry::checkNegativeHit() const
1461 {
1462     if (!EBIT_TEST(flags, ENTRY_NEGCACHED))
1463         return 0;
1464
1465     if (expires <= squid_curtime)
1466         return 0;
1467
1468     if (store_status != STORE_OK)
1469         return 0;
1470
1471     return 1;
1472 }
1473
1474 /**
1475  * Set object for negative caching.
1476  * Preserves any expiry information given by the server.
1477  * In absence of proper expiry info it will set to expire immediately,
1478  * or with HTTP-violations enabled the configured negative-TTL is observed
1479  */
1480 void
1481 StoreEntry::negativeCache()
1482 {
1483     // XXX: should make the default for expires 0 instead of -1
1484     //      so we can distinguish "Expires: -1" from nothing.
1485     if (expires <= 0)
1486 #if USE_HTTP_VIOLATIONS
1487         expires = squid_curtime + Config.negativeTtl;
1488 #else
1489         expires = squid_curtime;
1490 #endif
1491     EBIT_SET(flags, ENTRY_NEGCACHED);
1492 }
1493
1494 void
1495 storeFreeMemory(void)
1496 {
1497     Store::Root(NULL);
1498 #if USE_CACHE_DIGESTS
1499
1500     if (store_digest)
1501         cacheDigestDestroy(store_digest);
1502
1503 #endif
1504
1505     store_digest = NULL;
1506 }
1507
1508 int
1509 expiresMoreThan(time_t expires, time_t when)
1510 {
1511     if (expires < 0)            /* No Expires given */
1512         return 1;
1513
1514     return (expires > (squid_curtime + when));
1515 }
1516
1517 int
1518 StoreEntry::validToSend() const
1519 {
1520     if (EBIT_TEST(flags, RELEASE_REQUEST))
1521         return 0;
1522
1523     if (EBIT_TEST(flags, ENTRY_NEGCACHED))
1524         if (expires <= squid_curtime)
1525             return 0;
1526
1527     if (EBIT_TEST(flags, ENTRY_ABORTED))
1528         return 0;
1529
1530     return 1;
1531 }
1532
1533 void
1534 StoreEntry::timestampsSet()
1535 {
1536     const HttpReply *reply = getReply();
1537     time_t served_date = reply->date;
1538     int age = reply->header.getInt(HDR_AGE);
1539     /* Compute the timestamp, mimicking RFC2616 section 13.2.3. */
1540     /* make sure that 0 <= served_date <= squid_curtime */
1541
1542     if (served_date < 0 || served_date > squid_curtime)
1543         served_date = squid_curtime;
1544
1545     /* Bug 1791:
1546      * If the returned Date: is more than 24 hours older than
1547      * the squid_curtime, then one of us needs to use NTP to set our
1548      * clock.  We'll pretend that our clock is right.
1549      */
1550     else if (served_date < (squid_curtime - 24 * 60 * 60) )
1551         served_date = squid_curtime;
1552
1553     /*
1554      * Compensate with Age header if origin server clock is ahead
1555      * of us and there is a cache in between us and the origin
1556      * server.  But DONT compensate if the age value is larger than
1557      * squid_curtime because it results in a negative served_date.
1558      */
1559     if (age > squid_curtime - served_date)
1560         if (squid_curtime > age)
1561             served_date = squid_curtime - age;
1562
1563     // compensate for Squid-to-server and server-to-Squid delays
1564     if (mem_obj && mem_obj->request) {
1565         const time_t request_sent =
1566             mem_obj->request->hier.peer_http_request_sent.tv_sec;
1567         if (0 < request_sent && request_sent < squid_curtime)
1568             served_date -= (squid_curtime - request_sent);
1569     }
1570
1571     if (reply->expires > 0 && reply->date > -1)
1572         expires = served_date + (reply->expires - reply->date);
1573     else
1574         expires = reply->expires;
1575
1576     lastmod = reply->last_modified;
1577
1578     timestamp = served_date;
1579 }
1580
1581 void
1582 StoreEntry::registerAbort(STABH * cb, void *data)
1583 {
1584     assert(mem_obj);
1585     assert(mem_obj->abort.callback == NULL);
1586     mem_obj->abort.callback = cb;
1587     mem_obj->abort.data = cbdataReference(data);
1588 }
1589
1590 void
1591 StoreEntry::unregisterAbort()
1592 {
1593     assert(mem_obj);
1594     if (mem_obj->abort.callback) {
1595         mem_obj->abort.callback = NULL;
1596         cbdataReferenceDone(mem_obj->abort.data);
1597     }
1598 }
1599
1600 void
1601 StoreEntry::dump(int l) const
1602 {
1603     debugs(20, l, "StoreEntry->key: " << getMD5Text());
1604     debugs(20, l, "StoreEntry->next: " << next);
1605     debugs(20, l, "StoreEntry->mem_obj: " << mem_obj);
1606     debugs(20, l, "StoreEntry->timestamp: " << timestamp);
1607     debugs(20, l, "StoreEntry->lastref: " << lastref);
1608     debugs(20, l, "StoreEntry->expires: " << expires);
1609     debugs(20, l, "StoreEntry->lastmod: " << lastmod);
1610     debugs(20, l, "StoreEntry->swap_file_sz: " << swap_file_sz);
1611     debugs(20, l, "StoreEntry->refcount: " << refcount);
1612     debugs(20, l, "StoreEntry->flags: " << storeEntryFlags(this));
1613     debugs(20, l, "StoreEntry->swap_dirn: " << swap_dirn);
1614     debugs(20, l, "StoreEntry->swap_filen: " << swap_filen);
1615     debugs(20, l, "StoreEntry->lock_count: " << lock_count);
1616     debugs(20, l, "StoreEntry->mem_status: " << mem_status);
1617     debugs(20, l, "StoreEntry->ping_status: " << ping_status);
1618     debugs(20, l, "StoreEntry->store_status: " << store_status);
1619     debugs(20, l, "StoreEntry->swap_status: " << swap_status);
1620 }
1621
1622 /*
1623  * NOTE, this function assumes only two mem states
1624  */
1625 void
1626 StoreEntry::setMemStatus(mem_status_t new_status)
1627 {
1628     if (new_status == mem_status)
1629         return;
1630
1631     if (UsingSmp()) {
1632         assert(new_status != IN_MEMORY); // we do not call this otherwise
1633         // This method was designed to update replacement policy, not to
1634         // actually purge something from the memory cache (TODO: rename?).
1635         // Shared memory cache does not have a policy that needs updates.
1636         mem_status = new_status;
1637         return;
1638     }
1639
1640     assert(mem_obj != NULL);
1641
1642     if (new_status == IN_MEMORY) {
1643         assert(mem_obj->inmem_lo == 0);
1644
1645         if (EBIT_TEST(flags, ENTRY_SPECIAL)) {
1646             debugs(20, 4, "StoreEntry::setMemStatus: not inserting special " << mem_obj->url << " into policy");
1647         } else {
1648             mem_policy->Add(mem_policy, this, &mem_obj->repl);
1649             debugs(20, 4, "StoreEntry::setMemStatus: inserted mem node " << mem_obj->url << " key: " << getMD5Text());
1650         }
1651
1652         hot_obj_count++; // TODO: maintain for the shared hot cache as well
1653     } else {
1654         if (EBIT_TEST(flags, ENTRY_SPECIAL)) {
1655             debugs(20, 4, "StoreEntry::setMemStatus: special entry " << mem_obj->url);
1656         } else {
1657             mem_policy->Remove(mem_policy, this, &mem_obj->repl);
1658             debugs(20, 4, "StoreEntry::setMemStatus: removed mem node " << mem_obj->url);
1659         }
1660
1661         hot_obj_count--;
1662     }
1663
1664     mem_status = new_status;
1665 }
1666
1667 const char *
1668 StoreEntry::url() const
1669 {
1670     if (this == NULL)
1671         return "[null_entry]";
1672     else if (mem_obj == NULL)
1673         return "[null_mem_obj]";
1674     else
1675         return mem_obj->url;
1676 }
1677
1678 void
1679 StoreEntry::createMemObject(const char *aUrl, const char *aLogUrl)
1680 {
1681     if (mem_obj)
1682         return;
1683
1684     if (hidden_mem_obj) {
1685         debugs(20, 3, HERE << "restoring " << hidden_mem_obj);
1686         mem_obj = hidden_mem_obj;
1687         hidden_mem_obj = NULL;
1688         mem_obj->resetUrls(aUrl, aLogUrl);
1689         return;
1690     }
1691
1692     mem_obj = new MemObject(aUrl, aLogUrl);
1693 }
1694
1695 /* this just sets DELAY_SENDING */
1696 void
1697 StoreEntry::buffer()
1698 {
1699     EBIT_SET(flags, DELAY_SENDING);
1700 }
1701
1702 /* this just clears DELAY_SENDING and Invokes the handlers */
1703 void
1704 StoreEntry::flush()
1705 {
1706     if (EBIT_TEST(flags, DELAY_SENDING)) {
1707         EBIT_CLR(flags, DELAY_SENDING);
1708         invokeHandlers();
1709     }
1710 }
1711
1712 int64_t
1713 StoreEntry::objectLen() const
1714 {
1715     assert(mem_obj != NULL);
1716     return mem_obj->object_sz;
1717 }
1718
1719 int64_t
1720 StoreEntry::contentLen() const
1721 {
1722     assert(mem_obj != NULL);
1723     assert(getReply() != NULL);
1724     return objectLen() - getReply()->hdr_sz;
1725 }
1726
1727 HttpReply const *
1728 StoreEntry::getReply () const
1729 {
1730     if (NULL == mem_obj)
1731         return NULL;
1732
1733     return mem_obj->getReply();
1734 }
1735
1736 void
1737 StoreEntry::reset()
1738 {
1739     assert (mem_obj);
1740     debugs(20, 3, "StoreEntry::reset: " << url());
1741     mem_obj->reset();
1742     HttpReply *rep = (HttpReply *) getReply();       // bypass const
1743     rep->reset();
1744     expires = lastmod = timestamp = -1;
1745 }
1746
1747 /*
1748  * storeFsInit
1749  *
1750  * This routine calls the SETUP routine for each fs type.
1751  * I don't know where the best place for this is, and I'm not going to shuffle
1752  * around large chunks of code right now (that can be done once its working.)
1753  */
1754 void
1755 storeFsInit(void)
1756 {
1757     storeReplSetup();
1758 }
1759
1760 /*
1761  * called to add another store removal policy module
1762  */
1763 void
1764 storeReplAdd(const char *type, REMOVALPOLICYCREATE * create)
1765 {
1766     int i;
1767
1768     /* find the number of currently known repl types */
1769     for (i = 0; storerepl_list && storerepl_list[i].typestr; i++) {
1770         if (strcmp(storerepl_list[i].typestr, type) == 0) {
1771             debugs(20, 1, "WARNING: Trying to load store replacement policy " << type << " twice.");
1772             return;
1773         }
1774     }
1775
1776     /* add the new type */
1777     storerepl_list = static_cast<storerepl_entry_t *>(xrealloc(storerepl_list, (i + 2) * sizeof(storerepl_entry_t)));
1778
1779     memset(&storerepl_list[i + 1], 0, sizeof(storerepl_entry_t));
1780
1781     storerepl_list[i].typestr = type;
1782
1783     storerepl_list[i].create = create;
1784 }
1785
1786 /*
1787  * Create a removal policy instance
1788  */
1789 RemovalPolicy *
1790 createRemovalPolicy(RemovalPolicySettings * settings)
1791 {
1792     storerepl_entry_t *r;
1793
1794     for (r = storerepl_list; r && r->typestr; r++) {
1795         if (strcmp(r->typestr, settings->type) == 0)
1796             return r->create(settings->args);
1797     }
1798
1799     debugs(20, 1, "ERROR: Unknown policy " << settings->type);
1800     debugs(20, 1, "ERROR: Be sure to have set cache_replacement_policy");
1801     debugs(20, 1, "ERROR:   and memory_replacement_policy in squid.conf!");
1802     fatalf("ERROR: Unknown policy %s\n", settings->type);
1803     return NULL;                /* NOTREACHED */
1804 }
1805
1806 #if 0
1807 void
1808 storeSwapFileNumberSet(StoreEntry * e, sfileno filn)
1809 {
1810     if (e->swap_file_number == filn)
1811         return;
1812
1813     if (filn < 0) {
1814         assert(-1 == filn);
1815         storeDirMapBitReset(e->swap_file_number);
1816         storeDirLRUDelete(e);
1817         e->swap_file_number = -1;
1818     } else {
1819         assert(-1 == e->swap_file_number);
1820         storeDirMapBitSet(e->swap_file_number = filn);
1821         storeDirLRUAdd(e);
1822     }
1823 }
1824
1825 #endif
1826
1827
1828 /*
1829  * Replace a store entry with
1830  * a new reply. This eats the reply.
1831  */
1832 void
1833 StoreEntry::replaceHttpReply(HttpReply *rep, bool andStartWriting)
1834 {
1835     debugs(20, 3, "StoreEntry::replaceHttpReply: " << url());
1836
1837     if (!mem_obj) {
1838         debugs(20, 0, "Attempt to replace object with no in-memory representation");
1839         return;
1840     }
1841
1842     mem_obj->replaceHttpReply(rep);
1843
1844     if (andStartWriting)
1845         startWriting();
1846 }
1847
1848
1849 void
1850 StoreEntry::startWriting()
1851 {
1852     Packer p;
1853
1854     /* TODO: when we store headers serparately remove the header portion */
1855     /* TODO: mark the length of the headers ? */
1856     /* We ONLY want the headers */
1857     packerToStoreInit(&p, this);
1858
1859     assert (isEmpty());
1860     assert(mem_obj);
1861
1862     const HttpReply *rep = getReply();
1863     assert(rep);
1864
1865     rep->packHeadersInto(&p);
1866     mem_obj->markEndOfReplyHeaders();
1867
1868     httpBodyPackInto(&rep->body, &p);
1869
1870     packerClean(&p);
1871 }
1872
1873
1874 char const *
1875 StoreEntry::getSerialisedMetaData()
1876 {
1877     StoreMeta *tlv_list = storeSwapMetaBuild(this);
1878     int swap_hdr_sz;
1879     char *result = storeSwapMetaPack(tlv_list, &swap_hdr_sz);
1880     storeSwapTLVFree(tlv_list);
1881     assert (swap_hdr_sz >= 0);
1882     mem_obj->swap_hdr_sz = (size_t) swap_hdr_sz;
1883     return result;
1884 }
1885
1886 bool
1887 StoreEntry::swapoutPossible()
1888 {
1889     if (!Config.cacheSwap.n_configured)
1890         return false;
1891
1892     /* should we swap something out to disk? */
1893     debugs(20, 7, "storeSwapOut: " << url());
1894     debugs(20, 7, "storeSwapOut: store_status = " << storeStatusStr[store_status]);
1895
1896     assert(mem_obj);
1897     MemObject::SwapOut::Decision &decision = mem_obj->swapout.decision;
1898
1899     // if we decided that swapout is not possible, do not repeat same checks
1900     if (decision == MemObject::SwapOut::swImpossible) {
1901         debugs(20, 3, "storeSwapOut: already rejected");
1902         return false;
1903     }
1904
1905     // this flag may change so we must check it even if we already said "yes"
1906     if (EBIT_TEST(flags, ENTRY_ABORTED)) {
1907         assert(EBIT_TEST(flags, RELEASE_REQUEST));
1908         // StoreEntry::abort() already closed the swap out file, if any
1909         decision = MemObject::SwapOut::swImpossible;
1910         return false;
1911     }
1912
1913     // if we decided that swapout is possible, do not repeat same checks
1914     if (decision == MemObject::SwapOut::swPossible) {
1915         debugs(20, 3, "storeSwapOut: already allowed");
1916         return true;
1917     }
1918
1919     // if we are swapping out already, do not repeat same checks
1920     if (swap_status != SWAPOUT_NONE) {
1921         debugs(20, 3, "storeSwapOut: already started");
1922         decision = MemObject::SwapOut::swPossible;
1923         return true;
1924     }
1925
1926     if (!checkCachable()) {
1927         debugs(20, 3, "storeSwapOut: not cachable");
1928         decision = MemObject::SwapOut::swImpossible;
1929         return false;
1930     }
1931
1932     if (EBIT_TEST(flags, ENTRY_SPECIAL)) {
1933         debugs(20, 3, "storeSwapOut: " << url() << " SPECIAL");
1934         decision = MemObject::SwapOut::swImpossible;
1935         return false;
1936     }
1937
1938     // check cache_dir max-size limit if all cache_dirs have it
1939     if (store_maxobjsize >= 0) {
1940         // TODO: add estimated store metadata size to be conservative
1941
1942         // use guaranteed maximum if it is known
1943         const int64_t expectedEnd = mem_obj->expectedReplySize();
1944         debugs(20, 7, "storeSwapOut: expectedEnd = " << expectedEnd);
1945         if (expectedEnd > store_maxobjsize) {
1946             debugs(20, 3, "storeSwapOut: will not fit: " << expectedEnd <<
1947                 " > " << store_maxobjsize);
1948             decision = MemObject::SwapOut::swImpossible;
1949             return false; // known to outgrow the limit eventually
1950         }
1951
1952         // use current minimum (always known)
1953         const int64_t currentEnd = mem_obj->endOffset();
1954         if (currentEnd > store_maxobjsize) {
1955             debugs(20, 3, "storeSwapOut: does not fit: " << currentEnd <<
1956                 " > " << store_maxobjsize);
1957             decision = MemObject::SwapOut::swImpossible;
1958             return false; // already does not fit and may only get bigger
1959         }
1960
1961         // prevent default swPossible answer for yet unknown length
1962         if (expectedEnd < 0) {
1963             debugs(20, 3, "storeSwapOut: wait for more info: " <<
1964                 store_maxobjsize);
1965             return false; // may fit later, but will be rejected now
1966         }
1967     }
1968
1969     decision = MemObject::SwapOut::swPossible;
1970     return true;
1971 }
1972
1973 void
1974 StoreEntry::trimMemory()
1975 {
1976     /*
1977      * DPW 2007-05-09
1978      * Bug #1943.  We must not let go any data for IN_MEMORY
1979      * objects.  We have to wait until the mem_status changes.
1980      */
1981     if (mem_status == IN_MEMORY)
1982         return;
1983
1984     if (!swapOutAble()) {
1985         if (mem_obj->policyLowestOffsetToKeep(0) == 0) {
1986             /* Nothing to do */
1987             return;
1988         }
1989         /*
1990          * Its not swap-able, and we're about to delete a chunk,
1991          * so we must make it PRIVATE.  This is tricky/ugly because
1992          * for the most part, we treat swapable == cachable here.
1993          */
1994         releaseRequest();
1995         mem_obj->trimUnSwappable ();
1996     } else {
1997         mem_obj->trimSwappable ();
1998     }
1999 }
2000
2001 bool
2002 StoreEntry::modifiedSince(HttpRequest * request) const
2003 {
2004     int object_length;
2005     time_t mod_time = lastmod;
2006
2007     if (mod_time < 0)
2008         mod_time = timestamp;
2009
2010     debugs(88, 3, "modifiedSince: '" << url() << "'");
2011
2012     debugs(88, 3, "modifiedSince: mod_time = " << mod_time);
2013
2014     if (mod_time < 0)
2015         return true;
2016
2017     /* Find size of the object */
2018     object_length = getReply()->content_length;
2019
2020     if (object_length < 0)
2021         object_length = contentLen();
2022
2023     if (mod_time > request->ims) {
2024         debugs(88, 3, "--> YES: entry newer than client");
2025         return true;
2026     } else if (mod_time < request->ims) {
2027         debugs(88, 3, "-->  NO: entry older than client");
2028         return false;
2029     } else if (request->imslen < 0) {
2030         debugs(88, 3, "-->  NO: same LMT, no client length");
2031         return false;
2032     } else if (request->imslen == object_length) {
2033         debugs(88, 3, "-->  NO: same LMT, same length");
2034         return false;
2035     } else {
2036         debugs(88, 3, "--> YES: same LMT, different length");
2037         return true;
2038     }
2039 }
2040
2041 bool
2042 StoreEntry::hasIfMatchEtag(const HttpRequest &request) const
2043 {
2044     const String reqETags = request.header.getList(HDR_IF_MATCH);
2045     return hasOneOfEtags(reqETags, false);
2046 }
2047
2048 bool
2049 StoreEntry::hasIfNoneMatchEtag(const HttpRequest &request) const
2050 {
2051     const String reqETags = request.header.getList(HDR_IF_NONE_MATCH);
2052     // weak comparison is allowed only for HEAD or full-body GET requests
2053     const bool allowWeakMatch = !request.flags.range &&
2054                                 (request.method == METHOD_GET || request.method == METHOD_HEAD);
2055     return hasOneOfEtags(reqETags, allowWeakMatch);
2056 }
2057
2058 /// whether at least one of the request ETags matches entity ETag
2059 bool
2060 StoreEntry::hasOneOfEtags(const String &reqETags, const bool allowWeakMatch) const
2061 {
2062     const ETag repETag = getReply()->header.getETag(HDR_ETAG);
2063     if (!repETag.str)
2064         return strListIsMember(&reqETags, "*", ',');
2065
2066     bool matched = false;
2067     const char *pos = NULL;
2068     const char *item;
2069     int ilen;
2070     while (!matched && strListGetItem(&reqETags, ',', &item, &ilen, &pos)) {
2071         if (!strncmp(item, "*", ilen))
2072             matched = true;
2073         else {
2074             String str;
2075             str.append(item, ilen);
2076             ETag reqETag;
2077             if (etagParseInit(&reqETag, str.termedBuf())) {
2078                 matched = allowWeakMatch ? etagIsWeakEqual(repETag, reqETag) :
2079                           etagIsStrongEqual(repETag, reqETag);
2080             }
2081         }
2082     }
2083     return matched;
2084 }
2085
2086 SwapDir::Pointer
2087 StoreEntry::store() const
2088 {
2089     assert(0 <= swap_dirn && swap_dirn < Config.cacheSwap.n_configured);
2090     return INDEXSD(swap_dirn);
2091 }
2092
2093 void
2094 StoreEntry::unlink()
2095 {
2096     store()->unlink(*this); // implies disconnect()
2097     swap_filen = -1;
2098     swap_dirn = -1;
2099     swap_status = SWAPOUT_NONE;
2100 }
2101
2102 /*
2103  * return true if the entry is in a state where
2104  * it can accept more data (ie with write() method)
2105  */
2106 bool
2107 StoreEntry::isAccepting() const
2108 {
2109     if (STORE_PENDING != store_status)
2110         return false;
2111
2112     if (EBIT_TEST(flags, ENTRY_ABORTED))
2113         return false;
2114
2115     return true;
2116 }
2117
2118 std::ostream &operator <<(std::ostream &os, const StoreEntry &e)
2119 {
2120     return os << e.swap_filen << '@' << e.swap_dirn << '=' <<
2121         e.mem_status << '/' << e.ping_status << '/' << e.store_status << '/' <<
2122         e.swap_status;
2123 }
2124
2125 /* NullStoreEntry */
2126
2127 NullStoreEntry NullStoreEntry::_instance;
2128
2129 NullStoreEntry *
2130 NullStoreEntry::getInstance()
2131 {
2132     return &_instance;
2133 }
2134
2135 char const *
2136 NullStoreEntry::getMD5Text() const
2137 {
2138     return "N/A";
2139 }
2140
2141 void
2142 NullStoreEntry::operator delete(void*)
2143 {
2144     fatal ("Attempt to delete NullStoreEntry\n");
2145 }
2146
2147 char const *
2148 NullStoreEntry::getSerialisedMetaData()
2149 {
2150     return NULL;
2151 }
2152
2153 #if !_USE_INLINE_
2154 #include "Store.cci"
2155 #endif