src/store_dir.cc

   1
   2 /*
   3  * $Id$
   4  *
   5  * DEBUG: section 47    Store Directory Routines
   6  * AUTHOR: Duane Wessels
   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 "Store.h"
  38 #include "MemObject.h"
  39 #include "MemStore.h"
  40 #include "mem_node.h"
  41 #include "SquidMath.h"
  42 #include "SquidTime.h"
  43 #include "SwapDir.h"
  44 #include "swap_log_op.h"
  45
  46 #if HAVE_STATVFS
  47 #if HAVE_SYS_STATVFS_H
  48 #include <sys/statvfs.h>
  49 #endif
  50 #endif /* HAVE_STATVFS */
  51 /* statfs() needs <sys/param.h> and <sys/mount.h> on BSD systems */
  52 #if HAVE_SYS_PARAM_H
  53 #include <sys/param.h>
  54 #endif
  55 #if HAVE_SYS_MOUNT_H
  56 #include <sys/mount.h>
  57 #endif
  58 /* Windows and Linux use sys/vfs.h */
  59 #if HAVE_SYS_VFS_H
  60 #include <sys/vfs.h>
  61 #endif
  62
  63 #include "StoreHashIndex.h"
  64
  65 static STDIRSELECT storeDirSelectSwapDirRoundRobin;
  66 static STDIRSELECT storeDirSelectSwapDirLeastLoad;
  67
  68 /*
  69  * store_dirs_rebuilding is initialized to _1_ as a hack so that
  70  * storeDirWriteCleanLogs() doesn't try to do anything unless _all_
  71  * cache_dirs have been read.  For example, without this hack, Squid
  72  * will try to write clean log files if -kparse fails (becasue it
  73  * calls fatal()).
  74  */
  75 int StoreController::store_dirs_rebuilding = 1;
  76
  77 StoreController::StoreController() : swapDir (new StoreHashIndex())
  78     , memStore(NULL)
  79 {}
  80
  81 StoreController::~StoreController()
  82 {
  83     delete memStore;
  84 }
  85
  86 /*
  87  * This function pointer is set according to 'store_dir_select_algorithm'
  88  * in squid.conf.
  89  */
  90 STDIRSELECT *storeDirSelectSwapDir = storeDirSelectSwapDirLeastLoad;
  91
  92 void
  93 StoreController::init()
  94 {
  95     // XXX: add: if (UsingSmp())
  96     memStore = new MemStore;
  97     memStore->init();
  98
  99     swapDir->init();
 100
 101     if (0 == strcasecmp(Config.store_dir_select_algorithm, "round-robin")) {
 102         storeDirSelectSwapDir = storeDirSelectSwapDirRoundRobin;
 103         debugs(47, 1, "Using Round Robin store dir selection");
 104     } else {
 105         storeDirSelectSwapDir = storeDirSelectSwapDirLeastLoad;
 106         debugs(47, 1, "Using Least Load store dir selection");
 107     }
 108 }
 109
 110 void
 111 StoreController::createOneStore(Store &aStore)
 112 {
 113     /*
 114      * On Windows, fork() is not available.
 115      * The following is a workaround for create store directories sequentially
 116      * when running on native Windows port.
 117      */
 118 #ifndef _SQUID_MSWIN_
 119
 120     if (fork())
 121         return;
 122
 123 #endif
 124
 125     aStore.create();
 126
 127 #ifndef _SQUID_MSWIN_
 128
 129     exit(0);
 130
 131 #endif
 132 }
 133
 134 void
 135 StoreController::create()
 136 {
 137     swapDir->create();
 138
 139 #ifndef _SQUID_MSWIN_
 140
 141     pid_t pid;
 142
 143     do {
 144         int status;
 145 #ifdef _SQUID_NEXT_
 146
 147         pid = wait3(&status, WNOHANG, NULL);
 148 #else
 149
 150         pid = waitpid(-1, &status, 0);
 151 #endif
 152
 153     } while (pid > 0 || (pid < 0 && errno == EINTR));
 154
 155 #endif
 156 }
 157
 158 /**
 159  * Determine whether the given directory can handle this object
 160  * size
 161  *
 162  * Note: if the object size is -1, then the only swapdirs that
 163  * will return true here are ones that have min and max unset,
 164  * ie any-sized-object swapdirs. This is a good thing.
 165  */
 166 bool
 167 SwapDir::objectSizeIsAcceptable(int64_t objsize) const
 168 {
 169     // If the swapdir has no range limits, then it definitely can
 170     if (min_objsize <= 0 && max_objsize == -1)
 171         return true;
 172
 173     /*
 174      * If the object size is -1 and the storedir has limits we
 175      * can't store it there.
 176      */
 177     if (objsize == -1)
 178         return false;
 179
 180     // Else, make sure that the object size will fit.
 181     return min_objsize <= objsize && max_objsize > objsize;
 182 }
 183
 184
 185 /*
 186  * This new selection scheme simply does round-robin on all SwapDirs.
 187  * A SwapDir is skipped if it is over the max_size (100%) limit, or
 188  * overloaded.
 189  */
 190 static int
 191 storeDirSelectSwapDirRoundRobin(const StoreEntry * e)
 192 {
 193     static int dirn = 0;
 194     int i;
 195     int load;
 196     RefCount<SwapDir> sd;
 197
 198     // e->objectLen() is negative at this point when we are still STORE_PENDING
 199     ssize_t objsize = e->mem_obj->expectedReplySize();
 200     if (objsize != -1)
 201         objsize += e->mem_obj->swap_hdr_sz;
 202
 203     for (i = 0; i < Config.cacheSwap.n_configured; i++) {
 204         if (++dirn >= Config.cacheSwap.n_configured)
 205             dirn = 0;
 206
 207         sd = dynamic_cast<SwapDir *>(INDEXSD(dirn));
 208
 209         if (!sd->canStore(*e, objsize, load))
 210             continue;
 211
 212         if (load < 0 || load > 1000) {
 213             continue;
 214         }
 215
 216         return dirn;
 217     }
 218
 219     return -1;
 220 }
 221
 222 /*
 223  * Spread load across all of the store directories
 224  *
 225  * Note: We should modify this later on to prefer sticking objects
 226  * in the *tightest fit* swapdir to conserve space, along with the
 227  * actual swapdir usage. But for now, this hack will do while
 228  * testing, so you should order your swapdirs in the config file
 229  * from smallest maxobjsize to unlimited (-1) maxobjsize.
 230  *
 231  * We also have to choose nleast == nconf since we need to consider
 232  * ALL swapdirs, regardless of state. Again, this is a hack while
 233  * we sort out the real usefulness of this algorithm.
 234  */
 235 static int
 236 storeDirSelectSwapDirLeastLoad(const StoreEntry * e)
 237 {
 238     ssize_t most_free = 0, cur_free;
 239     ssize_t least_objsize = -1;
 240     int least_load = INT_MAX;
 241     int load;
 242     int dirn = -1;
 243     int i;
 244     RefCount<SwapDir> SD;
 245
 246     // e->objectLen() is negative at this point when we are still STORE_PENDING
 247     ssize_t objsize = e->mem_obj->expectedReplySize();
 248
 249     if (objsize != -1)
 250         objsize += e->mem_obj->swap_hdr_sz;
 251
 252     for (i = 0; i < Config.cacheSwap.n_configured; i++) {
 253         SD = dynamic_cast<SwapDir *>(INDEXSD(i));
 254         SD->flags.selected = 0;
 255
 256         if (!SD->canStore(*e, objsize, load))
 257             continue;
 258
 259         if (load < 0 || load > 1000)
 260             continue;
 261
 262         if (load > least_load)
 263             continue;
 264
 265         cur_free = SD->max_size - SD->cur_size;
 266
 267         /* If the load is equal, then look in more details */
 268         if (load == least_load) {
 269             /* closest max_objsize fit */
 270
 271             if (least_objsize != -1)
 272                 if (SD->max_objsize > least_objsize || SD->max_objsize == -1)
 273                     continue;
 274
 275             /* most free */
 276             if (cur_free < most_free)
 277                 continue;
 278         }
 279
 280         least_load = load;
 281         least_objsize = SD->max_objsize;
 282         most_free = cur_free;
 283         dirn = i;
 284     }
 285
 286     if (dirn >= 0)
 287         dynamic_cast<SwapDir *>(INDEXSD(dirn))->flags.selected = 1;
 288
 289     return dirn;
 290 }
 291
 292 /*
 293  * An entry written to the swap log MUST have the following
 294  * properties.
 295  *   1.  It MUST be a public key.  It does no good to log
 296  *       a public ADD, change the key, then log a private
 297  *       DEL.  So we need to log a DEL before we change a
 298  *       key from public to private.
 299  *   2.  It MUST have a valid (> -1) swap_filen.
 300  */
 301 void
 302 storeDirSwapLog(const StoreEntry * e, int op)
 303 {
 304     assert (e);
 305     assert(!EBIT_TEST(e->flags, KEY_PRIVATE));
 306     assert(e->swap_filen >= 0);
 307     /*
 308      * icons and such; don't write them to the swap log
 309      */
 310
 311     if (EBIT_TEST(e->flags, ENTRY_SPECIAL))
 312         return;
 313
 314     assert(op > SWAP_LOG_NOP && op < SWAP_LOG_MAX);
 315
 316     debugs(20, 3, "storeDirSwapLog: " <<
 317            swap_log_op_str[op] << " " <<
 318            e->getMD5Text() << " " <<
 319            e->swap_dirn << " " <<
 320            std::hex << std::uppercase << std::setfill('0') << std::setw(8) << e->swap_filen);
 321
 322     dynamic_cast<SwapDir *>(INDEXSD(e->swap_dirn))->logEntry(*e, op);
 323 }
 324
 325 void
 326 StoreController::updateSize(int64_t size, int sign)
 327 {
 328     fatal("StoreController has no independent size\n");
 329 }
 330
 331 void
 332 SwapDir::updateSize(int64_t size, int sign)
 333 {
 334     int64_t blks = (size + fs.blksize - 1) / fs.blksize;
 335     int64_t k = ((blks * fs.blksize) >> 10) * sign;
 336     cur_size += k;
 337
 338     if (sign > 0)
 339         n_disk_objects++;
 340     else if (sign < 0)
 341         n_disk_objects--;
 342 }
 343
 344 void
 345 StoreController::stat(StoreEntry &output) const
 346 {
 347     storeAppendPrintf(&output, "Store Directory Statistics:\n");
 348     storeAppendPrintf(&output, "Store Entries          : %lu\n",
 349                       (unsigned long int)StoreEntry::inUseCount());
 350     storeAppendPrintf(&output, "Maximum Swap Size      : %"PRIu64" KB\n",
 351                       maxSize());
 352     storeAppendPrintf(&output, "Current Store Swap Size: %8lu KB\n",
 353                       currentSize());
 354     storeAppendPrintf(&output, "Current Capacity       : %"PRId64"%% used, %"PRId64"%% free\n",
 355                       Math::int64Percent(currentSize(), maxSize()),
 356                       Math::int64Percent((maxSize() - currentSize()), maxSize()));
 357
 358     if (memStore)
 359         memStore->stat(output);
 360
 361     /* now the swapDir */
 362     swapDir->stat(output);
 363 }
 364
 365 /* if needed, this could be taught to cache the result */
 366 uint64_t
 367 StoreController::maxSize() const
 368 {
 369     /* TODO: include memory cache ? */
 370     return swapDir->maxSize();
 371 }
 372
 373 uint64_t
 374 StoreController::minSize() const
 375 {
 376     /* TODO: include memory cache ? */
 377     return swapDir->minSize();
 378 }
 379
 380 uint64_t
 381 StoreController::currentSize() const
 382 {
 383     return swapDir->currentSize();
 384 }
 385
 386 uint64_t
 387 StoreController::currentCount() const
 388 {
 389     return swapDir->currentCount();
 390 }
 391
 392 void
 393 SwapDir::diskFull()
 394 {
 395     if (cur_size >= max_size)
 396         return;
 397
 398     max_size = cur_size;
 399
 400     debugs(20, 1, "WARNING: Shrinking cache_dir #" << index << " to " << cur_size << " KB");
 401 }
 402
 403 void
 404 storeDirOpenSwapLogs(void)
 405 {
 406     for (int dirn = 0; dirn < Config.cacheSwap.n_configured; ++dirn)
 407         dynamic_cast<SwapDir *>(INDEXSD(dirn))->openLog();
 408 }
 409
 410 void
 411 storeDirCloseSwapLogs(void)
 412 {
 413     for (int dirn = 0; dirn < Config.cacheSwap.n_configured; ++dirn)
 414         dynamic_cast<SwapDir *>(INDEXSD(dirn))->closeLog();
 415 }
 416
 417 /*
 418  *  storeDirWriteCleanLogs
 419  *
 420  *  Writes a "clean" swap log file from in-memory metadata.
 421  *  This is a rewrite of the original function to troll each
 422  *  StoreDir and write the logs, and flush at the end of
 423  *  the run. Thanks goes to Eric Stern, since this solution
 424  *  came out of his COSS code.
 425  */
 426 int
 427 storeDirWriteCleanLogs(int reopen)
 428 {
 429     const StoreEntry *e = NULL;
 430     int n = 0;
 431
 432     struct timeval start;
 433     double dt;
 434     RefCount<SwapDir> sd;
 435     int dirn;
 436     int notdone = 1;
 437
 438     if (StoreController::store_dirs_rebuilding) {
 439         debugs(20, 1, "Not currently OK to rewrite swap log.");
 440         debugs(20, 1, "storeDirWriteCleanLogs: Operation aborted.");
 441         return 0;
 442     }
 443
 444     debugs(20, 1, "storeDirWriteCleanLogs: Starting...");
 445     getCurrentTime();
 446     start = current_time;
 447
 448     for (dirn = 0; dirn < Config.cacheSwap.n_configured; dirn++) {
 449         sd = dynamic_cast<SwapDir *>(INDEXSD(dirn));
 450
 451         if (sd->writeCleanStart() < 0) {
 452             debugs(20, 1, "log.clean.start() failed for dir #" << sd->index);
 453             continue;
 454         }
 455     }
 456
 457     /*
 458      * This may look inefficient as CPU wise it is more efficient to do this
 459      * sequentially, but I/O wise the parallellism helps as it allows more
 460      * hdd spindles to be active.
 461      */
 462     while (notdone) {
 463         notdone = 0;
 464
 465         for (dirn = 0; dirn < Config.cacheSwap.n_configured; dirn++) {
 466             sd = dynamic_cast<SwapDir *>(INDEXSD(dirn));
 467
 468             if (NULL == sd->cleanLog)
 469                 continue;
 470
 471             e = sd->cleanLog->nextEntry();
 472
 473             if (!e)
 474                 continue;
 475
 476             notdone = 1;
 477
 478             if (!sd->canLog(*e))
 479                 continue;
 480
 481             sd->cleanLog->write(*e);
 482
 483             if ((++n & 0xFFFF) == 0) {
 484                 getCurrentTime();
 485                 debugs(20, 1, "  " << std::setw(7) << n  <<
 486                        " entries written so far.");
 487             }
 488         }
 489     }
 490
 491     /* Flush */
 492     for (dirn = 0; dirn < Config.cacheSwap.n_configured; dirn++)
 493         dynamic_cast<SwapDir *>(INDEXSD(dirn))->writeCleanDone();
 494
 495     if (reopen)
 496         storeDirOpenSwapLogs();
 497
 498     getCurrentTime();
 499
 500     dt = tvSubDsec(start, current_time);
 501
 502     debugs(20, 1, "  Finished.  Wrote " << n << " entries.");
 503     debugs(20, 1, "  Took "<< std::setw(3)<< std::setprecision(2) << dt <<
 504            " seconds ("<< std::setw(6) << ((double) n / (dt > 0.0 ? dt : 1.0)) << " entries/sec).");
 505
 506
 507     return n;
 508 }
 509
 510 StoreSearch *
 511 StoreController::search(String const url, HttpRequest *request)
 512 {
 513     /* cheat, for now you can't search the memory hot cache */
 514     return swapDir->search(url, request);
 515 }
 516
 517 StorePointer
 518 StoreHashIndex::store(int const x) const
 519 {
 520     return INDEXSD(x);
 521 }
 522
 523 SwapDir &
 524 StoreHashIndex::dir(const int i) const
 525 {
 526     SwapDir *sd = dynamic_cast<SwapDir*>(INDEXSD(i));
 527     assert(sd);
 528     return *sd;
 529 }
 530
 531 void
 532 StoreController::sync(void)
 533 {
 534     if (memStore)
 535         memStore->sync();
 536     swapDir->sync();
 537 }
 538
 539 /*
 540  * handle callbacks all avaliable fs'es
 541  */
 542 int
 543 StoreController::callback()
 544 {
 545     /* This will likely double count. Thats ok. */
 546     PROF_start(storeDirCallback);
 547
 548     /* mem cache callbacks ? */
 549     int result = swapDir->callback();
 550
 551     PROF_stop(storeDirCallback);
 552
 553     return result;
 554 }
 555
 556 int
 557 storeDirGetBlkSize(const char *path, int *blksize)
 558 {
 559 #if HAVE_STATVFS
 560
 561     struct statvfs sfs;
 562
 563     if (statvfs(path, &sfs)) {
 564         debugs(50, 1, "" << path << ": " << xstrerror());
 565         *blksize = 2048;
 566         return 1;
 567     }
 568
 569     *blksize = (int) sfs.f_frsize;
 570 #else
 571
 572     struct statfs sfs;
 573
 574     if (statfs(path, &sfs)) {
 575         debugs(50, 1, "" << path << ": " << xstrerror());
 576         *blksize = 2048;
 577         return 1;
 578     }
 579
 580     *blksize = (int) sfs.f_bsize;
 581 #endif
 582     /*
 583      * Sanity check; make sure we have a meaningful value.
 584      */
 585
 586     if (*blksize < 512)
 587         *blksize = 2048;
 588
 589     return 0;
 590 }
 591
 592 #define fsbtoblk(num, fsbs, bs) \
 593     (((fsbs) != 0 && (fsbs) < (bs)) ? \
 594             (num) / ((bs) / (fsbs)) : (num) * ((fsbs) / (bs)))
 595 int
 596 storeDirGetUFSStats(const char *path, int *totl_kb, int *free_kb, int *totl_in, int *free_in)
 597 {
 598 #if HAVE_STATVFS
 599
 600     struct statvfs sfs;
 601
 602     if (statvfs(path, &sfs)) {
 603         debugs(50, 1, "" << path << ": " << xstrerror());
 604         return 1;
 605     }
 606
 607     *totl_kb = (int) fsbtoblk(sfs.f_blocks, sfs.f_frsize, 1024);
 608     *free_kb = (int) fsbtoblk(sfs.f_bfree, sfs.f_frsize, 1024);
 609     *totl_in = (int) sfs.f_files;
 610     *free_in = (int) sfs.f_ffree;
 611 #else
 612
 613     struct statfs sfs;
 614
 615     if (statfs(path, &sfs)) {
 616         debugs(50, 1, "" << path << ": " << xstrerror());
 617         return 1;
 618     }
 619
 620     *totl_kb = (int) fsbtoblk(sfs.f_blocks, sfs.f_bsize, 1024);
 621     *free_kb = (int) fsbtoblk(sfs.f_bfree, sfs.f_bsize, 1024);
 622     *totl_in = (int) sfs.f_files;
 623     *free_in = (int) sfs.f_ffree;
 624 #endif
 625
 626     return 0;
 627 }
 628
 629 void
 630 allocate_new_swapdir(SquidConfig::_cacheSwap * swap)
 631 {
 632     if (swap->swapDirs == NULL) {
 633         swap->n_allocated = 4;
 634         swap->swapDirs = static_cast<StorePointer *>(xcalloc(swap->n_allocated, sizeof(StorePointer)));
 635     }
 636
 637     if (swap->n_allocated == swap->n_configured) {
 638         StorePointer *tmp;
 639         swap->n_allocated <<= 1;
 640         tmp = static_cast<StorePointer *>(xcalloc(swap->n_allocated, sizeof(StorePointer)));
 641         memcpy(tmp, swap->swapDirs, swap->n_configured * sizeof(SwapDir *));
 642         xfree(swap->swapDirs);
 643         swap->swapDirs = tmp;
 644     }
 645 }
 646
 647 void
 648 free_cachedir(SquidConfig::_cacheSwap * swap)
 649 {
 650     int i;
 651     /* DON'T FREE THESE FOR RECONFIGURE */
 652
 653     if (reconfiguring)
 654         return;
 655
 656     for (i = 0; i < swap->n_configured; i++) {
 657         /* TODO XXX this lets the swapdir free resources asynchronously
 658         * swap->swapDirs[i]->deactivate();
 659         * but there may be such a means already.
 660         * RBC 20041225
 661         */
 662         swap->swapDirs[i] = NULL;
 663     }
 664
 665     safe_free(swap->swapDirs);
 666     swap->swapDirs = NULL;
 667     swap->n_allocated = 0;
 668     swap->n_configured = 0;
 669 }
 670
 671 /* this should be a virtual method on StoreEntry,
 672  * i.e. e->referenced()
 673  * so that the entry can notify the creating Store
 674  */
 675 void
 676 StoreController::reference(StoreEntry &e)
 677 {
 678     /* Notify the fs that we're referencing this object again */
 679
 680     if (e.swap_dirn > -1)
 681         e.store()->reference(e);
 682
 683     // Notify the memory cache that we're referencing this object again
 684     if (memStore && e.mem_status == IN_MEMORY)
 685         memStore->reference(e);
 686
 687     // TODO: move this code to a non-shared memory cache class when we have it
 688     if (e.mem_obj) {
 689         if (mem_policy->Referenced)
 690             mem_policy->Referenced(mem_policy, &e, &e.mem_obj->repl);
 691     }
 692 }
 693
 694 void
 695 StoreController::dereference(StoreEntry & e)
 696 {
 697     /* Notify the fs that we're not referencing this object any more */
 698
 699     if (e.swap_filen > -1)
 700         e.store()->dereference(e);
 701
 702     // Notify the memory cache that we're not referencing this object any more
 703     if (memStore && e.mem_status == IN_MEMORY)
 704         memStore->dereference(e);
 705
 706     // TODO: move this code to a non-shared memory cache class when we have it
 707     if (e.mem_obj) {
 708         if (mem_policy->Dereferenced)
 709             mem_policy->Dereferenced(mem_policy, &e, &e.mem_obj->repl);
 710     }
 711 }
 712
 713 StoreEntry *
 714 StoreController::get(const cache_key *key)
 715 {
 716     if (StoreEntry *e = swapDir->get(key)) {
 717         // TODO: ignore and maybe handleIdleEntry() unlocked intransit entries
 718         // because their backing store slot may be gone already.
 719         debugs(20, 3, HERE << "got in-transit entry: " << *e);
 720         return e;
 721     }
 722
 723     if (memStore) {
 724         if (StoreEntry *e = memStore->get(key)) {
 725             debugs(20, 3, HERE << "got mem-cached entry: " << *e);
 726             return e;
 727         }
 728     }
 729
 730     // TODO: this disk iteration is misplaced; move to StoreHashIndex
 731     if (const int cacheDirs = Config.cacheSwap.n_configured) {
 732         // ask each cache_dir until the entry is found; use static starting
 733         // point to avoid asking the same subset of disks more often
 734         // TODO: coordinate with put() to be able to guess the right disk often
 735         static int idx = 0;
 736         for (int n = 0; n < cacheDirs; ++n) {
 737             idx = (idx + 1) % cacheDirs;
 738             SwapDir *sd = dynamic_cast<SwapDir*>(INDEXSD(idx));
 739             if (!sd->active())
 740                 continue;
 741
 742             if (StoreEntry *e = sd->get(key)) {
 743                 debugs(20, 3, HERE << "cache_dir " << idx <<
 744                     " got cached entry: " << *e);
 745                 return e;
 746             }
 747         }
 748     }
 749
 750     debugs(20, 4, HERE << "none of " << Config.cacheSwap.n_configured <<
 751         " cache_dirs have " << storeKeyText(key));
 752     return NULL;
 753 }
 754
 755 void
 756 StoreController::get(String const key, STOREGETCLIENT aCallback, void *aCallbackData)
 757 {
 758     fatal("not implemented");
 759 }
 760
 761 void
 762 StoreController::handleIdleEntry(StoreEntry &e)
 763 {
 764     bool keepInLocalMemory = false;
 765     if (memStore) {
 766         memStore->considerKeeping(e);
 767         // leave keepInLocalMemory false; memStore maintains its own cache
 768     } else {
 769         keepInLocalMemory = e.memoryCachable() && // entry is in good shape and
 770             // the local memory cache is not overflowing
 771             (mem_node::InUseCount() <= store_pages_max);
 772     }
 773
 774     dereference(e);
 775
 776     // XXX: Rock store specific: Since each SwapDir controls its index,
 777     // unlocked entries should not stay in the global store_table.
 778     if (fileno >= 0) {
 779         debugs(20, 5, HERE << "destroying unlocked entry: " << &e << ' ' << e);
 780         destroyStoreEntry(static_cast<hash_link*>(&e));
 781         return;
 782     }
 783
 784     // TODO: move this into [non-shared] memory cache class when we have one
 785     if (keepInLocalMemory) {
 786         e.setMemStatus(IN_MEMORY);
 787         e.mem_obj->unlinkRequest();
 788     } else {
 789         e.purgeMem(); // may free e
 790     }
 791 }
 792
 793 StoreHashIndex::StoreHashIndex()
 794 {
 795     if (store_table)
 796         abort();
 797     assert (store_table == NULL);
 798 }
 799
 800 StoreHashIndex::~StoreHashIndex()
 801 {
 802     if (store_table) {
 803         hashFreeItems(store_table, destroyStoreEntry);
 804         hashFreeMemory(store_table);
 805         store_table = NULL;
 806     }
 807 }
 808
 809 int
 810 StoreHashIndex::callback()
 811 {
 812     int result = 0;
 813     int j;
 814     static int ndir = 0;
 815
 816     do {
 817         j = 0;
 818
 819         for (int i = 0; i < Config.cacheSwap.n_configured; i++) {
 820             if (ndir >= Config.cacheSwap.n_configured)
 821                 ndir = ndir % Config.cacheSwap.n_configured;
 822
 823             int temp_result = store(ndir)->callback();
 824
 825             ++ndir;
 826
 827             j += temp_result;
 828
 829             result += temp_result;
 830
 831             if (j > 100)
 832                 fatal ("too much io\n");
 833         }
 834     } while (j > 0);
 835
 836     ndir++;
 837
 838     return result;
 839 }
 840
 841 void
 842 StoreHashIndex::create()
 843 {
 844     for (int i = 0; i < Config.cacheSwap.n_configured; i++) {
 845         if (dir(i).active())
 846             store(i)->create();
 847     }
 848 }
 849
 850 /* Lookup an object in the cache.
 851  * return just a reference to object, don't start swapping in yet. */
 852 StoreEntry *
 853 StoreHashIndex::get(const cache_key *key)
 854 {
 855     PROF_start(storeGet);
 856     debugs(20, 3, "storeGet: looking up " << storeKeyText(key));
 857     StoreEntry *p = static_cast<StoreEntry *>(hash_lookup(store_table, key));
 858     PROF_stop(storeGet);
 859     return p;
 860 }
 861
 862 void
 863 StoreHashIndex::get(String const key, STOREGETCLIENT aCallback, void *aCallbackData)
 864 {
 865     fatal("not implemented");
 866 }
 867
 868 void
 869 StoreHashIndex::init()
 870 {
 871     /* Calculate size of hash table (maximum currently 64k buckets).  */
 872     /* this is very bogus, its specific to the any Store maintaining an
 873      * in-core index, not global */
 874     size_t buckets = (Store::Root().maxSize() + ( Config.memMaxSize >> 10)) / Config.Store.avgObjectSize;
 875     debugs(20, 1, "Swap maxSize " << Store::Root().maxSize() <<
 876            " + " << ( Config.memMaxSize >> 10) << " KB, estimated " << buckets << " objects");
 877     buckets /= Config.Store.objectsPerBucket;
 878     debugs(20, 1, "Target number of buckets: " << buckets);
 879     /* ideally the full scan period should be configurable, for the
 880      * moment it remains at approximately 24 hours.  */
 881     store_hash_buckets = storeKeyHashBuckets(buckets);
 882     debugs(20, 1, "Using " << store_hash_buckets << " Store buckets");
 883     debugs(20, 1, "Max Mem  size: " << ( Config.memMaxSize >> 10) << " KB");
 884     debugs(20, 1, "Max Swap size: " << Store::Root().maxSize() << " KB");
 885
 886     store_table = hash_create(storeKeyHashCmp,
 887                               store_hash_buckets, storeKeyHashHash);
 888
 889     for (int i = 0; i < Config.cacheSwap.n_configured; i++) {
 890         /* this starts a search of the store dirs, loading their
 891          * index. under the new Store api this should be
 892          * driven by the StoreHashIndex, not by each store.
 893         *
 894         * That is, the HashIndex should perform a search of each dir it is
 895         * indexing to do the hash insertions. The search is then able to
 896         * decide 'from-memory', or 'from-clean-log' or 'from-dirty-log' or
 897         * 'from-no-log'.
 898         *
 899          * Step 1: make the store rebuilds use a search internally
 900         * Step 2: change the search logic to use the four modes described
 901         *         above
 902         * Step 3: have the hash index walk the searches itself.
 903          */
 904         if (dir(i).active())
 905             store(i)->init();
 906     }
 907 }
 908
 909 uint64_t
 910 StoreHashIndex::maxSize() const
 911 {
 912     uint64_t result = 0;
 913
 914     for (int i = 0; i < Config.cacheSwap.n_configured; i++) {
 915         if (dir(i).doReportStat())
 916             result += store(i)->maxSize();
 917     }
 918
 919     return result;
 920 }
 921
 922 uint64_t
 923 StoreHashIndex::minSize() const
 924 {
 925     uint64_t result = 0;
 926
 927     for (int i = 0; i < Config.cacheSwap.n_configured; i++) {
 928         if (dir(i).doReportStat())
 929             result += store(i)->minSize();
 930     }
 931
 932     return result;
 933 }
 934
 935 uint64_t
 936 StoreHashIndex::currentSize() const
 937 {
 938     uint64_t result = 0;
 939
 940     for (int i = 0; i < Config.cacheSwap.n_configured; i++) {
 941         if (dir(i).doReportStat())
 942             result += store(i)->currentSize();
 943     }
 944
 945     return result;
 946 }
 947
 948 uint64_t
 949 StoreHashIndex::currentCount() const
 950 {
 951     uint64_t result = 0;
 952
 953     for (int i = 0; i < Config.cacheSwap.n_configured; i++) {
 954         if (dir(i).doReportStat())
 955             result += store(i)->currentCount();
 956     }
 957
 958     return result;
 959 }
 960
 961 void
 962 StoreHashIndex::stat(StoreEntry & output) const
 963 {
 964     int i;
 965
 966     /* Now go through each store, calling its stat routine */
 967
 968     for (i = 0; i < Config.cacheSwap.n_configured; i++) {
 969         storeAppendPrintf(&output, "\n");
 970         store(i)->stat(output);
 971     }
 972 }
 973
 974 void
 975 StoreHashIndex::reference(StoreEntry&)
 976 {}
 977
 978 void
 979 StoreHashIndex::dereference(StoreEntry&)
 980 {}
 981
 982 void
 983 StoreHashIndex::maintain()
 984 {
 985     int i;
 986     /* walk each fs */
 987
 988     for (i = 0; i < Config.cacheSwap.n_configured; i++) {
 989         /* XXX FixMe: This should be done "in parallell" on the different
 990          * cache_dirs, not one at a time.
 991          */
 992         /* call the maintain function .. */
 993         store(i)->maintain();
 994     }
 995 }
 996
 997 void
 998 StoreHashIndex::updateSize(int64_t, int)
 999 {}
1000
1001 void
1002 StoreHashIndex::sync()
1003 {
1004     for (int i = 0; i < Config.cacheSwap.n_configured; ++i)
1005         store(i)->sync();
1006 }
1007
1008 StoreSearch *
1009 StoreHashIndex::search(String const url, HttpRequest *)
1010 {
1011     if (url.size())
1012         fatal ("Cannot search by url yet\n");
1013
1014     return new StoreSearchHashIndex (this);
1015 }
1016
1017 CBDATA_CLASS_INIT(StoreSearchHashIndex);
1018
1019 StoreSearchHashIndex::StoreSearchHashIndex(RefCount<StoreHashIndex> aSwapDir) : sd(aSwapDir), _done (false), bucket (0)
1020 {}
1021
1022 /* do not link
1023 StoreSearchHashIndex::StoreSearchHashIndex(StoreSearchHashIndex const &);
1024 */
1025
1026 StoreSearchHashIndex::~StoreSearchHashIndex()
1027 {}
1028
1029 void
1030 StoreSearchHashIndex::next(void (aCallback)(void *), void *aCallbackData)
1031 {
1032     next();
1033     aCallback (aCallbackData);
1034 }
1035
1036 bool
1037 StoreSearchHashIndex::next()
1038 {
1039     if (entries.size())
1040         entries.pop_back();
1041
1042     while (!isDone() && !entries.size())
1043         copyBucket();
1044
1045     return currentItem() != NULL;
1046 }
1047
1048 bool
1049 StoreSearchHashIndex::error() const
1050 {
1051     return false;
1052 }
1053
1054 bool
1055 StoreSearchHashIndex::isDone() const
1056 {
1057     return bucket >= store_hash_buckets || _done;
1058 }
1059
1060 StoreEntry *
1061 StoreSearchHashIndex::currentItem()
1062 {
1063     if (!entries.size())
1064         return NULL;
1065
1066     return entries.back();
1067 }
1068
1069 void
1070 StoreSearchHashIndex::copyBucket()
1071 {
1072     /* probably need to lock the store entries...
1073      * we copy them all to prevent races on the links. */
1074     debugs(47, 3, "StoreSearchHashIndex::copyBucket #" << bucket);
1075     assert (!entries.size());
1076     hash_link *link_ptr = NULL;
1077     hash_link *link_next = NULL;
1078     link_next = hash_get_bucket(store_table, bucket);
1079
1080     while (NULL != (link_ptr = link_next)) {
1081         link_next = link_ptr->next;
1082         StoreEntry *e = (StoreEntry *) link_ptr;
1083
1084         entries.push_back(e);
1085     }
1086
1087     bucket++;
1088     debugs(47,3, "got entries: " << entries.size());
1089 }