src/store_io.cc

   1 /*
   2  * Copyright (C) 1996-2017 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 #include "squid.h"
  10 #include "MemObject.h"
  11 #include "SquidConfig.h"
  12 #include "Store.h"
  13 #include "store/Disk.h"
  14 #include "store/Disks.h"
  15
  16 StoreIoStats store_io_stats;
  17
  18 /*
  19  * submit a request to create a cache object for writing.
  20  * The StoreEntry structure is sent as a hint to the filesystem
  21  * to what will be stored in this object, to allow the filesystem
  22  * to select different polices depending on object size or type.
  23  */
  24 StoreIOState::Pointer
  25 storeCreate(StoreEntry * e, StoreIOState::STFNCB * file_callback, StoreIOState::STIOCB * close_callback, void *callback_data)
  26 {
  27     assert (e);
  28
  29     ++store_io_stats.create.calls;
  30
  31     /*
  32      * Pick the swapdir
  33      * We assume that the header has been packed by now ..
  34      */
  35     const sdirno dirn = storeDirSelectSwapDir(e);
  36
  37     if (dirn == -1) {
  38         debugs(20, 2, "storeCreate: no swapdirs for " << *e);
  39         ++store_io_stats.create.select_fail;
  40         return NULL;
  41     }
  42
  43     debugs(20, 2, "storeCreate: Selected dir " << dirn << " for " << *e);
  44     SwapDir *SD = dynamic_cast<SwapDir *>(INDEXSD(dirn));
  45
  46     /* Now that we have a fs to use, call its storeCreate function */
  47     StoreIOState::Pointer sio = SD->createStoreIO(*e, file_callback, close_callback, callback_data);
  48
  49     if (sio == NULL)
  50         ++store_io_stats.create.create_fail;
  51     else
  52         ++store_io_stats.create.success;
  53
  54     return sio;
  55 }
  56
  57 /*
  58  * storeOpen() is purely for reading ..
  59  */
  60 StoreIOState::Pointer
  61 storeOpen(StoreEntry * e, StoreIOState::STFNCB * file_callback, StoreIOState::STIOCB * callback,
  62           void *callback_data)
  63 {
  64     return e->disk().openStoreIO(*e, file_callback, callback, callback_data);
  65 }
  66
  67 void
  68 storeClose(StoreIOState::Pointer sio, int how)
  69 {
  70     if (sio->flags.closing) {
  71         debugs(20,3,HERE << "storeClose: flags.closing already set, bailing");
  72         return;
  73     }
  74
  75     sio->flags.closing = true;
  76
  77     debugs(20,3,HERE << "storeClose: calling sio->close(" << how << ")");
  78     sio->close(how);
  79 }
  80
  81 void
  82 storeRead(StoreIOState::Pointer sio, char *buf, size_t size, off_t offset, StoreIOState::STRCB * callback, void *callback_data)
  83 {
  84     sio->read_(buf, size, offset, callback, callback_data);
  85 }
  86
  87 void
  88 storeIOWrite(StoreIOState::Pointer sio, char const *buf, size_t size, off_t offset, FREE * free_func)
  89 {
  90     sio->write(buf,size,offset,free_func);
  91 }
  92