src/StoreIOState.h

   1
   2 /*
   3  *
   4  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   5  * ----------------------------------------------------------
   6  *
   7  *  Squid is the result of efforts by numerous individuals from
   8  *  the Internet community; see the CONTRIBUTORS file for full
   9  *  details.   Many organizations have provided support for Squid's
  10  *  development; see the SPONSORS file for full details.  Squid is
  11  *  Copyrighted (C) 2001 by the Regents of the University of
  12  *  California; see the COPYRIGHT file for full details.  Squid
  13  *  incorporates software developed and/or copyrighted by other
  14  *  sources; see the CREDITS file for full details.
  15  *
  16  *  This program is free software; you can redistribute it and/or modify
  17  *  it under the terms of the GNU General Public License as published by
  18  *  the Free Software Foundation; either version 2 of the License, or
  19  *  (at your option) any later version.
  20  *
  21  *  This program is distributed in the hope that it will be useful,
  22  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  *  GNU General Public License for more details.
  25  *
  26  *  You should have received a copy of the GNU General Public License
  27  *  along with this program; if not, write to the Free Software
  28  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  29  *
  30  */
  31
  32 #ifndef SQUID_STOREIOSTATE_H
  33 #define SQUID_STOREIOSTATE_H
  34
  35 #include "base/RefCount.h"
  36 #include "cbdata.h"
  37
  38 class StoreIOState : public RefCountable
  39 {
  40
  41 public:
  42     typedef RefCount<StoreIOState> Pointer;
  43
  44     /*
  45      * STRCB is the "store read callback".  STRCB functions are
  46      * passed to storeRead().  Examples of STRCB callbacks are:
  47      * storeClientReadBody
  48      * storeClientReadHeader
  49      */
  50     typedef void STRCB(void *their_data, const char *buf, ssize_t len, StoreIOState::Pointer self);
  51
  52     /*
  53      * STFNCB is the "store file number callback."  It is called
  54      * when an underlying storage module has allocated the swap
  55      * file number and also indicates that the swap file has been
  56      * opened for reading or writing.  STFNCB functions are passed
  57      * to storeCreate() and storeOpen().  Examples of STFNCB callbacks
  58      * are:
  59      * storeSwapInFileNotify
  60      * storeSwapOutFileNotify
  61      */
  62     typedef void STFNCB(void *their_data, int errflag, StoreIOState::Pointer self);
  63
  64     /*
  65      * STIOCB is the "store close callback" for store files.  It
  66      * is called when the store file is closed.  STIOCB functions
  67      * are passed to storeCreate() and storeOpen(). Examples of
  68      * STIOCB callbacks are:
  69      * storeSwapOutFileClosed
  70      * storeSwapInFileClosed
  71      */
  72     typedef void STIOCB(void *their_data, int errflag, StoreIOState::Pointer self);
  73
  74     /* StoreIOState does not get mempooled - it's children do */
  75     void *operator new (size_t amount);
  76     void operator delete (void *address);
  77     virtual ~StoreIOState();
  78
  79     StoreIOState();
  80
  81     off_t offset() const;
  82
  83     virtual void read_(char *buf, size_t size, off_t offset, STRCB * callback, void *callback_data) = 0;
  84     virtual void write(char const *buf, size_t size, off_t offset, FREE * free_func) = 0;
  85
  86     typedef enum {
  87         wroteAll, ///< success: caller supplied all data it wanted to swap out
  88         writerGone, ///< failure: caller left before swapping out everything
  89         readerDone ///< success or failure: either way, stop swapping in
  90     } CloseHow;
  91     virtual void close(int how) = 0; ///< finish or abort swapping per CloseHow
  92
  93     sdirno swap_dirn;
  94     sfileno swap_filen;
  95     StoreEntry *e;              /* Need this so the FS layers can play god */
  96     mode_t mode;
  97     off_t offset_; ///< number of bytes written or read for this entry so far
  98     STFNCB *file_callback;      /* called on delayed sfileno assignments */
  99     STIOCB *callback;
 100     void *callback_data;
 101
 102     struct {
 103         STRCB *callback;
 104         void *callback_data;
 105     } read;
 106
 107     struct {
 108         unsigned int closing:1; /* debugging aid */
 109     } flags;
 110 };
 111
 112 StoreIOState::Pointer storeCreate(StoreEntry *, StoreIOState::STFNCB *, StoreIOState::STIOCB *, void *);
 113 StoreIOState::Pointer storeOpen(StoreEntry *, StoreIOState::STFNCB *, StoreIOState::STIOCB *, void *);
 114 void storeClose(StoreIOState::Pointer, int how);
 115 void storeRead(StoreIOState::Pointer, char *, size_t, off_t, StoreIOState::STRCB *, void *);
 116 void storeIOWrite(StoreIOState::Pointer, char const *, size_t, off_t, FREE *);
 117
 118 #endif /* SQUID_STOREIOSTATE_H */