src/StoreIOState.h

   1
   2 /*
   3  * $Id$
   4  *
   5  *
   6  * SQUID Web Proxy Cache          http://www.squid-cache.org/
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   9  *  Squid is the result of efforts by numerous individuals from
  10  *  the Internet community; see the CONTRIBUTORS file for full
  11  *  details.   Many organizations have provided support for Squid's
  12  *  development; see the SPONSORS file for full details.  Squid is
  13  *  Copyrighted (C) 2001 by the Regents of the University of
  14  *  California; see the COPYRIGHT file for full details.  Squid
  15  *  incorporates software developed and/or copyrighted by other
  16  *  sources; see the CREDITS file for full details.
  17  *
  18  *  This program is free software; you can redistribute it and/or modify
  19  *  it under the terms of the GNU General Public License as published by
  20  *  the Free Software Foundation; either version 2 of the License, or
  21  *  (at your option) any later version.
  22  *
  23  *  This program is distributed in the hope that it will be useful,
  24  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  25  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  26  *  GNU General Public License for more details.
  27  *
  28  *  You should have received a copy of the GNU General Public License
  29  *  along with this program; if not, write to the Free Software
  30  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  31  *
  32  */
  33
  34 #ifndef SQUID_STOREIOSTATE_H
  35 #define SQUID_STOREIOSTATE_H
  36
  37 #include "cbdata.h"
  38 #include "RefCount.h"
  39
  40 class StoreIOState : public RefCountable
  41 {
  42
  43 public:
  44     typedef RefCount<StoreIOState> Pointer;
  45
  46     /*
  47      * STRCB is the "store read callback".  STRCB functions are
  48      * passed to storeRead().  Examples of STRCB callbacks are:
  49      * storeClientReadBody
  50      * storeClientReadHeader
  51      */
  52     typedef void STRCB(void *their_data, const char *buf, ssize_t len, StoreIOState::Pointer self);
  53
  54     /*
  55      * STFNCB is the "store file number callback."  It is called
  56      * when an underlying storage module has allocated the swap
  57      * file number and also indicates that the swap file has been
  58      * opened for reading or writing.  STFNCB functions are passed
  59      * to storeCreate() and storeOpen().  Examples of STFNCB callbacks
  60      * are:
  61      * storeSwapInFileNotify
  62      * storeSwapOutFileNotify
  63      */
  64     typedef void STFNCB(void *their_data, int errflag, StoreIOState::Pointer self);
  65
  66     /*
  67      * STIOCB is the "store close callback" for store files.  It
  68      * is called when the store file is closed.  STIOCB functions
  69      * are passed to storeCreate() and storeOpen(). Examples of
  70      * STIOCB callbacks are:
  71      * storeSwapOutFileClosed
  72      * storeSwapInFileClosed
  73      */
  74     typedef void STIOCB(void *their_data, int errflag, StoreIOState::Pointer self);
  75
  76     /* StoreIOState does not get mempooled - it's children do */
  77     void *operator new (size_t amount);
  78     void operator delete (void *address);
  79     virtual ~StoreIOState();
  80
  81     StoreIOState();
  82
  83     off_t offset() const;
  84
  85     virtual void read_(char *buf, size_t size, off_t offset, STRCB * callback, void *callback_data) = 0;
  86     virtual void write(char const *buf, size_t size, off_t offset, FREE * free_func) = 0;
  87
  88     typedef enum {
  89        wroteAll, ///< success: caller supplied all data it wanted to swap out
  90        writerGone, ///< failure: caller left before swapping out everything
  91        readerDone ///< success or failure: either way, stop swapping in
  92     } CloseHow;
  93     virtual void close(int how) = 0; ///< finish or abort swapping per CloseHow
  94
  95     sdirno swap_dirn;
  96     sfileno swap_filen;
  97     StoreEntry *e;              /* Need this so the FS layers can play god */
  98     mode_t mode;
  99     off_t offset_; ///< number of bytes written or read for this entry so far
 100     STFNCB *file_callback;      /* called on delayed sfileno assignments */
 101     STIOCB *callback;
 102     void *callback_data;
 103
 104     struct {
 105         STRCB *callback;
 106         void *callback_data;
 107     } read;
 108
 109     struct {
 110         unsigned int closing:1; /* debugging aid */
 111     } flags;
 112 };
 113
 114 StoreIOState::Pointer storeCreate(StoreEntry *, StoreIOState::STFNCB *, StoreIOState::STIOCB *, void *);
 115 StoreIOState::Pointer storeOpen(StoreEntry *, StoreIOState::STFNCB *, StoreIOState::STIOCB *, void *);
 116 SQUIDCEXTERN void storeClose(StoreIOState::Pointer, int how);
 117 SQUIDCEXTERN void storeRead(StoreIOState::Pointer, char *, size_t, off_t, StoreIOState::STRCB *, void *);
 118 SQUIDCEXTERN void storeIOWrite(StoreIOState::Pointer, char const *, size_t, off_t, FREE *);
 119
 120 #endif /* SQUID_STOREIOSTATE_H */