src/DiskIO/DiskFile.h

   1
   2 /*
   3  * $Id: DiskFile.h,v 1.1 2004/12/20 16:30:38 robertc Exp $
   4  *
   5  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   6  * ----------------------------------------------------------
   7  *
   8  *  Squid is the result of efforts by numerous individuals from
   9  *  the Internet community; see the CONTRIBUTORS file for full
  10  *  details.   Many organizations have provided support for Squid's
  11  *  development; see the SPONSORS file for full details.  Squid is
  12  *  Copyrighted (C) 2001 by the Regents of the University of
  13  *  California; see the COPYRIGHT file for full details.  Squid
  14  *  incorporates software developed and/or copyrighted by other
  15  *  sources; see the CREDITS file for full details.
  16  *
  17  *  This program is free software; you can redistribute it and/or modify
  18  *  it under the terms of the GNU General Public License as published by
  19  *  the Free Software Foundation; either version 2 of the License, or
  20  *  (at your option) any later version.
  21  *
  22  *  This program is distributed in the hope that it will be useful,
  23  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  *  GNU General Public License for more details.
  26  *
  27  *  You should have received a copy of the GNU General Public License
  28  *  along with this program; if not, write to the Free Software
  29  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  30  *
  31  * Copyright (c) 2003 Robert Collins <robertc@squid-cache.org>
  32  */
  33
  34 #ifndef SQUID_DISKFILE_H
  35 #define SQUID_DISKFILE_H
  36
  37 #include "squid.h"
  38
  39 #include "RefCount.h"
  40
  41 class IORequestor;
  42
  43 class ReadRequest;
  44
  45 class WriteRequest;
  46
  47 class DiskFile : public RefCountable
  48 {
  49
  50 public:
  51     typedef RefCount<DiskFile> Pointer;
  52     virtual void open (int, mode_t, RefCount<IORequestor>) = 0;
  53     virtual void create (int, mode_t, RefCount<IORequestor>) = 0;
  54     virtual void read(ReadRequest *) = 0;
  55     virtual void write(WriteRequest *) = 0;
  56     virtual void close () = 0;
  57     virtual bool canRead() const = 0;
  58     virtual bool canWrite() const {return true;}
  59
  60     /* During miogration only */
  61     virtual int getFD() const {return -1;}
  62
  63     virtual bool error() const = 0;
  64
  65     /* Inform callers if there is IO in progress */
  66     virtual bool ioInProgress() const = 0;
  67 };
  68
  69 #endif /* SQUID_DISKFILE_H */