src/DiskIO/DiskDaemon/DiskdIOStrategy.h

   1
   2 /*
   3  * $Id: DiskdIOStrategy.h,v 1.2 2006/05/22 19:58:51 wessels Exp $
   4  *
   5  * DEBUG: section 79    Squid-side DISKD I/O functions.
   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  * Copyright (c) 2003, Robert Collins <robertc@squid-cache.org>
  35  */
  36
  37 #ifndef __STORE_DISKDIOSTRATEGY_H__
  38 #define __STORE_DISKDIOSTRATEGY_H__
  39
  40 /*
  41  * magic2 is the point at which we start blocking on msgsnd/msgrcv.
  42  * If a queue has magic2 (or more) messages away, then we read the
  43  * queue until the level falls below magic2.  Recommended value
  44  * is 75% of SHMBUFS. magic1 is the number of messages away which we
  45  * stop allowing open/create for.
  46  */
  47
  48 struct diomsg;
  49
  50 class SharedMemory
  51 {
  52
  53 public:
  54     void put(off_t);
  55
  56     void *get
  57     (off_t *);
  58
  59     void init (int ikey, int magic2);
  60
  61     int nbufs;
  62
  63     char *buf;
  64
  65     char *inuse_map;
  66
  67     int id;
  68 };
  69
  70 #include "DiskIO/DiskIOStrategy.h"
  71 #include "StoreIOState.h"
  72
  73 class DiskFile;
  74
  75 class DiskdFile;
  76
  77 class ReadRequest;
  78
  79 class DiskdIOStrategy : public DiskIOStrategy
  80 {
  81
  82 public:
  83     DiskdIOStrategy();
  84     virtual bool shedLoad();
  85     virtual int load();
  86     virtual RefCount<DiskFile> newFile(char const *path);
  87     virtual void unlinkFile (char const *);
  88     virtual ConfigOption *getOptionTree() const;
  89     virtual void init();
  90     virtual void sync();
  91     virtual int callback();
  92     virtual void statfs(StoreEntry & sentry)const;
  93     int send(int mtype, int id, DiskdFile *theFile, int size, int offset, off_t shm_offset, RefCountable_ *);
  94     /* public for accessing return address's */
  95     SharedMemory shm;
  96
  97 private:
  98     static size_t newInstance();
  99     static size_t nextInstanceID;
 100     void openFailed();
 101     bool optionQ1Parse(char const *option, const char *value, int reconfiguring);
 102     void optionQ1Dump(StoreEntry * e) const;
 103     bool optionQ2Parse(char const *option, const char *value, int reconfiguring);
 104     void optionQ2Dump(StoreEntry * e) const;
 105     int send(int mtype, int id, RefCount<StoreIOState> sio, int size, int offset, off_t shm_offset);
 106     void handle(diomsg * M);
 107     void unlinkDone(diomsg * M);
 108     int magic1;
 109     int magic2;
 110     int away;
 111     int smsgid;
 112     int rmsgid;
 113     int wfd;
 114     size_t instanceID;
 115 };
 116
 117 #define SHMBUF_BLKSZ SM_PAGE_SIZE
 118
 119
 120 struct diskd_stats_t
 121 {
 122     int open_fail_queue_len;
 123     int block_queue_len;
 124     int max_away;
 125     int max_shmuse;
 126     int shmbuf_count;
 127     int sent_count;
 128     int recv_count;
 129     int sio_id;
 130
 131     struct
 132     {
 133         int ops;
 134         int success;
 135         int fail;
 136     }
 137
 138     open, create, close, unlink, read, write;
 139 };
 140
 141 extern diskd_stats_t diskd_stats;
 142
 143 #endif