src/DiskIO/DiskDaemon/DiskdIOStrategy.h

   1 /*
   2  * Copyright (C) 1996-2014 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 /* DEBUG: section 79    Squid-side DISKD I/O functions. */
  10
  11 #ifndef __STORE_DISKDIOSTRATEGY_H__
  12 #define __STORE_DISKDIOSTRATEGY_H__
  13
  14 struct diomsg;
  15
  16 /// \ingroup diskd
  17 class SharedMemory
  18 {
  19
  20 public:
  21     void put(ssize_t);
  22
  23     void *get(ssize_t *);
  24
  25     void init(int ikey, int magic2);
  26
  27     int nbufs;
  28
  29     char *buf;
  30
  31     char *inuse_map;
  32
  33     int id;
  34 };
  35
  36 #include "DiskIO/DiskIOStrategy.h"
  37 #include "StoreIOState.h"
  38
  39 class DiskFile;
  40
  41 class DiskdFile;
  42 class Lock;
  43 class ReadRequest;
  44
  45 /// \ingroup diskd
  46 class DiskdIOStrategy : public DiskIOStrategy
  47 {
  48
  49 public:
  50     DiskdIOStrategy();
  51     virtual bool shedLoad();
  52     virtual int load();
  53     virtual RefCount<DiskFile> newFile(char const *path);
  54     virtual bool unlinkdUseful() const;
  55     virtual void unlinkFile (char const *);
  56     virtual ConfigOption *getOptionTree() const;
  57     virtual void init();
  58     virtual void sync();
  59     virtual int callback();
  60     virtual void statfs(StoreEntry & sentry) const;
  61     int send(int mtype, int id, DiskdFile *theFile, size_t size, off_t offset, ssize_t shm_offset, Lock *requestor);
  62
  63     /** public for accessing return address's */
  64     SharedMemory shm;
  65
  66 private:
  67     static size_t newInstance();
  68     static size_t nextInstanceID;
  69     void openFailed();
  70     bool optionQ1Parse(char const *option, const char *value, int reconfiguring);
  71     void optionQ1Dump(StoreEntry * e) const;
  72     bool optionQ2Parse(char const *option, const char *value, int reconfiguring);
  73     void optionQ2Dump(StoreEntry * e) const;
  74     int send(int mtype, int id, RefCount<StoreIOState> sio, size_t size, off_t offset, ssize_t shm_offset);
  75     int SEND(diomsg * M, int mtype, int id, size_t size, off_t offset, ssize_t shm_offset);
  76     void handle(diomsg * M);
  77     void unlinkDone(diomsg * M);
  78
  79     /**
  80      * magic1 is the number of messages away which we
  81      * stop allowing open/create for.
  82      */
  83     int magic1;
  84
  85     /**
  86      * magic2 is the point at which we start blocking on msgsnd/msgrcv.
  87      * If a queue has magic2 (or more) messages away, then we read the
  88      * queue until the level falls below magic2.  Recommended value
  89      * is 75% of SHMBUFS.
  90      */
  91     int magic2;
  92
  93     int away;
  94     int smsgid;
  95     int rmsgid;
  96     int wfd;
  97     size_t instanceID;
  98 };
  99
 100 /// \ingroup diskd
 101 #define SHMBUF_BLKSZ SM_PAGE_SIZE
 102
 103 /// \ingroup diskd
 104 struct diskd_stats_t {
 105     int open_fail_queue_len;
 106     int block_queue_len;
 107     int max_away;
 108     int max_shmuse;
 109     int shmbuf_count;
 110     int sent_count;
 111     int recv_count;
 112     int sio_id;
 113
 114     struct {
 115         int ops;
 116         int success;
 117         int fail;
 118     }
 119
 120     open, create, close, unlink, read, write;
 121 };
 122
 123 /// \ingroup diskd
 124 extern diskd_stats_t diskd_stats;
 125
 126 #endif
 127