src/fs/ufs/UFSStoreState.h

   1 /*
   2  * Copyright (C) 1996-2015 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 #ifndef SQUID_FS_UFS_UFSSTORESTATE_H
  10 #define SQUID_FS_UFS_UFSSTORESTATE_H
  11
  12 #include "DiskIO/IORequestor.h"
  13 #include "SquidList.h"
  14 #include "StoreIOState.h"
  15
  16 namespace Fs
  17 {
  18 namespace Ufs
  19 {
  20
  21 class UFSStoreState : public StoreIOState, public IORequestor
  22 {
  23     CBDATA_CLASS(UFSStoreState);
  24
  25 public:
  26     UFSStoreState(SwapDir * SD, StoreEntry * anEntry, STIOCB * callback_, void *callback_data_);
  27     ~UFSStoreState();
  28     virtual void close(int how);
  29     virtual void closeCompleted();
  30     // protected:
  31     virtual void ioCompletedNotification();
  32     virtual void readCompleted(const char *buf, int len, int errflag, RefCount<ReadRequest>);
  33     virtual void writeCompleted(int errflag, size_t len, RefCount<WriteRequest>);
  34     RefCount<DiskFile> theFile;
  35     bool opening;
  36     bool creating;
  37     bool closing;
  38     bool reading;
  39     bool writing;
  40     /* StoreIOState API */
  41     void read_(char *buf, size_t size, off_t offset, STRCB * callback, void *callback_data);
  42     virtual bool write(char const *buf, size_t size, off_t offset, FREE * free_func);
  43
  44 protected:
  45     virtual void doCloseCallback (int errflag);
  46
  47     class _queued_read
  48     {
  49         MEMPROXY_CLASS(UFSStoreState::_queued_read);
  50     public:
  51         char *buf;
  52         size_t size;
  53         off_t offset;
  54         STRCB *callback;
  55         void *callback_data;
  56
  57     };
  58
  59     class _queued_write
  60     {
  61         MEMPROXY_CLASS(UFSStoreState::_queued_write);
  62     public:
  63         char const *buf;
  64         size_t size;
  65         off_t offset;
  66         FREE *free_func;
  67
  68     };
  69
  70     /** \todo These should be in the IO strategy */
  71
  72     struct {
  73         /**
  74          * DPW 2006-05-24
  75          * the write_draining flag is used to avoid recursion inside
  76          * the UFSStoreState::drainWriteQueue() method.
  77          */
  78         bool write_draining;
  79         /**
  80          * DPW 2006-05-24
  81          * The try_closing flag is set by UFSStoreState::tryClosing()
  82          * when UFSStoreState wants to close the file, but cannot
  83          * because of pending I/Os.  If set, UFSStoreState will
  84          * try to close again in the I/O callbacks.
  85          */
  86         bool try_closing;
  87     } flags;
  88     link_list *pending_reads;
  89     link_list *pending_writes;
  90     void queueRead(char *, size_t, off_t, STRCB *, void *);
  91     void queueWrite(char const *, size_t, off_t, FREE *);
  92     bool kickReadQueue();
  93     void drainWriteQueue();
  94     void tryClosing();
  95     char *read_buf;
  96
  97 private:
  98     void openDone();
  99     void freePending();
 100     void doWrite();
 101 };
 102
 103 } //namespace Ufs
 104 } //namespace Fs
 105
 106 #endif /* SQUID_FS_UFS_UFSSTORESTATE_H */
 107