src/fs/ufs/UFSStoreState.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 #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 /// \ingroup UFS
  21 class UFSStoreState : public StoreIOState, public IORequestor
  22 {
  23 public:
  24     UFSStoreState(SwapDir * SD, StoreEntry * anEntry, STIOCB * callback_, void *callback_data_);
  25     ~UFSStoreState();
  26     virtual void close(int how);
  27     virtual void closeCompleted();
  28     // protected:
  29     virtual void ioCompletedNotification();
  30     virtual void readCompleted(const char *buf, int len, int errflag, RefCount<ReadRequest>);
  31     virtual void writeCompleted(int errflag, size_t len, RefCount<WriteRequest>);
  32     RefCount<DiskFile> theFile;
  33     bool opening;
  34     bool creating;
  35     bool closing;
  36     bool reading;
  37     bool writing;
  38     /* StoreIOState API */
  39     void read_(char *buf, size_t size, off_t offset, STRCB * callback, void *callback_data);
  40     virtual bool write(char const *buf, size_t size, off_t offset, FREE * free_func);
  41
  42 protected:
  43     virtual void doCloseCallback (int errflag);
  44
  45     class _queued_read
  46     {
  47     public:
  48         MEMPROXY_CLASS(UFSStoreState::_queued_read);
  49         char *buf;
  50         size_t size;
  51         off_t offset;
  52         STRCB *callback;
  53         void *callback_data;
  54
  55     };
  56
  57     class _queued_write
  58     {
  59     public:
  60         MEMPROXY_CLASS(UFSStoreState::_queued_write);
  61         char const *buf;
  62         size_t size;
  63         off_t offset;
  64         FREE *free_func;
  65
  66     };
  67
  68     /** \todo These should be in the IO strategy */
  69
  70     struct {
  71         /**
  72          * DPW 2006-05-24
  73          * the write_draining flag is used to avoid recursion inside
  74          * the UFSStoreState::drainWriteQueue() method.
  75          */
  76         bool write_draining;
  77         /**
  78          * DPW 2006-05-24
  79          * The try_closing flag is set by UFSStoreState::tryClosing()
  80          * when UFSStoreState wants to close the file, but cannot
  81          * because of pending I/Os.  If set, UFSStoreState will
  82          * try to close again in the I/O callbacks.
  83          */
  84         bool try_closing;
  85     } flags;
  86     link_list *pending_reads;
  87     link_list *pending_writes;
  88     void queueRead(char *, size_t, off_t, STRCB *, void *);
  89     void queueWrite(char const *, size_t, off_t, FREE *);
  90     bool kickReadQueue();
  91     void drainWriteQueue();
  92     void tryClosing();
  93     char *read_buf;
  94
  95 private:
  96     void openDone();
  97     void freePending();
  98     void doWrite();
  99     CBDATA_CLASS2(UFSStoreState);
 100 };
 101
 102 MEMPROXY_CLASS_INLINE(UFSStoreState::_queued_read);
 103 MEMPROXY_CLASS_INLINE(UFSStoreState::_queued_write);
 104
 105 } //namespace Ufs
 106 } //namespace Fs
 107
 108 #endif /* SQUID_FS_UFS_UFSSTORESTATE_H */