src/DiskIO/Mmapped/MmappedFile.h

   1 /*
   2  * Copyright (C) 1996-2017 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_MMAPPEDFILE_H
  10 #define SQUID_MMAPPEDFILE_H
  11
  12 #include "cbdata.h"
  13 #include "DiskIO/DiskFile.h"
  14 #include "DiskIO/IORequestor.h"
  15
  16 class MmappedFile : public DiskFile
  17 {
  18     CBDATA_CLASS(MmappedFile);
  19
  20 public:
  21     MmappedFile(char const *path);
  22     ~MmappedFile();
  23     virtual void open(int flags, mode_t mode, RefCount<IORequestor> callback);
  24     virtual void create(int flags, mode_t mode, RefCount<IORequestor> callback);
  25     virtual void read(ReadRequest *);
  26     virtual void write(WriteRequest *);
  27     virtual void close();
  28     virtual bool error() const;
  29     virtual int getFD() const { return fd;}
  30
  31     virtual bool canRead() const;
  32     virtual bool canWrite() const;
  33     virtual bool ioInProgress() const;
  34
  35 private:
  36     char const *path_;
  37     RefCount<IORequestor> ioRequestor;
  38     //RefCount<ReadRequest> readRequest;
  39     //RefCount<WriteRequest> writeRequest;
  40     int fd;
  41
  42     // mmapped memory leads to SEGV and bus errors if it maps beyond file
  43     int64_t minOffset; ///< enforced if not negative (to preserve file headers)
  44     int64_t maxOffset; ///< enforced if not negative (to avoid crashes)
  45
  46     bool error_;
  47
  48     void doClose();
  49 };
  50
  51 #endif /* SQUID_MMAPPEDFILE_H */
  52