src/DiskIO/Mmapped/MmappedFile.h

   1 /*
   2  * Copyright (C) 1996-2022 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() override;
  23     void open(int flags, mode_t mode, RefCount<IORequestor> callback) override;
  24     void create(int flags, mode_t mode, RefCount<IORequestor> callback) override;
  25     void read(ReadRequest *) override;
  26     void write(WriteRequest *) override;
  27     void close() override;
  28     bool error() const override;
  29     int getFD() const override { return fd;}
  30
  31     bool canRead() const override;
  32     bool canWrite() const override;
  33     bool ioInProgress() const override;
  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