FileHandle.h revision f7ac0f19a1c8d0ad14bcf6456ce368b830fea886 
1//===- FileHandle.h -------------------------------------------------------===//
2//
3//                     The MCLinker Project
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9#ifndef MCLD_FILE_HANDLE_H
10#define MCLD_FILE_HANDLE_H
11#ifdef ENABLE_UNITTEST
12#include <gtest.h>
13#endif
14#include <mcld/Support/Path.h>
15#include <mcld/ADT/Flags.h>
16
17#include <errno.h>
18
19namespace mcld {
20
21/** \class FileHandle
22 *  \brief FileHandle class provides an interface for reading from and writing
23 *  to files.
24 *
25 *  Operators of FileHandle should neither throw exceptions nor call expressive
26 *  diagnostic output.
27 */
28class FileHandle
29{
30public:
31  enum IOState
32  {
33    GoodBit    = 0,       // no error
34    BadBit     = 1L << 0, // error due to the inappropriate operation
35    EOFBit     = 1L << 1, // reached End-Of-File
36    FailBit    = 1L << 2, // internal logic fail
37    DeputedBit = 1L << 3, // the file descriptor is delegated
38    IOStateEnd = 1L << 16
39  };
40
41  enum OpenModeEnum
42  {
43    NotOpen   = 0x00,
44    ReadOnly  = 0x01,
45    WriteOnly = 0x02,
46    ReadWrite = ReadOnly | WriteOnly,
47    Append    = 0x04,
48    Create    = 0x08,
49    Truncate  = 0x10,
50    Unknown   = 0xFF
51  };
52
53  typedef Flags<OpenModeEnum> OpenMode;
54
55  enum PermissionEnum
56  {
57    ReadOwner   = 0x0400,
58    WriteOwner  = 0x0200,
59    ExeOwner    = 0x0100,
60    ReadGroup   = 0x0040,
61    WriteGroup  = 0x0020,
62    ExeGroup    = 0x0010,
63    ReadOther   = 0x0004,
64    WriteOther  = 0x0002,
65    ExeOther    = 0x0001,
66    System      = 0xFFFF
67  };
68
69  typedef Flags<PermissionEnum> Permission;
70
71public:
72  FileHandle();
73
74  ~FileHandle();
75
76  /// open - open the file.
77  /// @return if we meet any trouble during opening the file, return false.
78  ///         use rdstate() to see what happens.
79  bool open(const sys::fs::Path& pPath,
80            OpenMode pMode,
81            Permission pPerm = System);
82
83  bool delegate(int pFD, OpenMode pMode = Unknown);
84
85  bool close();
86
87  void setState(IOState pState);
88
89  void cleanState(IOState pState = GoodBit);
90
91  // truncate - truncate the file up to the pSize.
92  bool truncate(size_t pSize);
93
94  bool read(void* pMemBuffer, size_t pStartOffset, size_t pLength);
95
96  bool write(const void* pMemBuffer, size_t pStartOffset, size_t pLength);
97
98  bool mmap(void*& pMemBuffer, size_t pStartOffset, size_t pLength);
99
100  bool munmap(void* pMemBuffer, size_t pLength);
101
102  // -----  observers  ----- //
103  const sys::fs::Path& path() const
104  { return m_Path; }
105
106  size_t size() const
107  { return m_Size; }
108
109  int handler() const
110  { return m_Handler; }
111
112  uint16_t rdstate() const
113  { return m_State; }
114
115  bool isOpened() const;
116
117  bool isGood() const;
118
119  bool isBad() const;
120
121  bool isFailed() const;
122
123  bool isOwned() const;
124
125  bool isReadable() const;
126
127  bool isWritable() const;
128
129  bool isReadWrite() const;
130
131  int error() const { return errno; }
132
133private:
134  sys::fs::Path m_Path;
135  int m_Handler;
136  unsigned int m_Size;
137  uint16_t m_State;
138  OpenMode m_OpenMode;
139};
140
141} // namespace of mcld
142
143#endif
144
145