FileHandle.h revision 533eae20118036f425f27bf0536ef0ccbb090b65 
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_SUPPORT_FILEHANDLE_H
10#define MCLD_SUPPORT_FILEHANDLE_H
11#include <mcld/Support/Path.h>
12#include <mcld/ADT/Flags.h>
13
14#include <errno.h>
15
16namespace mcld {
17
18/** \class FileHandle
19 *  \brief FileHandle class provides an interface for reading from and writing
20 *  to files.
21 *
22 *  Operators of FileHandle should neither throw exceptions nor call expressive
23 *  diagnostic output.
24 */
25class FileHandle
26{
27public:
28  enum IOState
29  {
30    GoodBit    = 0,       // no error
31    BadBit     = 1L << 0, // error due to the inappropriate operation
32    EOFBit     = 1L << 1, // reached End-Of-File
33    FailBit    = 1L << 2, // internal logic fail
34    DeputedBit = 1L << 3, // the file descriptor is delegated
35    IOStateEnd = 1L << 16
36  };
37
38  enum OpenModeEnum
39  {
40    NotOpen   = 0x00,
41    ReadOnly  = 0x01,
42    WriteOnly = 0x02,
43    ReadWrite = ReadOnly | WriteOnly,
44    Append    = 0x04,
45    Create    = 0x08,
46    Truncate  = 0x10,
47    Unknown   = 0xFF
48  };
49
50  typedef Flags<OpenModeEnum> OpenMode;
51
52  enum PermissionEnum
53  {
54    ReadOwner   = 0x0400,
55    WriteOwner  = 0x0200,
56    ExeOwner    = 0x0100,
57    ReadGroup   = 0x0040,
58    WriteGroup  = 0x0020,
59    ExeGroup    = 0x0010,
60    ReadOther   = 0x0004,
61    WriteOther  = 0x0002,
62    ExeOther    = 0x0001,
63    System      = 0xFFFF
64  };
65
66  typedef Flags<PermissionEnum> Permission;
67
68public:
69  FileHandle();
70
71  ~FileHandle();
72
73  /// open - open the file.
74  /// @return if we meet any trouble during opening the file, return false.
75  ///         use rdstate() to see what happens.
76  bool open(const sys::fs::Path& pPath,
77            OpenMode pMode,
78            Permission pPerm = System);
79
80  bool delegate(int pFD, OpenMode pMode = Unknown);
81
82  bool close();
83
84  void setState(IOState pState);
85
86  void cleanState(IOState pState = GoodBit);
87
88  // truncate - truncate the file up to the pSize.
89  bool truncate(size_t pSize);
90
91  bool read(void* pMemBuffer, size_t pStartOffset, size_t pLength);
92
93  bool write(const void* pMemBuffer, size_t pStartOffset, size_t pLength);
94
95  bool mmap(void*& pMemBuffer, size_t pStartOffset, size_t pLength);
96
97  bool munmap(void* pMemBuffer, size_t pLength);
98
99  // -----  observers  ----- //
100  const sys::fs::Path& path() const
101  { return m_Path; }
102
103  size_t size() const
104  { return m_Size; }
105
106  int handler() const
107  { return m_Handler; }
108
109  uint16_t rdstate() const
110  { return m_State; }
111
112  bool isOpened() const;
113
114  bool isGood() const;
115
116  bool isBad() const;
117
118  bool isFailed() const;
119
120  bool isOwned() const;
121
122  bool isReadable() const;
123
124  bool isWritable() const;
125
126  bool isReadWrite() const;
127
128  int error() const { return errno; }
129
130private:
131  sys::fs::Path m_Path;
132  int m_Handler;
133  unsigned int m_Size;
134  uint16_t m_State;
135  OpenMode m_OpenMode;
136};
137
138} // namespace of mcld
139
140#endif
141
142