FileHandle.h revision 6f75755c9204b1d8817ae5a65a2f7e5af0ec3f70 
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 <sys/stat.h>
18#include <errno.h>
19
20namespace mcld {
21
22/** \class FileHandle
23 *  \brief FileHandle class provides an interface for reading from and writing
24 *  to files.
25 *
26 *  Operators of FileHandle should neither throw exceptions nor call expressive
27 *  diagnostic output.
28 */
29class FileHandle
30{
31public:
32  enum IOState
33  {
34    GoodBit    = 0,       // no error
35    BadBit     = 1L << 0, // error due to the inappropriate operation
36    EOFBit     = 1L << 1, // reached End-Of-File
37    FailBit    = 1L << 2, // internal logic fail
38    DeputedBit = 1L << 3, // the file descriptor is delegated
39    IOStateEnd = 1L << 16
40  };
41
42  enum OpenModeEnum
43  {
44    NotOpen   = 0x00,
45    ReadOnly  = 0x01,
46    WriteOnly = 0x02,
47    ReadWrite = ReadOnly | WriteOnly,
48    Append    = 0x04,
49    Create    = 0x08,
50    Truncate  = 0x10,
51    Unknown   = 0xFF
52  };
53
54  typedef Flags<OpenModeEnum> OpenMode;
55
56  enum PermissionEnum
57  {
58    ReadOwner   = S_IRUSR,
59    WriteOwner  = S_IWUSR,
60    ExeOwner    = S_IXUSR,
61    ReadGroup   = S_IRGRP,
62    WriteGroup  = S_IWGRP,
63    ExeGroup    = S_IXGRP,
64    ReadOther   = S_IROTH,
65    WriteOther  = S_IWOTH,
66    ExeOther    = S_IXOTH,
67    System      = 0xFFFFFFFF
68  };
69
70  typedef Flags<PermissionEnum> Permission;
71
72public:
73  FileHandle();
74
75  ~FileHandle();
76
77  /// open - open the file.
78  /// @return if we meet any trouble during opening the file, return false.
79  ///         use rdstate() to see what happens.
80  bool open(const sys::fs::Path& pPath,
81            OpenMode pMode,
82            Permission pPerm = System);
83
84  bool delegate(int pFD, OpenMode pMode = Unknown);
85
86  bool close();
87
88  void setState(IOState pState);
89
90  void cleanState(IOState pState = GoodBit);
91
92  // truncate - truncate the file up to the pSize.
93  bool truncate(size_t pSize);
94
95  bool read(void* pMemBuffer, size_t pStartOffset, size_t pLength);
96
97  bool write(const void* pMemBuffer, size_t pStartOffset, size_t pLength);
98
99  bool mmap(void*& pMemBuffer, size_t pStartOffset, size_t pLength);
100
101  bool munmap(void* pMemBuffer, size_t pLength);
102
103  // -----  observers  ----- //
104  const sys::fs::Path& path() const
105  { return m_Path; }
106
107  size_t size() const
108  { return m_Size; }
109
110  int handler() const
111  { return m_Handler; }
112
113  uint16_t rdstate() const
114  { return m_State; }
115
116  bool isOpened() const;
117
118  bool isGood() const;
119
120  bool isBad() const;
121
122  bool isFailed() const;
123
124  bool isOwned() const;
125
126  bool isReadable() const;
127
128  bool isWritable() const;
129
130  bool isReadWrite() const;
131
132  int error() const { return errno; }
133
134private:
135  sys::fs::Path m_Path;
136  int m_Handler;
137  unsigned int m_Size;
138  uint16_t m_State;
139  OpenMode m_OpenMode;
140};
141
142} // namespace of mcld
143
144#endif
145
146