blob: e7132891dc1820e157b23c0a6f1a6fef44967840 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
|
/*=========================================================================
Program: CMake - Cross-Platform Makefile Generator
Module: $RCSfile$
Language: C++
Date: $Date$
Version: $Revision$
Copyright (c) 2002 Kitware, Inc., Insight Consortium. All rights reserved.
See Copyright.txt or http://www.cmake.org/HTML/Copyright.html for details.
This software is distributed WITHOUT ANY WARRANTY; without even
the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the above copyright notices for more information.
=========================================================================*/
#ifndef cmGeneratedFileStream_h
#define cmGeneratedFileStream_h
#include "cmStandardIncludes.h"
/** \class cmGeneratedFileStream
* \brief Output stream for generated files that does copy-if-different.
*
* Many files generated by CMake don't change each time they are generated.
* This class can be used in place of std::ofstream to open a file and
* write output to it. The class will automatically write output to a
* temporary file and copy it over an existing file only if the generated
* file has changed.
*/
class cmGeneratedFileStream
{
public:
/**
* The constructor takes the name of the file to be generated. It
* automatically generates a name for the temporary file.
*/
cmGeneratedFileStream(const char* name):
m_Name(name),
m_TempName(m_Name+".tmp"),
m_Stream(m_TempName.c_str()),
m_Copied(false),
m_AlwaysCopy(false)
{}
/**
* The destructor ensures that the file has been closed and copied if
* it has changed.
*/
~cmGeneratedFileStream() { this->DoCopy(); }
/**
* Get the real output stream.
*/
std::ostream& GetStream() { return m_Stream; }
/**
* Allow a test for whether the file is open.
*/
operator bool() { return m_Stream.good(); }
/**
* Close the file stream. This will cause the copy-if-different to the
* real file name to occur.
*/
void close() { this->DoCopy(); }
/**
* If always copy is true, then copy the file all the time without
* checking for differences. The default is false.
*/
bool SetAlwaysCopy(bool v) { m_AlwaysCopy = v; return v;}
private:
/**
* The name of the real file where output will be copied if it has changed.
*/
std::string m_Name;
/**
* The name of the temporary file.
*/
std::string m_TempName;
/**
* The real output stream used to write to the file.
*/
std::ofstream m_Stream;
/**
* Whether the temporary file has already been copied to the real file.
*/
bool m_Copied;
/**
* If always copy is true, then copy the file all the time without
* checking for differences. The default is false.
*/
bool m_AlwaysCopy;
/**
* Closes the temporary file and does the copy-if-different to the
* real file.
*/
void DoCopy()
{
if(!m_Copied)
{
m_Stream.close();
if(m_AlwaysCopy)
{
cmSystemTools::cmCopyFile(m_TempName.c_str(), m_Name.c_str());
}
else
{
cmSystemTools::CopyFileIfDifferent(m_TempName.c_str(),
m_Name.c_str());
}
cmSystemTools::RemoveFile(m_TempName.c_str());
m_Copied = true;
}
}
};
/**
* Allow a cmGeneratedFileStream to be used just as a real std::ostream
* would be.
*/
template <class T>
std::ostream& operator << (cmGeneratedFileStream& l, const T& r)
{
std::ostream& os = l.GetStream();
os << r;
return os;
}
#endif
|
