CMake/Source/cmGeneratedFileStream.h

149 lines
4.7 KiB
C++

/*============================================================================
CMake - Cross Platform Makefile Generator
Copyright 2000-2009 Kitware, Inc., Insight Software Consortium
Distributed under the OSI-approved BSD License (the "License");
see accompanying file Copyright.txt for details.
This software is distributed WITHOUT ANY WARRANTY; without even the
implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the License for more information.
============================================================================*/
#ifndef cmGeneratedFileStream_h
#define cmGeneratedFileStream_h
#include <cmConfigure.h>
#include "cmStandardIncludes.h"
#include <cmsys/FStream.hxx>
// This is the first base class of cmGeneratedFileStream. It will be
// created before and destroyed after the ofstream portion and can
// therefore be used to manage the temporary file.
class cmGeneratedFileStreamBase
{
protected:
// This constructor does not prepare the temporary file. The open
// method must be used.
cmGeneratedFileStreamBase();
// This constructor prepares the temporary output file.
cmGeneratedFileStreamBase(const char* name);
// The destructor renames the temporary output file to the real name.
~cmGeneratedFileStreamBase();
// Internal methods to handle the temporary file. Open is always
// called before the real stream is opened. Close is always called
// after the real stream is closed and Okay is set to whether the
// real stream was still valid for writing when it was closed.
void Open(const char* name);
bool Close();
// Internal file replacement implementation.
int RenameFile(const char* oldname, const char* newname);
// Internal file compression implementation.
int CompressFile(const char* oldname, const char* newname);
// The name of the final destination file for the output.
std::string Name;
// The name of the temporary file.
std::string TempName;
// Whether to do a copy-if-different.
bool CopyIfDifferent;
// Whether the real file stream was valid when it was closed.
bool Okay;
// Whether the destination file is compressed
bool Compress;
// Whether the destination file is compressed
bool CompressExtraExtension;
};
/** \class cmGeneratedFileStream
* \brief Output stream for generated files.
*
* File generation should be atomic so that if CMake is killed then a
* generated file is either the original version or the complete new
* version. This stream is used to make sure file generation is
* atomic. Optionally the output file is only replaced if its
* contents have changed to prevent the file modification time from
* being updated.
*/
class cmGeneratedFileStream : private cmGeneratedFileStreamBase,
public cmsys::ofstream
{
public:
typedef cmsys::ofstream Stream;
/**
* This constructor prepares a default stream. The open method must
* be used before writing to the stream.
*/
cmGeneratedFileStream();
/**
* This constructor takes the name of the file to be generated. It
* automatically generates a name for the temporary file. If the
* file cannot be opened an error message is produced unless the
* second argument is set to true.
*/
cmGeneratedFileStream(const char* name, bool quiet = false);
/**
* The destructor checks the stream status to be sure the temporary
* file was successfully written before allowing the original to be
* replaced.
*/
~cmGeneratedFileStream() CM_OVERRIDE;
/**
* Open an output file by name. This should be used only with a
* non-open stream. It automatically generates a name for the
* temporary file. If the file cannot be opened an error message is
* produced unless the second argument is set to true.
*/
cmGeneratedFileStream& Open(const char* name, bool quiet = false,
bool binaryFlag = false);
/**
* Close the output file. This should be used only with an open
* stream. The temporary file is atomically renamed to the
* destionation file if the stream is still valid when this method
* is called.
*/
bool Close();
/**
* Set whether copy-if-different is done.
*/
void SetCopyIfDifferent(bool copy_if_different);
/**
* Set whether compression is done.
*/
void SetCompression(bool compression);
/**
* Set whether compression has extra extension
*/
void SetCompressionExtraExtension(bool ext);
/**
* Set name of the file that will hold the actual output. This method allows
* the output file to be changed during the use of cmGeneratedFileStream.
*/
void SetName(const std::string& fname);
private:
cmGeneratedFileStream(cmGeneratedFileStream const&); // not implemented
};
#endif