ENH: Added Close method and updated Open method to allow streams to be reused.

Source/cmGeneratedFileStream.cxx

@@ -79,6 +79,22 @@ cmGeneratedFileStream::Open(const char* name, bool quiet)
   return *this;
 }
 
+//----------------------------------------------------------------------------
+cmGeneratedFileStream&
+cmGeneratedFileStream::Close()
+{
+  // Save whether the temporary output file is valid before closing.
+  m_Okay = (*this)?true:false;
+
+  // Close the temporary output file.
+  this->Stream::close();
+
+  // Remove the temporary file (possibly by renaming to the real file).
+  this->cmGeneratedFileStreamBase::Close();
+
+  return *this;
+}
+
 //----------------------------------------------------------------------------
 void cmGeneratedFileStream::SetCopyIfDifferent(bool copy_if_different)
 {
@@ -103,13 +119,29 @@ cmGeneratedFileStreamBase::cmGeneratedFileStreamBase():
 
 //----------------------------------------------------------------------------
 cmGeneratedFileStreamBase::cmGeneratedFileStreamBase(const char* name):
-  m_Name(name),
-  m_TempName(name),
+  m_Name(),
+  m_TempName(),
   m_CopyIfDifferent(false),
   m_Okay(false),
   m_Compress(false)
 {
+  this->Open(name);
+}
+
+//----------------------------------------------------------------------------
+cmGeneratedFileStreamBase::~cmGeneratedFileStreamBase()
+{
+  this->Close();
+}
+
+//----------------------------------------------------------------------------
+void cmGeneratedFileStreamBase::Open(const char* name)
+{
+  // Save the original name of the file.
+  m_Name = name;
+
   // Create the name of the temporary file.
+  m_TempName = name;
   m_TempName += ".tmp";
 
   // Make sure the temporary file that will be used is not present.
@@ -117,7 +149,7 @@ cmGeneratedFileStreamBase::cmGeneratedFileStreamBase(const char* name):
 }
 
 //----------------------------------------------------------------------------
-cmGeneratedFileStreamBase::~cmGeneratedFileStreamBase()
+void cmGeneratedFileStreamBase::Close()
 {
   std::string resname = m_Name;
   if ( m_Compress )
@@ -154,20 +186,6 @@ cmGeneratedFileStreamBase::~cmGeneratedFileStreamBase()
   cmSystemTools::RemoveFile(m_TempName.c_str());
 }
 
-//----------------------------------------------------------------------------
-void cmGeneratedFileStreamBase::Open(const char* name)
-{
-  // Save the original name of the file.
-  m_Name = name;
-
-  // Create the name of the temporary file.
-  m_TempName = name;
-  m_TempName += ".tmp";
-
-  // Make sure the temporary file that will be used is not present.
-  cmSystemTools::RemoveFile(m_TempName.c_str());
-}
-
 //----------------------------------------------------------------------------
 #ifdef CMAKE_BUILD_WITH_CMAKE
 int cmGeneratedFileStreamBase::CompressFile(const char* oldname,

Source/cmGeneratedFileStream.h

@@ -35,8 +35,12 @@ protected:
   // The destructor renames the temporary output file to the real name.
   ~cmGeneratedFileStreamBase();
 
-  // Internal method to setup the instance for a given file name.
+  // 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 m_Okay is set to whether the
+  // real stream was still valid for writing when it was closed.
   void Open(const char* name);
+  void Close();
 
   // Internal file replacement implementation.
   int RenameFile(const char* oldname, const char* newname);
@@ -53,7 +57,7 @@ protected:
   // Whether to do a copy-if-different.
   bool m_CopyIfDifferent;
 
-  // Whether the destination file should be replaced.
+  // Whether the real file stream was valid when it was closed.
   bool m_Okay;
 
   // Whether the destionation file is compressed
@@ -99,12 +103,20 @@ public:
 
   /**
    * Open an output file by name.  This should be used only with a
-   * default-constructed 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.
+   * 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);
 
+  /**
+   * 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.
+   */
+  cmGeneratedFileStream& Close();
+
   /**
    * Set whether copy-if-different is done.
    */