Import Geant4 6.0.0 source tree

2016-06-09 10:41:53 +02:00
parent 4aea781e80
commit 96686e0c8f
6560 changed files with 153347 additions and 238155 deletions
@@ -0,0 +1,117 @@
+#ifndef BACKBUFFER_H
+#define BACKBUFFER_H
+
+#include "zipios++/zipios-config.h"
+
+#include <algorithm>
+
+#include "zipios++/meta-iostreams.h"
+#include <vector>
+
+#include "zipios++/fcollexceptions.h"
+#include "zipios++/ziphead.h"
+#include "zipios++/zipheadio.h"
+#include "zipios++/virtualseeker.h"
+#include "zipios_common.h"
+
+namespace zipios {
+
+using std::ios ;
+using std::cerr ;
+using std::endl ;
+
+/** A BackBuffer instance is useful for reading the last part of a
+    file in an efficient manner, when it is not known exactly how far
+    back (towards the front!) to go, to find the start of the desired
+    data block.  BackBuffer is a vector< unsigned char > that fills
+    itself with data from a file by reading chunks from the end of the
+    file progressing towards the start. Upon construction the
+    BackBuffer instance is associated with a file and a chunksize can
+    be specified. To read a chunk of the file into the BackBuffer call
+    readChunk(). */
+class BackBuffer : public vector< unsigned char > {
+public:
+  /** BackBuffer constructor.
+      @param is The istream to read the data from. The stream must be seekable,
+      as BackBuffer will reposition the file position to read chunks from the back
+      of the file.
+      @param chunk_size specifies the size of the chunks to read the file into 
+      the BackBuffer in.
+      @throw FCollException Thrown if the VirtualSeeker vs that has been specified is 
+      invalid for the istream is.  */
+  inline explicit BackBuffer( istream &is, VirtualSeeker vs = VirtualSeeker(), 
+			      int chunk_size = 1024 ) ;
+  /** Reads another chunk and returns the size of the chunk that has
+      been read. Returns 0 on I/O failure.
+      @param read_pointer When a new chunk is read in the already
+      stored bytes change position in the BackBuffer. read_pointer is
+      assumed by readChunk() to be a pointer into a position in the
+      BackBuffer, and is updated to point to the same position in the file
+      as it pointed to before the new chunk was read. */
+  inline int readChunk( int &read_pointer ) ;
+
+private:
+  VirtualSeeker _vs ;
+  int _chunk_size ;
+  istream &_is ;
+  streampos _file_pos ;
+  
+};
+
+BackBuffer::BackBuffer( istream &is, VirtualSeeker vs, int chunk_size ) 
+  : _vs        ( vs         ),
+    _chunk_size( chunk_size ),
+    _is        ( is         ) 
+{
+  _vs.vseekg( is, 0, ios::end ) ;
+  _file_pos = _vs.vtellg( is ) ;
+  // Only happens if _vs.startOffset() is a position
+  // in the file that lies after _vs.endOffset(), which
+  // is clearly not a valid situation.
+  if ( _file_pos < 0 )
+    throw FCollException( "Invalid virtual file endings" ) ;
+}
+
+int BackBuffer::readChunk( int &read_pointer ) {
+  // Update chunk_size and file position
+  _chunk_size = min<int> ( static_cast< int >( _file_pos ), _chunk_size ) ;
+  _file_pos -= _chunk_size ;
+  _vs.vseekg( _is, _file_pos, ios::beg ) ;
+  // Make space for _chunk_size new bytes first in buffer
+  insert ( begin(), _chunk_size, static_cast< char > ( 0 ) ) ; 
+  // Read in the next _chunk_size of bytes
+
+  readByteSeq ( _is, &( (*this)[ 0 ] ), _chunk_size ) ;
+  read_pointer += _chunk_size ;
+
+  if ( _is.good() )
+    return _chunk_size ;
+  else
+    return 0 ;
+}
+
+}
+#endif
+
+/** \file
+    The header file for BackBuffer
+*/
+
+/*
+  Zipios++ - a small C++ library that provides easy access to .zip files.
+  Copyright (C) 2000  Thomas Søndergaard
+  
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2 of the License, or (at your option) any later version.
+  
+  This library is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  Lesser General Public License for more details.
+  
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
+*/