1 files changed, 216 insertions, 0 deletions
diff --git a/khexedit/lib/kbigbuffer.cpp b/khexedit/lib/kbigbuffer.cpp
new file mode 100644
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--- /dev/null
+++ b/khexedit/lib/kbigbuffer.cpp
@@ -0,0 +1,216 @@
+/***************************************************************************
+                          kbigbuffer.cpp  -  description
+                             -------------------
+    begin                : Mit Jun 02 2003
+    copyright            : (C) 2003 by Friedrich W. H. Kossebau
+    email                : Friedrich.W.H@Kossebau.de
+ ***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   This library is free software; you can redistribute it and/or         *
+ *   modify it under the terms of the GNU Library General Public           *
+ *   License version 2 as published by the Free Software Foundation.       *
+ *                                                                         *
+ ***************************************************************************/
+
+
+// c specific
+#include <stdlib.h>
+// lib specific
+#include "kbigbuffer.h"
+
+using namespace KHE;
+
+KBigBuffer::KBigBuffer( int NP, int PS )
+ : NoOfUsedPages( NP ),
+   NoOfFreePages( NP ),
+   PageSize( PS ),
+   FirstPage( -1 ),
+   LastPage( -1 ),
+   Size( 0 )
+{
+  IsOpen = false;
+
+//   if( !filename.empty() )
+//     open(filename);
+}
+
+
+KBigBuffer::~KBigBuffer()
+{
+  if( File.isOpen() )
+    close();
+}
+
+
+
+bool KBigBuffer::prepareRange( KSection /*Range*/ ) const
+{
+  return true;
+}
+
+const char *KBigBuffer::dataSet( KSection /*Section*/ ) const
+{
+  return 0;
+}
+
+
+char KBigBuffer::datum( unsigned int DatumOffset ) const
+{
+//   std::cout << "reading datum " << DatumOffset << std::endl;
+  int OffsetInPage = DatumOffset - OffsetOfActualPage;
+  // there shouldn't be any need to check l
+  if( OffsetInPage >= 0 && OffsetInPage < (int)PageSize )
+    return ActualPage[OffsetInPage];
+
+  // load the page
+  unsigned int PageIndex = DatumOffset / PageSize;
+  ensurePageLoaded( PageIndex );
+  return ActualPage[DatumOffset-OffsetOfActualPage];
+}
+
+
+
+
+int KBigBuffer::insert( int /*Pos*/, const char*, int /*Length*/ )
+{
+  return 0;
+}
+
+int KBigBuffer::remove( KSection /*Section*/ )
+{
+  return 0;
+}
+
+unsigned int KBigBuffer::replace( KSection /*Section*/, const char*, unsigned int /*Length*/ )
+{
+  return 0;
+}
+
+int KBigBuffer::fill( char /*FillChar*/, int /*Length*/, unsigned int /*Pos*/ )
+{
+  return 0;
+}
+
+
+int KBigBuffer::move( int /*DestPos*/, KSection /*SourceSection*/ ) { return 0; }
+//int KBigBuffer::find( const char*, int /*Length*/, int /*Pos*/ ) const  { return 0; }
+int KBigBuffer::find( const char*/*KeyData*/, int /*Length*/, KSection /*Section*/ ) const { return 0; }
+
+int KBigBuffer::rfind( const char*, int /*Length*/, int /*Pos*/ ) const { return 0; }
+
+
+
+bool KBigBuffer::open( const QString& FileName )
+{
+  // clear old data
+  if( isOpen() && !close() ) // only occurs if close somehow fails.
+    return false;
+
+  File.setName( FileName );
+  if( !File.open(IO_ReadOnly|IO_Raw) )
+    return false;
+
+//   std::cout << "loading file " << FileName << std::endl;
+
+  int FileSize = File.size();
+  Size = FileSize;
+
+  // calculate necessary number of pages
+  int NoOfPages = FileSize/PageSize + 1;
+
+  // initialize Page pointers
+  Data.resize( NoOfPages );
+  for( KPageOfChar::iterator D=Data.begin(); D!=Data.end(); ++D )
+    *D = 0;
+
+  FirstPage = LastPage = 0;
+
+  return ensurePageLoaded( 0 );
+}
+
+
+bool KBigBuffer::close()
+{
+  if( !isOpen() )
+    return false;
+
+  File.close();
+
+  if( File.status() == IO_UnspecifiedError )
+    return false;
+
+//   std::cout << "closing file " << std::endl;
+
+  // free pages
+  for( KPageOfChar::iterator D=Data.begin(); D!=Data.end(); ++D )
+    delete [] *D;
+
+  FirstPage = LastPage = -1;
+  NoOfFreePages = NoOfUsedPages;
+
+  return true;
+}
+
+
+bool KBigBuffer::ensurePageLoaded( unsigned int PageIndex ) const
+{
+  if( !isOpen() )
+    return false;
+  // page loaded?
+  if( Data[PageIndex] != 0 )
+  {
+    ActualPage = Data[PageIndex];
+    OffsetOfActualPage = PageIndex * PageSize;
+    return true;
+  }
+
+  // no page available?
+  if( NoOfFreePages < 1 )
+  {
+    // free the page which is the furthest away from the page we are loading
+    if( abs(FirstPage-PageIndex) > abs(LastPage-PageIndex) )
+      while( !freePage(FirstPage++) );
+    else
+      while( !freePage(LastPage--) );
+  }
+
+//   std::cout << "loading page " << PageIndex << std::endl;
+  // create Page
+  Data[PageIndex] = new char[PageSize];
+  --NoOfFreePages;
+
+  // jump to position and read the page's data in
+  bool Success = File.at( (unsigned long)(PageIndex*PageSize) );
+  if( Success )
+    Success = File.readBlock( Data[PageIndex], PageSize ) > 0;
+
+  if( Success )
+  {
+    // correct bounds
+    if( (int)PageIndex < FirstPage )
+      FirstPage = PageIndex;
+
+    if( (int)PageIndex > LastPage )
+      LastPage = PageIndex;
+
+    ActualPage = Data[PageIndex];
+    OffsetOfActualPage = PageIndex * PageSize;
+  }
+
+  return Success;
+}
+
+
+bool KBigBuffer::freePage( unsigned int PageIndex ) const
+{
+  // check range and if is loaded at all
+  if( (unsigned int)PageIndex >= Data.size() || !Data[PageIndex] )
+    return false;
+//   std::cout << "freeing page " << PageIndex << std::endl;
+  delete [] Data[PageIndex];
+  Data[PageIndex] = 0;
+  ++NoOfFreePages;
+  return true;
+}