--- a/FileDBLink.cpp	Fri Aug 24 22:56:43 2012 +0200
+++ b/FileDBLink.cpp	Fri Aug 24 22:57:19 2012 +0200
@@ -35,12 +35,15 @@
   addFile(fileinfo.absoluteFilePath(), fileinfo.size(), fileinfo.lastModified());
 }
 
-void FileDBLink::addFile(const QString& path, qint64 size, const QDateTime& lastModified)
+QByteArray FileDBLink::computeHash(const QString& path, QCryptographicHash::Algorithm algorithm)
 {
-  QCryptographicHash hash( QCryptographicHash::Sha1 );
+  const static uint buffersize = 8192;
+  QCryptographicHash hash(algorithm);
   QFile file(path);
   if ( file.open( QIODevice::ReadOnly ) ) {
-    hash.addData( file.readAll() );
+    while(!file.atEnd()){
+      hash.addData(file.read(buffersize));
+    }
   }
   else {
     QString errorMsg = path + ": " + file.errorString();
@@ -51,10 +54,14 @@
     default:
       throw IOException(errorMsg);
     }
-  }
-  
-  addFile(path, size, lastModified, hash.result());
+  }  
+  return hash.result();
+}
 
+
+void FileDBLink::addFile(const QString& path, qint64 size, const QDateTime& lastModified)
+{
+  addFile(path, size, lastModified, computeHash(path));
 }
 
 void FileDBLink::updateFile(const QFileInfo& fileinfo)
@@ -64,23 +71,7 @@
 
 void FileDBLink::updateFile(const QString& path, qint64 size, const QDateTime& lastModified)
 {
-  QCryptographicHash hash( QCryptographicHash::Sha1 );
-  QFile file(path);
-  if ( file.open( QIODevice::ReadOnly ) ) {
-    hash.addData( file.readAll() );
-  }
-  else {
-    QString errorMsg = path + ": " + file.errorString();
-
-    switch (file.error()) {
-    case QFile::PermissionsError:
-      throw PermissionException(errorMsg);
-    default:
-      throw IOException(errorMsg);
-    }
-  }
-  
-  updateFile(path, size, lastModified, hash.result());
+  updateFile(path, size, lastModified, computeHash(path));
 }
 
 const QList<QSharedPointer<FileDBLink::DBInfo> > FileDBLink::sortOn(const QString& prefix, SORTORDER order, bool extended)

--- a/FileDBLink.hpp	Fri Aug 24 22:56:43 2012 +0200
+++ b/FileDBLink.hpp	Fri Aug 24 22:57:19 2012 +0200
@@ -89,6 +89,7 @@
 
   static QSharedPointer<DBInfo> computedValue(const QSharedPointer<DBInfo>& info, const QList<QSharedPointer<DBInfo> >&);
 
+  static QByteArray computeHash(const QString& path, QCryptographicHash::Algorithm = QCryptographicHash::Sha1);
 
 public:
   enum DBStatus { NONE = 0, MTIME_DIFFERENT, SAME};