private void DecodeDjvuDocument(DjvuReader reader)
{
//Check the first 4 bytes
CheckDjvuHeader(reader);
DecodeFormChunk(reader);
BuildPageList();
if (Navigation == null)
{
Navigation = new DocumentNavigator(this);
}
ActivePage = Pages.FirstOrDefault();
LastPage = Pages.Last();
FirstPage = Pages.First();
// Run the preload in the background with low priority
//var thread = new Thread(() =>
// {
// // Start after a bit
// Thread.Sleep(5000);
// Pages.ToList().ForEach(x => x.Preload());
// });
//thread.Priority = ThreadPriority.Lowest;
//thread.IsBackground = true;
//thread.Start();
//Task.Factory.StartNew(() => Parallel.ForEach(Pages, page => page.Preload()), TaskCreationOptions.LongRunning);
}
protected void Dispose(bool disposing)
{
if (_Disposed)
{
return;
}
if (disposing)
{
}
if (_Reader != null)
{
_Reader.Close();
_Reader = null;
}
for (int i = 0; i < _Pages?.Count; i++)
{
_Pages[i]?.Dispose();
}
_Pages?.Clear();
_Disposed = true;
}
public DjvuDocument(string location, int identifier)
{
Identifier = identifier;
_reader = new DjvuReader(location);
_name = Path.GetFileNameWithoutExtension(location);
_location = location;
DecodeDjvuDocument(_reader);
}
public DjvuDocument(Stream stream, string fileName)
{
Identifier = 0;
_reader = new DjvuReader(stream);
_name = Path.GetFileNameWithoutExtension(fileName);
_location = fileName;
DecodeDjvuDocument(_reader);
}
/// <summary>
/// Decodes the available IFF chunks
/// </summary>
/// <param name="reader"></param>
internal void DecodeRootForm(DjvuReader reader)
{
RootForm = DjvuParser.GetRootForm(reader, null, this);
RootForm.Initialize(reader);
foreach (IDjvuNode chunk in RootForm.Children)
{
chunk.Initialize(reader);
}
}
public void Load(string filePath, int identifier = 0)
{
Identifier = identifier;
_Reader = new DjvuReader(filePath);
_name = Path.GetFileNameWithoutExtension(filePath);
_location = filePath;
DecodeDjvuDocument(_Reader);
}
/// <summary>
/// Checks for a valid file header
/// </summary>
/// <param name="reader"></param>
private void CheckDjvuHeader(DjvuReader reader)
{
byte[] header = new byte[4];
reader.Read(header, 0, 4);
if (header[0] != 0x41 || header[1] != 0x54 || header[2] != 0x26 || header[3] != 0x54)
{
throw new Exception("File header is invalid");
}
}
/// <summary>
/// Clones the reader for parallel reading at the given position
/// </summary>
/// <returns></returns>
public DjvuReader CloneReader(long position, int length)
{
DjvuReader newReader = null;
// Clone the reader
newReader = _location != null ? new DjvuReader(_location) : new DjvuReader(BaseStream);
newReader.Position = position;
return(newReader.GetFixedLengthStream(length));
}
/// <summary>
/// Clones the reader for parallel reading at the given position
/// </summary>
/// <returns></returns>
public DjvuReader CloneReader(long position)
{
DjvuReader newReader = null;
// Clone the reader
newReader = _location != null ? new DjvuReader(_location) : new DjvuReader(BaseStream);
newReader.Position = position;
return(newReader);
}
internal void DecodeDjvuDocument(DjvuReader reader)
{
//Check the first 4 bytes
CheckDjvuHeader(reader);
DecodeRootForm(reader);
BuildPageList();
if (Navigation == null)
{
Navigation = new DocumentNavigator(this);
}
if (Pages?.Count > 0)
{
ActivePage = FirstPage = Pages[0];
LastPage = Pages[Pages.Count - 1];
}
}
/// <summary>
/// Clones the reader for parallel reading at the given position
/// </summary>
/// <returns></returns>
public IDjvuReader CloneReader(long position)
{
DjvuReader newReader = null;
// TODO Get rid of not properly synchronized clones or synchronize readers
// Do a deep clone with new BaseStream
if (_Location != null)
{
newReader = new DjvuReader(_Location);
}
else
{
MemoryStream stream = new MemoryStream((int)BaseStream.Length);
BaseStream.CopyTo(stream);
newReader = new DjvuReader(stream);
}
newReader.Position = position;
return(newReader);
}
/// <summary>
/// Checks for a valid DjVu AT&T file header
/// </summary>
/// <param name="reader"></param>
internal void CheckDjvuHeader(DjvuReader reader)
{
long previousPosition = reader.Position;
try
{
reader.Position = 0;
const uint expectedHeader = 0x54265441;
uint actual = reader.ReadUInt32();
if (expectedHeader != actual)
{
throw new DjvuFormatException("DjVu \"AT$T\" file header is invalid");
}
}
finally
{
reader.Position = previousPosition + 4;
}
}
/// <summary>
/// Decodes the available IFF chunks
/// </summary>
/// <param name="reader"></param>
private void DecodeFormChunk(DjvuReader reader)
{
_formChunk = new FormChunk(reader, null, this);
}
