public override long Seek(long offset, SeekOrigin origin)
{
long delta = 0; // Distance between absolute cursor position and specified position in bytes
if (origin.Equals(SeekOrigin.Current))
{
delta = offset;
}
else if (origin.Equals(SeekOrigin.Begin))
{
delta = offset - Position;
}
else if (origin.Equals(SeekOrigin.End))
{
delta = (streamSize + offset) - Position;
}
if (0 == delta)
{
return(Position);
}
else if (delta < 0)
{
// If cursor is still within buffer, jump within buffer
if ((cursorPosition + delta < bufferSize) && (cursorPosition + delta >= 0))
{
cursorPosition += (int)delta;
}
else // Jump outside buffer : move the whole buffer at the beginning of the zone to read
{
streamPosition = bufferOffset + cursorPosition + delta;
stream.Position = streamPosition;
fillBuffer();
}
}
else if (cursorPosition + delta < bufferSize) // Jump within buffer
{
cursorPosition += (int)delta;
}
else // Jump outside buffer: move the whole buffer at the beginning of the zone to read
{
streamPosition = bufferOffset + cursorPosition + delta;
stream.Position = streamPosition;
fillBuffer();
}
return(Position);
}
public override long Seek(long offset, SeekOrigin origin)
{
if (CanSeek)
{
if (origin.Equals(SeekOrigin.Begin))
{
Position = offset;
}
else if (origin.Equals(SeekOrigin.Current))
{
Position += offset;
}
else
{
Position = Length - offset;
}
// No positin is set, we need to adjust our streams to be in the righ section.
if (Position < s1.Length)
{
// we are in our first stream
s1.Seek(Position, SeekOrigin.Begin);
// If we move into stream one, then make sure to set the stream two to start reading from the beging.
s2.Seek(0, SeekOrigin.Begin);
}
else
{
// We are in the second stream.
// Posistion - s1.length is the relative position into stream 2.
s2.Seek(Position - s1.Length, SeekOrigin.Begin);
// If we are in s2, then move s1 to the end of itself.
s1.Seek(0, SeekOrigin.End);
}
return(Position);
}
else
{
throw new NotImplementedException();
}
}
public override long Seek(long offset, SeekOrigin origin)
{
if (CanSeek)
{
if (origin.Equals(SeekOrigin.Begin))
{
Position = offset;
}
else if (origin.Equals(SeekOrigin.Current))
{
Position += offset;
}
else
{
Position = Length - offset;
}
return(Position);
}
else
{
throw new NotImplementedException();
}
}