//------------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------
/// <summary>
/// Constructor
/// </summary>
/// <param name="baseStream">part stream - not closed - caller determines lifetime</param>
/// <param name="position">current logical stream position</param>
/// <param name="tempStream">should be an IsolatedStorageFileStream - not closed - caller determines lifetime</param>
/// <param name="transformer">class that does the compression/decompression</param>
/// <remarks>This class should only invoked when emulation is required.
/// Does not close any given stream, even when Close is called. This means that it requires
/// another wrapper Stream class.</remarks>
internal CompressEmulationStream(Stream baseStream, Stream tempStream, long position, IDeflateTransform transformer)
{
if (position < 0)
{
throw new ArgumentOutOfRangeException("position");
}
if (baseStream == null)
{
throw new ArgumentNullException("baseStream");
}
// seek and read required for emulation
if (!baseStream.CanSeek)
{
throw new InvalidOperationException(SR.SeekNotSupported);
}
if (!baseStream.CanRead)
{
throw new InvalidOperationException(SR.ReadNotSupported);
}
if (tempStream == null)
{
throw new ArgumentNullException("tempStream");
}
if (transformer == null)
{
throw new ArgumentNullException("transformer");
}
_baseStream = baseStream;
_tempStream = tempStream;
_transformer = transformer;
// extract to temporary stream
_baseStream.Position = 0;
_tempStream.Position = 0;
_transformer.Decompress(baseStream, tempStream);
// seek to the current logical position
_tempStream.Position = position;
}
//------------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------
/// <summary>
/// Constructor
/// </summary>
/// <param name="baseStream">part stream - not closed - caller determines lifetime</param>
/// <param name="position">current logical stream position</param>
/// <param name="tempStream">should be an IsolatedStorageFileStream - not closed - caller determines lifetime</param>
/// <param name="transformer">class that does the compression/decompression</param>
/// <remarks>This class should only invoked when emulation is required.
/// Does not close any given stream, even when Close is called. This means that it requires
/// another wrapper Stream class.</remarks>
internal CompressEmulationStream(Stream baseStream, Stream tempStream, long position, IDeflateTransform transformer)
{
if (position < 0)
throw new ArgumentOutOfRangeException("position");
if (baseStream == null)
throw new ArgumentNullException("baseStream");
// seek and read required for emulation
if (!baseStream.CanSeek)
throw new InvalidOperationException(SR.Get(SRID.SeekNotSupported));
if (!baseStream.CanRead)
throw new InvalidOperationException(SR.Get(SRID.ReadNotSupported));
if (tempStream == null)
throw new ArgumentNullException("tempStream");
if (transformer == null)
throw new ArgumentNullException("transformer");
_baseStream = baseStream;
_tempStream = tempStream;
_transformer = transformer;
// extract to temporary stream
_baseStream.Position = 0;
_tempStream.Position = 0;
_transformer.Decompress(baseStream, tempStream);
// seek to the current logical position
_tempStream.Position = position;
}
