internal static bool CopyStream(Stream source, Stream target, int bufferSize, long sourceSeekOffset, SeekOrigin sourceSeekOrigin, long targetSetLength, long targetSeekOffset, SeekOrigin targetSeekOrigin, Operation <int, bool> shouldCancel)
{
SharedUtil.ThrowIfEmpty(source, "source");
SharedUtil.ThrowIfEmpty(target, "target");
if (!source.CanRead || !target.CanWrite)
{
throw new IOException();
}
byte[] buffer = new byte[bufferSize = (bufferSize <= 0) ? 0x1000 : bufferSize];
if (((sourceSeekOffset > 0L) || ((sourceSeekOffset == 0L) && (sourceSeekOrigin != SeekOrigin.Current))) && source.CanSeek)
{
source.Seek(sourceSeekOffset, sourceSeekOrigin);
}
if (target.CanSeek)
{
if (targetSetLength > 0L)
{
target.SetLength(targetSetLength);
}
target.Seek(targetSeekOffset, targetSeekOrigin);
}
while (source.Position < source.Length)
{
long num;
if ((num = source.Length - source.Position) < bufferSize)
{
bufferSize = (int)num;
buffer = new byte[bufferSize];
}
source.Read(buffer, 0, bufferSize);
target.Write(buffer, 0, bufferSize);
target.Flush();
if ((shouldCancel != null) && shouldCancel(SharedUtil.Percent(source.Position, source.Length)))
{
return(false);
}
}
return(true);
}