我有30 GB的FileStream。我想从中获得2个(或更多)流,开始(0-50%)和结束(50%-100%)。如果我使用MemoryStream和CopyTo(),它将消耗30 GB的RAM,而我只需要新的分离流。这可能吗?
我为此任务制作了自己的流。测试得不好,但看起来还可以]
class SegmentedStream : Stream
{
Stream Stream { get; set; }
long StreamStart { get; set; }
long StreamLength { get; set; }
public SegmentedStream(Stream stream, long position, long size)
{
Stream = stream;
StreamStart = position;
StreamLength = size;
}
public override bool CanRead => true;
public override bool CanSeek => true;
public override bool CanWrite => false;
public override long Length => Math.Min((Stream.Length - StreamStart), StreamLength);
public override long Position { get => Stream.Position - StreamStart; set => Stream.Position = StreamStart + value; }
public override void Flush()
{
throw new NotImplementedException();
}
public override int Read(byte[] buffer, int offset, int count)
{
return Stream.Read(buffer, offset, count);
}
public override long Seek(long offset, SeekOrigin origin)
{
return Stream.Seek(StreamStart + offset, origin);
}
public override void SetLength(long value)
{
throw new NotImplementedException();
}
public override void Write(byte[] buffer, int offset, int count)
{
throw new NotImplementedException();
}
}