DecoderStream just reads first 65520 bytes about k4os.compression.lz4 HOT 5 CLOSED

I see nothing suspicious (apart from allocating buffer all the time). This is just a read part. Can you attach project which does both - writes data and reads data?

from k4os.compression.lz4.

I think I found the problem.
I assumed that diffStream.Read(buffer, 0, buffer.Length); always reads "buffer.length" bytes from the stream. I found out that LZ4DecoderStream sometimes reads less bytes.

from k4os.compression.lz4.

i have this problem too
i think you need give some info for this api to let other know this rule.

from k4os.compression.lz4.

I think the problem is that DecoderStream buffers its decoded data internal within a 65536 bytes buffer. User first has to read all these bytes before this buffer gets filled again. That's when DecoderStream returns less bytes than needed.
I also think that this fact should get mentioned somewhere in the description of the API.

from k4os.compression.lz4.

Well, it is documented in Stream API:
https://docs.microsoft.com/en-us/dotnet/api/system.io.stream.read?view=netframework-4.8

Returns
Int32
The total number of bytes read into the buffer. This can be less than the number of bytes requested if that many bytes are not currently available, or zero (0) if the end of the stream has been reached.

from k4os.compression.lz4.