function stream_properties()

in src/append.jl [256:278]

• 21 lines of code
• 6 McCabe index (conditional complexity)

function stream_properties(io::IO; convert::Bool=true)
    startpos = position(io)
    buff = similar(FILE_FORMAT_MAGIC_BYTES)
    start_magic = read!(io, buff) == FILE_FORMAT_MAGIC_BYTES
    seekend(io)
    len = position(io) - startpos
    skip(io, -length(FILE_FORMAT_MAGIC_BYTES))
    end_magic = read!(io, buff) == FILE_FORMAT_MAGIC_BYTES
    seek(io, startpos) 

    isstream = !(len > 24 && start_magic && end_magic)
    if isstream
        stream = Stream(io, convert=convert)
        for table in stream
            
            (stream.compression[] !== nothing) && break
        end
        seek(io, startpos) 
        return isstream, Tables.Schema(stream.names, stream.types), stream.compression[]
    else
        return isstream, nothing, nothing
    end
end