reader.fs

 module MessageProcessing=
           open System.IO

           type private DataMsg=
               |Raw of byte[]
               
           let empty (msg:ArraySegment<byte>)=
               let length=readInt msg.Offset msg.Array|>fst
               let stream=new MemoryStream(length+4)
               stream
               
           let write (seg:ArraySegment<byte>) (stream:MemoryStream)=stream.Write(seg.Array,seg.Offset,seg.Count)
               
           let private messageStore=MailboxProcessor.Start (fun inbox->
                let rec loop (state:(MemoryStream) option)=async{
                    let! (Raw m)=inbox.Receive()
                    let segment=new ArraySegment<byte>(m)
                    let data=state|>Option.defaultWith (fun ()->empty segment)
                    trace <| sprintf "current data position=%i capacity=%i"  data.Position data.Capacity
                    trace <| sprintf "new chunk size %i" segment.Count
                    let availSpace=data.Capacity-(int data.Position)
                    let count=Math.Min(segment.Count,availSpace)
                    let segToWrite=segment.Slice(0,count)
                    let nextSeg=segment.Slice(count)
                    write segToWrite data
                    if(data.Position=(data.Capacity|>int64)) then
                        parse (data.ToArray())|>Async.Start
                        data.Dispose()
                    if(nextSeg.Count=0) then
                        return! loop None
                     
                    else
                        let stream=empty nextSeg
                        write nextSeg stream
                        return! loop (Some stream)
          
                }
                loop None
           )