Frames is a simple multiplexing protocol I use when I need to ask for a lot of different things concurrently between two servers and I don't want to burn lots of file descriptors or rely on pipelining timings and such things to do it.

This should be usable anywhere you use a =net.Conn= today. There's some convenience support for HTTP as I'm using it quite a bit as an HTTP transport.

• Protocol

The protocol is really simple, just a 6 byte header followed by 0 or more bytes of data (maximum data size of 2^16).

|-------------+---------------------+-------------+----------| | Field | Type | Byte Offset | Byte Len | |-------------+---------------------+-------------+----------| | Data Length | unsigned 16-bit int | 0 | 2 | | Channel | unsigned 16-bit int | 2 | 2 | | Command | byte | 4 | 1 | | Status | byte | 5 | 1 |

** Definitions

*** Commands

|---------+------| | Command | ID | |---------+------| | Open | 0x00 | | Close | 0x01 | | Data | 0x02 |

*** Status

|---------+----| | Status | ID | |---------+----| | Success | 0 | | Error | 1 |

** Flow

A client begins by establishing a TCP connection. To do anything useful, it must first issue an =Open= command to get a new channel assigned. If this is successful (=Status= = =Success=), the client will get a response with the Command set to =Open= and the channel ID set to the new channel.

A client may open as many channels as necessary and then send =Data= packets along with the corresponding data.

A client MUST =Close= the channel when you're done with it if you intend to continue using the service. If the client is completely done, it MAY drop the underlying TCP connection and the server MUST clean up after you.