# Cold IO

It is the wrapper over `mio`. Allows to write a network application as a state machine to simplify testing.

## Proposer

The core entity is `Proposer` it working with the state machine that user implemented.

The `Proposer` provides the state machine a sequence of `Proposal`. For each `Proposal` state machine can return some `Request`.

## Proposal

It containing random number generator, elapsed time from previous proposal and one of the following messages:

* Wake - The first message that `Proposer` sends to the state machine. It needed for the state machine to provide a first request.
* Idle - The message that means nothing happened during some time.
* OnReadable/OnWritable - Some remote peer is ready to transmit/receive data. With this message a managed stream is provided. This object can be used only once.

## Managed Stream

The state machine receive `ReadOnce` object along with `OnReadable` event. The state machine can read it, or drop, or store for further use. The proposer will not send another `ReadOnce` until previous did not consumed. It can be dropped and the connection part (read or write) will be closed. If the state machine read the object, it will know how many bytes was read, and whether there will be more.

The state machine receive `WriteOnce` object along with `OnWritable` event. It is very similar to `ReadOnce`.

## Request

There are following elemental requests:

* Source of incoming connections. It can be a port, or nothing. It is planned to receive incoming connections from another thread.
* Blacklist a peer or a batch of peers.
* Connect to a peer or to a batch of peers.