rough framework

[lemu] / README.md

# LEMU

This is a (work-in-progress) text-based multi-user server engine, utilizing lua, libevent, and a concurrent work queue.
The intent is for client interaction to be primarily driven by lua scripting, with the server code itself only handling the heavy-lifting of IO, DB, et cetera.

Nota bene: this is currently a toy implementation, as an architecture for the lua-side has yet to be fleshed out, and is being developed by feel, trial, and error.

## Overview

The main thread runs the event loop, which primarily accepts new connections and feeds their line-based inputs into the thread pool for processing.  Connection hostname resolution and signal handling are also in the main thread.

Each connection has its own queue of input.  When a new line of input is added to a connection's queue and there were no other lines already queued, a new job is added to the workqueue to process that connection's input.

The main unresolved issue here is consistent server state-keeping between each worker-thread's lua processor.  The current stopgap solution is that each worker is totally independent and any global changes to the lua state will be queued as a task to update the common state.  The imagined ideal is a lock-enable native lua environment/table which would be shared by all workers.

## File Tour

        bsd_queue.h      - BSD's sys/queue.h, included here because Linux's version is dreadful
        command.c        - processes user input
        common.c         - utility functions
        connections.c    - manage and interact with active clients
        db.c             - persistent data storage
        lua_interface.c  - lua bindings to server and connections
        main.c           - cli
        notify.c         - logging abstraction
        server.c         - event loop, network stuff, glues everything together
    workqueue.c      - concurrent task runner