https://github.com/darrenldl/ocaml-tui-chat-demo
https://github.com/darrenldl/ocaml-tui-chat-demo
Last synced: about 1 month ago
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- Host: GitHub
- URL: https://github.com/darrenldl/ocaml-tui-chat-demo
- Owner: darrenldl
- License: mit
- Created: 2023-07-20T01:57:07.000Z (almost 2 years ago)
- Default Branch: main
- Last Pushed: 2023-07-20T02:23:31.000Z (almost 2 years ago)
- Last Synced: 2024-05-01T15:11:00.808Z (about 1 year ago)
- Language: OCaml
- Size: 218 KB
- Stars: 9
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# OCaml TUI chat demo
## Installation
#### Statically linked binaries
See [releases](https://github.com/darrenldl/ocaml-tui-chat-demo/releases)
#### Build from source
Build the container image
```
podman build . -t ocaml-tui-chat
```
and run `make` once inside the container, or `make release-static` for
statically linked binaries
## Usage
`chat` operates in either `server` mode:
or `client` mode:
### Server mode
```
chat server [--host HOST] [--port PORT] [--debug]
```
`[ ... ]` denotes optional arguments
- `HOST` specifies the address to listen on, defaults to 127.0.0.1
- `PORT` specifies the port to listen on, defaults to 5000
- `--debug` enables display of debugging information on the UI
Example screenshots:
### Client mode
```
chat client [--user-name USER_NAME] [--host HOST] [--port PORT] [--debug]
```
- `--user-name USER_NAME` sends a user name registration request upon connection to server
- `HOST` specifies the address of the server to connect to, defaults to 127.0.0.1
- `PORT` specifies the port of the server to connect to, defaults to 5000
- `--debug` enables display of debugging information on the UI
Example screenshots:
## Technical details
#### Overview
`Msg_stream` is a messaging layer above Eio flow/TCP socket
Server
Client
#### Protocol and Msg_stream
Some OCaml value paths may be prefixed by `lib/` or `bin/` to
distinguish when module name is the same
(In principle they should be lifted to user facing API level for customization
should `Chat_lib` become a public library rather than an internal library)
- Format
Byte order: big-endian
```
2 bytes | message id
1 byte | message type
4 bytes | payload length N
N bytes | payload
```
- Message types
- `Heartbeat`
- `Ack`
- `Data`
- `User_name_register`
- `Register_fail`
- `Register_okay`
- Idling and heartbeat
- Connection is considered dead if no messages arrive within `Params.idle_timeout_s` (currently 5s)
- Heartbeat fiber serves to indicate connection is still active
- Acknowledgement
- Upon reception of message of type `Data`, a message of type `Ack` should be sent back
to source immediately
- A connection is considered to have an old outstanding ack if age of any outstanding ack
is greater than `lib/Params.ack_old_threshold`
#### Server
- User name registration
- User names are allocated on a first come, first served basis, mainly for the purpose
of debugging
- User name only lasts for the duration of connection
- No connections may share a user name
- Dispatcher
- The maximum number of concurrent clients accepted is determined by `bin/Params.concurrent_client_count`
- This is tracked by a counting semaphore, which dispatcher tries to acquire in a loop (with a timeout to check
for termination condition)
#### TUI
- Currently if the message cannot be rendered by Nottui (via Uutf) due to not being a valid UTF-8 encoded message,
then a hex dump is shown instead
## Limitations
- No tests
- Text wrapping in TUI is not implemented
- Multithreading via domains is not done as Nottui/Lwd is not thread-safe, and will need to make an
entirely new layer over it essentially.
- Nottui input field does not accept pasting of text