nats-types

The nats-types crate contains an enum ProtocolMessage. This enum can be used to parse the string output from a NATS server as well as produce strings to be sent to a NATS server.

The primary use for this crate is to be used in support of building a NATS client, though other potential uses might be possible.

To produce a protocol message, simply create the enum:

extern crate nats_types;

use nats_types::{PublishMessage, ProtocolMessage};

let publish = ProtocolMessage::Publish( PublishMessage {
reply_to: Some("INBOX.42".to_string()),
subject: "workdispatch".to_string(),
payload_size: 11,
payload: b"Hello World".to_vec(),
});

let out = format!("{}", publish);
assert_eq!(out, "PUB workdispatch INBOX.42 11\r\nHello World\r\n");

The same message can be constructed from the 2-line message received from a NATS server:

extern crate nats_types;

use std::str::FromStr;
use nats_types::{ProtocolMessage};

let msg = "PUB FOO 11\r\nHello NATS!\r\n";
let protomsg = ProtocolMessage::from_str(&msg).unwrap();
if let ProtocolMessage::Publish(pubm) = protomsg {
assert_eq!(pubm.payload_size, 11);
assert_eq!(pubm.subject, "FOO");
assert_eq!(pubm.reply_to, None);
assert_eq!(pubm.payload, b"Hello NATS!");
}