damus.io

nostr.js (7448B)

---

 const nostrjs = (function nostrlib() {
 const WS = typeof WebSocket !== 'undefined' ? WebSocket : require('ws')
 
 function RelayPool(relays, opts)
 {
 	if (!(this instanceof RelayPool))
 		return new RelayPool(relays)
 
 	this.onfn = {}
 	this.relays = []
 
 	for (const relay of relays) {
 		this.add(relay)
 	}
 
 	return this
 }
 
 RelayPool.prototype.close = function relayPoolClose() {
 	for (const relay of this.relays) {
 		relay.close()
 	}
 }
 
 RelayPool.prototype.on = function relayPoolOn(method, fn) {
 	for (const relay of this.relays) {
 		this.onfn[method] = fn
 		relay.onfn[method] = fn.bind(null, relay)
 	}
 }
 
 RelayPool.prototype.has = function relayPoolHas(relayUrl) {
 	for (const relay of this.relays) {
 		if (relay.url === relayUrl)
 			return true
 	}
 
 	return false
 }
 
 RelayPool.prototype.setupHandlers = function relayPoolSetupHandlers()
 {
 	// setup its message handlers with the ones we have already
 	const keys = Object.keys(this.onfn)
 	for (const handler of keys) {
 		for (const relay of this.relays) {
 			relay.onfn[handler] = this.onfn[handler].bind(null, relay)
 		}
 	}
 }
 
 RelayPool.prototype.remove = function relayPoolRemove(url) {
 	let i = 0
 
 	for (const relay of this.relays) {
 		if (relay.url === url) {
 			relay.ws && relay.ws.close()
 			this.relays = this.replays.splice(i, 1)
 			return true
 		}
 
 		i += 1
 	}
 
 	return false
 }
 
 RelayPool.prototype.subscribe = function relayPoolSubscribe(sub_id, filters, relay_ids) {
 	const relays = relay_ids ? this.find_relays(relay_ids) : this.relays
 	for (const relay of relays) {
 		relay.subscribe(sub_id, filters)
 	}
 }
 
 RelayPool.prototype.unsubscribe = function relayPoolUnsubscibe(sub_id, relay_ids) {
 	const relays = relay_ids ? this.find_relays(relay_ids) : this.relays
 	for (const relay of relays) {
 		relay.unsubscribe(sub_id)
 	}
 }
 
 RelayPool.prototype.send = function relayPoolSend(payload, relay_ids) {
 	const relays = relay_ids ? this.find_relays(relay_ids) : this.relays
 	for (const relay of relays) {
 		relay.send(payload)
 	}
 }
 
 RelayPool.prototype.add = function relayPoolAdd(relay) {
 	if (relay instanceof Relay) {
 		if (this.has(relay.url))
 			return false
 
 		this.relays.push(relay)
 		this.setupHandlers()
 		return true
 	}
 
 	if (this.has(relay))
 		return false
 
 	const r = Relay(relay, this.opts)
 	this.relays.push(r)
 	this.setupHandlers()
 	return true
 }
 
 RelayPool.prototype.find_relays = function relayPoolFindRelays(relay_ids) {
 	if (relay_ids instanceof Relay)
 		return [relay_ids]
 
 	if (relay_ids.length === 0)
 		return []
 
 	if (!relay_ids[0])
 		throw new Error("what!?")
 
 	if (relay_ids[0] instanceof Relay)
 		return relay_ids
 
 	return this.relays.reduce((acc, relay) => {
 		if (relay_ids.some((rid) => relay.url === rid))
 			acc.push(relay)
 		return acc
 	}, [])
 }
 
 Relay.prototype.wait_connected = async function relay_wait_connected(data) {
 	let retry = 1000
 	while (true) {
 		if (!this.ws || this.ws.readyState !== 1) {
 			await sleep(retry)
 			retry *= 1.5
 		}
 		else {
 			return
 		}
 	}
 }
 
 
 function Relay(relay, opts={})
 {
 	if (!(this instanceof Relay))
 		return new Relay(relay, opts)
 
 	this.url = relay
 	this.opts = opts
 
 	if (opts.reconnect == null)
 		opts.reconnect = true
 
 	const me = this
 	me.onfn = {}
 
 	try {
 		init_websocket(me)
 	} catch (e) {
 		console.log(e)
 	}
 
 	return this
 }
 
 function init_websocket(me) {
 	let ws
 	try {
 		ws = me.ws = new WS(me.url);
 	} catch(e) {
 		return null
 	}
 	return new Promise((resolve, reject) => {
 		let resolved = false
 		ws.onmessage = (m) => { handle_nostr_message(me, m) }
 		ws.onclose = () => { 
 			if (me.onfn.close) 
 				me.onfn.close() 
 			if (me.reconnecting)
 				return reject(new Error("close during reconnect"))
 			if (!me.manualClose && me.opts.reconnect)
 				reconnect(me)
 		}
 		ws.onerror = () => { 
 			if (me.onfn.error)
 				me.onfn.error() 
 			if (me.reconnecting)
 				return reject(new Error("error during reconnect"))
 			if (me.opts.reconnect)
 				reconnect(me)
 		}
 		ws.onopen = () => {
 			if (me.onfn.open)
 				me.onfn.open()
 			else
 				console.log("no onopen???", me)
 
 			if (resolved) return
 
 			resolved = true
 			resolve(me)
 		}
 	});
 }
 
 function sleep(ms) {
     return new Promise(resolve => setTimeout(resolve, ms));
 }
 
 async function reconnect(me)
 {
 	const reconnecting = true
 	let n = 100
 	try {
 		me.reconnecting = true
 		await init_websocket(me)
 		me.reconnecting = false
 	} catch {
 		//console.error(`error thrown during reconnect... trying again in ${n} ms`)
 		await sleep(n)
 		n *= 1.5
 	}
 }
 
 Relay.prototype.on = function relayOn(method, fn) {
 	this.onfn[method] = fn
 }
 
 Relay.prototype.close = function relayClose() {
 	if (this.ws) {
 		this.manualClose = true
 		this.ws.close()
 	}
 }
 
 Relay.prototype.subscribe = function relay_subscribe(sub_id, filters) {
 	if (Array.isArray(filters))
 		this.send(["REQ", sub_id, ...filters])
 	else
 		this.send(["REQ", sub_id, filters])
 }
 
 Relay.prototype.unsubscribe = function relay_unsubscribe(sub_id) {
 	this.send(["CLOSE", sub_id])
 }
 
 Relay.prototype.send = async function relay_send(data) {
 	await this.wait_connected()
 	this.ws.send(JSON.stringify(data))
 }
 
 function handle_nostr_message(relay, msg)
 {
 	let data
 	try {
 		data = JSON.parse(msg.data)
 	} catch (e) {
 		console.error("handle_nostr_message", msg, e)
 		return
 	}
 	if (data.length >= 2) {
 		switch (data[0]) {
 		case "EVENT":
 			if (data.length < 3)
 				return
 			return relay.onfn.event && relay.onfn.event(data[1], data[2])
 		case "EOSE":
 			return relay.onfn.eose && relay.onfn.eose(data[1])
 		case "NOTICE":
 			return relay.onfn.notice && relay.onfn.notice(...data.slice(1))
 		}
 	}
 }
 
 async function sha256(message) {
 	if (crypto.subtle) {
 		const buffer = await crypto.subtle.digest('SHA-256', message);
 		return new Uint8Array(buffer);
 	} else if (require) {
 		const { createHash } = require('crypto');
 		const hash = createHash('sha256');
 		[message].forEach((m) => hash.update(m));
 		return Uint8Array.from(hash.digest());
 	} else {
 		throw new Error("The environment doesn't have sha256 function");
 	}
 }
 
 async function calculate_id(ev) {
 	const commit = event_commitment(ev)
 	const buf = new TextEncoder().encode(commit);                    
 	return hex_encode(await sha256(buf))
 }
 
 function event_commitment(ev) {
 	const {pubkey,created_at,kind,tags,content} = ev
 	return JSON.stringify([0, pubkey, created_at, kind, tags, content])
 }
 
 function hex_char(val) {
 	if (val < 10)
 		return String.fromCharCode(48 + val)
 	if (val < 16)
 		return String.fromCharCode(97 + val - 10)
 }
 
 function hex_encode(buf) {
 	let str = ""
 	for (let i = 0; i < buf.length; i++) {
 		const c = buf[i]
 		str += hex_char(c >> 4)
 		str += hex_char(c & 0xF)
 	}
 	return str
 }
 
 function char_to_hex(cstr) {
 	const c = cstr.charCodeAt(0)
 	// c >= 0 && c <= 9
 	if (c >= 48 && c <= 57) {
 		return c - 48;
 	}
 	// c >= a && c <= f
  	if (c >= 97 && c <= 102) {
 		return c - 97 + 10;
 	}
 	// c >= A && c <= F
  	if (c >= 65 && c <= 70) {
 		return c - 65 + 10;
 	}
 	return -1;
 }
 
 
 function hex_decode(str, buflen)
 {
 	let bufsize = buflen || 33
 	let c1, c2
 	let i = 0
 	let j = 0
 	let buf = new Uint8Array(bufsize)
 	let slen = str.length
 	while (slen > 1) {
 		if (-1==(c1 = char_to_hex(str[j])) || -1==(c2 = char_to_hex(str[j+1])))
 			return null;
 		if (!bufsize)
 			return null;
 		j += 2
 		slen -= 2
 		buf[i++] = (c1 << 4) | c2
 		bufsize--;
 	}
 
 	return buf
 }
 
 return {
 	RelayPool,
 	calculate_id,
 	event_commitment,
 	hex_encode,
 	hex_decode,
 }
 })()
 
 if (typeof module !== 'undefined' && module.exports)
 	module.exports = nostrjs