Files
xahaud/js/remote.js
2012-10-04 21:17:40 -04:00

330 lines
8.1 KiB
JavaScript

// Remote access to a server.
// - We never send binary data.
// - We use the W3C interface for node and browser compatibility:
// http://www.w3.org/TR/websockets/#the-websocket-interface
//
// YYY Will later provide a network access which use multiple instances of this.
// YYY A better model might be to allow requesting a target state: keep connected or not.
//
var util = require('util');
var WebSocket = require('ws');
// --> trusted: truthy, if remote is trusted
var Remote = function (trusted, websocket_ip, websocket_port, trace) {
this.trusted = trusted;
this.websocket_ip = websocket_ip;
this.websocket_port = websocket_port;
this.id = 0;
this.trace = trace;
this.ledger_closed = undefined;
this.ledger_current_index = undefined;
this.stand_alone = undefined;
// Cache information for accounts.
this.account = {};
// Cache for various ledgers.
// XXX Clear when ledger advances.
this.ledgers = {
'current' : {}
};
};
var remoteConfig = function (config, server, trace) {
var serverConfig = config.servers[server];
return new Remote(serverConfig.trusted, serverConfig.websocket_ip, serverConfig.websocket_port, trace);
};
// XXX This needs to be determined from the network.
var fees = {
'default' : 100,
'account_create' : 1000,
'nickname_create' : 1000,
'offer' : 100,
};
// For accounts we cache things like sequence numbers.
var accounts = {
// Consider sequence numbers stable if you know you're not generating bad transactions.
// Otherwise, clear it to have it automatically refreshed from the network.
// acount : { seq : __ }
};
Remote.method('connect_helper', function () {
var self = this;
if (this.trace) console.log("remote: connect: %s", this.url);
var ws = this.ws = new WebSocket(this.url);;
ws.response = {};
ws.onopen = function () {
if (this.trace) console.log("remote: onopen: %s", ws.readyState);
ws.onclose = undefined;
ws.onerror = undefined;
self.done(ws.readyState);
};
ws.onerror = function () {
if (this.trace) console.log("remote: onerror: %s", ws.readyState);
ws.onclose = undefined;
if (self.expire) {
if (this.trace) console.log("remote: was expired");
self.done(ws.readyState);
} else {
// Delay and retry.
setTimeout(function () {
if (this.trace) console.log("remote: retry");
self.connect_helper();
}, 50); // Retry rate 50ms.
}
};
// Covers failure to open.
ws.onclose = function () {
if (this.trace) console.log("remote: onclose: %s", ws.readyState);
ws.onerror = undefined;
self.done(ws.readyState);
};
// Node's ws module doesn't pass arguments to onmessage.
ws.on('message', function (json, flags) {
var message = JSON.parse(json);
// console.log("message: %s", json);
if (message.type !== 'response') {
console.log("unexpected message: %s", json);
} else {
var done = ws.response[message.id];
if (done) {
done(message);
} else {
console.log("unexpected message id: %s", json);
}
}
});
});
// Target state is connectted.
// done(readyState):
// --> readyState: OPEN, CLOSED
Remote.method('connect', function (done, timeout) {
var self = this;
this.url = util.format("ws://%s:%s", this.websocket_ip, this.websocket_port);
this.done = done;
if (timeout) {
if (this.trace) console.log("remote: expire: false");
this.expire = false;
setTimeout(function () {
if (this.trace) console.log("remote: expire: timeout");
self.expire = true;
}, timeout);
} else {
if (this.trace) console.log("remote: expire: false");
this.expire = true;
}
this.connect_helper();
});
// Target stated is disconnected.
Remote.method('disconnect', function (done) {
var ws = this.ws;
ws.onclose = function () {
if (this.trace) console.log("remote: onclose: %s", ws.readyState);
done(ws.readyState);
};
ws.close();
});
// Send a command. The comman should lack the id.
// <-> command: what to send, consumed.
Remote.method('request', function (request, onDone, onFailure) {
this.id += 1; // Advance id.
var ws = this.ws;
request.id = this.id;
ws.response[request.id] = function (response) {
if (this.trace) console.log("remote: response: %s", JSON.stringify(response));
if (onFailure && response.error)
{
onFailure(response);
}
else
{
onDone(response);
}
};
if (this.trace) console.log("remote: request: %s", JSON.stringify(request));
ws.send(JSON.stringify(request));
});
Remote.method('request_ledger_closed', function (onDone, onFailure) {
assert(this.trusted); // If not trusted, need to check proof.
this.request({ 'command' : 'ledger_closed' }, onDone, onFailure);
});
// Get the current proposed ledger entry. May be closed (and revised) at any time (even before returning).
// Only for use by unit tests.
Remote.method('request_ledger_current', function (onDone, onFailure) {
this.request({ 'command' : 'ledger_current' }, onDone, onFailure);
});
// <-> request:
// --> ledger : optional
// --> ledger_index : optional
// --> type
Remote.method('request_ledger_entry', function (req, onDone, onFailure) {
assert(this.trusted); // If not trusted, need to check proof, maybe talk packet protocol.
req.command = 'ledger_entry';
if (req.ledger_closed)
{
// XXX Initial implementation no caching.
this.request(req, onDone, onFailure);
}
else if (req.ledger_index)
{
// Current
// XXX Only allow with standalone mode. Must sync response with advance.
var entry;
switch (req.type) {
case 'account_root':
var cache = this.ledgers.current.account_root;
if (!cache)
{
cache = this.ledgers.current.account_root = {};
}
var entry = this.ledgers.current.account_root[req.account];
break;
default:
// This type not cached.
}
if (entry)
{
onDone(entry);
}
else
{
// Not cached.
// Submit request
this.request(req, function (r) {
// Got result.
switch (req.type) {
case 'account_root':
this.ledgers.current.account_root.account = r;
break;
default:
// This type not cached.
}
onDone(r);
}, onFailure);
}
}
});
// Submit a json transaction.
// done(value)
// <-> value: { 'status', status, 'result' : result, ... }
// done may be called up to 3 times.
Remote.method('submit', function (json, private_key, onDone, onFailure) {
var req = {};
req.command = 'submit';
req.json = json;
if (private_key && !this.trusted)
{
onFailure({ 'error' : 'untrustedSever', 'request' : req });
}
else
{
this.request(req, onDone, onFailure);
}
});
//
// Higher level functions.
//
// Subscribe to a server to get the current and closed ledger.
// XXX Set up routine to update on notification.
Remote.method('server_subscribe', function (onDone, onFailure) {
this.request(
{ 'command' : 'server_subscribe' },
function (r) {
this.ledger_current_index = r.ledger_current_index;
this.ledger_closed = r.ledger_closed;
this.stand_alone = r.stand_alone;
onDone();
},
onFailure
);
});
// Refresh accounts[account].seq
// done(result);
Remote.method('account_seq', function (account, onDone, onFailure) {
var account_root_entry = this.accounts[account];
if (account_root_entry && account_root_entry.seq)
{
onDone(account_root_entry.seq);
}
else
{
// Need to get the ledger entry.
this.request_ledger_entry(
{
'ledger' : this.ledger_closed,
'account_root' : account
},
function (r) {
// Extract the seqence number from the account root entry.
this.accounts[account].seq = r.seq;
onDone(r.seq);
},
onFailure
);
}
});
// A submit that fills in the sequence number.
Remote.method('submit_seq', function (onDone, onFailure) {
});
exports.Remote = Remote;
exports.remoteConfig = remoteConfig;
exports.fees = fees;
exports.accounts = accounts;
// vim:sw=2:sts=2:ts=8