telebit-relay.js/lib/device-tracker.js

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'use strict';
var Devices = module.exports;
Devices.add = function (store, servername, newDevice) {
if (!store[servername]) {
store[servername] = [];
}
var devices = store[servername];
devices.push(newDevice);
};
Devices.alias = function (store, servername, alias) {
if (!store[servername]) {
store[servername] = [];
}
if (!store[servername]._primary) {
store[servername]._primary = servername;
}
if (!store[servername].aliases) {
store[servername].aliases = {};
}
store[alias] = store[servername];
store[servername].aliases[alias] = true;
};
Devices.remove = function (store, servername, device) {
var devices = store[servername] || [];
var index = devices.indexOf(device);
if (index < 0) {
console.warn('attempted to remove non-present device', device.deviceId, 'from', servername);
return null;
}
return devices.splice(index, 1)[0];
};
Devices.list = function (store, servername) {
// efficient lookup first
if (store[servername] && store[servername].length) {
return store[servername]._primary && store[store[servername]._primary] || store[servername];
}
// There wasn't an exact match so check any of the wildcard domains, sorted longest
// first so the one with the biggest natural match with be found first.
var deviceList = [];
Object.keys(store).filter(function (pattern) {
return pattern[0] === '*' && store[pattern].length;
}).sort(function (a, b) {
return b.length - a.length;
}).some(function (pattern) {
// '.example.com' = '*.example.com'.split(1)
var subPiece = pattern.slice(1);
// '.com' = 'sub.example.com'.slice(-4)
// '.example.com' = 'sub.example.com'.slice(-12)
if (subPiece === servername.slice(-subPiece.length)) {
console.log('[Devices.list] "'+servername+'" matches "'+pattern+'"');
deviceList = store[pattern];
// Devices.alias(store, '*.example.com', 'sub.example.com'
// '*.example.com' retrieves a reference to 'example.com'
// and this reference then also referenced by 'sub.example.com'
// Hence this O(n) check is replaced with the O(1) check above
Devices.alias(store, pattern, servername);
return true;
}
});
return deviceList;
};
Devices.exist = function (store, servername) {
return !!(Devices.list(store, servername).length);
};
Devices.next = function (store, servername) {
var devices = Devices.list(store, servername);
var device;
if (devices._index >= devices.length) {
devices._index = 0;
}
device = devices[devices._index || 0];
devices._index = (devices._index || 0) + 1;
return device;
};