var makeRequest = function(url, args, secure, callback) {
var maxlen = 2048;
var path = url + "?" + qs.stringify(args);
if (path.length > maxlen) {
throw new Error("Request too long for google to handle (2048 characters).");
}
var options = {
uri: (secure ? 'https' : 'http') + '://' + path
};
if (GSV.config('proxy')) options.proxy = GSV.config('proxy');
if (typeof callback === 'function') {
request(options, function (error, res, data) {
if (error) {
return callback(error);
}
if (res.statusCode === 200) {
return callback(null, data);
}
return callback(new Error("Response status code: " + res.statusCode), data);
});
} else if(typeof callback == 'string') {
distfile = callback;
if (GSV.config('dist')) distfile = GSV.config('dist') + "/" + callback;
//TODO: async version?
request(options).pipe(fs.createWriteStream(distfile));
} else {
// console.log(typeof callback);
}
return options.uri;
};
exports.persist = function (opts) {
var db = this;
var per = new events.EventEmitter();
per.TO = 1;
per.FROM = 2;
per.BOTH = 3;
per.opts = { changes: {}, to: {}, from: {} }; // init to prevent undefined errors
per.config = function (opts) {
for (var i in opts) {
per.opts[i] = opts[i];
}
};
if (opts) {
per.config(opts);
}
per.startingTimeout = opts && opts.startingTimeout ? opts.startingTimeout: STARTING_RETRY_TIMEOUT;
per.maxTimeout = opts && opts.maxTimeout ? opts.maxTimeout: MAX_TIMEOUT;
per.backoff = opts && opts.backoff ? opts.backoff : BACKOFF;
per.connected = false;
var vars = {
retryTimeout: per.startingTimeout,
replicating: false,
connected: false
};
var state = {}, replicating = false;
state[per.TO] = vars;
state[per.FROM] = clone(vars);
function setup() {
return db.info().then(function (info) {
var d = per.opts.changes,
opts = { since: info.update_seq, live: true };
if (d.opts) {
opts = merge(opts, d.opts);
}
per.changes = db.changes(opts);
});
}
function addListeners(emitter, listeners) {
listeners.forEach(function (listener) {
var fn = emitter[listener['method']];
fn.call(emitter, listener['event'], listener['listener']);
});
}
// TODO: override window.XMLHttpRequest to test the following
/* istanbul ignore next */
function backoff(retryTimeout) {
return Math.min(per.maxTimeout, Math.floor(retryTimeout * per.backoff)); // exponential backoff
}
function disconnect() {
per.connected = false;
per.emit('disconnect');
}
// TODO: override window.XMLHttpRequest to test the following
/* istanbul ignore next */
function onError(err, direction) {
if (err.status === 405) { // unknown error
var s = state[direction];
s.connected = false;
s.retryTimeout = backoff(s.retryTimeout);
setTimeout(direction === per.TO ? replicateTo : replicateFrom, s.retryTimeout);
if (per.connected) {
disconnect();
}
}
}
function connect() {
per.connected = true;
per.emit('connect');
}
function onConnect(direction) {
var s = state[direction];
s.connected = true;
s.retryTimeout = per.startingTimeout;
removeConnectListeners(direction);
if (state[per.TO].connected && state[per.FROM].connected) {
connect();
}
}
function removeConnectListeners(direction) {
var emitter = direction === per.TO ? per.to : per.from;
var connectListener = state[direction].connectListener;
emitter.removeListener('change', connectListener);
emitter.removeListener('complete', connectListener);
emitter.removeListener('uptodate', connectListener);
}
function registerListeners(emitter, direction, listeners) {
// TODO: override window.XMLHttpRequest to test the following
/* istanbul ignore next */
emitter.on('error', function (err) {
onError(err, direction);
});
state[direction].connectListener = function () {
onConnect(direction);
};
var connectListener = state[direction].connectListener;
emitter.once('change', connectListener)
.once('complete', connectListener)
.once('uptodate', connectListener);
if (listeners) {
addListeners(emitter, listeners);
}
}
function replicate(direction) {
var d = direction === per.TO ? per.opts.to : per.opts.from,
method = direction === per.TO ? db.replicate.to : db.replicate.from;
var opts = { live: true }, url = d.url ? d.url : per.opts.url;
if (d.opts) {
opts = merge(opts, d.opts);
}
if (direction === per.TO) {
cancelTo();
} else {
cancelFrom();
}
var emitter = method(url, opts, d.onErr);
if (direction === per.TO) {
per.to = emitter;
} else {
per.from = emitter;
}
registerListeners(emitter, direction, d.listeners);
}
function replicateTo() {
replicate(per.TO);
}
function replicateFrom() {
replicate(per.FROM);
}
function startReplication(direction) {
if (!state[per.TO].replicating && (direction === per.BOTH || direction === per.TO)) {
state[per.TO].replicating = true;
replicateTo();
}
if (!state[per.FROM].replicating && (direction === per.BOTH || direction === per.FROM)) {
state[per.FROM].replicating = true;
replicateFrom();
}
}
per.start = function (direction) {
direction = direction ? direction : per.BOTH;
if (!replicating) {
return setup().then(function () {
replicating = true;
startReplication(direction);
});
} else {
return new utils.Promise(function () {
startReplication(direction);
});
}
};
function cancelChanges() {
if (per.changes) {
per.changes.cancel();
}
}
function cancelTo() {
if (per.to) {
per.to.cancel();
}
}
function cancelFrom() {
if (per.from) {
per.from.cancel();
}
}
per.cancel = function () {
cancelChanges();
cancelTo();
cancelFrom();
};
per.stop = function (direction) {
direction = direction ? direction : per.BOTH;
if (direction === per.BOTH || direction === per.TO) {
state[per.TO].replicating = false;
state[per.TO].connected = false;
cancelTo();
}
if (direction === per.BOTH || direction === per.FROM) {
state[per.FROM].replicating = false;
state[per.FROM].connected = false;
cancelFrom();
}
if (!state[per.TO].replicating && !state[per.FROM].replicating) {
cancelChanges();
}
disconnect();
};
if (opts && !opts.manual) {
per.start();
}
return per;
};