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var Timer = process.binding('timer').Timer;
var assert = process.assert;
/*
* To enable debug statements for the timers do NODE_DEBUG=8 ./node script.js
*/
var debugLevel = parseInt(process.env.NODE_DEBUG, 16);
function debug () {
if (debugLevel & 0x8) {
require('util').error.apply(this, arguments);
}
}
// IDLE TIMEOUTS
//
// Because often many sockets will have the same idle timeout we will not
// use one timeout watcher per item. It is too much overhead. Instead
// we'll use a single watcher for all sockets with the same timeout value
// and a linked list. This technique is described in the libev manual:
// http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#Be_smart_about_timeouts
// Object containing all lists, timers
// key = time in milliseconds
// value = list
var lists = {};
// show the most idle item
function peek (list) {
if (list._idlePrev == list) return null;
return list._idlePrev;
}
// remove the most idle item from the list
function shift (list) {
var first = list._idlePrev;
remove(first);
return first;
}
// remove a item from its list
function remove (item) {
item._idleNext._idlePrev = item._idlePrev;
item._idlePrev._idleNext = item._idleNext;
}
// remove a item from its list and place at the end.
function append (list, item) {
remove(item);
item._idleNext = list._idleNext;
item._idleNext._idlePrev = item;
item._idlePrev = list;
list._idleNext = item;
}
// the main function - creates lists on demand and the watchers associated
// with them.
function insert (item, msecs) {
item._idleStart = new Date();
item._idleTimeout = msecs;
if (!msecs) return;
var list;
if (lists[msecs]) {
list = lists[msecs];
} else {
list = new Timer();
list._idleNext = list;
list._idlePrev = list;
lists[msecs] = list;
list.callback = function () {
debug('timeout callback ' + msecs);
// TODO - don't stop and start the watcher all the time.
// just set its repeat
var now = new Date();
debug("now: " + now);
var first;
while (first = peek(list)) {
var diff = now - first._idleStart;
if (diff < msecs) {
list.again(msecs - diff);
debug(msecs + ' list wait because diff is ' + diff);
return;
} else {
remove(first);
assert(first != peek(list));
if (first._onTimeout) first._onTimeout();
}
}
debug(msecs + ' list empty');
assert(list._idleNext == list); // list is empty
list.stop();
};
}
if (list._idleNext == list) {
// if empty (re)start the timer
list.again(msecs);
}
append(list, item);
assert(list._idleNext != list); // list is not empty
}
var unenroll = exports.unenroll = function (item) {
if (item._idleNext) {
item._idleNext._idlePrev = item._idlePrev;
item._idlePrev._idleNext = item._idleNext;
var list = lists[item._idleTimeout];
// if empty then stop the watcher
//debug('unenroll');
if (list && list._idlePrev == list) {
//debug('unenroll: list empty');
list.stop();
}
}
};
// Does not start the time, just sets up the members needed.
exports.enroll = function (item, msecs) {
// if this item was already in a list somewhere
// then we should unenroll it from that
if (item._idleNext) unenroll(item);
item._idleTimeout = msecs;
item._idleNext = item;
item._idlePrev = item;
};
// call this whenever the item is active (not idle)
// it will reset its timeout.
exports.active = function (item) {
var msecs = item._idleTimeout;
if (msecs) {
var list = lists[msecs];
if (item._idleNext == item) {
insert(item, msecs);
} else {
// inline append
item._idleStart = new Date();
item._idleNext._idlePrev = item._idlePrev;
item._idlePrev._idleNext = item._idleNext;
item._idleNext = list._idleNext;
item._idleNext._idlePrev = item;
item._idlePrev = list;
list._idleNext = item;
}
}
};
// Timers
function addTimerListener (callback) {
var timer = this;
// Special case the no param case to avoid the extra object creation.
if (arguments.length > 2) {
var args = Array.prototype.slice.call(arguments, 2);
timer.callback = function () { callback.apply(timer, args); };
} else {
timer.callback = callback;
}
}
exports.setTimeout = function (callback, after) {
var timer = new Timer();
addTimerListener.apply(timer, arguments);
timer.start(after, 0);
return timer;
};
exports.setInterval = function (callback, repeat) {
var timer = new Timer();
addTimerListener.apply(timer, arguments);
timer.start(repeat, repeat ? repeat : 1);
return timer;
};
exports.clearTimeout = function (timer) {
if (timer instanceof Timer) {
timer.callback = null;
timer.stop();
}
};
exports.clearInterval = exports.clearTimeout;