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+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Event class for |CEventPump|.
+ */
+function CEvent (set, type, destObject, destMethod)
+{
+ this.set = set;
+ this.type = type;
+ this.destObject = destObject;
+ this.destMethod = destMethod;
+ this.hooks = new Array();
+
+}
+
+/**
+ * The event pump keeps a queue of pending events, processing them on-demand.
+ *
+ * You should never need to create an instance of this prototype; access the
+ * event pump through |client.eventPump|. Most code should only need to use the
+ * |addHook|, |getHook| and |removeHookByName| methods.
+ */
+function CEventPump (eventsPerStep)
+{
+ /* event routing stops after this many levels, safety valve */
+ this.MAX_EVENT_DEPTH = 50;
+ /* When there are this many 'used' items in a queue, always clean up. At
+ * this point it is MUCH more effecient to remove a block than a single
+ * item (i.e. removing 1000 is much much faster than removing 1 item 1000
+ * times [1]).
+ */
+ this.FORCE_CLEANUP_PTR = 1000;
+ /* If there are less than this many items in a queue, clean up. This keeps
+ * the queue empty normally, and is not that ineffecient [1].
+ */
+ this.MAX_AUTO_CLEANUP_LEN = 100;
+ this.eventsPerStep = eventsPerStep;
+ this.queue = new Array();
+ this.queuePointer = 0;
+ this.bulkQueue = new Array();
+ this.bulkQueuePointer = 0;
+ this.hooks = new Array();
+
+ /* [1] The delay when removing items from an array (with unshift or splice,
+ * and probably most operations) is NOT perportional to the number of items
+ * being removed, instead it is proportional to the number of items LEFT.
+ * Because of this, it is better to only remove small numbers of items when
+ * the queue is small (MAX_AUTO_CLEANUP_LEN), and when it is large remove
+ * only large chunks at a time (FORCE_CLEANUP_PTR), reducing the number of
+ * resizes being done.
+ */
+}
+
+CEventPump.prototype.onHook =
+function ep_hook(e, hooks)
+{
+ var h;
+
+ if (typeof hooks == "undefined")
+ hooks = this.hooks;
+
+ hook_loop:
+ for (h = hooks.length - 1; h >= 0; h--)
+ {
+ if (!hooks[h].enabled ||
+ !matchObject (e, hooks[h].pattern, hooks[h].neg))
+ continue hook_loop;
+
+ e.hooks.push(hooks[h]);
+ try
+ {
+ var rv = hooks[h].f(e);
+ }
+ catch(ex)
+ {
+ dd("hook #" + h + " '" +
+ ((typeof hooks[h].name != "undefined") ? hooks[h].name :
+ "") + "' had an error!");
+ dd(formatException(ex));
+ }
+ if ((typeof rv == "boolean") &&
+ (rv == false))
+ {
+ dd("hook #" + h + " '" +
+ ((typeof hooks[h].name != "undefined") ? hooks[h].name :
+ "") + "' stopped hook processing.");
+ return true;
+ }
+ }
+
+ return false;
+}
+
+/**
+ * Adds an event hook to be called when matching events are processed.
+ *
+ * All hooks should be given a meaningful name, to aid removal and debugging.
+ * For plugins, an ideal technique for the name is to use |plugin.id| as a
+ * prefix (e.g. <tt>plugin.id + "-my-super-hook"</tt>).
+ *
+ * @param f The function to call when an event matches |pattern|.
+ * @param name A unique name for the hook. Used for removing the hook and
+ * debugging.
+ * @param neg Optional. If specified with a |true| value, the hook will be
+ * called for events *not* matching |pattern|. Otherwise, the hook
+ * will be called for events matching |pattern|.
+ * @param enabled Optional. If specified, sets the initial enabled/disabled
+ * state of the hook. By default, hooks are enabled. See
+ * |getHook|.
+ * @param hooks Internal. Do not use.
+ */
+CEventPump.prototype.addHook =
+function ep_addhook(pattern, f, name, neg, enabled, hooks)
+{
+ if (typeof hooks == "undefined")
+ hooks = this.hooks;
+
+ if (typeof f != "function")
+ return false;
+
+ if (typeof enabled == "undefined")
+ enabled = true;
+ else
+ enabled = Boolean(enabled);
+
+ neg = Boolean(neg);
+
+ var hook = {
+ pattern: pattern,
+ f: f,
+ name: name,
+ neg: neg,
+ enabled: enabled
+ };
+
+ hooks.push(hook);
+
+ return hook;
+
+}
+
+/**
+ * Finds and returns data about a named event hook.
+ *
+ * You can use |getHook| to change the enabled state of an existing event hook:
+ * <tt>client.eventPump.getHook(myHookName).enabled = false;</tt>
+ * <tt>client.eventPump.getHook(myHookName).enabled = true;</tt>
+ *
+ * @param name The unique hook name to find and return data about.
+ * @param hooks Internal. Do not use.
+ * @returns If a match is found, an |Object| with properties matching the
+ * arguments to |addHook| is returned. Otherwise, |null| is returned.
+ */
+CEventPump.prototype.getHook =
+function ep_gethook(name, hooks)
+{
+ if (typeof hooks == "undefined")
+ hooks = this.hooks;
+
+ for (var h in hooks)
+ if (hooks[h].name.toLowerCase() == name.toLowerCase())
+ return hooks[h];
+
+ return null;
+
+}
+
+/**
+ * Removes an existing event hook by its name.
+ *
+ * @param name The unique hook name to find and remove.
+ * @param hooks Internal. Do not use.
+ * @returns |true| if the hook was found and removed, |false| otherwise.
+ */
+CEventPump.prototype.removeHookByName =
+function ep_remhookname(name, hooks)
+{
+ if (typeof hooks == "undefined")
+ hooks = this.hooks;
+
+ for (var h in hooks)
+ if (hooks[h].name.toLowerCase() == name.toLowerCase())
+ {
+ arrayRemoveAt (hooks, h);
+ return true;
+ }
+
+ return false;
+
+}
+
+CEventPump.prototype.removeHookByIndex =
+function ep_remhooki(idx, hooks)
+{
+ if (typeof hooks == "undefined")
+ hooks = this.hooks;
+
+ return arrayRemoveAt (hooks, idx);
+
+}
+
+CEventPump.prototype.addEvent =
+function ep_addevent (e)
+{
+ e.queuedAt = new Date();
+ this.queue.push(e);
+ return true;
+}
+
+CEventPump.prototype.addBulkEvent =
+function ep_addevent (e)
+{
+ e.queuedAt = new Date();
+ this.bulkQueue.push(e);
+ return true;
+}
+
+CEventPump.prototype.routeEvent =
+function ep_routeevent (e)
+{
+ var count = 0;
+
+ this.currentEvent = e;
+
+ e.level = 0;
+ while (e.destObject)
+ {
+ e.level++;
+ this.onHook (e);
+ var destObject = e.destObject;
+ e.currentObject = destObject;
+ e.destObject = (void 0);
+
+ switch (typeof destObject[e.destMethod])
+ {
+ case "function":
+ if (1)
+ try
+ {
+ destObject[e.destMethod] (e);
+ }
+ catch (ex)
+ {
+ if (typeof ex == "string")
+ {
+ dd ("Error routing event " + e.set + "." +
+ e.type + ": " + ex);
+ }
+ else
+ {
+ dd ("Error routing event " + e.set + "." +
+ e.type + ": " + dumpObjectTree(ex) +
+ " in " + e.destMethod + "\n" + ex);
+ if ("stack" in ex)
+ dd(ex.stack);
+ }
+ }
+ else
+ destObject[e.destMethod] (e);
+
+ if (count++ > this.MAX_EVENT_DEPTH)
+ throw "Too many events in chain";
+ break;
+
+ case "undefined":
+ //dd ("** " + e.destMethod + " does not exist.");
+ break;
+
+ default:
+ dd ("** " + e.destMethod + " is not a function.");
+ }
+
+ if ((e.type != "event-end") && (!e.destObject))
+ {
+ e.lastSet = e.set;
+ e.set = "eventpump";
+ e.lastType = e.type;
+ e.type = "event-end";
+ e.destMethod = "onEventEnd";
+ e.destObject = this;
+ }
+
+ }
+
+ delete this.currentEvent;
+
+ return true;
+
+}
+
+CEventPump.prototype.stepEvents =
+function ep_stepevents()
+{
+ var i = 0;
+ var st, en, e;
+
+ st = new Date();
+ while (i < this.eventsPerStep)
+ {
+ if (this.queuePointer >= this.queue.length)
+ break;
+
+ e = this.queue[this.queuePointer++];
+
+ if (e.type == "yield")
+ break;
+
+ this.routeEvent(e);
+ i++;
+ }
+ while (i < this.eventsPerStep)
+ {
+ if (this.bulkQueuePointer >= this.bulkQueue.length)
+ break;
+
+ e = this.bulkQueue[this.bulkQueuePointer++];
+
+ if (e.type == "yield")
+ break;
+
+ this.routeEvent(e);
+ i++;
+ }
+ en = new Date();
+
+ // i == number of items handled this time.
+ // We only want to do this if we handled at least 25% of our step-limit
+ // and if we have a sane interval between st and en (not zero).
+ if ((i * 4 >= this.eventsPerStep) && (en - st > 0))
+ {
+ // Calculate the number of events that can be processed in 400ms.
+ var newVal = (400 * i) / (en - st);
+
+ // If anything skews it majorly, limit it to a minimum value.
+ if (newVal < 10)
+ newVal = 10;
+
+ // Adjust the step-limit based on this "target" limit, but only do a
+ // 25% change (underflow filter).
+ this.eventsPerStep += Math.round((newVal - this.eventsPerStep) / 4);
+ }
+
+ // Clean up if we've handled a lot, or the queue is small.
+ if ((this.queuePointer >= this.FORCE_CLEANUP_PTR) ||
+ (this.queue.length <= this.MAX_AUTO_CLEANUP_LEN))
+ {
+ this.queue.splice(0, this.queuePointer);
+ this.queuePointer = 0;
+ }
+
+ // Clean up if we've handled a lot, or the queue is small.
+ if ((this.bulkQueuePointer >= this.FORCE_CLEANUP_PTR) ||
+ (this.bulkQueue.length <= this.MAX_AUTO_CLEANUP_LEN))
+ {
+ this.bulkQueue.splice(0, this.bulkQueuePointer);
+ this.bulkQueuePointer = 0;
+ }
+
+ return i;
+
+}
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