NMS: front: Prototyping of new generic poller

Not used yet

1 files changed, 142 insertions, 0 deletions

diff --git a/web/nms.gathering.org/js/nms-data.js b/web/nms.gathering.org/js/nms-data.js
new file mode 100644
index 0000000..4dda8e4
--- /dev/null
+++ b/web/nms.gathering.org/js/nms-data.js
@@ -0,0 +1,142 @@
+"use strict";
+
+/**************************************************************************
+ *                                                                        *
+ * THIS IS WORK IN PROGRESS, NOT CURRENTLY USED!                          *
+ *                                                                        *
+ * It WILL eventually replace large chunks of nms.js. But we're not there *
+ * yet.                                                                   *
+ *                                                                        *
+ **************************************************************************/
+
+
+/*
+ * This file/module/whatever is an attempt to gather all data collection in
+ * one place.
+ *
+ * It is work in progress.
+ *
+ * The basic idea is to have all periodic data updates unified here, with
+ * stats, tracking of "ajax overflows" and general-purpose error handling
+ * and callbacks and whatnot, instead of all the custom stuff that we
+ * started out with.
+ *
+ * Public interfaces:
+ * nmsData.data[name] - actual data
+ * nmsData.registerSource() - add a source, will be polled periodicall
+ * nmsData.updateSource() - issue a one-off update, outside of whatever
+ * 			    periodic polling might take place
+ */
+
+
+var nmsData = nmsData || {
+	data: {}, // Actual data
+	sources: {},
+
+	// Tracks metdata (hashes/timestamps)
+	poller: {
+		hashes:{}, 
+		time:{}
+	},
+	// setInterval handlers (and more?)
+	pollers: {
+
+	},
+	stats: {
+		identicalFetches:0,
+		outstandingAjaxRequests:0,
+		ajaxOverflow:0,
+		pollClears:0,
+		pollSets:0
+	}
+};
+
+/*
+ * Register a source.
+ *
+ * name: "Local" name. Maps to nmsData.data[name]
+ * remotename: The primary attribute to get from the remote source.
+ * target: URL of the source
+ * cb: Optional callback
+ * cbdata: Optional callback data
+ *
+ * Update frequency will (eventually) be handled by parsing max-age from
+ * the source. Right now it's hardcoded.
+ *
+ * FIXME: Should be unified with nmsTimers() somehow.
+ */
+nmsData.registerSource = function(name, remotename, target, cb, cbdata) {
+	if(this.pollers[name]) {
+		clearInterval(this.pollers[name]);
+		this.stats.pollClears++;
+	}
+	this.sources[name] = { remotename: remotename, target: target, cb: cb, cbdata: cbdata };
+	this.pollers[name] = setInterval(function(){nmsData.updateSource(name)}, 1000);
+	this.stats.pollSets++;
+}
+
+/*
+ * Updates a source.
+ *
+ * Called on interval, but can also be used to update a source after a
+ * known action that updates the underlying data (e.g: update comments
+ * after a comment is posted).
+ */
+nmsData.updateSource = function(name) {
+	nmsData.genericUpdater(name,
+		this.sources[name].remotename,
+		this.sources[name].target,
+		this.sources[name].cb,
+		this.sources[name].cbdata);
+}
+
+/*
+ * Updates nmsData.data[name] with data fetched from remote target in
+ * variable "remotename". If a callback is provided, it is called with
+ * argument meh.
+ *
+ * This also populates nms.pollers[name] with the server-provided hash.
+ * Only if a change is detected is the callback issued.
+ *
+ * Used by registerSource.
+ */
+nmsData.genericUpdater = function(name, remotename, target, cb, meh) {
+	if (this.stats.outstandingAjaxRequests > 5) {
+		this.stats.ajaxOverflow++;
+		return;
+	}
+	this.stats.outstandingAjaxRequests++;
+	var now = "";
+	/*
+	if (nms.now != false)
+		now = "now=" + nms.now;
+	if (now != "") {
+		if (target.match("\\?"))
+			now = "&" + now;
+		else
+			now = "?" + now;
+	}
+	*/
+	$.ajax({
+		type: "GET",
+		url: target + now,
+		dataType: "text",
+		success: function (data, textStatus, jqXHR) {
+			var  indata = JSON.parse(data);
+			if (nmsData.poller.hashes[name] != indata['hash']) {
+				nmsData.data[name] = indata[remotename];
+				nmsData.poller.hashes[name] = indata['hash'];
+				nmsData.poller.time[name] = indata['time'];
+				if (cb != undefined) {
+					cb(meh);
+				}
+			} else {
+				nmsData.stats.identicalFetches++;
+			}
+		},
+		complete: function(jqXHR, textStatus) {
+			nmsData.stats.outstandingAjaxRequests--;
+			//updateAjaxInfo();
+		}
+	});
+};