luci-app-statistics: rearrange graph display

- Add a per-plugin overview tab that contains the (non-detail) graphs of
   each plugin instance, similar to the old Lua based implementation
 - Numerically order plugin instances starting with numbers
 - Avoid multiple renderings of the same graphs
 - Fix legend of tcpconns graphs
 - Move cpufreq distribution and transition charts to detail tabs

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

applications/luci-app-statistics/htdocs/luci-static/resources/statistics/rrdtool.js

@@ -259,7 +259,17 @@ return L.Class.extend({
 	},
 
 	pluginInstances: function(hostInstance, pluginName) {
-		return Object.keys((rrdtree[hostInstance] || {})[pluginName] || {}).sort();
+		return Object.keys((rrdtree[hostInstance] || {})[pluginName] || {}).sort(function(a, b) {
+			var x = a.match(/^(\d+)\b/),
+			    y = b.match(/^(\d+)\b/);
+
+			if (!x != !y)
+				return !x - !y;
+			else if (x && y && x[0] != y[0])
+				return +x[0] - +y[0];
+			else
+				return a > b;
+		});
 	},
 
 	dataTypes: function(hostInstance, pluginName, pluginInstance) {
@@ -279,6 +289,21 @@ return L.Class.extend({
 		return (graphdefs[pluginName] != null);
 	},
 
+	hasInstanceDetails: function(hostInstance, pluginName, pluginInstance) {
+		var def = graphdefs[pluginName];
+
+		if (!def || typeof(def.rrdargs) != 'function')
+			return false;
+
+		var optlist = this._forcelol(def.rrdargs(this, hostInstance, pluginName, pluginInstance, null, false));
+
+		for (var i = 0; i < optlist.length; i++)
+			if (optlist[i].detail)
+				return true;
+
+		return false;
+	},
+
 	_mkpath: function(host, plugin, plugin_instance, dtype, data_instance) {
 		var path = host + '/' + plugin;
 
@@ -304,7 +329,7 @@ return L.Class.extend({
 		return L.isObject(list[0]) ? list : [ list ];
 	},
 
-	_rrdtool: function(def, rrd, timespan, width, height) {
+	_rrdtool: function(def, rrd, timespan, width, height, cache) {
 		var cmdline = [
 			'graph', '-', '-a', 'PNG',
 			'-s', 'NOW-%s'.format(timespan || this.opts.timespan),
@@ -322,6 +347,15 @@ return L.Class.extend({
 			cmdline.push(opt);
 		}
 
+		if (L.isObject(cache)) {
+			var key = sfh(cmdline.join('\0'));
+
+			if (!cache.hasOwnProperty(key))
+				cache[key] = fs.exec_direct('/usr/bin/rrdtool', cmdline, 'blob', true);
+
+			return cache[key];
+		}
+
 		return fs.exec_direct('/usr/bin/rrdtool', cmdline, 'blob', true);
 	},
 
@@ -682,7 +716,7 @@ return L.Class.extend({
 		return defs;
 	},
 
-	render: function(plugin, plugin_instance, is_index, hostname, timespan, width, height) {
+	render: function(plugin, plugin_instance, is_index, hostname, timespan, width, height, cache) {
 		var pngs = [];
 
 		/* check for a whole graph handler */
@@ -705,7 +739,7 @@ return L.Class.extend({
 					/* render all diagrams */
 					for (var j = 0; j < diagrams.length; j++) {
 						/* exec */
-						_images[i][j] = this._rrdtool(diagrams[j], null, timespan, width, height);
+						_images[i][j] = this._rrdtool(diagrams[j], null, timespan, width, height, cache);
 					}
 				}
 			}

applications/luci-app-statistics/htdocs/luci-static/resources/statistics/rrdtool/definitions/cpufreq.js

@@ -22,6 +22,7 @@ return L.Class.extend({
 
 	    if (uci.get("luci_statistics", "collectd_cpufreq", "ExtraItems")) {
 			var transitions = {
+				detail: true,
 				title: "%H: Frequency transitions - core %pi",
 				alt_autoscale: true,
 				vlabel: "Transitions",
@@ -35,6 +36,7 @@ return L.Class.extend({
 			};
 
 			var percentage = {
+				detail: true,
 				title: "%H: Frequency distribution - core %pi",
 				alt_autoscale: true,
 				vlabel: "Percent",

applications/luci-app-statistics/htdocs/luci-static/resources/statistics/rrdtool/definitions/tcpconns.js

@@ -21,6 +21,11 @@ return L.Class.extend({
 					options: {
 						load__ESTABLISHED: { title: "%di", noarea: true }
 					}
+				},
+				options: {
+					tcp_connections__value: {
+						title: '%di'
+					}
 				}
 			}
 		};

applications/luci-app-statistics/htdocs/luci-static/resources/view/statistics/graphs.js

@@ -14,8 +14,11 @@ return L.view.extend({
 
 	updatePluginTab: function(host, span, time, ev) {
 		var container = ev.target,
+		    width = Math.max(200, container.offsetWidth - 100),
 		    plugin = ev.detail.tab,
-		    plugin_instances = rrdtool.pluginInstances(host.value, plugin);
+		    render_instances = [],
+		    plugin_instances = rrdtool.pluginInstances(host.value, plugin),
+		    cache = {};
 
 		activePlugin = plugin;
 
@@ -25,20 +28,41 @@ return L.view.extend({
 			])
 		]);
 
-		Promise.all(plugin_instances.map(function(instance) {
+		for (var i = 0; i < plugin_instances.length; i++)
-			return rrdtool.render(plugin, instance, false, host.value, span.value, Math.max(200, container.offsetWidth - 100));
+			if (rrdtool.hasInstanceDetails(host.value, plugin, plugin_instances[i]))
+				render_instances.push(plugin_instances[i]);
+
+		if (render_instances.length == 0 || render_instances.length > 1)
+			render_instances.unshift('-');
+
+		Promise.all(render_instances.map(function(instance) {
+			if (instance == '-') {
+				var tasks = [];
+
+				for (var i = 0; i < plugin_instances.length; i++)
+					tasks.push(rrdtool.render(plugin, plugin_instances[i], true, host.value, span.value, width, null, cache));
+
+				return Promise.all(tasks).then(function(blobs) {
+					return Array.prototype.concat.apply([], blobs);
+				});
+			}
+			else {
+				return rrdtool.render(plugin, instance, false, host.value, span.value, width, null, cache);
+			}
 		})).then(function(blobs) {
 			var multiple = blobs.length > 1;
 
 			L.dom.content(container, E('div', {}, blobs.map(function(blobs, i) {
-				var plugin_instance = plugin_instances[i];
+				var plugin_instance = i ? plugin_instances[i-1] : plugin_instances.join('|'),
+				    title = '%s: %s'.format(rrdtool.pluginTitle(plugin), i ? plugin_instance : _('Overview'));
 
 				return E('div', {
 					'class': 'center',
 					'data-tab': multiple ? i : null,
-					'data-tab-title': multiple ? '%s: %s'.format(rrdtool.pluginTitle(plugin), plugin_instances[i]) : null,
+					'data-tab-title': multiple ? title : null,
 					'data-plugin': plugin,
-					'data-plugin-instance': plugin_instances[i],
+					'data-plugin-instance': plugin_instance,
+					'data-is-index': i ? null : true,
 					'cbi-tab-active': function(ev) { activeInstance = ev.target.getAttribute('data-plugin-instance') }
 				}, blobs.map(function(blob) {
 					return E('img', {
@@ -50,7 +74,7 @@ return L.view.extend({
 			if (multiple)
 				ui.tabs.initTabGroup(container.lastElementChild.childNodes);
 			else
-				activeInstance = plugin_instances[0];
+				activeInstance = plugin_instances.join('|');
 		});
 	},
 
@@ -87,9 +111,15 @@ return L.view.extend({
 	},
 
 	refreshGraphs: function(host, span, time, container) {
-		var div = document.querySelector('[data-plugin="%s"][data-plugin-instance="%s"]'.format(activePlugin, activeInstance || ''));
+		var div = document.querySelector('[data-plugin="%s"][data-plugin-instance="%s"]'.format(activePlugin, activeInstance || '')),
+		    width = Math.max(200, container.offsetWidth - 100),
+		    render_instances = activeInstance.split(/\|/);
 
-		return rrdtool.render(activePlugin, activeInstance || '', false, host.value, span.value, Math.max(200, container.offsetWidth - 100)).then(function(blobs) {
+		return Promise.all(render_instances.map(function(render_instance) {
+			return rrdtool.render(activePlugin, render_instance || '', div.hasAttribute('data-is-index'), host.value, span.value, width);
+		})).then(function(blobs) {
+			return Array.prototype.concat.apply([], blobs);
+		}).then(function(blobs) {
 			return Promise.all(blobs.map(function(blob) {
 				return new Promise(function(resolveFn, rejectFn) {
 					var img = E('img', { 'src': URL.createObjectURL(new Blob([blob], { type: 'image/png' })) });