Initial checkin of Metrics LineGraph Component

Commit creates the first version of a reusable LineGraph component, which graphs
the results of cockroach time series query.

It's a bit bare-bones in appearance, but is already reusable and should provide
a good foundation for building our admin monitor pages.

resource/ui/css/graph.css

@@ -0,0 +1,19 @@
+.line {
+  fill: none;
+  stroke-width: 1.5px;
+}
+
+.line0 {
+  stroke:red;
+}
+
+.line1 {
+  stroke:blue;
+}
+
+.axis path,
+.axis line {
+  fill: none;
+  stroke: #000;
+  shape-rendering: crispEdges;
+}

resource/ui/index.html

@@ -23,6 +23,7 @@
     <link href='https://fonts.googleapis.com/css?family=Source+Sans+Pro:400,900|Source+Code+Pro' rel='stylesheet' type='text/css'>
     <link rel="stylesheet" href="/css/app.css">
     <link rel="stylesheet" href="/css/rest_explorer.css"> <!-- TODO(andybons): @import-like behavior -->
+    <link rel="stylesheet" href="/css/graph.css"> <!-- TODO(andybons): @import-like behavior -->
     <script src="/js/libs/d3/3.3.5/d3.min.js"></script>
     <script src="/js/libs/mithriljs/0.2.0/mithril.min.js"></script>
     <title>Cockroach</title>
@@ -32,6 +33,7 @@
       <a href="#/" class="appNav-link appNav-homeName">Cockroach</a>
       <a href="#/monitor" class="appNav-link">Monitor</a>
       <a href="#/rest-explorer" class="appNav-link">REST Explorer</a>
+      <a href="#/graph" class="appNav-link">Graph</a>
     </header>
     <div id="root" class="fullHeightContainer"></div>
     <script src="/js/app.js"></script>

resource/ui/ts/app.ts

@@ -2,6 +2,7 @@
 /// <reference path="typings/mithriljs/mithril.d.ts" />
 /// <reference path="pages/rest_explorer.ts" />
 /// <reference path="pages/monitor.ts" />
+/// <reference path="pages/graph.ts" />
 
 // Author: Andrew Bonventre (andybons@gmail.com)
 // Author: Bram Gruneir (bramgruneir@gmail.com)
@@ -10,4 +11,5 @@ m.route.mode = "hash";
 m.route(document.getElementById("root"), "/rest-explorer", {
     "/rest-explorer": AdminViews.RestExplorer.Page,
     "/monitor": AdminViews.Monitor.Page,
+    "/graph": AdminViews.Graph.Page,
 });

resource/ui/ts/components/metrics.ts

@@ -0,0 +1,142 @@
+// source: components/metrics.ts
+/// <reference path="../typings/mithriljs/mithril.d.ts" />
+/// <reference path="../typings/d3/d3.d.ts" />
+/// <reference path="../models/timeseries.ts" />
+
+/** 
+ * Components defines reusable components which may be used on multiple pages,
+ * or multiple times on the same page.
+ */
+module Components {
+    /**
+     * Metrics contains components used to display metrics data.
+     */
+    export module Metrics {
+        /**
+         * LineGraph displays a line graph of the data returned from a time
+         * series query.
+         */
+        export module LineGraph {
+            /**
+             * ViewModel is the model for a specific LineGraph - in addition to
+             * the backing Query object, it also maintains other per-component
+             * display options.
+             */
+            interface ViewModel {
+                width:number;
+                height:number;
+                query:Models.Metrics.Query;
+                key?:number;
+            }
+
+            /**
+             * Controller maintains the functionality needed for a single
+             * LineGraph.
+             */
+            class Controller {
+                margin = {top:20, right:20, bottom: 30, left:60};
+
+                // Width and height of the area containing the graph lines.
+                private chartWidth: number;
+                private chartHeight: number;
+
+                // Scales and Axes.
+                private timeScale = d3.time.scale();
+                private valScale = d3.scale.linear(); 
+                private timeAxis = d3.svg.axis().scale(this.timeScale).orient("bottom");
+                private valAxis = d3.svg.axis().scale(this.valScale).orient("left");
+
+                // Line data interpreter.
+                private line = d3.svg.line()
+                    .x((d) => this.timeScale(d.timestamp_nanos/1.0e6))
+                    .y((d) => this.valScale(d.value));
+
+                private color = d3.scale.category10();
+
+                // Query results.
+                results;
+                error = m.prop("");
+
+                constructor(public vm:ViewModel) {
+                    this.chartWidth = vm.width - this.margin.left - this.margin.right;
+                    this.chartHeight = vm.height - this.margin.top - this.margin.bottom;
+
+                    // Initialize axes.
+                    this.timeScale.range([0, this.chartWidth]);
+                    this.valScale.range([this.chartHeight, 0]);
+
+                    // Query for initial result set.
+                    this.results = vm.query.query().then(null, this.error);
+                }
+
+                /** drawGraph gets direct access to the svg element of the graph
+                 * after it is added to DOM. When the SVG element is first
+                 * initialized, we use D3 to draw the data from the query.
+                 */
+                drawGraph = (element:Element, isInitialized:boolean, context:any) => {
+                    if (!isInitialized) {
+                        var data:Models.Metrics.QueryResult[] = this.results().results;
+
+                        // Scale value axis based on data.
+                        this.valScale.domain([
+                                d3.min(data, (d) => d3.min(d.datapoints, (dp) => dp.value)),
+                                d3.max(data, (d) => d3.max(d.datapoints, (dp) => dp.value))
+                        ]);
+                        this.timeScale.domain([this.vm.query.start, this.vm.query.end]);
+
+                        var svg = d3.select(element)
+                        .attr("width", this.vm.width)
+                        .attr("height", this.vm.height)
+                        .append("g")
+                        .attr("transform", 
+                                "translate(" + this.margin.left + "," + this.margin.top + ")");
+                        svg.append("g")
+                            .attr("class", "x axis")
+                            .attr("transform", "translate(0," + this.chartHeight + ")") 
+                            .call(this.timeAxis);
+                        svg.append("g")
+                            .attr("class", "y axis")
+                            .call(this.valAxis);
+
+                        // append lines
+                        svg.selectAll(".line")
+                            .data(data)
+                            .enter()
+                            .append("path")
+                            .attr("class", (d,i) => "line line" + i)
+                            .attr("d", (d) => this.line(d.datapoints))
+                            .style("stroke", (d) => this.color(d.name));
+                    }
+                }
+            }
+
+            export function controller(model:ViewModel) {
+                return new Controller(model);
+            }
+
+            export function view(ctrl) {
+                if (ctrl.error()) {
+                    return m("", "error loading graph:" + ctrl.error());
+                } else if (ctrl.results()) {
+                    return m("svg.graph", {config: ctrl.drawGraph}); 
+                } else {
+                    return m("", "loading...");
+                }
+            }
+
+            /**
+             * create instantiates a single instance of the LineGraph component
+             * which displays data from the supplied Metrics.Query object.
+             *
+             * @param key The key param is used by mithril to track objects in lists which can be rearranged.
+             */
+            export function create(width:number, height:number, query:Models.Metrics.Query, key?:number){
+                var vm:ViewModel = {width:width, height:height, query:query}
+                if (!!key) {
+                    vm.key = key;
+                }
+                return m.component(LineGraph, vm)
+            }
+        }
+    }
+}