An attempt at making some live graphs of relevant stats. Needs more thought.

git-svn-id: https://www.unprompted.com/svn/projects/tildefriends/trunk@3780 ed5197a5-7fde-0310-b194-c3ffbd925b24

core/client.js

@@ -8,6 +8,8 @@ var gFiles = {};
 var gApp = {files: {}};
 var gEditor;
 var gSplit;
+var gStats = {};
+var gGraph;
 
 var kErrorColor = "#dc322f";
 var kStatusColor = "#fff";
@@ -77,6 +79,7 @@ function edit() {
 		return;
 	}
 
+	closeStats();
 	gSplit = Split(['#editPane', '#viewPane'], {minSize: 0});
 
 	ensureLoaded([
@@ -152,6 +155,15 @@ function trace() {
 	request.send();
 }
 
+function stats() {
+	closeEditor();
+	gSplit = Split(['#statsPane', '#viewPane'], {minSize: 0});
+	document.getElementById("statsPane").style.display = 'flex';
+	gGraph = new SmoothieChart({ grid: { strokeStyle: 'rgb(125, 0, 0)', fillStyle: 'rgb(60, 0, 0)', lineWidth: 1, millisPerLine: 10000, verticalSections: 6 } });
+	gStats = {};
+	gGraph.streamTo(document.getElementById('graph'), 10000);
+}
+
 function guessMode(name) {
 	return name.endsWith(".js") ? "javascript" :
 		name.endsWith(".html") ? "htmlmixed" :
@@ -252,10 +264,20 @@ function load() {
 	request.send();
 }
 
-function closeEditor() {
+function closeStats() {
-	document.getElementById("editPane").style.display = 'none';
+	document.getElementById("statsPane").style.display = 'none';
+	if (gSplit) {
 		gSplit.destroy();
 		gSplit = undefined;
+	}
+}
+
+function closeEditor() {
+	document.getElementById("editPane").style.display = 'none';
+	if (gSplit) {
+		gSplit.destroy();
+		gSplit = undefined;
+	}
 }
 
 function explodePath() {
@@ -422,12 +444,25 @@ function receive(message) {
 	} else if (message && message.action == "ping") {
 		gSocket.send(JSON.stringify({action: "pong"}));
 	} else if (message && message.action == "error") {
+		if (message.error) {
 			if (typeof(message.error) == 'string') {
 				setStatusMessage(message.error, '#f00', false);
 			} else {
 				setStatusMessage(message.error.message + '\n' + message.error.stack, '#f00', false);
 			}
-		console.log(message.error);
+		}
+		console.log('error', message);
+	} else if (message && message.action == "stats") {
+		if (gGraph) {
+			var now = new Date().getTime();
+			for (var key of Object.keys(message.stats)) {
+				if (!gStats[key]) {
+					gStats[key] = new TimeSeries();
+					gGraph.addTimeSeries(gStats[key]);
+				}
+				gStats[key].append(now, message.stats[key]);
+			}
+		}
 	}
 }
 
@@ -440,7 +475,6 @@ function keyEvent(event) {
 		charCode: event.charCode,
 		character: String.fromCharCode(event.keyCode || event.which),
 		altKey: event.altKey,
-
 	});
 }
 

core/core.js

@@ -293,6 +293,7 @@ var kStaticFiles = [
 
 	{uri: '/split.min.js'},
 	{uri: '/split.min.js.map'},
+	{uri: '/smoothie.js'},
 	{uri: '/codemirror/codemirror.min.js'},
 	{uri: '/codemirror/base16-dark.min.css'},
 	{uri: '/codemirror/matchesonscrollbar.min.css'},
@@ -562,6 +563,16 @@ async function loadSettings() {
 	}
 }
 
+function sendStats() {
+	for (var process of Object.values(gProcesses)) {
+		if (process.app) {
+			process.app.send({action: 'stats', stats: getStats()});
+		}
+	}
+	setTimeout(sendStats, 1000);
+}
+setTimeout(sendStats, 1000);
+
 loadSettings().then(function() {
 	var auth = require("auth");
 	var httpd = require("httpd");

core/index.html

@@ -14,6 +14,7 @@
 			<a href="/">home</a>
 			<a href="#" onclick="event.preventDefault(); edit()">edit</a>
 			<a href="#" onclick="event.preventDefault(); trace()">trace</a>
+			<a href="#" onclick="event.preventDefault(); stats()">stats</a>
 			<span id="status"></span>
 			<span id="login"></span>
 		</div>
@@ -42,11 +43,18 @@
 					</div>
 				</div>
 			</div>
+			<div id="statsPane" class="vbox" style="display: none">
+				<div class="hbox">
+					<input type="button" id="closeStats" name="closeStats" value="Close" onclick="closeStats()">
+				</div>
+				<canvas id="graph" width="320" height="240"></canvas>
+			</div>
 			<div id="viewPane" class="vbox" style="flex: 1 0 50%; overflow: auto">
 				<iframe id="document" sandbox="allow-forms allow-scripts allow-top-navigation allow-modals" style="width: 100%; height: 100%; border: 0"></iframe>
 			</div>
 		</div>
 		<script src="/static/split.min.js"></script>
+		<script src="/static/smoothie.js"></script>
 		<script src="/static/client.js"></script>
 	</body>
 </html>

core/smoothie.js

@@ -0,0 +1,968 @@
+// MIT License:
+//
+// Copyright (c) 2010-2013, Joe Walnes
+//               2013-2017, Drew Noakes
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+/**
+ * Smoothie Charts - http://smoothiecharts.org/
+ * (c) 2010-2013, Joe Walnes
+ *     2013-2017, Drew Noakes
+ *
+ * v1.0: Main charting library, by Joe Walnes
+ * v1.1: Auto scaling of axis, by Neil Dunn
+ * v1.2: fps (frames per second) option, by Mathias Petterson
+ * v1.3: Fix for divide by zero, by Paul Nikitochkin
+ * v1.4: Set minimum, top-scale padding, remove timeseries, add optional timer to reset bounds, by Kelley Reynolds
+ * v1.5: Set default frames per second to 50... smoother.
+ *       .start(), .stop() methods for conserving CPU, by Dmitry Vyal
+ *       options.interpolation = 'bezier' or 'line', by Dmitry Vyal
+ *       options.maxValue to fix scale, by Dmitry Vyal
+ * v1.6: minValue/maxValue will always get converted to floats, by Przemek Matylla
+ * v1.7: options.grid.fillStyle may be a transparent color, by Dmitry A. Shashkin
+ *       Smooth rescaling, by Kostas Michalopoulos
+ * v1.8: Set max length to customize number of live points in the dataset with options.maxDataSetLength, by Krishna Narni
+ * v1.9: Display timestamps along the bottom, by Nick and Stev-io
+ *       (https://groups.google.com/forum/?fromgroups#!topic/smoothie-charts/-Ywse8FCpKI%5B1-25%5D)
+ *       Refactored by Krishna Narni, to support timestamp formatting function
+ * v1.10: Switch to requestAnimationFrame, removed the now obsoleted options.fps, by Gergely Imreh
+ * v1.11: options.grid.sharpLines option added, by @drewnoakes
+ *        Addressed warning seen in Firefox when seriesOption.fillStyle undefined, by @drewnoakes
+ * v1.12: Support for horizontalLines added, by @drewnoakes
+ *        Support for yRangeFunction callback added, by @drewnoakes
+ * v1.13: Fixed typo (#32), by @alnikitich
+ * v1.14: Timer cleared when last TimeSeries removed (#23), by @davidgaleano
+ *        Fixed diagonal line on chart at start/end of data stream, by @drewnoakes
+ * v1.15: Support for npm package (#18), by @dominictarr
+ *        Fixed broken removeTimeSeries function (#24) by @davidgaleano
+ *        Minor performance and tidying, by @drewnoakes
+ * v1.16: Bug fix introduced in v1.14 relating to timer creation/clearance (#23), by @drewnoakes
+ *        TimeSeries.append now deals with out-of-order timestamps, and can merge duplicates, by @zacwitte (#12)
+ *        Documentation and some local variable renaming for clarity, by @drewnoakes
+ * v1.17: Allow control over font size (#10), by @drewnoakes
+ *        Timestamp text won't overlap, by @drewnoakes
+ * v1.18: Allow control of max/min label precision, by @drewnoakes
+ *        Added 'borderVisible' chart option, by @drewnoakes
+ *        Allow drawing series with fill but no stroke (line), by @drewnoakes
+ * v1.19: Avoid unnecessary repaints, and fixed flicker in old browsers having multiple charts in document (#40), by @asbai
+ * v1.20: Add SmoothieChart.getTimeSeriesOptions and SmoothieChart.bringToFront functions, by @drewnoakes
+ * v1.21: Add 'step' interpolation mode, by @drewnoakes
+ * v1.22: Add support for different pixel ratios. Also add optional y limit formatters, by @copacetic
+ * v1.23: Fix bug introduced in v1.22 (#44), by @drewnoakes
+ * v1.24: Fix bug introduced in v1.23, re-adding parseFloat to y-axis formatter defaults, by @siggy_sf
+ * v1.25: Fix bug seen when adding a data point to TimeSeries which is older than the current data, by @Nking92
+ *        Draw time labels on top of series, by @comolosabia
+ *        Add TimeSeries.clear function, by @drewnoakes
+ * v1.26: Add support for resizing on high device pixel ratio screens, by @copacetic
+ * v1.27: Fix bug introduced in v1.26 for non whole number devicePixelRatio values, by @zmbush
+ * v1.28: Add 'minValueScale' option, by @megawac
+ *        Fix 'labelPos' for different size of 'minValueString' 'maxValueString', by @henryn
+ * v1.29: Support responsive sizing, by @drewnoakes
+ * v1.29.1: Include types in package, and make property optional, by @TrentHouliston
+ * v1.30: Fix inverted logic in devicePixelRatio support, by @scanlime
+ * v1.31: Support tooltips, by @Sly1024 and @drewnoakes
+ * v1.32: Support frame rate limit, by @dpuyosa
+ * v1.33: Use Date static method instead of instance, by @nnnoel
+ *        Fix bug with tooltips when multiple charts on a page, by @jpmbiz70
+ */
+
+;(function(exports) {
+
+  // Date.now polyfill
+  Date.now = Date.now || function() { return new Date().getTime(); };
+
+  var Util = {
+    extend: function() {
+      arguments[0] = arguments[0] || {};
+      for (var i = 1; i < arguments.length; i++)
+      {
+        for (var key in arguments[i])
+        {
+          if (arguments[i].hasOwnProperty(key))
+          {
+            if (typeof(arguments[i][key]) === 'object') {
+              if (arguments[i][key] instanceof Array) {
+                arguments[0][key] = arguments[i][key];
+              } else {
+                arguments[0][key] = Util.extend(arguments[0][key], arguments[i][key]);
+              }
+            } else {
+              arguments[0][key] = arguments[i][key];
+            }
+          }
+        }
+      }
+      return arguments[0];
+    },
+    binarySearch: function(data, value) {
+      var low = 0,
+          high = data.length;
+      while (low < high) {
+        var mid = (low + high) >> 1;
+        if (value < data[mid][0])
+          high = mid;
+        else
+          low = mid + 1;
+      }
+      return low;
+    }
+  };
+
+  /**
+   * Initialises a new <code>TimeSeries</code> with optional data options.
+   *
+   * Options are of the form (defaults shown):
+   *
+   * <pre>
+   * {
+   *   resetBounds: true,        // enables/disables automatic scaling of the y-axis
+   *   resetBoundsInterval: 3000 // the period between scaling calculations, in millis
+   * }
+   * </pre>
+   *
+   * Presentation options for TimeSeries are specified as an argument to <code>SmoothieChart.addTimeSeries</code>.
+   *
+   * @constructor
+   */
+  function TimeSeries(options) {
+    this.options = Util.extend({}, TimeSeries.defaultOptions, options);
+    this.clear();
+  }
+
+  TimeSeries.defaultOptions = {
+    resetBoundsInterval: 3000,
+    resetBounds: true
+  };
+
+  /**
+   * Clears all data and state from this TimeSeries object.
+   */
+  TimeSeries.prototype.clear = function() {
+    this.data = [];
+    this.maxValue = Number.NaN; // The maximum value ever seen in this TimeSeries.
+    this.minValue = Number.NaN; // The minimum value ever seen in this TimeSeries.
+  };
+
+  /**
+   * Recalculate the min/max values for this <code>TimeSeries</code> object.
+   *
+   * This causes the graph to scale itself in the y-axis.
+   */
+  TimeSeries.prototype.resetBounds = function() {
+    if (this.data.length) {
+      // Walk through all data points, finding the min/max value
+      this.maxValue = this.data[0][1];
+      this.minValue = this.data[0][1];
+      for (var i = 1; i < this.data.length; i++) {
+        var value = this.data[i][1];
+        if (value > this.maxValue) {
+          this.maxValue = value;
+        }
+        if (value < this.minValue) {
+          this.minValue = value;
+        }
+      }
+    } else {
+      // No data exists, so set min/max to NaN
+      this.maxValue = Number.NaN;
+      this.minValue = Number.NaN;
+    }
+  };
+
+  /**
+   * Adds a new data point to the <code>TimeSeries</code>, preserving chronological order.
+   *
+   * @param timestamp the position, in time, of this data point
+   * @param value the value of this data point
+   * @param sumRepeatedTimeStampValues if <code>timestamp</code> has an exact match in the series, this flag controls
+   * whether it is replaced, or the values summed (defaults to false.)
+   */
+  TimeSeries.prototype.append = function(timestamp, value, sumRepeatedTimeStampValues) {
+    // Rewind until we hit an older timestamp
+    var i = this.data.length - 1;
+    while (i >= 0 && this.data[i][0] > timestamp) {
+      i--;
+    }
+
+    if (i === -1) {
+      // This new item is the oldest data
+      this.data.splice(0, 0, [timestamp, value]);
+    } else if (this.data.length > 0 && this.data[i][0] === timestamp) {
+      // Update existing values in the array
+      if (sumRepeatedTimeStampValues) {
+        // Sum this value into the existing 'bucket'
+        this.data[i][1] += value;
+        value = this.data[i][1];
+      } else {
+        // Replace the previous value
+        this.data[i][1] = value;
+      }
+    } else if (i < this.data.length - 1) {
+      // Splice into the correct position to keep timestamps in order
+      this.data.splice(i + 1, 0, [timestamp, value]);
+    } else {
+      // Add to the end of the array
+      this.data.push([timestamp, value]);
+    }
+
+    this.maxValue = isNaN(this.maxValue) ? value : Math.max(this.maxValue, value);
+    this.minValue = isNaN(this.minValue) ? value : Math.min(this.minValue, value);
+  };
+
+  TimeSeries.prototype.dropOldData = function(oldestValidTime, maxDataSetLength) {
+    // We must always keep one expired data point as we need this to draw the
+    // line that comes into the chart from the left, but any points prior to that can be removed.
+    var removeCount = 0;
+    while (this.data.length - removeCount >= maxDataSetLength && this.data[removeCount + 1][0] < oldestValidTime) {
+      removeCount++;
+    }
+    if (removeCount !== 0) {
+      this.data.splice(0, removeCount);
+    }
+  };
+
+  /**
+   * Initialises a new <code>SmoothieChart</code>.
+   *
+   * Options are optional, and should be of the form below. Just specify the values you
+   * need and the rest will be given sensible defaults as shown:
+   *
+   * <pre>
+   * {
+   *   minValue: undefined,                      // specify to clamp the lower y-axis to a given value
+   *   maxValue: undefined,                      // specify to clamp the upper y-axis to a given value
+   *   maxValueScale: 1,                         // allows proportional padding to be added above the chart. for 10% padding, specify 1.1.
+   *   minValueScale: 1,                         // allows proportional padding to be added below the chart. for 10% padding, specify 1.1.
+   *   yRangeFunction: undefined,                // function({min: , max: }) { return {min: , max: }; }
+   *   scaleSmoothing: 0.125,                    // controls the rate at which y-value zoom animation occurs
+   *   millisPerPixel: 20,                       // sets the speed at which the chart pans by
+   *   enableDpiScaling: true,                   // support rendering at different DPI depending on the device
+   *   yMinFormatter: function(min, precision) { // callback function that formats the min y value label
+   *     return parseFloat(min).toFixed(precision);
+   *   },
+   *   yMaxFormatter: function(max, precision) { // callback function that formats the max y value label
+   *     return parseFloat(max).toFixed(precision);
+   *   },
+   *   maxDataSetLength: 2,
+   *   interpolation: 'bezier'                   // one of 'bezier', 'linear', or 'step'
+   *   timestampFormatter: null,                 // optional function to format time stamps for bottom of chart
+   *                                             // you may use SmoothieChart.timeFormatter, or your own: function(date) { return ''; }
+   *   scrollBackwards: false,                   // reverse the scroll direction of the chart
+   *   horizontalLines: [],                      // [ { value: 0, color: '#ffffff', lineWidth: 1 } ]
+   *   grid:
+   *   {
+   *     fillStyle: '#000000',                   // the background colour of the chart
+   *     lineWidth: 1,                           // the pixel width of grid lines
+   *     strokeStyle: '#777777',                 // colour of grid lines
+   *     millisPerLine: 1000,                    // distance between vertical grid lines
+   *     sharpLines: false,                      // controls whether grid lines are 1px sharp, or softened
+   *     verticalSections: 2,                    // number of vertical sections marked out by horizontal grid lines
+   *     borderVisible: true                     // whether the grid lines trace the border of the chart or not
+   *   },
+   *   labels
+   *   {
+   *     disabled: false,                        // enables/disables labels showing the min/max values
+   *     fillStyle: '#ffffff',                   // colour for text of labels,
+   *     fontSize: 15,
+   *     fontFamily: 'sans-serif',
+   *     precision: 2
+   *   },
+   *   tooltip: false                            // show tooltip when mouse is over the chart
+   *   tooltipLine: {                            // properties for a vertical line at the cursor position
+   *     lineWidth: 1,
+   *     strokeStyle: '#BBBBBB'
+   *   },
+   *   tooltipFormatter: SmoothieChart.tooltipFormatter, // formatter function for tooltip text
+   *   responsive: false,                        // whether the chart should adapt to the size of the canvas
+   *   limitFPS: 0                         // maximum frame rate the chart will render at, in FPS (zero means no limit)
+   * }
+   * </pre>
+   *
+   * @constructor
+   */
+  function SmoothieChart(options) {
+    this.options = Util.extend({}, SmoothieChart.defaultChartOptions, options);
+    this.seriesSet = [];
+    this.currentValueRange = 1;
+    this.currentVisMinValue = 0;
+    this.lastRenderTimeMillis = 0;
+
+    this.mousemove = this.mousemove.bind(this);
+    this.mouseout = this.mouseout.bind(this);
+  }
+
+  /** Formats the HTML string content of the tooltip. */
+  SmoothieChart.tooltipFormatter = function (timestamp, data) {
+      var timestampFormatter = this.options.timestampFormatter || SmoothieChart.timeFormatter,
+          lines = [timestampFormatter(new Date(timestamp))];
+
+      for (var i = 0; i < data.length; ++i) {
+        lines.push('<span style="color:' + data[i].series.options.strokeStyle + '">' +
+        this.options.yMaxFormatter(data[i].value, this.options.labels.precision) + '</span>');
+      }
+
+      return lines.join('<br>');
+  };
+
+  SmoothieChart.defaultChartOptions = {
+    millisPerPixel: 20,
+    enableDpiScaling: true,
+    yMinFormatter: function(min, precision) {
+      return parseFloat(min).toFixed(precision);
+    },
+    yMaxFormatter: function(max, precision) {
+      return parseFloat(max).toFixed(precision);
+    },
+    maxValueScale: 1,
+    minValueScale: 1,
+    interpolation: 'bezier',
+    scaleSmoothing: 0.125,
+    maxDataSetLength: 2,
+    scrollBackwards: false,
+    grid: {
+      fillStyle: '#000000',
+      strokeStyle: '#777777',
+      lineWidth: 1,
+      sharpLines: false,
+      millisPerLine: 1000,
+      verticalSections: 2,
+      borderVisible: true
+    },
+    labels: {
+      fillStyle: '#ffffff',
+      disabled: false,
+      fontSize: 10,
+      fontFamily: 'monospace',
+      precision: 2
+    },
+    horizontalLines: [],
+    tooltip: false,
+    tooltipLine: {
+      lineWidth: 1,
+      strokeStyle: '#BBBBBB'
+    },
+    tooltipFormatter: SmoothieChart.tooltipFormatter,
+    responsive: false,
+    limitFPS: 0
+  };
+
+  // Based on http://inspirit.github.com/jsfeat/js/compatibility.js
+  SmoothieChart.AnimateCompatibility = (function() {
+    var requestAnimationFrame = function(callback, element) {
+          var requestAnimationFrame =
+            window.requestAnimationFrame        ||
+            window.webkitRequestAnimationFrame  ||
+            window.mozRequestAnimationFrame     ||
+            window.oRequestAnimationFrame       ||
+            window.msRequestAnimationFrame      ||
+            function(callback) {
+              return window.setTimeout(function() {
+                callback(Date.now());
+              }, 16);
+            };
+          return requestAnimationFrame.call(window, callback, element);
+        },
+        cancelAnimationFrame = function(id) {
+          var cancelAnimationFrame =
+            window.cancelAnimationFrame ||
+            function(id) {
+              clearTimeout(id);
+            };
+          return cancelAnimationFrame.call(window, id);
+        };
+
+    return {
+      requestAnimationFrame: requestAnimationFrame,
+      cancelAnimationFrame: cancelAnimationFrame
+    };
+  })();
+
+  SmoothieChart.defaultSeriesPresentationOptions = {
+    lineWidth: 1,
+    strokeStyle: '#ffffff'
+  };
+
+  /**
+   * Adds a <code>TimeSeries</code> to this chart, with optional presentation options.
+   *
+   * Presentation options should be of the form (defaults shown):
+   *
+   * <pre>
+   * {
+   *   lineWidth: 1,
+   *   strokeStyle: '#ffffff',
+   *   fillStyle: undefined
+   * }
+   * </pre>
+   */
+  SmoothieChart.prototype.addTimeSeries = function(timeSeries, options) {
+    this.seriesSet.push({timeSeries: timeSeries, options: Util.extend({}, SmoothieChart.defaultSeriesPresentationOptions, options)});
+    if (timeSeries.options.resetBounds && timeSeries.options.resetBoundsInterval > 0) {
+      timeSeries.resetBoundsTimerId = setInterval(
+        function() {
+          timeSeries.resetBounds();
+        },
+        timeSeries.options.resetBoundsInterval
+      );
+    }
+  };
+
+  /**
+   * Removes the specified <code>TimeSeries</code> from the chart.
+   */
+  SmoothieChart.prototype.removeTimeSeries = function(timeSeries) {
+    // Find the correct timeseries to remove, and remove it
+    var numSeries = this.seriesSet.length;
+    for (var i = 0; i < numSeries; i++) {
+      if (this.seriesSet[i].timeSeries === timeSeries) {
+        this.seriesSet.splice(i, 1);
+        break;
+      }
+    }
+    // If a timer was operating for that timeseries, remove it
+    if (timeSeries.resetBoundsTimerId) {
+      // Stop resetting the bounds, if we were
+      clearInterval(timeSeries.resetBoundsTimerId);
+    }
+  };
+
+  /**
+   * Gets render options for the specified <code>TimeSeries</code>.
+   *
+   * As you may use a single <code>TimeSeries</code> in multiple charts with different formatting in each usage,
+   * these settings are stored in the chart.
+   */
+  SmoothieChart.prototype.getTimeSeriesOptions = function(timeSeries) {
+    // Find the correct timeseries to remove, and remove it
+    var numSeries = this.seriesSet.length;
+    for (var i = 0; i < numSeries; i++) {
+      if (this.seriesSet[i].timeSeries === timeSeries) {
+        return this.seriesSet[i].options;
+      }
+    }
+  };
+
+  /**
+   * Brings the specified <code>TimeSeries</code> to the top of the chart. It will be rendered last.
+   */
+  SmoothieChart.prototype.bringToFront = function(timeSeries) {
+    // Find the correct timeseries to remove, and remove it
+    var numSeries = this.seriesSet.length;
+    for (var i = 0; i < numSeries; i++) {
+      if (this.seriesSet[i].timeSeries === timeSeries) {
+        var set = this.seriesSet.splice(i, 1);
+        this.seriesSet.push(set[0]);
+        break;
+      }
+    }
+  };
+
+  /**
+   * Instructs the <code>SmoothieChart</code> to start rendering to the provided canvas, with specified delay.
+   *
+   * @param canvas the target canvas element
+   * @param delayMillis an amount of time to wait before a data point is shown. This can prevent the end of the series
+   * from appearing on screen, with new values flashing into view, at the expense of some latency.
+   */
+  SmoothieChart.prototype.streamTo = function(canvas, delayMillis) {
+    this.canvas = canvas;
+    this.delay = delayMillis;
+    this.start();
+  };
+
+  SmoothieChart.prototype.getTooltipEl = function () {
+    // Create the tool tip element lazily
+    if (!this.tooltipEl) {
+      this.tooltipEl = document.createElement('div');
+      this.tooltipEl.className = 'smoothie-chart-tooltip';
+      this.tooltipEl.style.position = 'absolute';
+      this.tooltipEl.style.display = 'none';
+      document.body.appendChild(this.tooltipEl);
+    }
+    return this.tooltipEl;
+  };
+
+  SmoothieChart.prototype.updateTooltip = function () {
+    var el = this.getTooltipEl();
+
+    if (!this.mouseover || !this.options.tooltip) {
+      el.style.display = 'none';
+      return;
+    }
+
+    var time = this.lastRenderTimeMillis - (this.delay || 0);
+
+    // Round time down to pixel granularity, so motion appears smoother.
+    time -= time % this.options.millisPerPixel;
+
+    // x pixel to time
+    var t = this.options.scrollBackwards
+      ? time - this.mouseX * this.options.millisPerPixel
+      : time - (this.canvas.offsetWidth - this.mouseX) * this.options.millisPerPixel;
+
+    var data = [];
+
+     // For each data set...
+    for (var d = 0; d < this.seriesSet.length; d++) {
+      var timeSeries = this.seriesSet[d].timeSeries,
+          // find datapoint closest to time 't'
+          closeIdx = Util.binarySearch(timeSeries.data, t);
+
+      if (closeIdx > 0 && closeIdx < timeSeries.data.length) {
+        data.push({ series: this.seriesSet[d], index: closeIdx, value: timeSeries.data[closeIdx][1] });
+      }
+    }
+
+    if (data.length) {
+      el.innerHTML = this.options.tooltipFormatter.call(this, t, data);
+      el.style.display = 'block';
+    } else {
+      el.style.display = 'none';
+    }
+  };
+
+  SmoothieChart.prototype.mousemove = function (evt) {
+    this.mouseover = true;
+    this.mouseX = evt.offsetX;
+    this.mouseY = evt.offsetY;
+    this.mousePageX = evt.pageX;
+    this.mousePageY = evt.pageY;
+
+    var el = this.getTooltipEl();
+    el.style.top = Math.round(this.mousePageY) + 'px';
+    el.style.left = Math.round(this.mousePageX) + 'px';
+    this.updateTooltip();
+  };
+
+  SmoothieChart.prototype.mouseout = function () {
+    this.mouseover = false;
+    this.mouseX = this.mouseY = -1;
+    if (SmoothieChart.tooltipEl)
+      SmoothieChart.tooltipEl.style.display = 'none';
+  };
+
+  /**
+   * Make sure the canvas has the optimal resolution for the device's pixel ratio.
+   */
+  SmoothieChart.prototype.resize = function () {
+    var dpr = !this.options.enableDpiScaling || !window ? 1 : window.devicePixelRatio,
+        width, height;
+    if (this.options.responsive) {
+      // Newer behaviour: Use the canvas's size in the layout, and set the internal
+      // resolution according to that size and the device pixel ratio (eg: high DPI)
+      width = this.canvas.offsetWidth;
+      height = this.canvas.offsetHeight;
+
+      if (width !== this.lastWidth) {
+        this.lastWidth = width;
+        this.canvas.setAttribute('width', (Math.floor(width * dpr)).toString());
+      }
+      if (height !== this.lastHeight) {
+        this.lastHeight = height;
+        this.canvas.setAttribute('height', (Math.floor(height * dpr)).toString());
+      }
+    } else if (dpr !== 1) {
+      // Older behaviour: use the canvas's inner dimensions and scale the element's size
+      // according to that size and the device pixel ratio (eg: high DPI)
+      width = parseInt(this.canvas.getAttribute('width'));
+      height = parseInt(this.canvas.getAttribute('height'));
+
+      if (!this.originalWidth || (Math.floor(this.originalWidth * dpr) !== width)) {
+        this.originalWidth = width;
+        this.canvas.setAttribute('width', (Math.floor(width * dpr)).toString());
+        this.canvas.style.width = width + 'px';
+        this.canvas.getContext('2d').scale(dpr, dpr);
+      }
+
+      if (!this.originalHeight || (Math.floor(this.originalHeight * dpr) !== height)) {
+        this.originalHeight = height;
+        this.canvas.setAttribute('height', (Math.floor(height * dpr)).toString());
+        this.canvas.style.height = height + 'px';
+        this.canvas.getContext('2d').scale(dpr, dpr);
+      }
+    }
+  };
+
+  /**
+   * Starts the animation of this chart.
+   */
+  SmoothieChart.prototype.start = function() {
+    if (this.frame) {
+      // We're already running, so just return
+      return;
+    }
+
+    this.canvas.addEventListener('mousemove', this.mousemove);
+    this.canvas.addEventListener('mouseout', this.mouseout);
+
+    // Renders a frame, and queues the next frame for later rendering
+    var animate = function() {
+      this.frame = SmoothieChart.AnimateCompatibility.requestAnimationFrame(function() {
+        this.render();
+        animate();
+      }.bind(this));
+    }.bind(this);
+
+    animate();
+  };
+
+  /**
+   * Stops the animation of this chart.
+   */
+  SmoothieChart.prototype.stop = function() {
+    if (this.frame) {
+      SmoothieChart.AnimateCompatibility.cancelAnimationFrame(this.frame);
+      delete this.frame;
+      this.canvas.removeEventListener('mousemove', this.mousemove);
+      this.canvas.removeEventListener('mouseout', this.mouseout);
+    }
+  };
+
+  SmoothieChart.prototype.updateValueRange = function() {
+    // Calculate the current scale of the chart, from all time series.
+    var chartOptions = this.options,
+        chartMaxValue = Number.NaN,
+        chartMinValue = Number.NaN;
+
+    for (var d = 0; d < this.seriesSet.length; d++) {
+      // TODO(ndunn): We could calculate / track these values as they stream in.
+      var timeSeries = this.seriesSet[d].timeSeries;
+      if (!isNaN(timeSeries.maxValue)) {
+        chartMaxValue = !isNaN(chartMaxValue) ? Math.max(chartMaxValue, timeSeries.maxValue) : timeSeries.maxValue;
+      }
+
+      if (!isNaN(timeSeries.minValue)) {
+        chartMinValue = !isNaN(chartMinValue) ? Math.min(chartMinValue, timeSeries.minValue) : timeSeries.minValue;
+      }
+    }
+
+    // Scale the chartMaxValue to add padding at the top if required
+    if (chartOptions.maxValue != null) {
+      chartMaxValue = chartOptions.maxValue;
+    } else {
+      chartMaxValue *= chartOptions.maxValueScale;
+    }
+
+    // Set the minimum if we've specified one
+    if (chartOptions.minValue != null) {
+      chartMinValue = chartOptions.minValue;
+    } else {
+      chartMinValue -= Math.abs(chartMinValue * chartOptions.minValueScale - chartMinValue);
+    }
+
+    // If a custom range function is set, call it
+    if (this.options.yRangeFunction) {
+      var range = this.options.yRangeFunction({min: chartMinValue, max: chartMaxValue});
+      chartMinValue = range.min;
+      chartMaxValue = range.max;
+    }
+
+    if (!isNaN(chartMaxValue) && !isNaN(chartMinValue)) {
+      var targetValueRange = chartMaxValue - chartMinValue;
+      var valueRangeDiff = (targetValueRange - this.currentValueRange);
+      var minValueDiff = (chartMinValue - this.currentVisMinValue);
+      this.isAnimatingScale = Math.abs(valueRangeDiff) > 0.1 || Math.abs(minValueDiff) > 0.1;
+      this.currentValueRange += chartOptions.scaleSmoothing * valueRangeDiff;
+      this.currentVisMinValue += chartOptions.scaleSmoothing * minValueDiff;
+    }
+
+    this.valueRange = { min: chartMinValue, max: chartMaxValue };
+  };
+
+  SmoothieChart.prototype.render = function(canvas, time) {
+    var nowMillis = Date.now();
+
+    // Respect any frame rate limit.
+    if (this.options.limitFPS > 0 && nowMillis - this.lastRenderTimeMillis < (1000/this.options.limitFPS))
+      return;
+
+    if (!this.isAnimatingScale) {
+      // We're not animating. We can use the last render time and the scroll speed to work out whether
+      // we actually need to paint anything yet. If not, we can return immediately.
+
+      // Render at least every 1/6th of a second. The canvas may be resized, which there is
+      // no reliable way to detect.
+      var maxIdleMillis = Math.min(1000/6, this.options.millisPerPixel);
+
+      if (nowMillis - this.lastRenderTimeMillis < maxIdleMillis) {
+        return;
+      }
+    }
+
+    this.resize();
+    this.updateTooltip();
+
+    this.lastRenderTimeMillis = nowMillis;
+
+    canvas = canvas || this.canvas;
+    time = time || nowMillis - (this.delay || 0);
+
+    // Round time down to pixel granularity, so motion appears smoother.
+    time -= time % this.options.millisPerPixel;
+
+    var context = canvas.getContext('2d'),
+        chartOptions = this.options,
+        dimensions = { top: 0, left: 0, width: canvas.clientWidth, height: canvas.clientHeight },
+        // Calculate the threshold time for the oldest data points.
+        oldestValidTime = time - (dimensions.width * chartOptions.millisPerPixel),
+        valueToYPixel = function(value) {
+          var offset = value - this.currentVisMinValue;
+          return this.currentValueRange === 0
+            ? dimensions.height
+            : dimensions.height - (Math.round((offset / this.currentValueRange) * dimensions.height));
+        }.bind(this),
+        timeToXPixel = function(t) {
+          if(chartOptions.scrollBackwards) {
+            return Math.round((time - t) / chartOptions.millisPerPixel);
+          }
+          return Math.round(dimensions.width - ((time - t) / chartOptions.millisPerPixel));
+        };
+
+    this.updateValueRange();
+
+    context.font = chartOptions.labels.fontSize + 'px ' + chartOptions.labels.fontFamily;
+
+    // Save the state of the canvas context, any transformations applied in this method
+    // will get removed from the stack at the end of this method when .restore() is called.
+    context.save();
+
+    // Move the origin.
+    context.translate(dimensions.left, dimensions.top);
+
+    // Create a clipped rectangle - anything we draw will be constrained to this rectangle.
+    // This prevents the occasional pixels from curves near the edges overrunning and creating
+    // screen cheese (that phrase should need no explanation).
+    context.beginPath();
+    context.rect(0, 0, dimensions.width, dimensions.height);
+    context.clip();
+
+    // Clear the working area.
+    context.save();
+    context.fillStyle = chartOptions.grid.fillStyle;
+    context.clearRect(0, 0, dimensions.width, dimensions.height);
+    context.fillRect(0, 0, dimensions.width, dimensions.height);
+    context.restore();
+
+    // Grid lines...
+    context.save();
+    context.lineWidth = chartOptions.grid.lineWidth;
+    context.strokeStyle = chartOptions.grid.strokeStyle;
+    // Vertical (time) dividers.
+    if (chartOptions.grid.millisPerLine > 0) {
+      context.beginPath();
+      for (var t = time - (time % chartOptions.grid.millisPerLine);
+           t >= oldestValidTime;
+           t -= chartOptions.grid.millisPerLine) {
+        var gx = timeToXPixel(t);
+        if (chartOptions.grid.sharpLines) {
+          gx -= 0.5;
+        }
+        context.moveTo(gx, 0);
+        context.lineTo(gx, dimensions.height);
+      }
+      context.stroke();
+      context.closePath();
+    }
+
+    // Horizontal (value) dividers.
+    for (var v = 1; v < chartOptions.grid.verticalSections; v++) {
+      var gy = Math.round(v * dimensions.height / chartOptions.grid.verticalSections);
+      if (chartOptions.grid.sharpLines) {
+        gy -= 0.5;
+      }
+      context.beginPath();
+      context.moveTo(0, gy);
+      context.lineTo(dimensions.width, gy);
+      context.stroke();
+      context.closePath();
+    }
+    // Bounding rectangle.
+    if (chartOptions.grid.borderVisible) {
+      context.beginPath();
+      context.strokeRect(0, 0, dimensions.width, dimensions.height);
+      context.closePath();
+    }
+    context.restore();
+
+    // Draw any horizontal lines...
+    if (chartOptions.horizontalLines && chartOptions.horizontalLines.length) {
+      for (var hl = 0; hl < chartOptions.horizontalLines.length; hl++) {
+        var line = chartOptions.horizontalLines[hl],
+            hly = Math.round(valueToYPixel(line.value)) - 0.5;
+        context.strokeStyle = line.color || '#ffffff';
+        context.lineWidth = line.lineWidth || 1;
+        context.beginPath();
+        context.moveTo(0, hly);
+        context.lineTo(dimensions.width, hly);
+        context.stroke();
+        context.closePath();
+      }
+    }
+
+    // For each data set...
+    for (var d = 0; d < this.seriesSet.length; d++) {
+      context.save();
+      var timeSeries = this.seriesSet[d].timeSeries,
+          dataSet = timeSeries.data,
+          seriesOptions = this.seriesSet[d].options;
+
+      // Delete old data that's moved off the left of the chart.
+      timeSeries.dropOldData(oldestValidTime, chartOptions.maxDataSetLength);
+
+      // Set style for this dataSet.
+      context.lineWidth = seriesOptions.lineWidth;
+      context.strokeStyle = seriesOptions.strokeStyle;
+      // Draw the line...
+      context.beginPath();
+      // Retain lastX, lastY for calculating the control points of bezier curves.
+      var firstX = 0, lastX = 0, lastY = 0;
+      for (var i = 0; i < dataSet.length && dataSet.length !== 1; i++) {
+        var x = timeToXPixel(dataSet[i][0]),
+            y = valueToYPixel(dataSet[i][1]);
+
+        if (i === 0) {
+          firstX = x;
+          context.moveTo(x, y);
+        } else {
+          switch (chartOptions.interpolation) {
+            case "linear":
+            case "line": {
+              context.lineTo(x,y);
+              break;
+            }
+            case "bezier":
+            default: {
+              // Great explanation of Bezier curves: http://en.wikipedia.org/wiki/Bezier_curve#Quadratic_curves
+              //
+              // Assuming A was the last point in the line plotted and B is the new point,
+              // we draw a curve with control points P and Q as below.
+              //
+              // A---P
+              //     |
+              //     |
+              //     |
+              //     Q---B
+              //
+              // Importantly, A and P are at the same y coordinate, as are B and Q. This is
+              // so adjacent curves appear to flow as one.
+              //
+              context.bezierCurveTo( // startPoint (A) is implicit from last iteration of loop
+                Math.round((lastX + x) / 2), lastY, // controlPoint1 (P)
+                Math.round((lastX + x)) / 2, y, // controlPoint2 (Q)
+                x, y); // endPoint (B)
+              break;
+            }
+            case "step": {
+              context.lineTo(x,lastY);
+              context.lineTo(x,y);
+              break;
+            }
+          }
+        }
+
+        lastX = x; lastY = y;
+      }
+
+      if (dataSet.length > 1) {
+        if (seriesOptions.fillStyle) {
+          // Close up the fill region.
+          context.lineTo(dimensions.width + seriesOptions.lineWidth + 1, lastY);
+          context.lineTo(dimensions.width + seriesOptions.lineWidth + 1, dimensions.height + seriesOptions.lineWidth + 1);
+          context.lineTo(firstX, dimensions.height + seriesOptions.lineWidth);
+          context.fillStyle = seriesOptions.fillStyle;
+          context.fill();
+        }
+
+        if (seriesOptions.strokeStyle && seriesOptions.strokeStyle !== 'none') {
+          context.stroke();
+        }
+        context.closePath();
+      }
+      context.restore();
+    }
+
+    if (chartOptions.tooltip && this.mouseX >= 0) {
+      // Draw vertical bar to show tooltip position
+      context.lineWidth = chartOptions.tooltipLine.lineWidth;
+      context.strokeStyle = chartOptions.tooltipLine.strokeStyle;
+      context.beginPath();
+      context.moveTo(this.mouseX, 0);
+      context.lineTo(this.mouseX, dimensions.height);
+      context.closePath();
+      context.stroke();
+      this.updateTooltip();
+    }
+
+    // Draw the axis values on the chart.
+    if (!chartOptions.labels.disabled && !isNaN(this.valueRange.min) && !isNaN(this.valueRange.max)) {
+      var maxValueString = chartOptions.yMaxFormatter(this.valueRange.max, chartOptions.labels.precision),
+          minValueString = chartOptions.yMinFormatter(this.valueRange.min, chartOptions.labels.precision),
+          maxLabelPos = chartOptions.scrollBackwards ? 0 : dimensions.width - context.measureText(maxValueString).width - 2,
+          minLabelPos = chartOptions.scrollBackwards ? 0 : dimensions.width - context.measureText(minValueString).width - 2;
+      context.fillStyle = chartOptions.labels.fillStyle;
+      context.fillText(maxValueString, maxLabelPos, chartOptions.labels.fontSize);
+      context.fillText(minValueString, minLabelPos, dimensions.height - 2);
+    }
+
+    // Display timestamps along x-axis at the bottom of the chart.
+    if (chartOptions.timestampFormatter && chartOptions.grid.millisPerLine > 0) {
+      var textUntilX = chartOptions.scrollBackwards
+        ? context.measureText(minValueString).width
+        : dimensions.width - context.measureText(minValueString).width + 4;
+      for (var t = time - (time % chartOptions.grid.millisPerLine);
+           t >= oldestValidTime;
+           t -= chartOptions.grid.millisPerLine) {
+        var gx = timeToXPixel(t);
+        // Only draw the timestamp if it won't overlap with the previously drawn one.
+        if ((!chartOptions.scrollBackwards && gx < textUntilX) || (chartOptions.scrollBackwards && gx > textUntilX))  {
+          // Formats the timestamp based on user specified formatting function
+          // SmoothieChart.timeFormatter function above is one such formatting option
+          var tx = new Date(t),
+            ts = chartOptions.timestampFormatter(tx),
+            tsWidth = context.measureText(ts).width;
+
+          textUntilX = chartOptions.scrollBackwards
+            ? gx + tsWidth + 2
+            : gx - tsWidth - 2;
+
+          context.fillStyle = chartOptions.labels.fillStyle;
+          if(chartOptions.scrollBackwards) {
+            context.fillText(ts, gx, dimensions.height - 2);
+          } else {
+            context.fillText(ts, gx - tsWidth, dimensions.height - 2);
+          }
+        }
+      }
+    }
+
+    context.restore(); // See .save() above.
+  };
+
+  // Sample timestamp formatting function
+  SmoothieChart.timeFormatter = function(date) {
+    function pad2(number) { return (number < 10 ? '0' : '') + number }
+    return pad2(date.getHours()) + ':' + pad2(date.getMinutes()) + ':' + pad2(date.getSeconds());
+  };
+
+  exports.TimeSeries = TimeSeries;
+  exports.SmoothieChart = SmoothieChart;
+
+})(typeof exports === 'undefined' ? this : exports);
+

src/task.c

@@ -152,6 +152,7 @@ static JSValue _tf_task_get_parent(JSContext* context, JSValueConst this_val, in
 static JSValue _tf_task_exit(JSContext* context, JSValueConst this_val, int argc, JSValueConst* argv);
 static JSValue _tf_task_sandbox_require(JSContext* context, JSValueConst this_val, int argc, JSValueConst* argv);
 static JSValue _tf_task_trace(JSContext* context, JSValueConst this_val, int argc, JSValueConst* argv);
+static JSValue _tf_task_getStats(JSContext* context, JSValueConst this_val, int argc, JSValueConst* argv);
 static JSValue _tf_task_getFile(JSContext* context, JSValueConst this_val, int argc, JSValueConst* argv);
 
 static void _tf_task_sendPromiseMessage(tf_task_t* from, tf_taskstub_t* to, tf_task_message_t messageType, promiseid_t promise, JSValue result);
@@ -690,6 +691,17 @@ static JSValue _tf_task_trace(JSContext* context, JSValueConst this_val, int arg
 	return result;
 }
 
+static JSValue _tf_task_getStats(JSContext* context, JSValueConst this_val, int argc, JSValueConst* argv)
+{
+	tf_task_t* task = JS_GetContextOpaque(context);
+	JSValue result = JS_NewObject(context);
+	JS_SetPropertyStr(context, result, "child_count", JS_NewInt32(context, task->_child_count));
+	JS_SetPropertyStr(context, result, "import_count", JS_NewInt32(context, task->_import_count));
+	JS_SetPropertyStr(context, result, "export_count", JS_NewInt32(context, task->_export_count));
+	JS_SetPropertyStr(context, result, "promise_count", JS_NewInt32(context, task->_promise_count));
+	return result;
+}
+
 static JSValue _tf_task_getFile(JSContext* context, JSValueConst this_val, int argc, JSValueConst* argv)
 {
 	tf_task_t* task = JS_GetContextOpaque(context);
@@ -1388,6 +1400,7 @@ void tf_task_activate(tf_task_t* task)
 		}
 
 		JS_SetPropertyStr(context, global, "trace", JS_NewCFunction(context, _tf_task_trace, "trace", 1));
+		JS_SetPropertyStr(context, global, "getStats", JS_NewCFunction(context, _tf_task_getStats, "getStats", 0));
 	}
 	else
 	{