[DevTools] Add power profiler and power overview in timeline panel.

Source/devtools/front_end/TimelinePowerOverview.js

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * @constructor
+ * @extends {WebInspector.TimelineOverviewBase}

[pfeldman, 2014/03/11 12:24:02]

For now, you can add 

startTimeline and stopTimeline methods into TimelineOverviewBase. That's where
you'll start and stop your agent separately from the rest of the timeline.

[Pan, 2014/03/18 10:16:48]

Done.

+ * @param {!WebInspector.TimelineModel} model
+ */
+WebInspector.TimelinePowerOverview = function(model)

[pfeldman, 2014/03/11 12:24:02]

Yes, perfect. You should have your own overview type.

+{
+    WebInspector.TimelineOverviewBase.call(this, model);
+    this.element.id = "timeline-overview-power";
+    this._canvas.addEventListener("mousemove", this._onMouseMove.bind(this));
+    this._powerEventsHistogram = [];
+    this._maxPower = 0;
+    this._minPower = 0;
+    this._yFactor = 0;
+    this._powerDrawHeight = 0;
+    this._windowStartTime = 0;
+    this._windowEndTime = Infinity;
+}
+
+WebInspector.TimelinePowerOverview.prototype = {
+    windowChanged: function(startTime, endTime)

[pfeldman, 2014/03/11 12:24:02]

Please annotate every method.

+    {
+        this._windowStartTime = startTime;
+        this._windowEndTime = endTime;
+        this._drawEnergyMark(startTime, endTime);
+    },
+
+    _drawEnergyMark: function(startTime, endTime) {
+        // Clear previous power marks firstly.
+        this._restorePowerMarker();

[pfeldman, 2014/03/11 12:24:02]

Lets think if we can unify this with memory graph or cpu flame chart overview?
We seem to be craeting too many different canvases.

[Pan, 2014/03/12 13:11:20]

Hi @pfeldman,
thanks for your help, do you mean it is better to use html node to render the
marks(like the point in memory graph) rather than draw them the canvas?

Pan

+
+        // Clear previous energy consumption text.
+        this._restoreImageUnderMarker(this._energyTextSaver);
+
+        var startX = Math.round(this._xFactor * (startTime - this._model.minimumRecordTime()));
+        var endX = Math.round(this._xFactor * (endTime- this._model.minimumRecordTime()));
+        var energy = this._calculateEnergyInSelectedRegion(startX, endX);
+
+        if (!energy)
+          return;
+
+        // Draw energy consumption text.
+        var label = this._createTextLabel(WebInspector.UIString("%.2f\u2009joule", energy));
+        var textXPos = (startX + endX) > label.width ? Math.round((startX + endX - label.width) / 2) : Math.round((startX + endX) / 2);
+        var textYPos = Math.round(this._powerDrawHeight / 2);
+        this._context.beginPath();
+        this._energyTextSaver = this._saveRectImageUnderMarker(textXPos, textYPos - label.height, label.width, label.height + 2);
+        this._context.strokeStyle = "black";
+        this._context.fillStyle = "black";
+        this._context.fillText(label.name, textXPos, textYPos);
+        this._context.stroke();
+    },
+
+    _calculateEnergyInSelectedRegion: function(startX, endX) {
+
+        // If pos is on the power event, just the prev and next will be same to pos
+        function findAdjacents(pos, histograms) {
+            var prevPowerEventIndex;
+            var nextPowerEventIndex;
+            // Find previous power event.
+            for(var i = pos; i >= 0; i--) {
+                if (histograms[i]) {
+                    prevPowerEventIndex = i;
+                    break;
+                }
+            }
+            // Find next power event.
+            for(var i = pos; i < histograms.length; i++) {
+                if (histograms[i]) {
+                    nextPowerEventIndex= i;
+                    break;
+                }
+            }
+            // As pos may fall into a blank region, which only have next or prev. in this case we will return 0 timespan and xSpan.
+            return {
+                prev : prevPowerEventIndex,
+                next : nextPowerEventIndex,
+                timeSpan : (!prevPowerEventIndex || !nextPowerEventIndex) ? 0 : (histograms[nextPowerEventIndex].startTime - histograms[prevPowerEventIndex].startTime) / 1000, // in seconds
+                xSpan : (!prevPowerEventIndex || !nextPowerEventIndex) ? 0 : (nextPowerEventIndex - prevPowerEventIndex),
+                power : (!nextPowerEventIndex) ? 0 : histograms[nextPowerEventIndex].value
+            };
+        }
+
+        var energy = 0;
+        var startAdjancents = findAdjacents(startX, this._powerEventsHistogram);
+        var endAdjancents = findAdjacents(endX, this._powerEventsHistogram);
+
+        // Calculate energy consumption of sliced power events.
+        if (startAdjancents.prev !== endAdjancents.prev) { // Cross at least one power event.
+          if (startAdjancents.timeSpan)
+            energy += (startAdjancents.next - startX) / startAdjancents.xSpan * startAdjancents.timeSpan * startAdjancents.power;
+
+          if (endAdjancents.timeSpan)
+            energy += (endX- endAdjancents.prev) / endAdjancents.xSpan * endAdjancents.timeSpan * endAdjancents.power;
+
+        } else { // Start and end are in the same power event duration.
+            energy += (endX - startX) / startAdjancents.xSpan * startAdjancents.timeSpan * endAdjancents.power;
+        }
+
+        // Calculate energy consumption of internal power events.
+        var prevX = -1;
+        for(var i = startX; i <= endX; i++) {
+            if (!this._powerEventsHistogram[i])
+                continue;
+            if (prevX !== -1) {
+                var timeSpan = (this._powerEventsHistogram[i].startTime- this._powerEventsHistogram[prevX].startTime) / 1000;
+                energy += timeSpan * this._powerEventsHistogram[i].value;
+            }
+            prevX = i;
+        }
+
+        return energy;
+    },
+
+    _onMouseMove: function(event)
+    {
+        this._restorePowerMarker();
+        var powerValue;
+        var index = Math.round(event.offsetX);
+        var isInBlankArea = true;
+        for (var i = 0; i < index + 1; i++) {
+            if (this._powerEventsHistogram[i]) {
+                isInBlankArea = false;
+                break;
+            }
+        }
+        if (isInBlankArea)
+            return;
+
+        for (var i = index + 1; i < this._powerEventsHistogram.length; i++) {
+            if (this._powerEventsHistogram[i]) {
+                powerValue = this._powerEventsHistogram[i].value;
+                break;
+            }
+        }
+
+        var xPos = event.offsetX;
+        var yPos = this._powerDrawHeight - Math.round(this._yFactor * (powerValue - this._minPower));
+
+        this._drawPowerMark(xPos, yPos, powerValue);
+    },
+
+    update: function()
+    {
+        this.resetCanvas();
+        delete this._powerPointSaver;
+        delete this._powerTextSaver;
+        delete this._energyTextSaver;
+
+        this._powerEventsHistogram = [];
+        this._yFactor = 0;
+
+        var records = this._model.records();
+        if (!records.length)
+            return;
+
+        this._resetPowerBoundaries(records);
+
+        var histogram = this._prepareHistograms(records);
+
+        var height = this._powerDrawHeight;
+        // Draw power gridline and scales.
+        this._drawPowerGridline(this._minPower, this._maxPower, height);
+
+        // Draw power graph.
+        // As we only have power samples in timestamp, we should eliminated the first event as we don't know its start point.
+        var initialX = 0;
+        var initialY = 0;
+        var previousX = 0;
+        for (var k = 0; k < histogram.length; k++) {
+            var value = histogram[k];
+            if (value !== undefined) {
+                initialX = k;
+                previousX = k;
+                initialY = value;
+                break;
+            }
+        }
+
+        var ctx = this._context;
+        ctx.beginPath();
+        var isFirst = true;
+
+        for (var x = previousX + 1; x < histogram.length; x++) {
+            if (histogram[x] === undefined)
+                continue;
+            var currentY = height - histogram[x];
+            if (!isFirst) {
+                ctx.lineTo(previousX, currentY);
+            } else {
+                ctx.moveTo(initialX, currentY);
+                isFirst = false;
+            }
+            ctx.lineTo(x, currentY);
+            previousX = x;
+        }
+
+        ctx.lineWidth = 0.5;
+        ctx.strokeStyle = "rgba(20,0,0,0.8)";
+        ctx.stroke();
+
+        ctx.fillStyle = "rgba(255,192,0, 0.8);";
+        ctx.lineTo(previousX, this._canvas.height);
+        ctx.lineTo(initialX, this._canvas.height);
+        ctx.lineTo(initialX, height - initialY);
+        ctx.fill();
+        ctx.closePath();
+
+        // Draw energy for a selected time period.
+        if (this._windowStartTime > 0 && this._windowEndTime < Infinity && this._windowStartTime < this._windowEndTime)
+          this._drawEnergyMark(this._windowStartTime, this._windowEndTime);
+    },
+
+    _resetPowerBoundaries: function(allRecords)
+    {
+        var maxPower = 0;
+        var minPower = 100000000000;
+        var minTime = this._model.minimumRecordTime();
+        this._model.forAllRecords(function(r) {
+            record = r._record;
+            if (record.type !== WebInspector.TimelineModel.RecordType.SoC_Package)
+                return;
+            maxPower = Math.max(maxPower, record.value);
+            minPower = Math.min(minPower, record.value);
+        });
+        minPower = Math.min(minPower, maxPower);
+        this._maxPower = maxPower;
+        this._minPower = minPower;
+    },
+
+    _prepareHistograms: function(allRecords)
+    {
+        const lowerOffset = 3;
+        var width = this._canvas.width;
+        var height = this._canvas.height - lowerOffset;
+        var minTime = this._model.minimumRecordTime();
+        var maxTime = this._model.maximumRecordTime();
+        var xFactor = width / (maxTime - minTime);
+        var yFactor = height / (this._maxPower - this._minPower);
+        this._xFactor = xFactor;
+        this._yFactor = yFactor;
+
+        var histogram = new Array(width);
+        var powerEventsHistogram = new Array(width);
+        var minPower = this._minPower;
+        this._model.forAllRecords(function(r) {
+            record = r._record;
+            if (record.type !== WebInspector.TimelineModel.RecordType.SoC_Package)
+                return;
+            var x = Math.round((record.startTime - minTime) * xFactor);
+            var y = Math.round((record.value- minPower ) * yFactor);
+            histogram[x] = Math.max(histogram[x] || 0, y);
+            powerEventsHistogram[x] = record;
+        });
+
+        this._powerEventsHistogram = powerEventsHistogram;
+
+        // +1 so that the border always fit into the canvas area.
+        this._powerDrawHeight = height + 1;
+
+        return histogram;
+    },
+
+    _drawPowerGridline: function(minPower, maxPower, height)
+    {
+        var ctx = this._context;
+        var width = this._canvas.width;
+        var yFactor = (maxPower - minPower) / height;
+        const labelPadding = 4 * window.devicePixelRatio;
+
+        ctx.strokeStyle = "rgba(128,128,128,0.5)";
+        var gridHeight = height / 4;
+        var yPositions = [];
+        var powerScales = [];
+
+        for (var i = 1; i < 4; i++) {
+            var yPos = Math.round(gridHeight * i) - 0.5;
+            var powerScale = yFactor * (height - yPos) + minPower;
+
+            //draw gridline
+            ctx.beginPath();
+            ctx.moveTo(0, yPos);
+            ctx.lineTo(width, yPos);
+            ctx.stroke();
+
+            //draw scale for gridline
+            if (!powerScale)
+                continue;
+            ctx.beginPath();
+            var label = this._createTextLabel(WebInspector.UIString("%.2f\u2009watt", powerScale));
+            ctx.save();
+            this._context.fillStyle = "black";
+            ctx.fillText(label.name, 2, yPos - 2);
+            ctx.stroke();
+            ctx.restore();
+        }
+    },
+
+    _restorePowerMarker: function()
+    {
+        this._restoreImageUnderMarker(this._powerPointSaver);
+        delete this._powerPointSaver;
+
+        this._restoreImageUnderMarker(this._powerTextSaver);
+        delete this._powerTextSaver;
+    },
+
+    _drawPowerMark: function(xPointPos, yPointPos, powerValue)
+    {
+        // Draw power point.
+        const radius = 2;
+        this._powerPointSaver = this._saveArcImageUnderMarker(xPointPos, yPointPos, radius);
+        this._context.beginPath();
+        this._context.arc(xPointPos, yPointPos, radius, Math.PI*2, false)
+        this._context.strokeStyle = "red";
+        this._context.fillStyle = "red";
+        this._context.fill();
+        this._context.stroke();
+
+        // Draw power text.
+        var label = this._createTextLabel(WebInspector.UIString("%.2f\u2009watt", powerValue));
+        var textYPos = yPointPos - 3 - label.height > 0 ? yPointPos - 3: yPointPos + 3 + label.height;
+        var textXPos = xPointPos + label.width > this._canvas.width ? this._canvas.width - label.width : xPointPos;
+        this._context.beginPath();
+        this._powerTextSaver = this._saveRectImageUnderMarker(textXPos, textYPos - label.height, label.width, label.height);
+        this._context.fillText(label.name, textXPos, textYPos);
+        this._context.stroke();
+    },
+
+    _createTextLabel: function(labelName)
+    {
+        const labelPadding = 4 * window.devicePixelRatio;
+        var labelWidth = this._context.measureText(labelName).width + 2 * labelPadding;
+        var contextFont = this._context.font;
+        var labelHeight = contextFont.substr(0, contextFont.indexOf("px ")) - 0;
+        return { name : labelName,
+                 width : labelWidth,
+                 height : labelHeight
+                };
+    },
+
+    _saveArcImageUnderMarker: function(x, y, radius)
+    {
+        const w = radius + 1;
+        var imageData = this._context.getImageData(x - w, y - w, 2 * w, 2 * w);
+        return {
+            x: x - w,
+            y: y - w,
+            imageData: imageData
+        };
+    },
+
+    _saveRectImageUnderMarker: function(x, y, w, h)
+    {
+        var imageData = this._context.getImageData(x, y, w, h);
+        return {
+            x: x,
+            y: y,
+            imageData: imageData
+        };
+    },
+
+    _restoreImageUnderMarker: function(imageUnderMarker)
+    {
+        if (imageUnderMarker)
+            this._context.putImageData(imageUnderMarker.imageData, imageUnderMarker.x, imageUnderMarker.y);
+    },
+
+    __proto__: WebInspector.TimelineOverviewBase.prototype
+}