Reland https://codereview.chromium.org/286903025

bench/TimerData.cpp

Index: bench/TimerData.cpp
diff --git a/bench/TimerData.cpp b/bench/TimerData.cpp
index a86f29394f722146f183be555c4b45bf92a39424..ba682f0e2458255ddd619be58c5f6f37487e888c 100644
--- a/bench/TimerData.cpp
+++ b/bench/TimerData.cpp
@@ -5,7 +5,6 @@
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
-
 #include "TimerData.h"
 
 #include "BenchTimer.h"
@@ -140,3 +139,88 @@ SkString TimerData::getResult(const char* doubleFormat,
     }
     return str;
 }
+
+#ifdef SK_BUILD_JSON_WRITER
+Json::Value TimerData::getJSON(uint32_t timerFlags, 
+                               Result result,
+                               int itersPerTiming) {
+    SkASSERT(itersPerTiming >= 1);
+    Json::Value dataNode;
+    Json::Value wallNode, truncWall, cpuNode, truncCpu, gpuNode;
+    if (!fCurrTiming) {
+        return dataNode;
+    }
+
+    int numTimings = fCurrTiming;
+
+    double wallMin = std::numeric_limits<double>::max();
+    double truncWallMin = std::numeric_limits<double>::max();
+    double cpuMin = std::numeric_limits<double>::max();
+    double truncCpuMin = std::numeric_limits<double>::max();
+    double gpuMin = std::numeric_limits<double>::max();
+
+    double wallSum = 0;
+    double truncWallSum = 0;
+    double cpuSum = 0;
+    double truncCpuSum = 0;
+    double gpuSum = 0;
+
+    for (int i = 0; i < numTimings; ++i) {
+        if (kPerIter_Result == result) {
+            wallNode.append(fWallTimes[i] / itersPerTiming);
+            truncWall.append(fTruncatedWallTimes[i] / itersPerTiming);
+            cpuNode.append(fCpuTimes[i] / itersPerTiming);
+            truncCpu.append(fTruncatedCpuTimes[i] / itersPerTiming);
+            gpuNode.append(fGpuTimes[i] / itersPerTiming);
+        } else if (kMin_Result == result) {
+            wallMin = SkTMin(wallMin, fWallTimes[i]);
+            truncWallMin = SkTMin(truncWallMin, fTruncatedWallTimes[i]);
+            cpuMin = SkTMin(cpuMin, fCpuTimes[i]);
+            truncCpuMin = SkTMin(truncCpuMin, fTruncatedCpuTimes[i]);
+            gpuMin = SkTMin(gpuMin, fGpuTimes[i]);
+        } else {
+            SkASSERT(kAvg_Result == result);
+            wallSum += fWallTimes[i];
+            truncWallSum += fTruncatedWallTimes[i];
+            cpuSum += fCpuTimes[i];
+            truncCpuSum += fTruncatedCpuTimes[i];
+        }
+
+        // We always track the GPU sum because whether it is non-zero indicates if valid gpu times
+        // were recorded at all.
+        gpuSum += fGpuTimes[i];
+    }
+
+    if (kMin_Result == result) {
+        wallNode.append(wallMin / itersPerTiming);
+        truncWall.append(truncWallMin / itersPerTiming);
+        cpuNode.append(cpuMin / itersPerTiming);
+        truncCpu.append(truncCpuMin / itersPerTiming);
+        gpuNode.append(gpuMin / itersPerTiming);
+    } else if (kAvg_Result == result) {
+        int divisor = numTimings * itersPerTiming;
+        wallNode.append(wallSum / divisor);
+        truncWall.append(truncWallSum / divisor);
+        cpuNode.append(cpuSum / divisor);
+        truncCpu.append(truncCpuSum / divisor);
+        gpuNode.append(gpuSum / divisor);
+    }
+
+    if (timerFlags & kWall_Flag) {
+        dataNode["wall"] = wallNode;
+    }
+    if (timerFlags & kTruncatedWall_Flag) {
+        dataNode["truncWall"] = truncWall;
+    }
+    if (timerFlags & kCpu_Flag) {
+        dataNode["cpu"] = cpuNode;
+    }
+    if (timerFlags & kTruncatedCpu_Flag) {
+        dataNode["trucCpu"] = truncCpu;
+    }
+    if ((timerFlags & kGpu_Flag) && gpuSum > 0) {
+        dataNode["gpu"] = gpuNode;
+    }
+    return dataNode;
+}
+#endif  // SK_BUILD_JSON_WRITER