Add experimental tool to turn Bazel Json profiles into graphs.

RELNOTES: None
PiperOrigin-RevId: 208509424

2 files changed, 158 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/profiler/BUILD b/src/main/java/com/google/devtools/build/lib/profiler/BUILD
index 85c506dceb..bf703c4d4d 100644
--- a/src/main/java/com/google/devtools/build/lib/profiler/BUILD
+++ b/src/main/java/com/google/devtools/build/lib/profiler/BUILD
@@ -43,3 +43,16 @@ java_library(
         "//third_party:jsr305",
     ],
 )
+
+java_binary(
+    name = "profiler-grapher",
+    srcs = glob([
+        "grapher/*.java",
+    ]),
+    main_class = "com.google.devtools.build.lib.profiler.grapher.ProfileGrapher",
+    deps = [
+        ":profiler",
+        "//third_party:gson",
+        "//third_party:guava",
+    ],
+)
diff --git a/src/main/java/com/google/devtools/build/lib/profiler/grapher/ProfileGrapher.java b/src/main/java/com/google/devtools/build/lib/profiler/grapher/ProfileGrapher.java
new file mode 100644
index 0000000000..6f77404c21
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/profiler/grapher/ProfileGrapher.java
@@ -0,0 +1,145 @@
+// Copyright 2018 The Bazel Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+package com.google.devtools.build.lib.profiler.grapher;
+
+import com.google.common.collect.ImmutableList;
+import com.google.devtools.build.lib.profiler.CpuUsageTimeSeries;
+import com.google.gson.stream.JsonReader;
+import java.io.BufferedReader;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.StringJoiner;
+
+/**
+ * An experimental tool to turn Json profiles into graphs. Do not depend on the continuing existence
+ * of this tool.
+ *
+ * <p>Run this tool like so: bazel run \
+ * //src/main/java/com/google/devtools/build/lib/profiler:profiler-grapher \
+ * -- /path/to/command.profile > /tmp/tmp.csv
+ *
+ * <p>Plot the resulting CSV with gnuplot like so: gnuplot -p -e \
+ * set datafile sep ','; plot for [col=1:3] '/tmp/tmp.csv' using col lw 2 with lines \
+ * title columnheader"
+ */
+public class ProfileGrapher {
+  public static final long DEFAULT_BUCKET_SIZE_MILLIS = 1000;
+
+  public static void main(String[] args) throws IOException {
+    if (args.length != 1) {
+      System.err.println("Requires filename of a Bazel profile in Chrome event trace format.");
+      System.exit(1);
+    }
+    String filename = args[0];
+
+    // TODO(twerth): Make it possible to select the set of profiler task descriptions on the command
+    // line.
+    ImmutableList<String> profilerTaskDescriptions =
+        ImmutableList.of(
+            "Remote execution process wall time",
+            "action processing",
+            "Remote execution file fetching");
+    Map<String, CpuUsageTimeSeries> seriesMap = new LinkedHashMap<>();
+    for (String profilerTaskDescription : profilerTaskDescriptions) {
+      seriesMap.put(profilerTaskDescription, new CpuUsageTimeSeries(0, DEFAULT_BUCKET_SIZE_MILLIS));
+    }
+
+    long maxEndTime = 0;
+    // TODO(twerth): Support gzip compressed profiles.
+    try (JsonReader reader =
+        new JsonReader(
+            new BufferedReader(
+                new InputStreamReader(new FileInputStream(filename), StandardCharsets.UTF_8)))) {
+      reader.beginArray();
+      while (reader.hasNext()) {
+        reader.beginObject();
+        Map<String, Object> data = new HashMap<>();
+        while (reader.hasNext()) {
+          String name = reader.nextName();
+          Object value;
+          switch (reader.peek()) {
+            case BOOLEAN:
+              value = reader.nextBoolean();
+              break;
+            case NUMBER:
+              value = reader.nextDouble();
+              break;
+            case STRING:
+              value = reader.nextString();
+              break;
+            default:
+              reader.skipValue();
+              continue;
+          }
+          data.put(name, value);
+        }
+        Object cat = data.get("cat");
+        CpuUsageTimeSeries series = seriesMap.get(cat);
+        if (series != null) {
+          Long endTimeMillis = decodeAndAdd(series, data);
+          if (endTimeMillis != null) {
+            maxEndTime = Math.max(maxEndTime, endTimeMillis);
+          }
+        }
+        reader.endObject();
+      }
+      reader.endArray();
+    }
+
+    // Instead of generating a CSV here, we could generate Json and use the Google Charts API to
+    // generate interactive web graphs (https://developers.google.com/chart/).
+    int len = (int) (maxEndTime / DEFAULT_BUCKET_SIZE_MILLIS) + 1;
+    double[][] numbers = new double[seriesMap.size()][];
+    List<Map.Entry<String, CpuUsageTimeSeries>> allSeries = new ArrayList<>(seriesMap.entrySet());
+    // Write the titles in the first line of the CSV
+    StringJoiner stringJoiner = new StringJoiner(",");
+    for (int i = 0; i < numbers.length; i++) {
+      stringJoiner.add(allSeries.get(i).getKey());
+      numbers[i] = allSeries.get(i).getValue().toDoubleArray(len);
+    }
+    System.out.println(stringJoiner.toString());
+
+    for (int i = 0; i < numbers[0].length; i++) {
+      stringJoiner = new StringJoiner(",");
+      for (int j = 0; j < numbers.length; j++) {
+        stringJoiner.add(String.valueOf(numbers[j][i]));
+      }
+      System.out.println(stringJoiner.toString());
+    }
+  }
+
+  /**
+   * Decodes the start time and duration from the data, adds it to the given series and returns the
+   * end time in milliseconds if it was possible to decode the data, otherwise null.
+   */
+  private static Long decodeAndAdd(CpuUsageTimeSeries series, Map<String, Object> data) {
+    Double ts = (Double) data.get("ts");
+    Double dur = (Double) data.get("dur");
+    if (ts == null || dur == null) {
+      return null;
+    }
+    long durationMillis = Math.round(dur.doubleValue() / 1000);
+    long startTimeMillis = Math.round(ts.doubleValue() / 1000);
+    long endTimeMillis = startTimeMillis + durationMillis;
+    series.addRange(startTimeMillis, endTimeMillis);
+    return endTimeMillis;
+  }
+}