Add stats about cache hits and execution strategies to Bazel's UI.

Fixes: 2846

RELNOTES: Bazel now displays information about remote cache hits and execution strategies used in its UI after every build and test, and adds a corresponding line "process stats" to BuildToolLogs in BEP.
PiperOrigin-RevId: 191441770

2 files changed, 121 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/runtime/BuildSummaryStatsModule.java b/src/main/java/com/google/devtools/build/lib/runtime/BuildSummaryStatsModule.java
index 927355d9a9..4d2cdcef78 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/BuildSummaryStatsModule.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/BuildSummaryStatsModule.java
@@ -18,6 +18,7 @@ import com.google.common.collect.ImmutableList;
 import com.google.common.eventbus.EventBus;
 import com.google.common.eventbus.Subscribe;
 import com.google.devtools.build.lib.actions.ActionKeyContext;
+import com.google.devtools.build.lib.actions.ActionResultReceivedEvent;
 import com.google.devtools.build.lib.buildeventstream.BuildToolLogs;
 import com.google.devtools.build.lib.buildtool.BuildRequest;
 import com.google.devtools.build.lib.buildtool.buildevent.BuildCompleteEvent;
@@ -50,11 +51,14 @@ public class BuildSummaryStatsModule extends BlazeModule {
   private boolean enabled;
   private boolean discardActions;
 
+  private SpawnStats spawnStats;
+
   @Override
   public void beforeCommand(CommandEnvironment env) {
     this.reporter = env.getReporter();
     this.eventBus = env.getEventBus();
     this.actionKeyContext = env.getSkyframeExecutor().getActionKeyContext();
+    this.spawnStats = new SpawnStats();
     eventBus.register(this);
   }
 
@@ -63,6 +67,7 @@ public class BuildSummaryStatsModule extends BlazeModule {
     this.criticalPathComputer = null;
     this.eventBus = null;
     this.reporter = null;
+    this.spawnStats = null;
   }
 
   @Override
@@ -81,6 +86,11 @@ public class BuildSummaryStatsModule extends BlazeModule {
   }
 
   @Subscribe
+  public void actionResultReceived(ActionResultReceivedEvent event) {
+    spawnStats.countActionResult(event.getActionResult());
+  }
+
+  @Subscribe
   public void buildComplete(BuildCompleteEvent event) {
     try {
       // We might want to make this conditional on a flag; it can sometimes be a bit of a nuisance.
@@ -115,6 +125,11 @@ public class BuildSummaryStatsModule extends BlazeModule {
       }
 
       reporter.handle(Event.info(Joiner.on(", ").join(items)));
+
+      String spawnSummary = spawnStats.getSummary();
+      reporter.handle(Event.info(spawnSummary));
+      statistics.add(Pair.of("process stats", ByteString.copyFromUtf8(spawnSummary)));
+
       reporter.post(new BuildToolLogs(statistics, ImmutableList.of()));
     } finally {
       criticalPathComputer = null;
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/SpawnStats.java b/src/main/java/com/google/devtools/build/lib/runtime/SpawnStats.java
new file mode 100644
index 0000000000..dcb68ca8a9
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/runtime/SpawnStats.java
@@ -0,0 +1,106 @@
+// 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.runtime;
+
+import com.google.common.collect.ConcurrentHashMultiset;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.Multiset;
+import com.google.devtools.build.lib.actions.ActionResult;
+import com.google.devtools.build.lib.actions.SpawnResult;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import javax.annotation.concurrent.ThreadSafe;
+
+/** Collects results from SpawnResult. */
+@ThreadSafe
+class SpawnStats {
+  private final ConcurrentHashMultiset<String> runners = ConcurrentHashMultiset.create();
+  private static final ImmutableList<String> REPORT_FIRST = ImmutableList.of("remote cache hit");
+
+  public void countActionResult(ActionResult actionResult) {
+    for (SpawnResult r : actionResult.spawnResults()) {
+      countRunnerName(r.getRunnerName());
+    }
+  }
+
+  public void countRunnerName(String runner) {
+    runners.add(runner);
+  }
+
+  private static class ResultString {
+    StringBuilder result = new StringBuilder();
+    String firstRunner;
+    int spawnsCount = 0;
+    int runnersNum = 0;
+
+    public int spawnsCount() {
+      return spawnsCount;
+    }
+
+    public void add(String name, int count) {
+      spawnsCount += count;
+      runnersNum += 1;
+
+      if (runnersNum == 1) {
+        firstRunner = name;
+      }
+
+      if (result.length() > 0) {
+        result.append(", ");
+      }
+      result.append(count);
+      result.append(" ");
+      result.append(name);
+    }
+
+    @Override
+    public String toString() {
+      if (runnersNum == 0) {
+        return "";
+      }
+      if (runnersNum == 1) {
+        return ", " + firstRunner;
+      }
+      return ": " + result;
+    }
+  }
+
+  /*
+   * Returns a human-readable summary of spawns counted.
+   */
+  public String getSummary() {
+    ResultString result = new ResultString();
+
+    // First report cache results.
+    for (String s : REPORT_FIRST) {
+      int count = runners.setCount(s, 0);
+      if (count > 0) {
+        result.add(s, count);
+      }
+    }
+
+    // Sort the rest alphabetically
+    ArrayList<Multiset.Entry<String>> list = new ArrayList<>(runners.entrySet());
+    Collections.sort(list, Comparator.comparing(e -> e.getElement()));
+
+    for (Multiset.Entry<String> e : list) {
+      result.add(e.getElement(), e.getCount());
+    }
+
+    int total = result.spawnsCount();
+    return total + " process" + (total == 1 ? "" : "es") + result + ".";
+  }
+}