BuildEventStreamerModule: catch early build events

Abusing the checkEnvironment method, register early on the event bus
and catch all events till the time we are supposed to process the options.
This solves the problem that events relevant to the build event stream are
posted (e.g., the GotOptions event) before(!) we know if a BuildEventStreamer
is required.

--
Change-Id: Iac63302351b862772638791932bcaa58b60b22fb
Reviewed-on: https://cr.bazel.build/9457
PiperOrigin-RevId: 151123359
MOS_MIGRATED_REVID=151123359

1 files changed, 32 insertions, 6 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/runtime/BuildEventStreamerModule.java b/src/main/java/com/google/devtools/build/lib/runtime/BuildEventStreamerModule.java
index 47f5b089d6..983aeb38e5 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/BuildEventStreamerModule.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/BuildEventStreamerModule.java
@@ -22,6 +22,8 @@ import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Optional;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
+import com.google.common.eventbus.Subscribe;
+import com.google.devtools.build.lib.buildeventstream.BuildEvent;
 import com.google.devtools.build.lib.buildeventstream.BuildEventTransport;
 import com.google.devtools.build.lib.buildeventstream.PathConverter;
 import com.google.devtools.build.lib.buildeventstream.transports.BuildEventStreamOptions;
@@ -31,6 +33,8 @@ import com.google.devtools.build.lib.vfs.Path;
 import com.google.devtools.common.options.OptionsBase;
 import com.google.devtools.common.options.OptionsProvider;
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
 
 
 /** Module responsible for configuring BuildEventStreamer and transports. */
@@ -38,26 +42,48 @@ public class BuildEventStreamerModule extends BlazeModule {
 
   private CommandEnvironment commandEnvironment;
 
+  private static class BuildEventRecorder {
+    private final List<BuildEvent> events = new ArrayList<>();
+
+    @Subscribe
+    public void buildEvent(BuildEvent event) {
+      events.add(event);
+    }
+
+    List<BuildEvent> getEvents() {
+      return events;
+    }
+  }
+
+  private BuildEventRecorder buildEventRecorder;
+
   @Override
   public Iterable<Class<? extends OptionsBase>> getCommandOptions(Command command) {
     return ImmutableList.<Class<? extends OptionsBase>>of(BuildEventStreamOptions.class);
   }
 
   @Override
-  public void beforeCommand(Command command, CommandEnvironment commandEnvironment)
-      throws AbruptExitException {
+  public void checkEnvironment(CommandEnvironment commandEnvironment) {
     this.commandEnvironment = commandEnvironment;
+    this.buildEventRecorder = new BuildEventRecorder();
+    commandEnvironment.getEventBus().register(buildEventRecorder);
   }
 
   @Override
   public void handleOptions(OptionsProvider optionsProvider) {
     checkState(commandEnvironment != null, "Methods called out of order");
-    Optional<BuildEventStreamer> streamer =
+    Optional<BuildEventStreamer> maybeStreamer =
         tryCreateStreamer(optionsProvider, commandEnvironment.getBlazeModuleEnvironment());
-    if (streamer.isPresent()) {
-      commandEnvironment.getReporter().addHandler(streamer.get());
-      commandEnvironment.getEventBus().register(streamer.get());
+    if (maybeStreamer.isPresent()) {
+      BuildEventStreamer streamer = maybeStreamer.get();
+      commandEnvironment.getReporter().addHandler(streamer);
+      commandEnvironment.getEventBus().register(streamer);
+      for (BuildEvent event : buildEventRecorder.getEvents()) {
+        streamer.buildEvent(event);
+      }
     }
+    commandEnvironment.getEventBus().unregister(buildEventRecorder);
+    this.buildEventRecorder = null;
   }
 
   @VisibleForTesting