experimental UI: use LoadingProgressReceiver

Subscribe to the LoadingPhaseStartedEvent to get the LoadingProgressReceiver;
use it to provide information about the loading progress. As this event will not
be raised by the LegacyLoadingPhaseRunner, do not depend on this event and still
produce a sensible status bar if it is never raised.

--
Change-Id: I1db24ceaf7de4fc42d00b02f470066cb38c877b4
Reviewed-on: https://bazel-review.googlesource.com/#/c/3270
MOS_MIGRATED_REVID=119261675

3 files changed, 38 insertions, 1 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/runtime/ExperimentalEventHandler.java b/src/main/java/com/google/devtools/build/lib/runtime/ExperimentalEventHandler.java
index dc488bd6e0..cfa284f7d9 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/ExperimentalEventHandler.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/ExperimentalEventHandler.java
@@ -24,6 +24,7 @@ import com.google.devtools.build.lib.buildtool.buildevent.ExecutionProgressRecei
 import com.google.devtools.build.lib.events.Event;
 import com.google.devtools.build.lib.events.EventKind;
 import com.google.devtools.build.lib.pkgcache.LoadingPhaseCompleteEvent;
+import com.google.devtools.build.lib.skyframe.LoadingPhaseStartedEvent;
 import com.google.devtools.build.lib.util.Clock;
 import com.google.devtools.build.lib.util.io.AnsiTerminal;
 import com.google.devtools.build.lib.util.io.LineCountingAnsiTerminalWriter;
@@ -150,6 +151,12 @@ public class ExperimentalEventHandler extends BlazeCommandEventHandler {
   }
 
   @Subscribe
+  public void loadingStarted(LoadingPhaseStartedEvent event) {
+    stateTracker.loadingStarted(event);
+    refresh();
+  }
+
+  @Subscribe
   public void loadingComplete(LoadingPhaseCompleteEvent event) {
     stateTracker.loadingComplete(event);
     refresh();
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/ExperimentalStateTracker.java b/src/main/java/com/google/devtools/build/lib/runtime/ExperimentalStateTracker.java
index 0764d53778..bddd3c086e 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/ExperimentalStateTracker.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/ExperimentalStateTracker.java
@@ -22,6 +22,8 @@ import com.google.devtools.build.lib.buildtool.buildevent.BuildCompleteEvent;
 import com.google.devtools.build.lib.buildtool.buildevent.BuildStartingEvent;
 import com.google.devtools.build.lib.buildtool.buildevent.ExecutionProgressReceiverAvailableEvent;
 import com.google.devtools.build.lib.pkgcache.LoadingPhaseCompleteEvent;
+import com.google.devtools.build.lib.skyframe.LoadingPhaseStartedEvent;
+import com.google.devtools.build.lib.skyframe.LoadingProgressReceiver;
 import com.google.devtools.build.lib.util.Clock;
 import com.google.devtools.build.lib.util.io.AnsiTerminalWriter;
 
@@ -54,6 +56,7 @@ class ExperimentalStateTracker {
   private boolean ok;
 
   private ExecutionProgressReceiver executionProgressReceiver;
+  private LoadingProgressReceiver loadingProgressReceiver;
 
   ExperimentalStateTracker(Clock clock) {
     this.runningActions = new ArrayDeque<>();
@@ -68,7 +71,13 @@ class ExperimentalStateTracker {
     additionalMessage = "";
   }
 
+  void loadingStarted(LoadingPhaseStartedEvent event) {
+    status = null;
+    loadingProgressReceiver = event.getLoadingProgressReceiver();
+  }
+
   void loadingComplete(LoadingPhaseCompleteEvent event) {
+    loadingProgressReceiver = null;
     int count = event.getTargets().size();
     status = "Analysing";
     additionalMessage = "" + count + " targets";
@@ -159,6 +168,12 @@ class ExperimentalStateTracker {
     if (runningActions.size() >= 1) {
       return true;
     }
+    if (loadingProgressReceiver != null) {
+      // This is kind-of a hack: since the event handler does not get informed about updates
+      // in the loading phase, indicate that the progress bar might change even though no
+      // explicit update event is known to the event handler.
+      return true;
+    }
     return false;
   }
 
@@ -172,6 +187,14 @@ class ExperimentalStateTracker {
       terminalWriter.append(status + ":").normal().append(" " + additionalMessage);
       return;
     }
+    if (loadingProgressReceiver != null) {
+      terminalWriter
+          .okStatus()
+          .append("Loading:")
+          .normal()
+          .append(" " + loadingProgressReceiver.progressState());
+      return;
+    }
     if (executionProgressReceiver != null) {
       terminalWriter.okStatus().append(executionProgressReceiver.getProgressString());
     } else {
diff --git a/src/test/shell/integration/experimental_ui_test.sh b/src/test/shell/integration/experimental_ui_test.sh
index bb350bca2c..eea40c0cc8 100755
--- a/src/test/shell/integration/experimental_ui_test.sh
+++ b/src/test/shell/integration/experimental_ui_test.sh
@@ -140,6 +140,13 @@ function test_subcommand_notdefault {
   expect_not_log "dragons"
 }
 
-
+function test_loading_progress {
+  bazel clean || fail "bazel clean failed"
+  bazel test --experimental_ui \
+    --experimental_skyframe_target_pattern_evaluator pkg:true 2>$TEST_log \
+    || fail "bazel test failed"
+  # some progress indicator is shown during loading
+  expect_log 'Loading.*[0-9,]* / [0-9,]*'
+}
 
 run_suite "Integration tests for bazel's experimental UI"