Add an option to enable an experimental UI

By enabling this option (default is off), a new, still experimental
UI will be used. As it is developped from scratch, this commit simply
implements a UI that does not produce any output at all.

--
Change-Id: I895c0e0744c008212efc7bdfca1457f7907c9b64
Reviewed-on: https://bazel-review.googlesource.com/#/c/3009/
MOS_MIGRATED_REVID=115441032

1 files changed, 8 insertions, 2 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommandDispatcher.java b/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommandDispatcher.java
index 8daee39a0a..262c796db9 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommandDispatcher.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommandDispatcher.java
@@ -624,7 +624,10 @@ public class BlazeCommandDispatcher {
   private EventHandler createEventHandler(OutErr outErr,
       BlazeCommandEventHandler.Options eventOptions) {
     EventHandler eventHandler;
-    if ((eventOptions.useColor() || eventOptions.useCursorControl())) {
+    if (eventOptions.experimentalUi) {
+      // The experimental event handler is not to be rate limited.
+      return new ExperimentalEventHandler(outErr, eventOptions);
+    } else if ((eventOptions.useColor() || eventOptions.useCursorControl())) {
       eventHandler = new FancyTerminalEventHandler(outErr, eventOptions);
     } else {
       eventHandler = new BlazeCommandEventHandler(outErr, eventOptions);
@@ -640,7 +643,10 @@ public class BlazeCommandDispatcher {
     if (eventHandler instanceof FancyTerminalEventHandler) {
       // Make sure that the terminal state of the old event handler is clear
       // before creating a new one.
-      ((FancyTerminalEventHandler)eventHandler).resetTerminal();
+      ((FancyTerminalEventHandler) eventHandler).resetTerminal();
+    }
+    if (eventHandler instanceof ExperimentalEventHandler) {
+      ((ExperimentalEventHandler) eventHandler).resetTerminal();
     }
   }