Fix getVersion without decision event (#309)

* Fix getVersion without decision event
* Add sleep before signal
* Use completable future instead of sleep

Author: Liang Mei

src/main/java/com/uber/cadence/internal/replay/DecisionsHelper.java

@@ -701,10 +701,6 @@ String getAndIncrementNextId() {
     return String.valueOf(idCounter++);
   }
 
-  HistoryEvent getDecisionEvent(long eventId) {
-    return decisionEvents.getDecisionEvent(eventId);
-  }
-
   Optional<HistoryEvent> getOptionalDecisionEvent(long eventId) {
     return decisionEvents.getOptionalDecisionEvent(eventId);
   }

src/main/java/com/uber/cadence/internal/replay/HistoryHelper.java

@@ -78,18 +78,10 @@ public List<HistoryEvent> getEvents() {
       return events;
     }
 
-    public List<HistoryEvent> getDecisionEvents() {
+    List<HistoryEvent> getDecisionEvents() {
       return decisionEvents;
     }
 
-    HistoryEvent getDecisionEvent(long eventId) {
-      int index = (int) (eventId - nextDecisionEventId);
-      if (index < 0 || index >= decisionEvents.size()) {
-        throw new IllegalArgumentException("No decision event found at eventId=" + eventId);
-      }
-      return decisionEvents.get(index);
-    }
-
     Optional<HistoryEvent> getOptionalDecisionEvent(long eventId) {
       int index = (int) (eventId - nextDecisionEventId);
       if (index < 0 || index >= decisionEvents.size()) {

src/main/java/com/uber/cadence/internal/replay/MarkerHandler.java

@@ -134,11 +134,12 @@ Optional<byte[]> handle(
 
   private Optional<byte[]> getMarkerDataFromHistory(
       long eventId, String markerId, int expectedAcccessCount, DataConverter converter) {
-    HistoryEvent event = decisions.getDecisionEvent(eventId);
-    if (event.getEventType() != EventType.MarkerRecorded) {
+    Optional<HistoryEvent> event = decisions.getOptionalDecisionEvent(eventId);
+    if (!event.isPresent() || event.get().getEventType() != EventType.MarkerRecorded) {
       return Optional.empty();
     }
-    MarkerRecordedEventAttributes attributes = event.getMarkerRecordedEventAttributes();
+
+    MarkerRecordedEventAttributes attributes = event.get().getMarkerRecordedEventAttributes();
     String name = attributes.getMarkerName();
     if (!markerName.equals(name)) {
       return Optional.empty();

src/test/java/com/uber/cadence/workflow/WorkflowTest.java

@@ -114,7 +114,7 @@ public class WorkflowTest {
    */
   private static final boolean DEBUGGER_TIMEOUTS = false;
 
-  public static final String ANNOTATION_TASK_LIST = "WorkflowTest-testExecute[Docker]";
+  private static final String ANNOTATION_TASK_LIST = "WorkflowTest-testExecute[Docker]";
 
   private TracingWorkflowInterceptorFactory tracer;
   private static final boolean useDockerService =
@@ -3733,6 +3733,58 @@ public void testGetVersion() {
         "executeActivity customActivity1");
   }
 
+  static CompletableFuture<Boolean> executionStarted = new CompletableFuture<>();
+  public static class TestGetVersionWithoutDecisionEventWorkflowImpl implements TestWorkflowSignaled {
+
+    CompletablePromise<Boolean> signalReceived = Workflow.newPromise();
+
+    @Override
+    public String execute() {
+      try {
+        if (!getVersionExecuted.contains("getVersionWithoutDecisionEvent")) {
+          // Execute getVersion in non-replay mode.
+          getVersionExecuted.add("getVersionWithoutDecisionEvent");
+          executionStarted.complete(true);
+          signalReceived.get();
+        } else {
+          // Execute getVersion in replay mode. In this case we have no decision event, only a signal.
+          int version = Workflow.getVersion("test_change", Workflow.DEFAULT_VERSION, 1);
+          if (version == Workflow.DEFAULT_VERSION) {
+            signalReceived.get();
+            return "result 1";
+          } else {
+            return "result 2";
+          }
+        }
+      } catch (Exception e) {
+        throw new RuntimeException("failed to get from signal");
+      }
+
+      throw new RuntimeException("unreachable");
+    }
+
+    @Override
+    public void signal1(String arg) {
+      signalReceived.complete(true);
+    }
+  }
+
+  @Test
+  public void testGetVersionWithoutDecisionEvent() throws Exception {
+    Assume.assumeTrue("skipping as there will be no replay", disableStickyExecution);
+    executionStarted = new CompletableFuture<>();
+    getVersionExecuted.remove("getVersionWithoutDecisionEvent");
+    startWorkerFor(TestGetVersionWithoutDecisionEventWorkflowImpl.class);
+    TestWorkflowSignaled workflowStub =
+        workflowClient.newWorkflowStub(
+            TestWorkflowSignaled.class, newWorkflowOptionsBuilder(taskList).build());
+    WorkflowClient.start(workflowStub::execute);
+    executionStarted.get();
+    workflowStub.signal1("test signal");
+    String result = workflowStub.execute();
+    assertEquals("result 1", result);
+  }
+
   // The following test covers the scenario where getVersion call is removed before a
   // non-version-marker decision.
   public static class TestGetVersionRemovedInReplayWorkflowImpl implements TestWorkflow1 {