New event: update requested (#351)

Add new event EVENT_TYPE_WORKFLOW_EXECUTION_UPDATE_REQUESTED for update reapply.

temporal/api/enums/v1/event_type.proto

@@ -167,4 +167,8 @@ enum EventType {
     EVENT_TYPE_ACTIVITY_PROPERTIES_MODIFIED_EXTERNALLY = 45;
     // Workflow properties modified by user workflow code
     EVENT_TYPE_WORKFLOW_PROPERTIES_MODIFIED = 46;
+    // An update was requested. Note that not all update requests result in this
+    // event. See UpdateRequestedEventOrigin for situations in which this event
+    // is created.
+    EVENT_TYPE_WORKFLOW_EXECUTION_UPDATE_REQUESTED = 47;
 }

temporal/api/enums/v1/reset.proto

@@ -36,6 +36,8 @@ enum ResetReapplyExcludeType {
     RESET_REAPPLY_EXCLUDE_TYPE_UNSPECIFIED = 0;
     // Exclude signals when reapplying events.
     RESET_REAPPLY_EXCLUDE_TYPE_SIGNAL = 1;
+    // Exclude updates when reapplying events.
+    RESET_REAPPLY_EXCLUDE_TYPE_UPDATE = 2;
 }
 
 // Event types to include when reapplying events. Deprecated: applications

temporal/api/enums/v1/update.proto

@@ -54,3 +54,13 @@ enum UpdateWorkflowExecutionLifecycleStage {
     // on a worker and has either been rejected or returned a value or an error.
     UPDATE_WORKFLOW_EXECUTION_LIFECYCLE_STAGE_COMPLETED = 3;
 }
+
+// Records why a WorkflowExecutionUpdateRequestedEvent was written to history.
+// Note that not all update requests result in this event.
+enum UpdateRequestedEventOrigin {
+    UPDATE_REQUESTED_EVENT_ORIGIN_UNSPECIFIED = 0;
+    // The UpdateRequested event was created when reapplying events during reset
+    // or replication. I.e. an accepted update on one branch of workflow history
+    // was converted into a requested update on a different branch.
+    UPDATE_REQUESTED_EVENT_ORIGIN_REAPPLY = 1;
+}

temporal/api/history/v1/message.proto

@@ -36,6 +36,7 @@ import "google/protobuf/timestamp.proto";
 
 import "temporal/api/enums/v1/event_type.proto";
 import "temporal/api/enums/v1/failed_cause.proto";
+import "temporal/api/enums/v1/update.proto";
 import "temporal/api/enums/v1/workflow.proto";
 import "temporal/api/common/v1/message.proto";
 import "temporal/api/failure/v1/message.proto";
@@ -749,6 +750,12 @@ message WorkflowExecutionUpdateRejectedEventAttributes {
     temporal.api.failure.v1.Failure failure = 5;
 }
 
+message WorkflowExecutionUpdateRequestedEventAttributes {
+    // The update request associated with this event.
+    temporal.api.update.v1.Request request = 1;
+    // An explanation of why this event was written to history.
+    temporal.api.enums.v1.UpdateRequestedEventOrigin origin = 2;
+}
 
 // History events are the method by which Temporal SDKs advance (or recreate) workflow state.
 // See the `EventType` enum for more info about what each event is for.
@@ -814,6 +821,7 @@ message HistoryEvent {
         WorkflowPropertiesModifiedExternallyEventAttributes workflow_properties_modified_externally_event_attributes = 49;
         ActivityPropertiesModifiedExternallyEventAttributes activity_properties_modified_externally_event_attributes = 50;
         WorkflowPropertiesModifiedEventAttributes workflow_properties_modified_event_attributes = 51;
+        WorkflowExecutionUpdateRequestedEventAttributes workflow_execution_update_requested_event_attributes = 52;
     }
 }