From 7c11a2b73279046f31e5bb0a6e1e9ac0df9f3ef3 Mon Sep 17 00:00:00 2001
From: Areek Zillur <areek.zillur@elasticsearch.com>
Date: Fri, 21 Oct 2016 14:48:50 -0400
Subject: [PATCH] cleanup and improve documentation for TWA

---
 .../action/bulk/TransportShardBulkAction.java |  4 ++--
 .../action/delete/TransportDeleteAction.java  |  4 ++--
 .../action/index/TransportIndexAction.java    |  6 ++---
 .../replication/TransportWriteAction.java     | 22 ++++++++-----------
 .../TransportWriteActionTests.java            | 14 ++++++------
 5 files changed, 23 insertions(+), 27 deletions(-)

diff --git a/core/src/main/java/org/elasticsearch/action/bulk/TransportShardBulkAction.java b/core/src/main/java/org/elasticsearch/action/bulk/TransportShardBulkAction.java
index b765e19a200..d97fc47af25 100644
--- a/core/src/main/java/org/elasticsearch/action/bulk/TransportShardBulkAction.java
+++ b/core/src/main/java/org/elasticsearch/action/bulk/TransportShardBulkAction.java
@@ -101,7 +101,7 @@ public class TransportShardBulkAction extends TransportWriteAction<BulkShardRequ
     }
 
     @Override
-    protected WritePrimaryResult onPrimaryShard(BulkShardRequest request, IndexShard primary) throws Exception {
+    protected WritePrimaryResult shardOperationOnPrimary(BulkShardRequest request, IndexShard primary) throws Exception {
         final IndexMetaData metaData = primary.indexSettings().getIndexMetaData();
 
         long[] preVersions = new long[request.items().length];
@@ -321,7 +321,7 @@ public class TransportShardBulkAction extends TransportWriteAction<BulkShardRequ
     }
 
     @Override
-    protected WriteReplicaResult onReplicaShard(BulkShardRequest request, IndexShard replica) throws Exception {
+    protected WriteReplicaResult shardOperationOnReplica(BulkShardRequest request, IndexShard replica) throws Exception {
         Translog.Location location = null;
         for (int i = 0; i < request.items().length; i++) {
             BulkItemRequest item = request.items()[i];
diff --git a/core/src/main/java/org/elasticsearch/action/delete/TransportDeleteAction.java b/core/src/main/java/org/elasticsearch/action/delete/TransportDeleteAction.java
index 17d5d3fd9dd..e90d9c1f5b0 100644
--- a/core/src/main/java/org/elasticsearch/action/delete/TransportDeleteAction.java
+++ b/core/src/main/java/org/elasticsearch/action/delete/TransportDeleteAction.java
@@ -122,7 +122,7 @@ public class TransportDeleteAction extends TransportWriteAction<DeleteRequest, D
     }
 
     @Override
-    protected WritePrimaryResult onPrimaryShard(DeleteRequest request, IndexShard primary) {
+    protected WritePrimaryResult shardOperationOnPrimary(DeleteRequest request, IndexShard primary) throws Exception {
         final Engine.Delete operation = executeDeleteRequestOnPrimary(request, primary);
         final DeleteResponse response = operation.hasFailure() ? null :
                 new DeleteResponse(primary.shardId(), request.type(), request.id(), operation.version(), operation.found());
@@ -130,7 +130,7 @@ public class TransportDeleteAction extends TransportWriteAction<DeleteRequest, D
     }
 
     @Override
-    protected WriteReplicaResult onReplicaShard(DeleteRequest request, IndexShard replica) {
+    protected WriteReplicaResult shardOperationOnReplica(DeleteRequest request, IndexShard replica) throws Exception {
         final Engine.Operation operation = executeDeleteRequestOnReplica(request, replica);
         return new WriteReplicaResult(request, operation.getTranslogLocation(), operation.getFailure(), replica);
     }
diff --git a/core/src/main/java/org/elasticsearch/action/index/TransportIndexAction.java b/core/src/main/java/org/elasticsearch/action/index/TransportIndexAction.java
index d514a321f14..be830862c92 100644
--- a/core/src/main/java/org/elasticsearch/action/index/TransportIndexAction.java
+++ b/core/src/main/java/org/elasticsearch/action/index/TransportIndexAction.java
@@ -139,16 +139,16 @@ public class TransportIndexAction extends TransportWriteAction<IndexRequest, Ind
     }
 
     @Override
-    protected WritePrimaryResult onPrimaryShard(IndexRequest request, IndexShard primary) throws Exception {
+    protected WritePrimaryResult shardOperationOnPrimary(IndexRequest request, IndexShard primary) throws Exception {
         final Engine.Operation operation = executeIndexRequestOnPrimary(request, primary, mappingUpdatedAction);
         final IndexResponse response = operation.hasFailure() ? null :
                 new IndexResponse(primary.shardId(), request.type(), request.id(), operation.version(),
-                    ((Engine.Index) operation).isCreated());
+                        ((Engine.Index) operation).isCreated());
         return new WritePrimaryResult(request, response, operation.getTranslogLocation(), operation.getFailure(), primary);
     }
 
     @Override
-    protected WriteReplicaResult onReplicaShard(IndexRequest request, IndexShard replica) {
+    protected WriteReplicaResult shardOperationOnReplica(IndexRequest request, IndexShard replica) throws Exception {
         final Engine.Operation operation = executeIndexRequestOnReplica(request, replica);
         return new WriteReplicaResult(request, operation.getTranslogLocation(), operation.getFailure(), replica);
     }
diff --git a/core/src/main/java/org/elasticsearch/action/support/replication/TransportWriteAction.java b/core/src/main/java/org/elasticsearch/action/support/replication/TransportWriteAction.java
index feac9066357..eb6073d7ad4 100644
--- a/core/src/main/java/org/elasticsearch/action/support/replication/TransportWriteAction.java
+++ b/core/src/main/java/org/elasticsearch/action/support/replication/TransportWriteAction.java
@@ -44,6 +44,7 @@ import java.util.function.Supplier;
 
 /**
  * Base class for transport actions that modify data in some shard like index, delete, and shardBulk.
+ * Allows performing async actions (e.g. refresh) after performing write operations on primary and replica shards
  */
 public abstract class TransportWriteAction<
             Request extends ReplicatedWriteRequest<Request>,
@@ -61,26 +62,21 @@ public abstract class TransportWriteAction<
 
     /**
      * Called on the primary with a reference to the primary {@linkplain IndexShard} to modify.
+     *
+     * @return the result of the operation on primary, including current translog location and operation response and failure
+     * async refresh is performed on the <code>primary</code> shard according to the <code>Request</code> refresh policy
      */
-    protected abstract WritePrimaryResult onPrimaryShard(Request request, IndexShard primary) throws Exception;
+    @Override
+    protected abstract WritePrimaryResult shardOperationOnPrimary(Request request, IndexShard primary) throws Exception;
 
     /**
      * Called once per replica with a reference to the replica {@linkplain IndexShard} to modify.
      *
-     * @return the result of the replication operation containing either the translog location of the {@linkplain IndexShard}
-     * after the write was completed or a failure if the operation failed
+     * @return the result of the operation on replica, including current translog location and operation response and failure
+     * async refresh is performed on the <code>replica</code> shard according to the <code>ReplicaRequest</code> refresh policy
      */
-    protected abstract WriteReplicaResult onReplicaShard(ReplicaRequest request, IndexShard replica) throws Exception;
-
     @Override
-    protected final WritePrimaryResult shardOperationOnPrimary(Request request, IndexShard primary) throws Exception {
-        return onPrimaryShard(request, primary);
-    }
-
-    @Override
-    protected final WriteReplicaResult shardOperationOnReplica(ReplicaRequest request, IndexShard replica) throws Exception {
-        return onReplicaShard(request, replica);
-    }
+    protected abstract WriteReplicaResult shardOperationOnReplica(ReplicaRequest request, IndexShard replica) throws Exception;
 
     /**
      * Result of taking the action on the primary.
diff --git a/core/src/test/java/org/elasticsearch/action/support/replication/TransportWriteActionTests.java b/core/src/test/java/org/elasticsearch/action/support/replication/TransportWriteActionTests.java
index 15aed84e1f6..66251c92abf 100644
--- a/core/src/test/java/org/elasticsearch/action/support/replication/TransportWriteActionTests.java
+++ b/core/src/test/java/org/elasticsearch/action/support/replication/TransportWriteActionTests.java
@@ -136,19 +136,19 @@ public class TransportWriteActionTests extends ESTestCase {
         }
 
         @Override
-        protected WritePrimaryResult onPrimaryShard(TestRequest request, IndexShard primary) throws Exception {
+        protected TestResponse newResponseInstance() {
+            return new TestResponse();
+        }
+
+        @Override
+        protected WritePrimaryResult shardOperationOnPrimary(TestRequest request, IndexShard primary) throws Exception {
             return new WritePrimaryResult(request, new TestResponse(), location, null, primary);
         }
 
         @Override
-        protected WriteReplicaResult onReplicaShard(TestRequest request, IndexShard replica) {
+        protected WriteReplicaResult shardOperationOnReplica(TestRequest request, IndexShard replica) throws Exception {
             return new WriteReplicaResult(request, location, null, replica);
         }
-
-        @Override
-        protected TestResponse newResponseInstance() {
-            return new TestResponse();
-        }
     }
 
     private static class TestRequest extends ReplicatedWriteRequest<TestRequest> {