From 223856e871049b2e84be886ab6a58d9fe73435f2 Mon Sep 17 00:00:00 2001
From: Solomon Duskis <sduskis@google.com>
Date: Tue, 30 Apr 2019 12:06:05 -0400
Subject: [PATCH] Pub/Sub: Streamining publisher proto creation. Using a
 prebuit List is faster than adding elements one at a time to a proto list.

---
 .../com/google/cloud/pubsub/v1/Publisher.java | 22 +++++++++++++------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/google-cloud-clients/google-cloud-pubsub/src/main/java/com/google/cloud/pubsub/v1/Publisher.java b/google-cloud-clients/google-cloud-pubsub/src/main/java/com/google/cloud/pubsub/v1/Publisher.java
index 2ec77aaa9d2b..90b010bc4b17 100644
--- a/google-cloud-clients/google-cloud-pubsub/src/main/java/com/google/cloud/pubsub/v1/Publisher.java
+++ b/google-cloud-clients/google-cloud-pubsub/src/main/java/com/google/cloud/pubsub/v1/Publisher.java
@@ -272,13 +272,13 @@ public void publishAllOutstanding() {
   }
 
   private ApiFuture<PublishResponse> publishCall(OutstandingBatch outstandingBatch) {
-    PublishRequest.Builder publishRequest = PublishRequest.newBuilder();
-    publishRequest.setTopic(topicName);
-    for (OutstandingPublish outstandingPublish : outstandingBatch.outstandingPublishes) {
-      publishRequest.addMessages(outstandingPublish.message);
-    }
-
-    return publisherStub.publishCallable().futureCall(publishRequest.build());
+    return publisherStub
+        .publishCallable()
+        .futureCall(
+            PublishRequest.newBuilder()
+                .setTopic(topicName)
+                .addAllMessages(outstandingBatch.getMessages())
+                .build());
   }
 
   private void publishOutstandingBatch(final OutstandingBatch outstandingBatch) {
@@ -342,6 +342,14 @@ private static final class OutstandingBatch {
     int size() {
       return outstandingPublishes.size();
     }
+
+    private List<PubsubMessage> getMessages() {
+      List<PubsubMessage> results = new ArrayList<>(outstandingPublishes.size());
+      for (OutstandingPublish outstandingPublish : outstandingPublishes) {
+        results.add(outstandingPublish.message);
+      }
+      return results;
+    }
   }
 
   private static final class OutstandingPublish {