From 180ec67f241105b6555f16590e8ac41f837b8dab Mon Sep 17 00:00:00 2001
From: Hanzhen Yi <hzyi@google.com>
Date: Fri, 15 Jun 2018 12:10:42 -0700
Subject: [PATCH] Fix code review issues

---
 .../main/java/com/google/cloud/spanner/SpannerImpl.java  | 6 +-----
 .../com/google/cloud/spanner/spi/v1/GapicSpannerRpc.java | 9 +++++++++
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/SpannerImpl.java b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/SpannerImpl.java
index e67129c92d2d..6b4c4b25ba16 100644
--- a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/SpannerImpl.java
+++ b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/SpannerImpl.java
@@ -1069,11 +1069,7 @@ CloseableIterator<PartialResultSet> startStream(@Nullable ByteString resumeToken
                           : request.toBuilder().setResumeToken(resumeToken).build(),
                       stream.consumer(),
                       session.options);
-              // StreamController does not auto-request 1 message. Kick it off mannually
-              call.request(1);
-              if (prefetchChunks > 1) {
-                call.request(prefetchChunks - 1);
-              }
+              call.request(prefetchChunks);
               stream.setCall(call);
               return stream;
             }
diff --git a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/GapicSpannerRpc.java b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/GapicSpannerRpc.java
index 394107661671..6e4346ab0857 100644
--- a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/GapicSpannerRpc.java
+++ b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/GapicSpannerRpc.java
@@ -125,6 +125,12 @@ public GapicSpannerRpc(SpannerOptions options) {
     this.projectId = options.getProjectId();
     this.projectName = PROJECT_NAME_TEMPLATE.instantiate("project", this.projectId);
 
+    // TODO(hzyi): inject userAgent to headerProvider so that it
+    // can be picked up by ChannelProvider
+
+    // create a metadataProvider which combines both internal headers and
+    // per-method-call extra headers for channelProvider to inject the headers
+    // for rpc calls
     ApiClientHeaderProvider.Builder internalHeaderProviderBuilder =
         ApiClientHeaderProvider.newBuilder();
     ApiClientHeaderProvider internalHeaderProvider =
@@ -528,6 +534,9 @@ public SpannerResponseObserver(ResultStreamConsumer consumer) {
 
     @Override
     public void onStart(StreamController controller) {
+
+      // Disable the auto flow control to allow client library
+      // set the number of messages it prefers to request
       controller.disableAutoInboundFlowControl();
       this.controller = controller;
     }