Revert "perf: Skip gRPC trailers for StreamingRead & ExecuteStreamingSql (#3661)"

This reverts commit bd4b1f5.

Author: sakthivelmanii

google-cloud-spanner/src/main/java/com/google/cloud/spanner/GrpcStreamIterator.java

@@ -52,7 +52,6 @@ class GrpcStreamIterator extends AbstractIterator<PartialResultSet>
   private TimeUnit streamWaitTimeoutUnit;
   private long streamWaitTimeoutValue;
   private SpannerException error;
-  private boolean done;
 
   @VisibleForTesting
   GrpcStreamIterator(int prefetchChunks, boolean cancelQueryWhenClientIsClosed) {
@@ -167,17 +166,11 @@ private class ConsumerImpl implements SpannerRpc.ResultStreamConsumer {
     @Override
     public void onPartialResultSet(PartialResultSet results) {
       addToStream(results);
-      if (results.getLast()) {
-        done = true;
-        addToStream(END_OF_STREAM);
-      }
     }
 
     @Override
     public void onCompleted() {
-      if (!done) {
-        addToStream(END_OF_STREAM);
-      }
+      addToStream(END_OF_STREAM);
     }
 
     @Override

google-cloud-spanner/src/test/java/com/google/cloud/spanner/GrpcResultSetTest.java

@@ -19,7 +19,6 @@
 import static com.google.common.testing.SerializableTester.reserialize;
 import static com.google.common.truth.Truth.assertThat;
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertThrows;
 import static org.junit.Assert.assertTrue;
 
@@ -1116,58 +1115,4 @@ public void getProtoEnumList() {
           resultSet.getProtoEnum(0, Genre::forNumber);
         });
   }
-
-  @Test
-  public void verifyResultSetWithLastTrue() {
-    long[] longArray = {111, 333, 444, 0, -1, -2234, Long.MAX_VALUE, Long.MIN_VALUE};
-
-    consumer.onPartialResultSet(
-        PartialResultSet.newBuilder()
-            .setMetadata(
-                makeMetadata(Type.struct(Type.StructField.of("f", Type.array(Type.int64())))))
-            .addValues(Value.int64Array(longArray).toProto())
-            .setLast(false)
-            .build());
-    assertTrue(resultSet.next());
-    consumer.onPartialResultSet(
-        PartialResultSet.newBuilder()
-            .setMetadata(
-                makeMetadata(Type.struct(Type.StructField.of("f", Type.array(Type.int64())))))
-            .addValues(Value.int64Array(longArray).toProto())
-            .setLast(true)
-            .build());
-    assertTrue(resultSet.next());
-    assertFalse(resultSet.next());
-    consumer.onCompleted();
-  }
-
-  @Test
-  public void shouldThrowDeadlineExceededIfLastTrueIsNotReceived() {
-    long[] longArray = {111, 333, 444, 0, -1, -2234, Long.MAX_VALUE, Long.MIN_VALUE};
-
-    consumer.onPartialResultSet(
-        PartialResultSet.newBuilder()
-            .setMetadata(
-                makeMetadata(Type.struct(Type.StructField.of("f", Type.array(Type.int64())))))
-            .addValues(Value.int64Array(longArray).toProto())
-            .setLast(false)
-            .build());
-    assertTrue(resultSet.next());
-    consumer.onPartialResultSet(
-        PartialResultSet.newBuilder()
-            .setMetadata(
-                makeMetadata(Type.struct(Type.StructField.of("f", Type.array(Type.int64())))))
-            .addValues(Value.int64Array(longArray).toProto())
-            .setLast(false)
-            .build());
-    assertTrue(resultSet.next());
-    SpannerException spannerException =
-        assertThrows(
-            SpannerException.class,
-            () -> {
-              assertThat(resultSet.next()).isFalse();
-            });
-    assertEquals("DEADLINE_EXCEEDED: stream wait timeout", spannerException.getMessage());
-    consumer.onCompleted();
-  }
 }