more noop channel primer changes

Change-Id: I3baa8e93bc614efe21f1159a708be36881120e34

Author: nicholsl

google-cloud-bigtable/clirr-ignored-differences.xml

@@ -397,21 +397,26 @@
         <to>*</to>
     </difference>
     <difference>
-        <!-- InternalApi was updated -->
         <differenceType>4001</differenceType>
         <className>com/google/cloud/bigtable/data/v2/stub/BigtableChannelPrimer</className>
-        <to>*</to>
+        <to>com/google/api/gax/grpc/ChannelPrimer</to>
     </difference>
     <difference>
-        <!-- InternalApi was updated -->
         <differenceType>4001</differenceType>
         <className>com/google/cloud/bigtable/data/v2/stub/NoOpChannelPrimer</className>
-        <to>*</to>
+        <to>com/google/api/gax/grpc/ChannelPrimer</to>
     </difference>
     <difference>
         <differenceType>7005</differenceType>
         <className>com/google/cloud/bigtable/gaxx/grpc/BigtableChannelPool</className>
         <method>*create*</method>
         <to>*</to>
     </difference>
+    <difference>
+        <!-- InternalApi was updated -->
+        <differenceType>7005</differenceType>
+        <className>com/google/cloud/bigtable/gaxx/grpc/BigtableTransportChannelProvider</className>
+        <method>*create*</method>
+        <to>*</to>
+    </difference>
 </differences>

google-cloud-bigtable/src/main/java/com/google/cloud/bigtable/data/v2/stub/NoOpChannelPrimer.java

@@ -36,6 +36,8 @@ public void primeChannel(ManagedChannel managedChannel) {
 
   @Override
   public SettableApiFuture<PingAndWarmResponse> sendPrimeRequestsAsync(ManagedChannel var1) {
-    return null;
+    SettableApiFuture future = SettableApiFuture.create();
+    future.set(PingAndWarmResponse.getDefaultInstance());
+    return future;
   }
 }

google-cloud-bigtable/src/main/java/com/google/cloud/bigtable/gaxx/grpc/ChannelPoolHealthChecker.java

@@ -18,6 +18,8 @@
 import com.google.api.core.SettableApiFuture;
 import com.google.auto.value.AutoValue;
 import com.google.bigtable.v2.PingAndWarmResponse;
+import com.google.cloud.bigtable.data.v2.stub.BigtableChannelPrimer;
+import com.google.cloud.bigtable.data.v2.stub.NoOpChannelPrimer;
 import com.google.cloud.bigtable.gaxx.grpc.BigtableChannelPool.Entry;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.ImmutableList;
@@ -113,9 +115,18 @@ public void stop() {
   @VisibleForTesting
   void runProbes() {
     for (Entry entry : this.entrySupplier.get()) {
-      Instant startTime = clock.instant();
-      SettableApiFuture<PingAndWarmResponse> probeFuture =
-          channelPrimer.sendPrimeRequestsAsync(entry.getManagedChannel());
+      final Instant startTime = clock.instant();
+      final SettableApiFuture<PingAndWarmResponse> probeFuture;
+
+      if (channelPrimer instanceof BigtableChannelPrimer) {
+        BigtableChannelPrimer primer = (BigtableChannelPrimer) channelPrimer;
+        probeFuture = primer.sendPrimeRequestsAsync(entry.getManagedChannel());
+      } else if (channelPrimer instanceof NoOpChannelPrimer) {
+        NoOpChannelPrimer primer = (NoOpChannelPrimer) channelPrimer;
+        probeFuture = primer.sendPrimeRequestsAsync(entry.getManagedChannel());
+      } else {
+        continue;
+      }
       probeFuture.addListener(() -> onComplete(entry, startTime, probeFuture), executor);
     }
   }