api: Hide internal metric APIs

Some APIs were marked experimental but had internal APIs in their
surface. These were all changed to internal. And then the internal APIs
were mostly hidden from generated documentation.

All these APIs will eventually become public and maybe even stable. But
they need some iteration before we're ready for others to start using
them.

Author: ejona86

api/build.gradle

@@ -55,7 +55,11 @@ dependencies {
 tasks.named("javadoc").configure {
     source sourceSets.context.allSource
     // We want io.grpc.Internal, but not io.grpc.Internal*
+    exclude 'io/grpc/*MetricInstrument.java'
+    exclude 'io/grpc/*MetricInstrumentRegistry.java'
     exclude 'io/grpc/Internal?*.java'
+    exclude 'io/grpc/MetricRecorder.java'
+    exclude 'io/grpc/MetricSink.java'
 }
 
 tasks.named("sourcesJar").configure {

api/src/main/java/io/grpc/ForwardingChannelBuilder2.java

@@ -258,7 +258,7 @@ public T disableServiceConfigLookUp() {
   }
 
   @Override
-  public T addMetricSink(MetricSink metricSink) {
+  protected T addMetricSink(MetricSink metricSink) {
     delegate().addMetricSink(metricSink);
     return thisT();
   }

api/src/main/java/io/grpc/InternalManagedChannelBuilder.java

@@ -19,6 +19,7 @@
 /**
  * Internal accessors for {@link ManagedChannelBuilder}.
  */
+@Internal
 public final class InternalManagedChannelBuilder {
   private InternalManagedChannelBuilder() {}
 
@@ -27,5 +28,10 @@ public static <T extends ManagedChannelBuilder<T>> T interceptWithTarget(
     return builder.interceptWithTarget(factory);
   }
 
+  public static <T extends ManagedChannelBuilder<T>> T addMetricSink(
+      ManagedChannelBuilder<T> builder, MetricSink metricSink) {
+    return builder.addMetricSink(metricSink);
+  }
+
   public interface InternalInterceptorFactory extends ManagedChannelBuilder.InterceptorFactory {}
 }

api/src/main/java/io/grpc/LoadBalancer.java

@@ -1255,7 +1255,7 @@ public NameResolverRegistry getNameResolverRegistry() {
      *
      * @since 1.64.0
      */
-    @ExperimentalApi("https://github.com/grpc/grpc-java/issues/11110")
+    @Internal
     public MetricRecorder getMetricRecorder() {
       return new MetricRecorder() {};
     }

api/src/main/java/io/grpc/ManagedChannelBuilder.java

@@ -628,8 +628,8 @@ public T disableServiceConfigLookUp() {
    * @return this
    * @since 1.64.0
    */
-  @ExperimentalApi("https://github.com/grpc/grpc-java/issues/11110")
-  public T addMetricSink(MetricSink metricSink) {
+  @Internal
+  protected T addMetricSink(MetricSink metricSink) {
     throw new UnsupportedOperationException();
   }
 

api/src/main/java/io/grpc/MetricSink.java

@@ -23,7 +23,7 @@
 /**
  * An internal interface representing a receiver or aggregator of gRPC metrics data.
  */
-@ExperimentalApi("https://github.com/grpc/grpc-java/issues/11110")
+@Internal
 public interface MetricSink {
 
   /**

core/src/main/java/io/grpc/internal/ManagedChannelImplBuilder.java

@@ -687,7 +687,7 @@ public ManagedChannelImplBuilder enableCheckAuthority() {
   }
 
   @Override
-  public ManagedChannelImplBuilder addMetricSink(MetricSink metricSink) {
+  protected ManagedChannelImplBuilder addMetricSink(MetricSink metricSink) {
     metricSinks.add(checkNotNull(metricSink, "metric sink"));
     return this;
   }

opentelemetry/src/main/java/io/grpc/opentelemetry/GrpcOpenTelemetry.java

@@ -145,7 +145,7 @@ public void configureServerBuilder(ServerBuilder<?> serverBuilder) {
    * Configures the given {@link ManagedChannelBuilder} with OpenTelemetry metrics instrumentation.
    */
   public void configureChannelBuilder(ManagedChannelBuilder<?> builder) {
-    builder.addMetricSink(sink);
+    InternalManagedChannelBuilder.addMetricSink(builder, sink);
     InternalManagedChannelBuilder.interceptWithTarget(
         builder, openTelemetryMetricsModule::getClientInterceptor);
   }

rls/src/test/java/io/grpc/rls/RlsLoadBalancerTest.java

@@ -42,6 +42,7 @@
 import io.grpc.ConnectivityStateInfo;
 import io.grpc.EquivalentAddressGroup;
 import io.grpc.ForwardingChannelBuilder2;
+import io.grpc.InternalManagedChannelBuilder;
 import io.grpc.LoadBalancer.CreateSubchannelArgs;
 import io.grpc.LoadBalancer.Helper;
 import io.grpc.LoadBalancer.PickDetailsConsumer;
@@ -310,10 +311,11 @@ public void metricsWithRealChannel() throws Exception {
         .start());
     MetricSink metrics = mock(MetricSink.class, delegatesTo(new NoopMetricSink()));
     ManagedChannel channel = grpcCleanupRule.register(
-        InProcessChannelBuilder.forName("fake-bigtable.googleapis.com")
-        .defaultServiceConfig(parseJson(getServiceConfigJsonStr()))
-        .addMetricSink(metrics)
-        .directExecutor()
+        InternalManagedChannelBuilder.addMetricSink(
+            InProcessChannelBuilder.forName("fake-bigtable.googleapis.com")
+            .defaultServiceConfig(parseJson(getServiceConfigJsonStr()))
+            .directExecutor(),
+        metrics)
         .build());
 
     StreamRecorder<Void> recorder = StreamRecorder.create();

xds/src/test/java/io/grpc/xds/WeightedRoundRobinLoadBalancerTest.java

@@ -44,6 +44,7 @@
 import io.grpc.ConnectivityStateInfo;
 import io.grpc.DoubleHistogramMetricInstrument;
 import io.grpc.EquivalentAddressGroup;
+import io.grpc.InternalManagedChannelBuilder;
 import io.grpc.LoadBalancer;
 import io.grpc.LoadBalancer.CreateSubchannelArgs;
 import io.grpc.LoadBalancer.Helper;
@@ -1268,11 +1269,13 @@ public void metricWithRealChannel() throws Exception {
         .start());
     MetricSink metrics = mock(MetricSink.class, delegatesTo(new NoopMetricSink()));
     Channel channel = grpcCleanupRule.register(
-        InProcessChannelBuilder.forName(serverName)
-        .defaultServiceConfig(Collections.singletonMap(
-            "loadBalancingConfig", Arrays.asList(Collections.singletonMap(
-                "weighted_round_robin", Collections.emptyMap()))))
-        .addMetricSink(metrics)
+        InternalManagedChannelBuilder.addMetricSink(
+            InProcessChannelBuilder.forName(serverName)
+            .defaultServiceConfig(Collections.singletonMap(
+                "loadBalancingConfig", Arrays.asList(Collections.singletonMap(
+                    "weighted_round_robin", Collections.emptyMap()))))
+            .directExecutor(),
+        metrics)
         .directExecutor()
         .build());