cronet: move call options APIs into an internal accessor class (#6073)

* cronet: move call options APIs into an internal accessor class

* Removed deprecated call option key.

cronet/src/main/java/io/grpc/cronet/CronetCallOptions.java

@@ -17,9 +17,6 @@
 package io.grpc.cronet;
 
 import io.grpc.CallOptions;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Collections;
 
 /** Call options for use with the Cronet transport. */
 public final class CronetCallOptions {
@@ -36,7 +33,7 @@ private CronetCallOptions() {}
    */
   @Deprecated
   public static final CallOptions.Key<Object> CRONET_ANNOTATION_KEY =
-      CallOptions.Key.create("cronet-annotation");
+      CronetClientStream.CRONET_ANNOTATION_KEY;
 
   /**
    * Returns a copy of {@code callOptions} with {@code annotation} included as one of the Cronet
@@ -48,18 +45,6 @@ private CronetCallOptions() {}
    * @param annotation the object to attach to the Cronet stream
    */
   public static CallOptions withAnnotation(CallOptions callOptions, Object annotation) {
-    Collection<Object> existingAnnotations = callOptions.getOption(CRONET_ANNOTATIONS_KEY);
-    ArrayList<Object> newAnnotations;
-    if (existingAnnotations == null) {
-      newAnnotations = new ArrayList<>();
-    } else {
-      newAnnotations = new ArrayList<>(existingAnnotations);
-    }
-    newAnnotations.add(annotation);
-    return callOptions.withOption(
-        CronetCallOptions.CRONET_ANNOTATIONS_KEY, Collections.unmodifiableList(newAnnotations));
+    return CronetClientStream.withAnnotation(callOptions, annotation);
   }
-
-  static final CallOptions.Key<Collection<Object>> CRONET_ANNOTATIONS_KEY =
-      CallOptions.Key.create("cronet-annotations");
 }

cronet/src/main/java/io/grpc/cronet/CronetClientStream.java

@@ -44,6 +44,7 @@
 import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
@@ -63,6 +64,14 @@ class CronetClientStream extends AbstractClientStream {
   private static final int READ_BUFFER_CAPACITY = 4 * 1024;
   private static final ByteBuffer EMPTY_BUFFER = ByteBuffer.allocateDirect(0);
   private static final String LOG_TAG = "grpc-java-cronet";
+
+  @Deprecated
+  static final CallOptions.Key<Object> CRONET_ANNOTATION_KEY =
+      CallOptions.Key.create("cronet-annotation");
+
+  static final CallOptions.Key<Collection<Object>> CRONET_ANNOTATIONS_KEY =
+      CallOptions.Key.create("cronet-annotations");
+
   private final String url;
   private final String userAgent;
   private final StatsTraceContext statsTraceCtx;
@@ -107,8 +116,8 @@ class CronetClientStream extends AbstractClientStream {
     this.idempotent = method.isIdempotent() || alwaysUsePut;
     // Only delay flushing header for unary rpcs.
     this.delayRequestHeader = (method.getType() == MethodDescriptor.MethodType.UNARY);
-    this.annotation = callOptions.getOption(CronetCallOptions.CRONET_ANNOTATION_KEY);
-    this.annotations = callOptions.getOption(CronetCallOptions.CRONET_ANNOTATIONS_KEY);
+    this.annotation = callOptions.getOption(CRONET_ANNOTATION_KEY);
+    this.annotations = callOptions.getOption(CRONET_ANNOTATIONS_KEY);
     this.state = new TransportState(maxMessageSize, statsTraceCtx, lock, transportTracer);
   }
 
@@ -127,6 +136,28 @@ public void setAuthority(String authority) {
     throw new UnsupportedOperationException("Cronet does not support overriding authority");
   }
 
+  /**
+   * Returns a copy of {@code callOptions} with {@code annotation} included as one of the Cronet
+   * annotation objects. When an RPC is made using a {@link CallOptions} instance returned by this
+   * method, the annotation objects will be attached to the underlying Cronet bidirectional stream.
+   * When the stream finishes, the user can retrieve the annotation objects via {@link
+   * org.chromium.net.RequestFinishedInfo.Listener}.
+   *
+   * @param annotation the object to attach to the Cronet stream
+   */
+  static CallOptions withAnnotation(CallOptions callOptions, Object annotation) {
+    Collection<Object> existingAnnotations = callOptions.getOption(CRONET_ANNOTATIONS_KEY);
+    ArrayList<Object> newAnnotations;
+    if (existingAnnotations == null) {
+      newAnnotations = new ArrayList<>();
+    } else {
+      newAnnotations = new ArrayList<>(existingAnnotations);
+    }
+    newAnnotations.add(annotation);
+    return callOptions.withOption(
+        CRONET_ANNOTATIONS_KEY, Collections.unmodifiableList(newAnnotations));
+  }
+
   class Sink implements AbstractClientStream.Sink {
     @Override
     public void writeHeaders(Metadata metadata, byte[] payload) {

cronet/src/main/java/io/grpc/cronet/InternalCronetCallOptions.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2019 The gRPC Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.grpc.cronet;
+
+import io.grpc.CallOptions;
+import io.grpc.Internal;
+
+/**
+ * Internal accessor class for call options using with the Cronet transport. This is intended for
+ * usage internal to the gRPC team. If you *really* think you need to use this, contact the gRPC
+ * team first.
+ */
+@Internal
+public final class InternalCronetCallOptions {
+
+  // Prevent instantiation
+  private InternalCronetCallOptions() {}
+
+  public static CallOptions withAnnotation(CallOptions callOptions, Object annotation) {
+    return CronetClientStream.withAnnotation(callOptions, annotation);
+  }
+}

cronet/src/test/java/io/grpc/cronet/CronetClientStreamTest.java

@@ -587,7 +587,7 @@ public void addCronetRequestAnnotation_deprecated() {
             false /* alwaysUsePut */,
             method,
             StatsTraceContext.NOOP,
-            CallOptions.DEFAULT.withOption(CronetCallOptions.CRONET_ANNOTATION_KEY, annotation),
+            CallOptions.DEFAULT.withOption(CronetClientStream.CRONET_ANNOTATION_KEY, annotation),
             transportTracer);
     callback.setStream(stream);
     when(factory.newBidirectionalStreamBuilder(