Add idempotent related getter and setter to MethodDescriptor

core/src/main/java/io/grpc/MethodDescriptor.java

@@ -53,6 +53,7 @@ public class MethodDescriptor<ReqT, RespT> {
   private final String fullMethodName;
   private final Marshaller<ReqT> requestMarshaller;
   private final Marshaller<RespT> responseMarshaller;
+  private final boolean idempotent;
 
   /**
    * The call type of a method.
@@ -148,16 +149,18 @@ public class MethodDescriptor<ReqT, RespT> {
       Marshaller<RequestT> requestMarshaller,
       Marshaller<ResponseT> responseMarshaller) {
     return new MethodDescriptor<RequestT, ResponseT>(
-        type, fullMethodName, requestMarshaller, responseMarshaller);
+        type, fullMethodName, requestMarshaller, responseMarshaller, false);
   }
 
   private MethodDescriptor(MethodType type, String fullMethodName,
                            Marshaller<ReqT> requestMarshaller,
-                           Marshaller<RespT> responseMarshaller) {
+                           Marshaller<RespT> responseMarshaller,
+                           boolean idempotent) {
     this.type = Preconditions.checkNotNull(type, "type");
     this.fullMethodName = Preconditions.checkNotNull(fullMethodName, "fullMethodName");
     this.requestMarshaller = Preconditions.checkNotNull(requestMarshaller, "requestMarshaller");
     this.responseMarshaller = Preconditions.checkNotNull(responseMarshaller, "responseMarshaller");
+    this.idempotent = idempotent;
   }
 
   /**
@@ -214,6 +217,26 @@ public class MethodDescriptor<ReqT, RespT> {
     return responseMarshaller.stream(response);
   }
 
+  /**
+   * Returns whether this method is idempotent.
+   */
+  @ExperimentalApi
+  public boolean isIdempotent() {
+    return idempotent;
+  }
+
+  /**
+   * Set idempotency on this method.
+   *
+   * @param idempotent the idempotency of this method.
+   * @return a new copy of MethodDescriptor.
+   */
+  @ExperimentalApi
+  public MethodDescriptor<ReqT, RespT> withIdempotent(boolean idempotent) {
+    return new MethodDescriptor<ReqT, RespT>(type, fullMethodName, requestMarshaller,
+        responseMarshaller, idempotent);
+  }
+
   /**
    * Generate the fully qualified method name.
    *

core/src/test/java/io/grpc/MethodDescriptorTest.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2016, Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *    * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *    * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *
+ *    * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package io.grpc;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import io.grpc.MethodDescriptor;
+import io.grpc.MethodDescriptor.MethodType;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/**
+ * Tests for {@link MethodDescriptor}.
+ */
+@RunWith(JUnit4.class)
+public class MethodDescriptorTest {
+  @Test
+  public void createMethodDescriptor() {
+    MethodDescriptor<String, String> descriptor = MethodDescriptor.<String, String>create(
+        MethodType.CLIENT_STREAMING, "/package.service/method", new StringMarshaller(),
+        new StringMarshaller());
+    assertEquals(MethodType.CLIENT_STREAMING, descriptor.getType());
+    assertEquals("/package.service/method", descriptor.getFullMethodName());
+    assertFalse(descriptor.isIdempotent());
+  }
+
+  @Test
+  public void idempotent() {
+    MethodDescriptor<String,String> descriptor = MethodDescriptor.<String, String>create(
+        MethodType.SERVER_STREAMING, "/package.service/method", new StringMarshaller(),
+        new StringMarshaller());    
+    assertFalse(descriptor.isIdempotent());
+
+    // Create a new desriptor by setting idempotent to true
+    MethodDescriptor<String, String> newDescriptor = descriptor.withIdempotent(true);
+    assertTrue(newDescriptor.isIdempotent());
+    // All other fields should staty the same
+    assertEquals(MethodType.SERVER_STREAMING, newDescriptor.getType());
+    assertEquals("/package.service/method", newDescriptor.getFullMethodName());
+  }
+}
+