Merge pull request googleapis#34 from shinfan/dev

Do not auto close channel if it is provided by user.

src/main/java/com/google/api/gax/grpc/ServiceApiSettings.java

@@ -21,7 +21,6 @@
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.ScheduledThreadPoolExecutor;
 
-//TODO(pongad): Don't close the channel if the user gives one to us
 /**
  * A settings class to configure a service api class.
  *
@@ -66,6 +65,10 @@ public ServiceApiSettings(ImmutableList<? extends ApiCallSettings> allMethods) {
       public ManagedChannel getChannel(Executor executor) {
         throw new RuntimeException("No Channel or ConnectionSettings provided.");
       }
+      @Override
+      public boolean shouldAutoClose() {
+        return true;
+      }
     };
     executorProvider = new ExecutorProvider() {
       private ScheduledExecutorService executor = null;
@@ -83,6 +86,7 @@ public ScheduledExecutorService getExecutor() {
   }
 
   private interface ChannelProvider {
+    boolean shouldAutoClose();
     ManagedChannel getChannel(Executor executor) throws IOException;
   }
 
@@ -98,6 +102,10 @@ public ServiceApiSettings provideChannelWith(final ManagedChannel channel) {
       public ManagedChannel getChannel(Executor executor) {
         return channel;
       }
+      @Override
+      public boolean shouldAutoClose() {
+        return false;
+      }
     };
     return this;
   }
@@ -125,6 +133,11 @@ public ManagedChannel getChannel(Executor executor) throws IOException {
         return channel;
       }
 
+      @Override
+      public boolean shouldAutoClose() {
+        return true;
+      }
+
       private String serviceHeader() {
         // GAX version only works when the package is invoked as a jar. Otherwise returns null.
         String gaxVersion = ChannelProvider.class.getPackage().getImplementationVersion();
@@ -152,6 +165,13 @@ public ManagedChannel getChannel() throws IOException {
     return channelProvider.getChannel(getExecutor());
   }
 
+  /**
+   * Returns true if the channel should be automatically closed with the API wrapper class.
+   */
+  public boolean shouldAutoCloseChannel() {
+    return channelProvider.shouldAutoClose();
+  }
+
   private interface ExecutorProvider {
     ScheduledExecutorService getExecutor();
   }