Remove Trailers

auth/src/test/java/io/grpc/auth/ClientAuthInterceptorTests.java

@@ -134,7 +134,7 @@ public void testCredentialsThrows() throws IOException {
     Metadata.Headers headers = new Metadata.Headers();
     interceptedCall.start(listener, headers);
     ArgumentCaptor<Status> statusCaptor = ArgumentCaptor.forClass(Status.class);
-    Mockito.verify(listener).onClose(statusCaptor.capture(), isA(Metadata.Trailers.class));
+    Mockito.verify(listener).onClose(statusCaptor.capture(), isA(Metadata.class));
     Assert.assertNull(headers.getAll(AUTHORIZATION));
     Mockito.verify(call, never()).start(listener, headers);
     Assert.assertEquals(Status.Code.UNAUTHENTICATED, statusCaptor.getValue().getCode());

benchmarks/src/jmh/java/io/grpc/benchmarks/netty/AbstractBenchmark.java

@@ -254,7 +254,7 @@ public void onMessage(ByteBuf message) {
 
                       @Override
                       public void onHalfClose() {
-                        call.close(Status.OK, new Metadata.Trailers());
+                        call.close(Status.OK, new Metadata());
                       }
 
                       @Override
@@ -287,7 +287,7 @@ public void onMessage(ByteBuf message) {
 
                       @Override
                       public void onHalfClose() {
-                        call.close(Status.OK, new Metadata.Trailers());
+                        call.close(Status.OK, new Metadata());
                       }
 
                       @Override
@@ -323,7 +323,7 @@ public void onMessage(ByteBuf message) {
 
                       @Override
                       public void onHalfClose() {
-                        call.close(Status.OK, new Metadata.Trailers());
+                        call.close(Status.OK, new Metadata());
                       }
 
                       @Override

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

@@ -475,7 +475,7 @@ private InactiveTransport(Status s) {
     @Override
     public ClientStream newStream(
         MethodDescriptor<?, ?> method, Headers headers, ClientStreamListener listener) {
-      listener.closed(shutdownStatus, new Metadata.Trailers());
+      listener.closed(shutdownStatus, new Metadata());
       return new ClientCallImpl.NoopClientStream();
     }
 

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

@@ -91,7 +91,7 @@ public abstract static class Listener<T> {
      * @param status the result of the remote call.
      * @param trailers metadata provided at call completion.
      */
-    public abstract void onClose(Status status, Metadata.Trailers trailers);
+    public abstract void onClose(Status status, Metadata trailers);
 
     /**
      * This indicates that the ClientCall is now capable of sending additional messages (via

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

@@ -201,7 +201,7 @@ public boolean isReady() {
   private void closeCallPrematurely(ClientStreamListener listener, Status status) {
     Preconditions.checkState(stream == null, "Stream already created");
     stream = new NoopClientStream();
-    listener.closed(status, new Metadata.Trailers());
+    listener.closed(status, new Metadata());
   }
 
   private ScheduledFuture<?> startDeadlineTimer(long timeoutMicros) {
@@ -267,7 +267,7 @@ public void run() {
     }
 
     @Override
-    public void closed(Status status, Metadata.Trailers trailers) {
+    public void closed(Status status, Metadata trailers) {
       if (status.getCode() == Status.Code.CANCELLED && deadlineNanoTime != null) {
         // When the server's deadline expires, it can only reset the stream with CANCEL and no
         // description. Since our timer may be delayed in firing, we double-check the deadline and
@@ -276,11 +276,11 @@ public void closed(Status status, Metadata.Trailers trailers) {
         if (deadlineNanoTime <= System.nanoTime()) {
           status = Status.DEADLINE_EXCEEDED;
           // Replace trailers to prevent mixing sources of status and trailers.
-          trailers = new Metadata.Trailers();
+          trailers = new Metadata();
         }
       }
       final Status savedStatus = status;
-      final Metadata.Trailers savedTrailers = trailers;
+      final Metadata savedTrailers = trailers;
       callExecutor.execute(new Runnable() {
         @Override
         public void run() {

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

@@ -164,7 +164,7 @@ public final void start(Listener<RespT> responseListener, Metadata.Headers heade
         // to a NO-OP one to prevent the IllegalStateException. The user will finally get notified
         // about the error through the listener.
         delegate = (ClientCall<ReqT, RespT>) NOOP_CALL;
-        responseListener.onClose(Status.fromThrowable(e), new Metadata.Trailers());
+        responseListener.onClose(Status.fromThrowable(e), new Metadata());
       }
     }
   }

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

@@ -52,7 +52,7 @@ public void onMessage(RespT message) {
   }
 
   @Override
-  public void onClose(Status status, Metadata.Trailers trailers) {
+  public void onClose(Status status, Metadata trailers) {
     delegate().onClose(status, trailers);
   }
 

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

@@ -61,7 +61,7 @@ public boolean isReady() {
   }
 
   @Override
-  public void close(Status status, Metadata.Trailers trailers) {
+  public void close(Status status, Metadata trailers) {
     delegate().close(status, trailers);
   }
 

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

@@ -56,7 +56,7 @@
  * </p>
  */
 @NotThreadSafe
-public abstract class Metadata {
+public class Metadata {
 
   /**
    * All binary headers should have this suffix in their names. Vice versa.
@@ -108,7 +108,7 @@ public Integer parseAsciiString(String serialized) {
    * Constructor called by the transport layer when it receives binary metadata.
    */
   // TODO(louiscryan): Convert to use ByteString so we can cache transformations
-  private Metadata(byte[]... binaryValues) {
+  public Metadata(byte[]... binaryValues) {
     for (int i = 0; i < binaryValues.length; i++) {
       String name = new String(binaryValues[i], US_ASCII);
       storeAdd(name, new MetadataEntry(name.endsWith(BINARY_HEADER_SUFFIX), binaryValues[++i]));
@@ -118,7 +118,7 @@ private Metadata(byte[]... binaryValues) {
   /**
    * Constructor called by the application layer when it wants to send metadata.
    */
-  private Metadata() {}
+  public Metadata() {}
 
   private void storeAdd(String name, MetadataEntry value) {
     List<MetadataEntry> values = store.get(name);
@@ -286,6 +286,11 @@ public void merge(Metadata other, Set<Key<?>> keys) {
     }
   }
 
+  @Override
+  public String toString() {
+    return "Metadata(" + toStringInternal() + ")";
+  }
+
   private String toStringInternal() {
     return store.toString();
   }
@@ -375,31 +380,19 @@ public String toString() {
   /**
    * Concrete instance for metadata attached to the end of the call. Only provided by
    * servers.
+   *
+   * @deprecated use Metadata instead.
    */
+  @Deprecated
   public static class Trailers extends Metadata {
-    /**
-     * Called by the transport layer to create trailers from their binary serialized values.
-     *
-     * <p>This method does not copy the provided byte arrays. The byte arrays must not be mutated.
-     */
-    public Trailers(byte[]... headers) {
-      super(headers);
-    }
-
     /**
      * Called by the application layer to construct trailers prior to passing them to the
      * transport for serialization.
      */
     public Trailers() {
     }
-
-    @Override
-    public String toString() {
-      return "Trailers(" + super.toStringInternal() + ")";
-    }
   }
 
-
   /**
    * Marshaller for metadata values that are serialized into raw binary.
    */

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

@@ -149,12 +149,12 @@ public boolean isReady() {
    * status} is not equal to {@link Status#OK}, then the call is said to have failed.
    *
    * <p>If {@code status} is not {@link Status#CANCELLED} and no errors or cancellations are known
-   * to have occured, then a {@link Listener#onComplete} notification should be expected.
+   * to have occurred, then a {@link Listener#onComplete} notification should be expected.
    * Otherwise {@link Listener#onCancel} has been or will be called.
    *
    * @throws IllegalStateException if call is already {@code close}d
    */
-  public abstract void close(Status status, Metadata.Trailers trailers);
+  public abstract void close(Status status, Metadata trailers);
 
   /**
    * Returns {@code true} when the call is cancelled and the server is encouraged to abort

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

@@ -308,14 +308,14 @@ public void run() {
               if (method == null) {
                 stream.close(
                     Status.UNIMPLEMENTED.withDescription("Method not found: " + methodName),
-                    new Metadata.Trailers());
+                    new Metadata());
                 timeout.cancel(true);
                 return;
               }
               listener = startCall(stream, methodName, method.getMethodDefinition(), timeout,
                   headers);
             } catch (Throwable t) {
-              stream.close(Status.fromThrowable(t), new Metadata.Trailers());
+              stream.close(Status.fromThrowable(t), new Metadata());
               timeout.cancel(true);
               throw Throwables.propagate(t);
             } finally {
@@ -410,9 +410,9 @@ private void setListener(ServerStreamListener listener) {
     }
 
     /**
-     * Like {@link ServerCall#close(Status, Metadata.Trailers)}, but thread-safe for internal use.
+     * Like {@link ServerCall#close(Status, Metadata)}, but thread-safe for internal use.
      */
-    private void internalClose(Status status, Metadata.Trailers trailers) {
+    private void internalClose(Status status, Metadata trailers) {
       // TODO(ejona86): this is not thread-safe :)
       stream.close(status, trailers);
     }
@@ -425,7 +425,7 @@ public void run() {
           try {
             getListener().messageRead(message);
           } catch (Throwable t) {
-            internalClose(Status.fromThrowable(t), new Metadata.Trailers());
+            internalClose(Status.fromThrowable(t), new Metadata());
             throw Throwables.propagate(t);
           }
         }
@@ -440,7 +440,7 @@ public void run() {
           try {
             getListener().halfClosed();
           } catch (Throwable t) {
-            internalClose(Status.fromThrowable(t), new Metadata.Trailers());
+            internalClose(Status.fromThrowable(t), new Metadata());
             throw Throwables.propagate(t);
           }
         }
@@ -504,7 +504,7 @@ public void sendMessage(RespT message) {
         stream.writeMessage(resp);
         stream.flush();
       } catch (Throwable t) {
-        close(Status.fromThrowable(t), new Metadata.Trailers());
+        close(Status.fromThrowable(t), new Metadata());
         throw Throwables.propagate(t);
       }
     }
@@ -515,7 +515,7 @@ public boolean isReady() {
     }
 
     @Override
-    public void close(Status status, Metadata.Trailers trailers) {
+    public void close(Status status, Metadata trailers) {
       Preconditions.checkState(!closeCalled, "call already closed");
       closeCalled = true;
       stream.close(status, trailers);

core/src/main/java/io/grpc/inprocess/InProcessTransport.java

@@ -107,7 +107,7 @@ public void run() {
   public synchronized ClientStream newStream(MethodDescriptor<?, ?> method,
       Metadata.Headers headers, ClientStreamListener clientStreamListener) {
     if (shutdownStatus != null) {
-      clientStreamListener.closed(shutdownStatus, new Metadata.Trailers());
+      clientStreamListener.closed(shutdownStatus, new Metadata());
       return new NoopClientStream();
     }
     InProcessStream stream = new InProcessStream();
@@ -195,7 +195,7 @@ private class InProcessServerStream implements ServerStream {
       @GuardedBy("this")
       private Status clientNotifyStatus;
       @GuardedBy("this")
-      private Metadata.Trailers clientNotifyTrailers;
+      private Metadata clientNotifyTrailers;
       // Only is intended to prevent double-close when client cancels.
       @GuardedBy("this")
       private boolean closed;
@@ -266,7 +266,7 @@ public synchronized void writeHeaders(Metadata.Headers headers) {
       }
 
       @Override
-      public void close(Status status, Metadata.Trailers trailers) {
+      public void close(Status status, Metadata trailers) {
         synchronized (this) {
           if (closed) {
             return;
@@ -306,7 +306,7 @@ private synchronized boolean internalCancel(Status status) {
             log.log(Level.WARNING, "Exception closing stream", t);
           }
         }
-        clientStreamListener.closed(status, new Metadata.Trailers());
+        clientStreamListener.closed(status, new Metadata());
         return true;
       }
     }

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

@@ -59,7 +59,7 @@ public abstract class AbstractClientStream<IdT> extends AbstractStream<IdT>
   // Stored status & trailers to report when deframer completes or
   // transportReportStatus is directly called.
   private Status status;
-  private Metadata.Trailers trailers;
+  private Metadata trailers;
   private Runnable closeListenerTask;
 
 
@@ -100,7 +100,7 @@ protected void inboundTransportError(Status errorStatus) {
     }
     // For transport errors we immediately report status to the application layer
     // and do not wait for additional payloads.
-    transportReportStatus(errorStatus, false, new Metadata.Trailers());
+    transportReportStatus(errorStatus, false, new Metadata());
   }
 
   /**
@@ -165,7 +165,7 @@ protected final void deframeFailed(Throwable cause) {
    * @param trailers the received trailers
    * @param status the status extracted from the trailers
    */
-  protected void inboundTrailersReceived(Metadata.Trailers trailers, Status status) {
+  protected void inboundTrailersReceived(Metadata trailers, Status status) {
     Preconditions.checkNotNull(trailers, "trailers");
     if (inboundPhase() == Phase.STATUS) {
       log.log(Level.INFO, "Received trailers on closed stream {0}\n {1}\n {2}",
@@ -212,7 +212,7 @@ protected final void internalSendFrame(WritableBuffer frame, boolean endOfStream
    * @param trailers new instance of {@code Trailers}, either empty or those returned by the server
    */
   public void transportReportStatus(final Status newStatus, boolean stopDelivery,
-      final Metadata.Trailers trailers) {
+      final Metadata trailers) {
     Preconditions.checkNotNull(newStatus, "newStatus");
 
     boolean closingLater = closeListenerTask != null && !stopDelivery;
@@ -240,7 +240,7 @@ public void transportReportStatus(final Status newStatus, boolean stopDelivery,
   /**
    * Creates a new {@link Runnable} to close the listener with the given status/trailers.
    */
-  private Runnable newCloseListenerTask(final Status status, final Metadata.Trailers trailers) {
+  private Runnable newCloseListenerTask(final Status status, final Metadata trailers) {
     return new Runnable() {
       @Override
       public void run() {
@@ -252,7 +252,7 @@ public void run() {
   /**
    * Closes the listener if not previously closed.
    */
-  private void closeListener(Status newStatus, Metadata.Trailers trailers) {
+  private void closeListener(Status newStatus, Metadata trailers) {
     if (!listenerClosed) {
       listenerClosed = true;
       closeDeframer();