Add test using a known-length input stream with getByteBuffer operati…

…on for protobuf parse.

protobuf-lite/src/test/java/io/grpc/protobuf/lite/ProtoLiteUtilsTest.java

@@ -29,6 +29,7 @@
 import com.google.protobuf.InvalidProtocolBufferException;
 import com.google.protobuf.Type;
 import io.grpc.Drainable;
+import io.grpc.HasByteBuffer;
 import io.grpc.KnownLength;
 import io.grpc.Metadata;
 import io.grpc.MethodDescriptor.Marshaller;
@@ -40,7 +41,9 @@
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.nio.ByteBuffer;
 import java.util.Arrays;
+import javax.annotation.Nullable;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
@@ -226,6 +229,16 @@ public void parseFromKnowLengthInputStream() throws Exception {
     assertEquals(expect, result);
   }
 
+  @Test
+  public void parseFromKnownLengthByteBufferInputStream() {
+    Marshaller<Type> marshaller = ProtoLiteUtils.marshaller(Type.getDefaultInstance());
+    Type expect = Type.newBuilder().setName("expected name").build();
+
+    Type result = marshaller.parse(
+        new CustomKnownLengthByteBufferInputStream(expect.toByteString().asReadOnlyByteBuffer()));
+    assertEquals(expect, result);
+  }
+
   @Test
   public void defaultMaxMessageSize() {
     assertEquals(GrpcUtil.DEFAULT_MAX_MESSAGE_SIZE, ProtoLiteUtils.DEFAULT_MAX_MESSAGE_SIZE);
@@ -253,4 +266,55 @@ public int read() throws IOException {
       return source[position++];
     }
   }
+
+  private static final class CustomKnownLengthByteBufferInputStream extends InputStream
+      implements KnownLength, HasByteBuffer {
+    private ByteBuffer source;
+
+    private CustomKnownLengthByteBufferInputStream(ByteBuffer source) {
+      this.source = source;
+    }
+
+    @Override
+    public int available() throws IOException {
+      return source.remaining();
+    }
+
+    @Override
+    public synchronized void mark(int readlimit) {
+      source.mark();
+    }
+
+    @Override
+    public synchronized void reset() throws IOException {
+      source.reset();
+    }
+
+    @Override
+    public boolean markSupported() {
+      return true;
+    }
+
+    @Override
+    public int read() throws IOException {
+      throw new UnsupportedOperationException("should not be called");
+    }
+
+    @Override
+    public long skip(long n) throws IOException {
+      source.position((int) (source.position() + n));
+      return n;
+    }
+
+    @Override
+    public boolean getByteBufferSupported() {
+      return true;
+    }
+
+    @Nullable
+    @Override
+    public ByteBuffer getByteBuffer() {
+      return source.slice();
+    }
+  }
 }