Support for lazily serialized values in Metadata.

api/src/main/java/io/grpc/InternalMetadata.java

@@ -114,7 +114,7 @@ public static <T> Object parsedValue(Key<T> key, T value) {
    * with some values pre-parsed. Metadata will mutate the passed in array.
    *
    * @param usedNames The number of names used.
-   * @param namesAndValues An array of iterleaved names and values,
+   * @param namesAndValues An array of interleaved names and values,
    *     with each name (at even indices) represented as a byte array,
    *     and each value (at odd indices) represented as either a byte
    *     array or an object returned by the {@link #parsedValue}

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

@@ -131,6 +131,11 @@ public String parseAsciiString(String serialized) {
   /**
    * Constructor called by the transport layer when it receives partially-parsed metadata.
    * Metadata will mutate the passed in array.
+   *
+   * @param usedNames the number of names
+   * @param namesAndValues an array of interleaved names and values, with each name
+   *     (at even indices) represented by a byte array, and values (at odd indices) as
+   *     described by {@link InternalMetadata#newMetadataWithParsedValues}.
    */
   Metadata(int usedNames, Object[] namesAndValues) {
     assert (namesAndValues.length & 1) == 0
@@ -188,9 +193,9 @@ private Object valueAsBytesOrStream(int i) {
   private <T> T valueAsT(int i, Key<T> key) {
     Object value = value(i);
     if (value instanceof byte[]) {
-      return key.parseBytes((byte[]) value(i));
+      return key.parseBytes((byte[]) value);
     } else {
-      return ((LazyValue<?>) value(i)).toObject(key);
+      return ((LazyValue<?>) value).toObject(key);
     }
   }
 
@@ -931,10 +936,7 @@ byte[] toBytes() {
     <T2> T2 toObject(Key<T2> key) {
       if (key.serializesToStreams()) {
         BinaryStreamMarshaller<T2> marshaller = getBinaryStreamMarshaller(key);
-        if (marshaller == this.marshaller) {
-          // The marshallers match so T2 == T.
-          return (T2) value;
-        } else if (marshaller != null) {
+        if (marshaller != null) {
           return marshaller.parseStream(toStream());
         }
       }

api/src/test/java/io/grpc/MetadataTest.java

@@ -475,7 +475,7 @@ public void createFromPartial() {
 
     Metadata h2 = new Metadata(3, partial);
     assertEquals(new Fish(LANCE), h2.get(KEY));
-    assertSame(anotherSalmon, h2.get(KEY_STREAMED));
+    assertEquals(anotherSalmon, h2.get(KEY_STREAMED));
     assertSame(anotherSalmon, h2.get(KEY_IMMUTABLE));
   }