Make DynamicCodec always memoize. Since it replaces Java serialization, which memoizes, we should too.

PiperOrigin-RevId: 191813677

Author: janakdr

src/main/java/com/google/devtools/build/lib/skyframe/serialization/DynamicCodec.java

@@ -58,6 +58,8 @@ public MemoizationStrategy getStrategy() {
   @Override
   public void serialize(SerializationContext context, Object obj, CodedOutputStream codedOut)
       throws SerializationException, IOException {
+    // TODO(janakr,shahan): Remove when memoization is on by default.
+    context = context.getMemoizingContext();
     for (Map.Entry<Field, Long> entry : offsets.entrySet()) {
       serializeField(context, codedOut, obj, entry.getKey().getType(), entry.getValue());
     }
@@ -135,6 +137,11 @@ public Object deserialize(DeserializationContext context, CodedInputStream coded
       throw new SerializationException("Could not instantiate object of type: " + type, e);
     }
     context.registerInitialValue(instance);
+    // We start memoizing if we weren't already doing so. We can't start before registering the
+    // initial value because the memoizer would get confused, since it doesn't have a tag for this
+    // object.
+    // TODO(janakr,shahan): Remove when memoization is on by default.
+    context = context.getMemoizingContext();
     for (Map.Entry<Field, Long> entry : offsets.entrySet()) {
       deserializeField(context, codedIn, instance, entry.getKey().getType(), entry.getValue());
     }

src/test/java/com/google/devtools/build/lib/skyframe/serialization/DynamicCodecTest.java

@@ -228,7 +228,6 @@ public void testArray() throws Exception {
                 new char[] {'a', 'b', 'c', 'x', 'y', 'z'},
                 new long[] {Long.MAX_VALUE, Long.MIN_VALUE, 27983741982341L, 52893748523495834L}))
         .addCodec(new DynamicCodec(ArrayExample.class))
-        .makeMemoizing()
         .runTests();
   }
 
@@ -262,7 +261,6 @@ public void testNestedArray() throws Exception {
                 }),
             new NestedArrayExample(new int[][] {{1, 2, 3}, null, {7}}))
         .addCodec(new DynamicCodec(NestedArrayExample.class))
-        .makeMemoizing()
         .runTests();
   }