Lookup a marshaler between {@code T} and {@code nativeType}.
Marshalers are looked up in the order they were registered; earlier registered
marshal queriers get priority.
// TODO: can avoid making a new token each time by code-genning
// the list of type tokens and native types from the keys (at the call sites)
MarshalToken<T> marshalToken = new MarshalToken<T>(typeToken, nativeType);
/*
* Marshalers are instantiated lazily once they are looked up; successive lookups
* will not instantiate new marshalers.
*/
Marshaler<T> marshaler =
(Marshaler<T>) sMarshalerMap.get(marshalToken);
if (sRegisteredMarshalQueryables.size() == 0) {
throw new AssertionError("No available query marshalers registered");
}
if (marshaler == null) {
// Query each marshaler to see if they support the native/managed type combination
for (MarshalQueryable<?> potentialMarshaler : sRegisteredMarshalQueryables) {
MarshalQueryable<T> castedPotential =
(MarshalQueryable<T>)potentialMarshaler;
if (castedPotential.isTypeMappingSupported(typeToken, nativeType)) {
marshaler = castedPotential.createMarshaler(typeToken, nativeType);
break;
}
}
if (marshaler == null) {
throw new UnsupportedOperationException(
"Could not find marshaler that matches the requested " +
"combination of type reference " +
typeToken + " and native type " +
MarshalHelpers.toStringNativeType(nativeType));
}
// Only put when no cached version exists to avoid +0.5ms lookup per call.
sMarshalerMap.put(marshalToken, marshaler);
}
return marshaler;
