public MethodInvoker getMethod(Class<?> clazz, String name, Class<?>[] parameters) {
MethodDescriptor mDescriptor = new MethodDescriptor(name, clazz, parameters);
MethodInvoker mInvoker = null;
List<Method> acceptableMethods = null;
LRUCache<MethodDescriptor, MethodInvoker> cache = cacheHolder.get();
mInvoker = cache.get(mDescriptor);
if (mInvoker == null) {
acceptableMethods = getMethodsByNameAndLength(clazz, name, parameters.length);
if (acceptableMethods.size() == 1) {
mInvoker = MethodInvoker.buildInvoker(acceptableMethods.get(0), parameters);
} else {
mInvoker = getBestMethod(acceptableMethods, parameters);
}
if (mInvoker != null && mInvoker.getCost() != -1) {
cache.put(mDescriptor, mInvoker);
} else {
String errorMessage =
"Method " + name + "(" + Arrays.toString(parameters) + ") does not exist";
logger.log(Level.WARNING, errorMessage);
throw new Py4JException(errorMessage);
}
}
return mInvoker;
}
private MethodInvoker getBestMethod(List<Method> acceptableMethods, Class<?>[] parameters) {
MethodInvoker lowestCost = null;
for (Method method : acceptableMethods) {
MethodInvoker temp = MethodInvoker.buildInvoker(method, parameters);
int cost = temp.getCost();
if (cost == -1) {
continue;
} else if (cost == 0) {
lowestCost = temp;
break;
} else if (lowestCost == null || cost < lowestCost.getCost()) {
lowestCost = temp;
}
}
return lowestCost;
}
private MethodInvoker getBestConstructor(
List<Constructor<?>> acceptableConstructors, Class<?>[] parameters) {
MethodInvoker lowestCost = null;
for (Constructor<?> constructor : acceptableConstructors) {
MethodInvoker temp = MethodInvoker.buildInvoker(constructor, parameters);
int cost = temp.getCost();
if (cost == -1) {
continue;
} else if (cost == 0) {
lowestCost = temp;
break;
} else if (lowestCost == null || cost < lowestCost.getCost()) {
lowestCost = temp;
}
}
return lowestCost;
}
