package org.mongodb.morphia.utils;
import org.bson.BSONObject;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
/**
* Helper to allow for optimizations for different types of Map/Collections
*
* @param <T> The key type of the map
* @param <V> The value type of the map/collection
* @author Scott Hernandez
*/
public final class IterHelper<T, V> {
@SuppressWarnings("unchecked")
public void loopMap(final Object x, final MapIterCallback<T, V> iter) {
if (x == null) {
return;
}
if (x instanceof Collection) {
throw new IllegalArgumentException("call loop instead");
}
if (x instanceof HashMap<?, ?>) {
if (((HashMap) x).isEmpty()) {
return;
}
final HashMap<?, ?> hm = (HashMap<?, ?>) x;
for (final Entry<?, ?> e : hm.entrySet()) {
iter.eval((T) e.getKey(), (V) e.getValue());
}
return;
}
if (x instanceof Map) {
final Map<T, V> m = (Map<T, V>) x;
for (final Entry<T, V> entry : m.entrySet()) {
iter.eval(entry.getKey(), entry.getValue());
}
return;
}
if (x instanceof BSONObject) {
final BSONObject m = (BSONObject) x;
for (final String k : m.keySet()) {
iter.eval((T) k, (V) m.get(k));
}
}
}
/**
* Calls eval for each entry found, or just once if the "x" isn't iterable/collection/list/etc. with "x"
*/
@SuppressWarnings({"unchecked"})
public void loopOrSingle(final Object x, final IterCallback<V> iter) {
if (x == null) {
return;
}
//A collection
if (x instanceof Collection<?>) {
final Collection<?> l = (Collection<?>) x;
for (final Object o : l) {
iter.eval((V) o);
}
return;
}
//An array of Object[]
if (x.getClass().isArray()) {
for (final Object o : (Object[]) x) {
iter.eval((V) o);
}
return;
}
iter.eval((V) x);
}
public abstract static class MapIterCallback<T, V> {
public abstract void eval(T t, V v);
}
public abstract static class IterCallback<V> {
public abstract void eval(V v);
}
}