JRubyArray.java

/*
 * Copyright © 2011, 2012 On-Site.com.
 * Copyright © 2015 Chris Jester-Young.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
 * for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this work. If not, see <http://www.gnu.org/licenses/>.
 *
 * Linking this library statically or dynamically with other modules is
 * making a combined work based on this library. Thus, the terms and
 * conditions of the GNU General Public License cover the whole combination.
 *
 * As a special exception, the copyright holders of this library give you
 * permission to link this library with independent modules to produce an
 * executable, regardless of the license terms of these independent modules,
 * and to copy and distribute the resulting executable under terms of your
 * choice, provided that you also meet, for each linked independent module,
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 */

package com.sun.tools.hat.internal.lang.jruby;

import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import com.google.common.collect.ImmutableList;

import com.sun.tools.hat.internal.lang.Models;
import com.sun.tools.hat.internal.lang.common.SafeArray;
import com.sun.tools.hat.internal.lang.common.SimpleCollectionModel;
import com.sun.tools.hat.internal.model.JavaInt;
import com.sun.tools.hat.internal.model.JavaObject;
import com.sun.tools.hat.internal.model.JavaObjectArray;
import com.sun.tools.hat.internal.model.JavaThing;

public class JRubyArray extends SimpleCollectionModel {
    private static final LoadingCache<SafeArray, ImmutableList<JavaThing>> ELEMENT_CACHE
            = CacheBuilder.newBuilder().softValues().build(
                    CacheLoader.from(arr -> ImmutableList.copyOf(arr.getElements())));

    private JRubyArray(JRuby factory, SafeArray arr, int begin, int length) {
        super(factory, () -> ELEMENT_CACHE.getUnchecked(arr).subList(begin, begin + length));
    }

    public static JRubyArray make(JRuby factory, JavaObject obj) {
        JavaObjectArray arr = Models.getFieldThing(obj, "values", JavaObjectArray.class);
        JavaInt begin = Models.getFieldThing(obj, "begin", JavaInt.class);
        JavaInt length = Models.getFieldThing(obj, "realLength", JavaInt.class);
        if (arr == null || begin == null || length == null)
            return null;
        return new JRubyArray(factory, new SafeArray(arr, factory.getNullThing()),
                begin.value, length.value);
    }
}