/*
 * Copyright 2016, Google Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.jf.dexlib2.writer.pool;

import com.google.common.collect.Maps;

import javax.annotation.Nonnull;
import java.util.Iterator;
import java.util.Map;

public class BasePool<Key, Value> implements Markable {
    @Nonnull protected final DexPool dexPool;
    @Nonnull protected final Map<Key, Value> internedItems = Maps.newLinkedHashMap();
    private int markedItemCount = -1;

    public BasePool(@Nonnull DexPool dexPool) {
        this.dexPool = dexPool;
    }

    public void mark() {
        markedItemCount = internedItems.size();
    }

    public void reset() {
        if (markedItemCount < 0) {
            throw new IllegalStateException("mark() must be called before calling reset()");
        }

        if (markedItemCount == internedItems.size()) {
            return;
        }

        Iterator<Key> keys = internedItems.keySet().iterator();
        for (int i=0; i<markedItemCount; i++) {
            keys.next();
        }
        while (keys.hasNext()) {
            keys.next();
            keys.remove();
        }
    }

    public int getItemCount() {
        return internedItems.size();
    }
}