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 * Copyright (c) 2015, 2025, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package jdk.internal.jimage.decompressor;

import java.io.IOException;
import java.util.zip.Inflater;

/**
 *
 * ZIP Decompressor
 *
 * @implNote This class needs to maintain JDK 8 source compatibility.
 *
 * It is used internally in the JDK to implement jimage/jrtfs access,
 * but also compiled and delivered as part of the jrtfs.jar to support access
 * to the jimage file provided by the shipped JDK by tools running on JDK 8.
 */
final class ZipDecompressor implements ResourceDecompressor {

    @Override
    public String getName() {
        return ZipDecompressorFactory.NAME;
    }

    static byte[] decompress(byte[] bytesIn, int offset, long originalSize) throws Exception {
        if (originalSize > Integer.MAX_VALUE) {
            throw new OutOfMemoryError("Required array size too large");
        }
        byte[] bytesOut = new byte[(int) originalSize];

        int count = 0;
        Inflater inflater = new Inflater();
        try {
            inflater.setInput(bytesIn, offset, bytesIn.length - offset);

            while (!inflater.finished() && count < originalSize) {
                count += inflater.inflate(bytesOut, count, bytesOut.length - count);
            }
        } finally {
            inflater.end();
        }

        if (count != originalSize) {
            throw new IOException("Resource content size mismatch");
        }

        return bytesOut;
    }

    @Override
    public byte[] decompress(StringsProvider reader, byte[] content, int offset,
            long originalSize) throws Exception {
        byte[] decompressed = decompress(content, offset, originalSize);
        return decompressed;
    }
}