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Apache Commons Compress defines an API for working with compression and archive formats. These include bzip2, gzip, pack200, LZMA, XZ, Snappy, traditional Unix Compress, DEFLATE, DEFLATE64, LZ4, Brotli, Zstandard and ar, cpio, jar, tar, zip, dump, 7z, arj.

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/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */
package org.apache.commons.compress.archivers.sevenz;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * Base Codec class.
 */
abstract class CoderBase {
    private final Class[] acceptableOptions;
    private static final byte[] NONE = new byte[0];

    /**
     * @param acceptableOptions types that can be used as options for this codec.
     */
    protected CoderBase(Class... acceptableOptions) {
        this.acceptableOptions = acceptableOptions;
    }

    /**
     * @return whether this method can extract options from the given object.
     */
    boolean canAcceptOptions(Object opts) {
        for (Class c : acceptableOptions) {
            if (c.isInstance(opts)) {
                return true;
            }
        }
        return false;
    }

    /**
     * @return property-bytes to write in a Folder block
     */
    byte[] getOptionsAsProperties(Object options) {
        return NONE;
    }

    /**
     * @return configuration options that have been used to create the given InputStream from the given Coder
     */
    Object getOptionsFromCoder(Coder coder, InputStream in) {
        return null;
    }

    /**
     * @return a stream that reads from in using the configured coder and password.
     */
    abstract InputStream decode(final InputStream in, final Coder coder, byte[] password) throws IOException;

    /**
     * @return a stream that writes to out using the given configuration.
     */
    OutputStream encode(final OutputStream out, final Object options) throws IOException {
        throw new UnsupportedOperationException("method doesn't support writing");
    }

    /**
     * If the option represents a number, return its integer
     * value, otherwise return the given default value.
     */
    protected static int numberOptionOrDefault(Object options, int defaultValue) {
        return options instanceof Number ? ((Number) options).intValue() : defaultValue;
    }
}