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JNI bindings for Zstd native library that provides fast and high compression lossless algorithm for Java and all JVM languages.

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package com.github.luben.zstd;

import com.github.luben.zstd.util.Native;

import java.io.Closeable;
import java.io.IOException;
import java.util.Arrays;

public class ZstdDictCompress implements Closeable {

    static {
        Native.load();
    }

    private long nativePtr = 0;

    /**
     * Convenience constructor to create a new dictionary for use with fast compress
     *
     * @param dict  buffer containing dictionary to load/parse with exact length
     * @param level compression level
     */
    public ZstdDictCompress(byte[] dict, int level) {
        this(dict, 0, dict.length, level);
    }

    /**
     * Create a new dictionary for use with fast compress
     *
     * @param dict   buffer containing dictionary
     * @param offset the offset into the buffer to read from
     * @param length number of bytes to use from the buffer
     * @param level  compression level
     */
    public ZstdDictCompress(byte[] dict, int offset, int length, int level) {
        byte[] _dict;
        if (0 == offset && length == dict.length) {
            _dict = dict;
        } else {
            _dict = Arrays.copyOfRange(dict, offset, offset + length);
        }

        if (_dict.length <= 0) {
            throw new IllegalArgumentException("Dictionary buffer is to short");
        }

        init(_dict, level);

        if (0 == nativePtr) {
            throw new IllegalStateException("ZSTD_createCDict failed");
        }
    }

    private native void init(byte[] dict, int level);

    private native void free();

    @Override
    public void close() throws IOException {
        free();
        nativePtr = 0;
    }
}