Alachisoft.NCache.Common.CompressionUtil Maven / Gradle / Ivy

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Internal package of Alachisoft.
There is a newer version: 5.3.3
package Alachisoft.NCache.Common;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

//C# TO JAVA CONVERTER TODO TASK: There is no preprocessor in Java:
//#if VS2003
//#endif

/**
 * Util class that compress and decompress values uing GZip provided solution
 */
public class CompressionUtil {
    private static final int Compressed = BitSetConstants.Compressed;


    /// 
    /// Compress value only if its greater then threshold
    /// 
    /// value to be compressed
    /// flag to be set if compression is successful
    /// threshold limit
    /// resultant value
    public static byte[] Compress(byte[] value, Alachisoft.NCache.Common.BitSet flag, long threshold) {
        if (value == null) return value;
        if (flag == null) return value;
        if (value.length <= threshold) return value;

        try {
            return Compress(value, flag);
        } catch (IOException ioe) {
            return value;
        } catch (Exception ex) {
            return value;
        }

    }

    public static byte[] Compress(byte[] value, Alachisoft.NCache.Common.BitSet flag) throws IOException {

        GZIPOutputStream ZippedObject = null;
        ByteArrayOutputStream memStream = null;
        try {
            memStream = new ByteArrayOutputStream();
            ZippedObject = new GZIPOutputStream(memStream);
            ZippedObject.write((byte[]) value, 0, ((byte[]) value).length);

            if (flag == null) flag = new BitSet();
            flag.SetBit((byte) BitSetConstants.Compressed);

            ZippedObject.close();
            ZippedObject.finish();
            memStream.close();

            return memStream.toByteArray();
        } catch (Exception ex) {
            flag.UnsetBit((byte) BitSetConstants.Compressed);
            return value;
        }
    }


    /// 
    /// Decompress the value
    /// 
    /// value to be decomrpessed
    /// flag
    /// decompressed value
    public static byte[] Decompress(byte[] value, Alachisoft.NCache.Common.BitSet flag) throws Exception {
        if (value == null) return value;
        if (flag == null) return value;
        if (flag.IsBitSet((byte) BitSetConstants.Compressed) == true) {
            try {
                return Decompress(value);
            } catch (Exception e) {
                throw e;
            }
        }

        return value;
    }

    /// 
    /// Decompress the value
    /// 
    /// value to be decomrpessed
    /// decompressed value
    public static byte[] Decompress(byte[] value) throws IOException {
        GZIPInputStream uncompressedValue = null;
        ByteArrayOutputStream result = null;

        uncompressedValue = new GZIPInputStream(new ByteArrayInputStream(value));
        result = new ByteArrayOutputStream();

        int count;
        byte[] tmp = new byte[2048];

        // Un-compress byte-array 2048 bytes at a time (in case it is large)
        while ((count = uncompressedValue.read(tmp, 0, tmp.length)) > 0) {
            result.write(tmp, 0, count);
        }

        result.close();
        uncompressedValue.close();
        return result.toByteArray();
    }

}