Examples with Compressor org.h2.compress.Compressor used on opensource projects

Example 1 with Compressor

use of org.h2.compress.Compressor in project h2database by h2database.

the class Page method write.

/**
 * Store the page and update the position.
 *
 * @param chunk the chunk
 * @param buff the target buffer
 * @return the position of the buffer just after the type
 */
private int write(Chunk chunk, WriteBuffer buff) {
    int start = buff.position();
    int len = keys.length;
    int type = children != null ? DataUtils.PAGE_TYPE_NODE : DataUtils.PAGE_TYPE_LEAF;
    buff.putInt(0).putShort((byte) 0).putVarInt(map.getId()).putVarInt(len);
    int typePos = buff.position();
    buff.put((byte) type);
    if (type == DataUtils.PAGE_TYPE_NODE) {
        writeChildren(buff);
        for (int i = 0; i <= len; i++) {
            buff.putVarLong(children[i].count);
        }
    }
    int compressStart = buff.position();
    map.getKeyType().write(buff, keys, len, true);
    if (type == DataUtils.PAGE_TYPE_LEAF) {
        map.getValueType().write(buff, values, len, false);
    }
    MVStore store = map.getStore();
    int expLen = buff.position() - compressStart;
    if (expLen > 16) {
        int compressionLevel = store.getCompressionLevel();
        if (compressionLevel > 0) {
            Compressor compressor;
            int compressType;
            if (compressionLevel == 1) {
                compressor = map.getStore().getCompressorFast();
                compressType = DataUtils.PAGE_COMPRESSED;
            } else {
                compressor = map.getStore().getCompressorHigh();
                compressType = DataUtils.PAGE_COMPRESSED_HIGH;
            }
            byte[] exp = new byte[expLen];
            buff.position(compressStart).get(exp);
            byte[] comp = new byte[expLen * 2];
            int compLen = compressor.compress(exp, expLen, comp, 0);
            int plus = DataUtils.getVarIntLen(compLen - expLen);
            if (compLen + plus < expLen) {
                buff.position(typePos).put((byte) (type + compressType));
                buff.position(compressStart).putVarInt(expLen - compLen).put(comp, 0, compLen);
            }
        }
    }
    int pageLength = buff.position() - start;
    int chunkId = chunk.id;
    int check = DataUtils.getCheckValue(chunkId) ^ DataUtils.getCheckValue(start) ^ DataUtils.getCheckValue(pageLength);
    buff.putInt(start, pageLength).putShort(start + 4, (short) check);
    if (pos != 0) {
        throw DataUtils.newIllegalStateException(DataUtils.ERROR_INTERNAL, "Page already stored");
    }
    pos = DataUtils.getPagePos(chunkId, start, pageLength, type);
    store.cachePage(pos, this, getMemory());
    if (type == DataUtils.PAGE_TYPE_NODE) {
        // cache again - this will make sure nodes stays in the cache
        // for a longer time
        store.cachePage(pos, this, getMemory());
    }
    long max = DataUtils.getPageMaxLength(pos);
    chunk.maxLen += max;
    chunk.maxLenLive += max;
    chunk.pageCount++;
    chunk.pageCountLive++;
    if (removedInMemory) {
        // if the page was removed _before_ the position was assigned, we
        // need to mark it removed here, so the fields are updated
        // when the next chunk is stored
        map.removePage(pos, memory);
    }
    return typePos + 1;
}

Example 2 with Compressor

use of org.h2.compress.Compressor in project h2database by h2database.

the class CompressTool method expand.

/**
 * Expands the compressed  data.
 *
 * @param in the byte array with the compressed data
 * @return the uncompressed data
 */
public byte[] expand(byte[] in) {
    int algorithm = in[0];
    Compressor compress = getCompressor(algorithm);
    try {
        int len = readVariableInt(in, 1);
        int start = 1 + getVariableIntLength(len);
        byte[] buff = Utils.newBytes(len);
        compress.expand(in, start, in.length - start, buff, 0, len);
        return buff;
    } catch (Exception e) {
        throw DbException.get(ErrorCode.COMPRESSION_ERROR, e);
    }
}

Example 3 with Compressor

use of org.h2.compress.Compressor in project h2database by h2database.

the class CompressTool method getCompressor.

private static Compressor getCompressor(String algorithm) {
    if (algorithm == null) {
        algorithm = "LZF";
    }
    int idx = algorithm.indexOf(' ');
    String options = null;
    if (idx > 0) {
        options = algorithm.substring(idx + 1);
        algorithm = algorithm.substring(0, idx);
    }
    int a = getCompressAlgorithm(algorithm);
    Compressor compress = getCompressor(a);
    compress.setOptions(options);
    return compress;
}

Example 4 with Compressor

use of org.h2.compress.Compressor in project h2database by h2database.

the class CompressTool method expand.

/**
 * INTERNAL
 */
public static void expand(byte[] in, byte[] out, int outPos) {
    int algorithm = in[0];
    Compressor compress = getCompressor(algorithm);
    try {
        int len = readVariableInt(in, 1);
        int start = 1 + getVariableIntLength(len);
        compress.expand(in, start, in.length - start, out, outPos, len);
    } catch (Exception e) {
        throw DbException.get(ErrorCode.COMPRESSION_ERROR, e);
    }
}

Example 5 with Compressor

use of org.h2.compress.Compressor in project h2database by h2database.

the class CompressTool method compress.

/**
 * Compressed the data using the specified algorithm. If no algorithm is
 * supplied, LZF is used
 *
 * @param in the byte array with the original data
 * @param algorithm the algorithm (LZF, DEFLATE)
 * @return the compressed data
 */
public byte[] compress(byte[] in, String algorithm) {
    int len = in.length;
    if (in.length < 5) {
        algorithm = "NO";
    }
    Compressor compress = getCompressor(algorithm);
    byte[] buff = getBuffer((len < 100 ? len + 100 : len) * 2);
    int newLen = compress(in, in.length, compress, buff);
    return Utils.copyBytes(buff, newLen);
}