Examples with DeflaterOutputStream com.jcraft.jzlib.DeflaterOutputStream used on opensource projects

Example 1 with DeflaterOutputStream

use of com.jcraft.jzlib.DeflaterOutputStream in project netxms by netxms.

the class NXCPMessage method createNXCPMessage.

/**
 * Create binary NXCP message
 *
 * @return byte stream ready to send
 */
public byte[] createNXCPMessage(boolean allowCompression) throws IOException {
    ByteArrayOutputStream byteStream = new ByteArrayOutputStream();
    DataOutputStream outputStream = new DataOutputStream(byteStream);
    if ((messageFlags & MF_CONTROL) == MF_CONTROL) {
        outputStream.writeShort(messageCode);
        outputStream.writeShort(messageFlags);
        // Size
        outputStream.writeInt(HEADER_SIZE);
        outputStream.writeInt((int) messageId);
        outputStream.writeInt((int) controlData);
    } else if ((messageFlags & MF_BINARY) == MF_BINARY) {
        byte[] payload = binaryData;
        boolean compressed = false;
        if (allowCompression && ((messageFlags & MF_STREAM) == 0) && (binaryData.length > 128)) {
            ByteArrayOutputStream compDataByteStream = new ByteArrayOutputStream();
            byte[] length = new byte[4];
            final int unpackedPadding = (8 - ((binaryData.length + HEADER_SIZE) % 8)) & 7;
            intToBytes(unpackedPadding + HEADER_SIZE, length, 0);
            // unpacked message size
            compDataByteStream.write(length);
            DeflaterOutputStream deflaterStream = new DeflaterOutputStream(compDataByteStream, new Deflater(JZlib.Z_BEST_COMPRESSION));
            deflaterStream.write(binaryData);
            deflaterStream.close();
            byte[] compPayload = compDataByteStream.toByteArray();
            if (compPayload.length < binaryData.length) {
                payload = compPayload;
                compressed = true;
            }
        }
        // wCode
        outputStream.writeShort(messageCode);
        // wFlags
        outputStream.writeShort(compressed ? (messageFlags | MF_COMPRESSED) : messageFlags);
        final int length = payload.length;
        final int padding = (8 - ((length + HEADER_SIZE) % 8)) & 7;
        final int packetSize = length + HEADER_SIZE + padding;
        // dwSize (padded to 8 bytes boundaries)
        outputStream.writeInt(packetSize);
        // dwId
        outputStream.writeInt((int) messageId);
        // dwNumVars, here used for real size of the payload (w/o headers and padding)
        outputStream.writeInt(binaryData.length);
        outputStream.write(payload);
        for (int i = 0; i < padding; i++) outputStream.writeByte(0);
    } else {
        // Create byte array with all variables
        for (final NXCPMessageField nxcpVariable : fields.values()) {
            final byte[] field = nxcpVariable.createNXCPDataField();
            outputStream.write(field);
        }
        byte[] payload = byteStream.toByteArray();
        boolean compressed = false;
        if (allowCompression && (payload.length > 128)) {
            byteStream = new ByteArrayOutputStream();
            byte[] length = new byte[4];
            intToBytes(payload.length + HEADER_SIZE, length, 0);
            byteStream.write(length);
            DeflaterOutputStream deflaterStream = new DeflaterOutputStream(byteStream, new Deflater(JZlib.Z_BEST_COMPRESSION));
            deflaterStream.write(payload);
            deflaterStream.close();
            final int padding = (8 - (byteStream.size() % 8)) & 7;
            for (int i = 0; i < padding; i++) byteStream.write(0);
            byte[] compPayload = byteStream.toByteArray();
            if (compPayload.length < payload.length - 4) {
                payload = compPayload;
                compressed = true;
            }
        }
        // Create message header in new byte stream and add payload
        byteStream = new ByteArrayOutputStream();
        // noinspection IOResourceOpenedButNotSafelyClosed
        outputStream = new DataOutputStream(byteStream);
        outputStream.writeShort(messageCode);
        outputStream.writeShort(messageFlags | (compressed ? MF_COMPRESSED : 0));
        // Size
        outputStream.writeInt(payload.length + HEADER_SIZE);
        outputStream.writeInt((int) messageId);
        outputStream.writeInt(fields.size());
        outputStream.write(payload);
    }
    return byteStream.toByteArray();
}

Example 2 with DeflaterOutputStream

use of com.jcraft.jzlib.DeflaterOutputStream in project netxms by netxms.

the class ZlibTest method testCompression.

public void testCompression() throws Exception {
    ByteArrayOutputStream bytesOut = new ByteArrayOutputStream();
    bytesOut.write(new byte[] { 0x01, 0x02, 0x03, 0x04 });
    DeflaterOutputStream zout = new DeflaterOutputStream(bytesOut, new Deflater(JZlib.Z_BEST_COMPRESSION));
    byte[] bytes = TEXT.getBytes();
    zout.write(bytes);
    zout.close();
    byte[] zbytes = bytesOut.toByteArray();
    ByteArrayInputStream bytesIn = new ByteArrayInputStream(zbytes);
    bytesIn.skip(4);
    InflaterInputStream zin = new InflaterInputStream(bytesIn);
    byte[] dbytes = new byte[bytes.length];
    DataInputStream din = new DataInputStream(zin);
    din.readFully(dbytes);
    assertTrue(Arrays.equals(bytes, dbytes));
    zin.close();
    System.out.println(String.format("Size: clear text %d, compressed %d", bytes.length, zbytes.length));
}