net.sourceforge.plantuml.zopfli.Zopfli Maven / Gradle / Ivy

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PlantUML is a component that allows to quickly write diagrams from text.

There is a newer version: 1.2024.8

// THIS FILE HAS BEEN GENERATED BY A PREPROCESSOR.

package net.sourceforge.plantuml.zopfli;

public class Zopfli {

	private static class Crc {

		private final static int[] table = makeTable();

		private static int[] makeTable() {
			int[] result = new int[256];

			for (int n = 0; n < 256; ++n) {
				int c = n;
				for (int k = 0; k < 8; ++k) {
					if ((c & 1) == 1) {
						c = 0xEDB88320 ^ (c >>> 1);
					} else {
						c = c >>> 1;
					}
				}
				result[n] = c;
			}

			return result;
		}

		public static int calculate(byte[] input) {
			int c = ~0;
			for (int i = 0, n = input.length; i < n; ++i) {
				c = table[(c ^ input[i]) & 0xFF] ^ (c >>> 8);
			}
			return ~c;
		}
	}

	private final Cookie cookie;

	public synchronized Buffer compress(Options options, byte[] input) {
		Buffer output = new Buffer();
		switch (options.outputType) {
		case GZIP:
			compressGzip(options, input, output);
			break;

		case ZLIB:
			compressZlib(options, input, output);
			break;
		case DEFLATE:
			Deflate.compress(cookie, options, input, output);
			break;
		default:
			throw new IllegalArgumentException("Unexpected output format: " + options.outputType);
		}
		return output;
	}

	/**
	 * Calculates the adler32 checksum of the data
	 */
	private static int adler32(byte[] data) {
		int s1 = 1;
		int s2 = 1 >> 16;
		int i = 0;
		while (i < data.length) {
			int tick = Math.min(data.length, i + 1024);
			while (i < tick) {
				s1 += data[i++];
				s2 += s1;
			}
			s1 %= 65521;
			s2 %= 65521;
		}

		return (s2 << 16) | s1;
	}

	private void compressZlib(Options options, byte[] input, Buffer output) {
		output.append((byte) 0x78);
		output.append((byte) 0x1E);

		Deflate.compress(cookie, options, input, output);

		int checksum = adler32(input);
		output.append((byte) ((checksum >> 24) & 0xFF));
		output.append((byte) ((checksum >> 16) & 0xFF));
		output.append((byte) ((checksum >> 8) & 0xFF));
		output.append((byte) (checksum & 0xFF));
	}

	private void compressGzip(Options options, byte[] input, Buffer output) {
		output.append((byte) 31);
		output.append((byte) 139);
		output.append((byte) 8);
		output.append((byte) 0);

		output.append((byte) 0);
		output.append((byte) 0);
		output.append((byte) 0);
		output.append((byte) 0);

		output.append((byte) 2);
		output.append((byte) 3);

		Deflate.compress(cookie, options, input, output);

		int crc = Crc.calculate(input);
		output.append((byte) (crc & 0xFF));
		output.append((byte) ((crc >> 8) & 0xFF));
		output.append((byte) ((crc >> 16) & 0xFF));
		output.append((byte) ((crc >> 24) & 0xFF));

		int size = input.length;
		output.append((byte) (size & 0xFF));
		output.append((byte) ((size >> 8) & 0xFF));
		output.append((byte) ((size >> 16) & 0xFF));
		output.append((byte) ((size >> 24) & 0xFF));
	}

	public Zopfli(int masterBlockSize) {
		cookie = new Cookie(masterBlockSize);
	}
}