net.sourceforge.plantuml.zopfli.Hash 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;

class Hash {

	// HASH_SHIFT = 5;
	// HASH_MASK = 32767;

	private static final int[] seq = new int[0x8000];

	static {
		int[] seq = Hash.seq;
		for (int i = 0, l = 0x8000; i < l; ++i) {
			seq[i] = i;
		}
	}

	final int[] head = new int[0x10000];
	final int[] prev = new int[0x8000];
	private final int[] hashVal = new int[0x8000];
	final int[] same = new int[0x8000];
	int val;

	private final int[] head2 = new int[0x10000];
	final int[] prev2 = new int[0x8000];
	final int[] hashVal2 = new int[0x8000];

	public Hash() {
	}

	public void init(byte[] input, int windowStart, int from, int to) {
		int[] hashVal = this.hashVal;
		int[] head = this.head;
		int[] same = this.same;
		int[] prev = this.prev;
		int[] hashVal2 = this.hashVal2;
		int[] head2 = this.head2;
		int[] prev2 = this.prev2;

		System.arraycopy(Cookie.intMOnes, 0, head, 0, 0x10000);
		System.arraycopy(Cookie.intMOnes, 0, hashVal, 0, 0x8000);
		System.arraycopy(Cookie.intZeroes, 0, same, 0x8000, 0);
		System.arraycopy(seq, 0, prev, 0, 0x8000);

		System.arraycopy(Cookie.intMOnes, 0, head2, 0, 0x10000);
		System.arraycopy(Cookie.intMOnes, 0, hashVal2, 0, 0x8000);
		System.arraycopy(seq, 0, prev2, 0, 0x8000);

		int val = (((input[windowStart] & 0xFF) << 5) ^ input[windowStart + 1] & 0xFF) & 0x7FFF;

		for (int i = windowStart; i < from; ++i) {
			int hPos = i & 0x7FFF;
			val = ((val << 5) ^ (i + 2 < to ? input[i + 2] & 0xFF : 0)) & 0x7FFF;

			hashVal[hPos] = val;
			int tmp = head[val];
			prev[hPos] = tmp != -1 && hashVal[tmp] == val ? tmp : hPos;
			head[val] = hPos;

			tmp = same[(i - 1) & 0x7FFF];
			if (tmp < 1) {
				tmp = 1;
			}
			tmp += i;
			byte b = input[i];
			while (tmp < to && b == input[tmp]) {
				tmp++;
			}
			tmp -= i;
			tmp--;
			same[hPos] = tmp;

			tmp = ((tmp - 3) & 0xFF) ^ val;
			hashVal2[hPos] = tmp;
			int h = head2[tmp];
			prev2[hPos] = h != -1 && hashVal2[h] == tmp ? h : hPos;
			head2[tmp] = hPos;
		}
		this.val = val;
	}

	/*
	 * private void updateHashValue(int c) { val = ((val << HASH_SHIFT) ^ c) &
	 * HASH_MASK; }
	 */

	public void updateHash(byte[] input, int pos, int end) {
		// WINDOW_MASK
		int hPos = pos & 0x7FFF;
		int val = this.val;

		val = ((val << 5) ^ (pos + 2 < end ? input[pos + 2] & 0xFF : 0)) & 0x7FFF;

		hashVal[hPos] = val;
		int tmp = head[val];
		prev[hPos] = (tmp != -1 && hashVal[tmp] == val) ? tmp : hPos;
		head[val] = hPos;

		tmp = same[(pos - 1) & 0x7FFF];
		if (tmp < 1) {
			tmp = 1;
		}
		tmp += pos;
		byte b = input[pos];
		while (tmp < end && b == input[tmp]) {
			tmp++;
		}
		tmp -= pos;
		tmp--;
		same[hPos] = tmp;

		tmp = ((tmp - 3) & 0xFF) ^ val;
		hashVal2[hPos] = tmp;
		int h = head2[tmp];
		prev2[hPos] = h != -1 && hashVal2[h] == tmp ? h : hPos;
		head2[tmp] = hPos;

		this.val = val;
	}
}