1 /*
2 * This file is part of Waarp Project (named also Waarp or GG).
3 *
4 * Copyright (c) 2019, Waarp SAS, and individual contributors by the @author
5 * tags. See the COPYRIGHT.txt in the distribution for a full listing of
6 * individual contributors.
7 *
8 * All Waarp Project is free software: you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation, either version 3 of the License, or (at your
11 * option) any later version.
12 *
13 * Waarp is distributed in the hope that it will be useful, but WITHOUT ANY
14 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
15 * A PARTICULAR PURPOSE. See the GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License along with
18 * Waarp . If not, see <http://www.gnu.org/licenses/>.
19 */
20
21 /*
22 * Licensed under the Apache License, Version 2.0 (the "License");
23 * you may not use this file except in compliance with the License.
24 * You may obtain a copy of the License at
25 *
26 * http://www.apache.org/licenses/LICENSE-2.0
27 *
28 * Unless required by applicable law or agreed to in writing, software
29 * distributed under the License is distributed on an "AS IS" BASIS,
30 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
31 * See the License for the specific language governing permissions and
32 * limitations under the License.
33 */
34 package org.waarp.compress.zstdsafe;
35
36 import java.util.Arrays;
37
38 class BlockCompressionState {
39 public final int[] hashTable;
40 public final int[] chainTable;
41
42 private final int baseAddress;
43
44 // starting point of the window with respect to baseAddress
45 private int windowBaseOffset;
46
47 public BlockCompressionState(final CompressionParameters parameters,
48 final int baseAddress) {
49 this.baseAddress = baseAddress;
50 hashTable = new int[1 << parameters.getHashLog()];
51 chainTable = new int[1 <<
52 parameters.getChainLog()]; // TODO: chain table not used by Strategy.FAST
53 }
54
55 public void reset() {
56 Arrays.fill(hashTable, 0);
57 Arrays.fill(chainTable, 0);
58 }
59
60 public void enforceMaxDistance(final int inputLimit, final int maxDistance) {
61 final int distance = inputLimit - baseAddress;
62
63 final int newOffset = distance - maxDistance;
64 if (windowBaseOffset < newOffset) {
65 windowBaseOffset = newOffset;
66 }
67 }
68
69 public int getBaseAddress() {
70 return baseAddress;
71 }
72
73 public int getWindowBaseOffset() {
74 return windowBaseOffset;
75 }
76 }