1 /*
2 * ====================================================================
3 * Licensed to the Apache Software Foundation (ASF) under one
4 * or more contributor license agreements. See the NOTICE file
5 * distributed with this work for additional information
6 * regarding copyright ownership. The ASF licenses this file
7 * to you under the Apache License, Version 2.0 (the
8 * "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing,
14 * software distributed under the License is distributed on an
15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16 * KIND, either express or implied. See the License for the
17 * specific language governing permissions and limitations
18 * under the License.
19 * ====================================================================
20 *
21 * This software consists of voluntary contributions made by many
22 * individuals on behalf of the Apache Software Foundation. For more
23 * information on the Apache Software Foundation, please see
24 * <http://www.apache.org/>.
25 *
26 */
27
28 package org.apache.hc.core5.http2.hpack;
29
30 import java.util.Arrays;
31
32 import org.apache.hc.core5.util.Asserts;
33
34 /**
35 * This Huffman codec implementation has been derived from Twitter HPack project
36 * (https://github.com/twitter/hpack)
37 */
38 final class HuffmanNode {
39
40 private final int symbol;
41 private final int bits;
42 private final HuffmanNode[] children;
43
44 HuffmanNode() {
45 this.symbol = 0;
46 this.bits = 8;
47 this.children = new HuffmanNode[256];
48 }
49
50 HuffmanNode(final int symbol, final int bits) {
51 this.symbol = symbol;
52 this.bits = bits;
53 this.children = null;
54 }
55
56 public int getBits() {
57 return this.bits;
58 }
59
60 public int getSymbol() {
61 return this.symbol;
62 }
63
64 public boolean hasChild(final int index) {
65 return this.children != null && this.children[index] != null;
66 }
67
68 public HuffmanNode getChild(final int index) {
69 return this.children != null ? this.children[index] : null;
70 }
71
72 void setChild(final int index, final HuffmanNode child) {
73 Asserts.notNull(this.children, "Children nodes");
74 this.children[index] = child;
75 }
76
77 public boolean isTerminal() {
78 return this.children == null;
79 }
80
81 @Override
82 public String toString() {
83 return "[" +
84 "symbol=" + symbol +
85 ", bits=" + bits +
86 ", children=" + Arrays.toString(children) +
87 ']';
88 }
89
90 }