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// 
// ========================================================================
// Copyright (c) 1995-2022 Mort Bay Consulting Pty Ltd and others.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
// 
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
// 
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
// 
// You may elect to redistribute this code under either of these licenses.
// ========================================================================
// 
package org.eclipse.jetty.util;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

/**
 *  A Trie String lookup data structure using a tree
 *  

This implementation is always case insensitive and is optimal for * a variable number of fixed strings with few special characters. *

*

This Trie is stored in a Tree and is unlimited in capacity

* *

This Trie is not Threadsafe and contains no mutual exclusion * or deliberate memory barriers. It is intended for an TreeTrie to be * built by a single thread and then used concurrently by multiple threads * and not mutated during that access. If concurrent mutations of the * Trie is required external locks need to be applied. *

* * @param the entry type * * @deprecated The Eclipse Jetty and Apache Felix Http Jetty packages are no longer supported. */ @Deprecated(since = "2021-05-27") public class TreeTrie extends AbstractTrie { private static final int[] LOOKUP = { // 0 1 2 3 4 5 6 7 8 9 A B C D E F /*0*/ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*1*/ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*2*/ 31, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 26, -1, 27, 30, -1, /*3*/ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 28, 29, -1, -1, -1, -1, /*4*/ -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, /*5*/ 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, /*6*/ -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, /*7*/ 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1 }; private static final int INDEX = 32; private final TreeTrie[] _nextIndex; private final List> _nextOther = new ArrayList<>(); private final char _c; private String _key; private V _value; public TreeTrie() { super(true); _nextIndex = new TreeTrie[INDEX]; _c = 0; } private TreeTrie(char c) { super(true); _nextIndex = new TreeTrie[INDEX]; this._c = c; } @Override public void clear() { Arrays.fill(_nextIndex, null); _nextOther.clear(); _key = null; _value = null; } @Override public boolean put(String s, V v) { TreeTrie t = this; int limit = s.length(); for (int k = 0; k < limit; k++) { char c = s.charAt(k); int index = c >= 0 && c < 0x7f ? LOOKUP[c] : -1; if (index >= 0) { if (t._nextIndex[index] == null) t._nextIndex[index] = new TreeTrie(c); t = t._nextIndex[index]; } else { TreeTrie n = null; for (int i = t._nextOther.size(); i-- > 0; ) { n = t._nextOther.get(i); if (n._c == c) break; n = null; } if (n == null) { n = new TreeTrie(c); t._nextOther.add(n); } t = n; } } t._key = v == null ? null : s; t._value = v; return true; } @Override public V get(String s, int offset, int len) { TreeTrie t = this; for (int i = 0; i < len; i++) { char c = s.charAt(offset + i); int index = c >= 0 && c < 0x7f ? LOOKUP[c] : -1; if (index >= 0) { if (t._nextIndex[index] == null) return null; t = t._nextIndex[index]; } else { TreeTrie n = null; for (int j = t._nextOther.size(); j-- > 0; ) { n = t._nextOther.get(j); if (n._c == c) break; n = null; } if (n == null) return null; t = n; } } return t._value; } @Override public V get(ByteBuffer b, int offset, int len) { TreeTrie t = this; for (int i = 0; i < len; i++) { byte c = b.get(offset + i); int index = c >= 0 && c < 0x7f ? LOOKUP[c] : -1; if (index >= 0) { if (t._nextIndex[index] == null) return null; t = t._nextIndex[index]; } else { TreeTrie n = null; for (int j = t._nextOther.size(); j-- > 0; ) { n = t._nextOther.get(j); if (n._c == c) break; n = null; } if (n == null) return null; t = n; } } return t._value; } @Override public V getBest(byte[] b, int offset, int len) { TreeTrie t = this; for (int i = 0; i < len; i++) { byte c = b[offset + i]; int index = c >= 0 && c < 0x7f ? LOOKUP[c] : -1; if (index >= 0) { if (t._nextIndex[index] == null) break; t = t._nextIndex[index]; } else { TreeTrie n = null; for (int j = t._nextOther.size(); j-- > 0; ) { n = t._nextOther.get(j); if (n._c == c) break; n = null; } if (n == null) break; t = n; } // Is the next Trie is a match if (t._key != null) { // Recurse so we can remember this possibility V best = t.getBest(b, offset + i + 1, len - i - 1); if (best != null) return best; break; } } return t._value; } @Override public V getBest(String s, int offset, int len) { TreeTrie t = this; for (int i = 0; i < len; i++) { byte c = (byte) (0xff & s.charAt(offset + i)); int index = c >= 0 && c < 0x7f ? LOOKUP[c] : -1; if (index >= 0) { if (t._nextIndex[index] == null) break; t = t._nextIndex[index]; } else { TreeTrie n = null; for (int j = t._nextOther.size(); j-- > 0; ) { n = t._nextOther.get(j); if (n._c == c) break; n = null; } if (n == null) break; t = n; } // Is the next Trie is a match if (t._key != null) { // Recurse so we can remember this possibility V best = t.getBest(s, offset + i + 1, len - i - 1); if (best != null) return best; break; } } return t._value; } @Override public V getBest(ByteBuffer b, int offset, int len) { if (b.hasArray()) return getBest(b.array(), b.arrayOffset() + b.position() + offset, len); return getBestByteBuffer(b, offset, len); } private V getBestByteBuffer(ByteBuffer b, int offset, int len) { TreeTrie t = this; int pos = b.position() + offset; for (int i = 0; i < len; i++) { byte c = b.get(pos++); int index = c >= 0 && c < 0x7f ? LOOKUP[c] : -1; if (index >= 0) { if (t._nextIndex[index] == null) break; t = t._nextIndex[index]; } else { TreeTrie n = null; for (int j = t._nextOther.size(); j-- > 0; ) { n = t._nextOther.get(j); if (n._c == c) break; n = null; } if (n == null) break; t = n; } // Is the next Trie is a match if (t._key != null) { // Recurse so we can remember this possibility V best = t.getBest(b, offset + i + 1, len - i - 1); if (best != null) return best; break; } } return t._value; } @Override public String toString() { StringBuilder buf = new StringBuilder(); toString(buf, this); if (buf.length() == 0) return "{}"; buf.setCharAt(0, '{'); buf.append('}'); return buf.toString(); } private static void toString(Appendable out, TreeTrie t) { if (t != null) { if (t._value != null) { try { out.append(','); out.append(t._key); out.append('='); out.append(t._value.toString()); } catch (IOException e) { throw new RuntimeException(e); } } for (int i = 0; i < INDEX; i++) { if (t._nextIndex[i] != null) toString(out, t._nextIndex[i]); } for (int i = t._nextOther.size(); i-- > 0; ) { toString(out, t._nextOther.get(i)); } } } @Override public Set keySet() { Set keys = new HashSet<>(); keySet(keys, this); return keys; } private static void keySet(Set set, TreeTrie t) { if (t != null) { if (t._key != null) set.add(t._key); for (int i = 0; i < INDEX; i++) { if (t._nextIndex[i] != null) keySet(set, t._nextIndex[i]); } for (int i = t._nextOther.size(); i-- > 0; ) { keySet(set, t._nextOther.get(i)); } } } @Override public boolean isFull() { return false; } }




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