| /* |
| * Copyright (C) 2008 The Guava Authors |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except |
| * in compliance with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software distributed under the License |
| * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express |
| * or implied. See the License for the specific language governing permissions and limitations under |
| * the License. |
| */ |
| |
| package com.google.thirdparty.publicsuffix; |
| |
| import com.google.common.annotations.GwtCompatible; |
| import com.google.common.base.Joiner; |
| import com.google.common.collect.ImmutableMap; |
| import com.google.common.collect.Lists; |
| import java.util.List; |
| |
| /** Parser for a map of reversed domain names stored as a serialized radix tree. */ |
| @GwtCompatible |
| final class TrieParser { |
| private static final Joiner PREFIX_JOINER = Joiner.on(""); |
| |
| /** |
| * Parses a serialized trie representation of a map of reversed public suffixes into an immutable |
| * map of public suffixes. |
| */ |
| static ImmutableMap<String, PublicSuffixType> parseTrie(CharSequence encoded) { |
| ImmutableMap.Builder<String, PublicSuffixType> builder = ImmutableMap.builder(); |
| int encodedLen = encoded.length(); |
| int idx = 0; |
| while (idx < encodedLen) { |
| idx += doParseTrieToBuilder(Lists.<CharSequence>newLinkedList(), encoded, idx, builder); |
| } |
| return builder.build(); |
| } |
| |
| /** |
| * Parses a trie node and returns the number of characters consumed. |
| * |
| * @param stack The prefixes that precede the characters represented by this node. Each entry of |
| * the stack is in reverse order. |
| * @param encoded The serialized trie. |
| * @param start An index in the encoded serialized trie to begin reading characters from. |
| * @param builder A map builder to which all entries will be added. |
| * @return The number of characters consumed from {@code encoded}. |
| */ |
| private static int doParseTrieToBuilder( |
| List<CharSequence> stack, |
| CharSequence encoded, |
| int start, |
| ImmutableMap.Builder<String, PublicSuffixType> builder) { |
| |
| int encodedLen = encoded.length(); |
| int idx = start; |
| char c = '\0'; |
| |
| // Read all of the characters for this node. |
| for (; idx < encodedLen; idx++) { |
| c = encoded.charAt(idx); |
| if (c == '&' || c == '?' || c == '!' || c == ':' || c == ',') { |
| break; |
| } |
| } |
| |
| stack.add(0, reverse(encoded.subSequence(start, idx))); |
| |
| if (c == '!' || c == '?' || c == ':' || c == ',') { |
| // '!' represents an interior node that represents a REGISTRY entry in the map. |
| // '?' represents a leaf node, which represents a REGISTRY entry in map. |
| // ':' represents an interior node that represents a private entry in the map |
| // ',' represents a leaf node, which represents a private entry in the map. |
| String domain = PREFIX_JOINER.join(stack); |
| if (domain.length() > 0) { |
| builder.put(domain, PublicSuffixType.fromCode(c)); |
| } |
| } |
| idx++; |
| |
| if (c != '?' && c != ',') { |
| while (idx < encodedLen) { |
| // Read all the children |
| idx += doParseTrieToBuilder(stack, encoded, idx, builder); |
| if (encoded.charAt(idx) == '?' || encoded.charAt(idx) == ',') { |
| // An extra '?' or ',' after a child node indicates the end of all children of this node. |
| idx++; |
| break; |
| } |
| } |
| } |
| stack.remove(0); |
| return idx - start; |
| } |
| |
| private static CharSequence reverse(CharSequence s) { |
| return new StringBuilder(s).reverse(); |
| } |
| } |