jars/icu4j-52_1/main/classes/core/src/com/ibm/icu/text/BytesDictionaryMatcher.java

   1 /*
   2  *******************************************************************************
   3  * Copyright (C) 2012, International Business Machines Corporation and         *
   4  * others. All Rights Reserved.                                                *
   5  *******************************************************************************
   6  */
   7 package com.ibm.icu.text;
   8
   9 import java.text.CharacterIterator;
  10
  11 import com.ibm.icu.impl.Assert;
  12 import com.ibm.icu.util.BytesTrie;
  13 import com.ibm.icu.util.BytesTrie.Result;
  14
  15 class BytesDictionaryMatcher extends DictionaryMatcher {
  16     private final byte[] characters;
  17     private final int transform;
  18
  19     public BytesDictionaryMatcher(byte[] chars, int transform) {
  20         characters = chars;
  21         Assert.assrt((transform & DictionaryData.TRANSFORM_TYPE_MASK) == DictionaryData.TRANSFORM_TYPE_OFFSET);
  22         // while there is only one transform type so far, save the entire transform constant so that
  23         // if we add any others, we need only change code in transform() and the assert above rather
  24         // than adding a "transform type" variable
  25         this.transform = transform;
  26     }
  27
  28     private int transform(int c) {
  29         if (c == 0x200D) {
  30             return 0xFF;
  31         } else if (c == 0x200C) {
  32             return 0xFE;
  33         }
  34
  35         int delta = c - (transform & DictionaryData.TRANSFORM_OFFSET_MASK);
  36         if (delta < 0 || 0xFD < delta) {
  37             return -1;
  38         }
  39         return delta;
  40     }
  41
  42     public int matches(CharacterIterator text_, int maxLength, int[] lengths, int[] count_, int limit, int[] values) {
  43         UCharacterIterator text = UCharacterIterator.getInstance(text_);
  44         BytesTrie bt = new BytesTrie(characters, 0);
  45         int c = text.nextCodePoint();
  46         Result result = bt.first(transform(c));
  47         // TODO: should numChars count Character.charCount() ?
  48         int numChars = 1;
  49         int count = 0;
  50         for (;;) {
  51             if (result.hasValue()) {
  52                 if (count < limit) {
  53                     if (values != null) {
  54                         values[count] = bt.getValue();
  55                     }
  56                     lengths[count] = numChars;
  57                     count++;
  58                 }
  59                 if (result == Result.FINAL_VALUE) {
  60                     break;
  61                 }
  62             } else if (result == Result.NO_MATCH) {
  63                 break;
  64             }
  65
  66             if (numChars >= maxLength) {
  67                 break;
  68             }
  69
  70             c = text.nextCodePoint();
  71             ++numChars;
  72             result = bt.next(transform(c));
  73         }
  74         count_[0] = count;
  75         return numChars;
  76     }
  77
  78     public int getType() {
  79         return DictionaryData.TRIE_TYPE_BYTES;
  80     }
  81 }
  82
  83