parser/html/javasrc/UTF16Buffer.java

   1 /*
   2  * Copyright (c) 2008-2010 Mozilla Foundation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  17  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  19  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  20  * DEALINGS IN THE SOFTWARE.
  21  */
  22
  23 package nu.validator.htmlparser.impl;
  24
  25 import nu.validator.htmlparser.annotation.NoLength;
  26
  27 /**
  28  * An UTF-16 buffer that knows the start and end indeces of its unconsumed
  29  * content.
  30  *
  31  * @version $Id$
  32  * @author hsivonen
  33  */
  34 public final class UTF16Buffer {
  35
  36     /**
  37      * The backing store of the buffer. May be larger than the logical content
  38      * of this <code>UTF16Buffer</code>.
  39      */
  40     private final @NoLength char[] buffer;
  41
  42     /**
  43      * The index of the first unconsumed character in the backing buffer.
  44      */
  45     private int start;
  46
  47     /**
  48      * The index of the slot immediately after the last character in the backing
  49      * buffer that is part of the logical content of this
  50      * <code>UTF16Buffer</code>.
  51      */
  52     private int end;
  53
  54     //[NOCPP[
  55
  56     /**
  57      * Constructor for wrapping an existing UTF-16 code unit array.
  58      *
  59      * @param buffer
  60      *            the backing buffer
  61      * @param start
  62      *            the index of the first character to consume
  63      * @param end
  64      *            the index immediately after the last character to consume
  65      */
  66     public UTF16Buffer(@NoLength char[] buffer, int start, int end) {
  67         this.buffer = buffer;
  68         this.start = start;
  69         this.end = end;
  70     }
  71
  72     // ]NOCPP]
  73
  74     /**
  75      * Returns the start index.
  76      *
  77      * @return the start index
  78      */
  79     public int getStart() {
  80         return start;
  81     }
  82
  83     /**
  84      * Sets the start index.
  85      *
  86      * @param start
  87      *            the start index
  88      */
  89     public void setStart(int start) {
  90         this.start = start;
  91     }
  92
  93     /**
  94      * Returns the backing buffer.
  95      *
  96      * @return the backing buffer
  97      */
  98     public @NoLength char[] getBuffer() {
  99         return buffer;
 100     }
 101
 102     /**
 103      * Returns the end index.
 104      *
 105      * @return the end index
 106      */
 107     public int getEnd() {
 108         return end;
 109     }
 110
 111     /**
 112      * Checks if the buffer has data left.
 113      *
 114      * @return <code>true</code> if there's data left
 115      */
 116     public boolean hasMore() {
 117         return start < end;
 118     }
 119
 120     /**
 121      * Returns <code>end - start</code>.
 122      *
 123      * @return <code>end - start</code>
 124      */
 125     public int getLength() {
 126         return end - start;
 127     }
 128
 129     /**
 130      * Adjusts the start index to skip over the first character if it is a line
 131      * feed and the previous character was a carriage return.
 132      *
 133      * @param lastWasCR
 134      *            whether the previous character was a carriage return
 135      */
 136     public void adjust(boolean lastWasCR) {
 137         if (lastWasCR && buffer[start] == '\n') {
 138             start++;
 139         }
 140     }
 141
 142     /**
 143      * Sets the end index.
 144      *
 145      * @param end
 146      *            the end index
 147      */
 148     public void setEnd(int end) {
 149         this.end = end;
 150     }
 151 }