Source code: java/nio/CharViewBufferImpl.java
1 /* CharViewBufferImpl.java --
2 Copyright (C) 2003, 2004 Free Software Foundation, Inc.
3
4 This file is part of GNU Classpath.
5
6 GNU Classpath is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
9 any later version.
10
11 GNU Classpath is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with GNU Classpath; see the file COPYING. If not, write to the
18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
19 02110-1301 USA.
20
21 Linking this library statically or dynamically with other modules is
22 making a combined work based on this library. Thus, the terms and
23 conditions of the GNU General Public License cover the whole
24 combination.
25
26 As a special exception, the copyright holders of this library give you
27 permission to link this library with independent modules to produce an
28 executable, regardless of the license terms of these independent
29 modules, and to copy and distribute the resulting executable under
30 terms of your choice, provided that you also meet, for each linked
31 independent module, the terms and conditions of the license of that
32 module. An independent module is a module which is not derived from
33 or based on this library. If you modify this library, you may extend
34 this exception to your version of the library, but you are not
35 obligated to do so. If you do not wish to do so, delete this
36 exception statement from your version. */
37
38
39 package java.nio;
40
41 class CharViewBufferImpl extends CharBuffer
42 {
43 /** Position in bb (i.e. a byte offset) where this buffer starts. */
44 private int offset;
45 private ByteBuffer bb;
46 private boolean readOnly;
47 private ByteOrder endian;
48
49 CharViewBufferImpl (ByteBuffer bb, int capacity)
50 {
51 super (capacity, capacity, 0, -1);
52 this.bb = bb;
53 this.offset = bb.position();
54 this.readOnly = bb.isReadOnly();
55 this.endian = bb.order();
56 if (bb.isDirect())
57 this.address = VMDirectByteBuffer.adjustAddress(bb.address, offset);
58 }
59
60 public CharViewBufferImpl (ByteBuffer bb, int offset, int capacity,
61 int limit, int position, int mark,
62 boolean readOnly, ByteOrder endian)
63 {
64 super (capacity, limit, position, mark);
65 this.bb = bb;
66 this.offset = offset;
67 this.readOnly = readOnly;
68 this.endian = endian;
69 if (bb.isDirect())
70 this.address = VMDirectByteBuffer.adjustAddress(bb.address, offset);
71 }
72
73 /**
74 * Reads the <code>char</code> at this buffer's current position,
75 * and then increments the position.
76 *
77 * @exception BufferUnderflowException If there are no remaining
78 * <code>char</code>s in this buffer.
79 */
80 public char get ()
81 {
82 int p = position();
83 char result = ByteBufferHelper.getChar(bb, (p << 1) + offset, endian);
84 position(p + 1);
85 return result;
86 }
87
88 /**
89 * Absolute get method. Reads the <code>char</code> at position
90 * <code>index</code>.
91 *
92 * @param index Position to read the <code>char</code> from.
93 *
94 * @exception IndexOutOfBoundsException If index is negative or not smaller
95 * than the buffer's limit.
96 */
97 public char get (int index)
98 {
99 return ByteBufferHelper.getChar(bb, (index << 1) + offset, endian);
100 }
101
102 public CharBuffer put (char value)
103 {
104 int p = position();
105 ByteBufferHelper.putChar(bb, (p << 1) + offset, value, endian);
106 position(p + 1);
107 return this;
108 }
109
110 public CharBuffer put (int index, char value)
111 {
112 ByteBufferHelper.putChar(bb, (index << 1) + offset, value, endian);
113 return this;
114 }
115
116 public CharBuffer compact ()
117 {
118 if (position () > 0)
119 {
120 int count = limit () - position ();
121 bb.shiftDown(offset, offset + 2 * position(), 2 * count);
122 position (count);
123 limit (capacity ());
124 }
125 else
126 {
127 position(limit());
128 limit(capacity());
129 }
130 return this;
131 }
132
133 public CharBuffer slice ()
134 {
135 // Create a sliced copy of this object that shares its content.
136 return new CharViewBufferImpl (bb, (position () >> 1) + offset,
137 remaining (), remaining (), 0, -1,
138 isReadOnly (), endian);
139 }
140
141 CharBuffer duplicate (boolean readOnly)
142 {
143 int pos = position();
144 reset();
145 int mark = position();
146 position(pos);
147 return new CharViewBufferImpl (bb, offset, capacity(), limit(),
148 pos, mark, readOnly, endian);
149 }
150
151 public CharBuffer duplicate ()
152 {
153 return duplicate(readOnly);
154 }
155
156 public CharBuffer asReadOnlyBuffer ()
157 {
158 return duplicate(true);
159 }
160
161 public CharSequence subSequence (int start, int end)
162 {
163 if (start < 0
164 || end < start
165 || end > length ())
166 throw new IndexOutOfBoundsException ();
167
168 return new CharViewBufferImpl (bb, array_offset, capacity (),
169 position () + end, position () + start,
170 -1, isReadOnly (), endian);
171 }
172
173 public boolean isReadOnly ()
174 {
175 return readOnly;
176 }
177
178 public boolean isDirect ()
179 {
180 return bb.isDirect ();
181 }
182
183 public ByteOrder order ()
184 {
185 return endian;
186 }
187 }