1 /*
2 * Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.nio;
27
28 import java.util.Objects;
29
30 // ## If the sequence is a string, use reflection to share its array
31
32 class StringCharBuffer // package-private
33 extends CharBuffer
34 {
35 CharSequence str;
36
37 StringCharBuffer(CharSequence s, int start, int end) { // package-private
38 super(-1, start, end, s.length());
39 int n = s.length();
40 Objects.checkFromToIndex(start, end, n);
41 str = s;
42 this.isReadOnly = true;
43 }
44
45 public CharBuffer slice() {
46 return new StringCharBuffer(str,
47 -1,
48 0,
49 this.remaining(),
50 this.remaining(),
51 offset + this.position());
52 }
53
54 @Override
55 public CharBuffer slice(int index, int length) {
56 Objects.checkFromIndexSize(index, length, limit());
57 return new StringCharBuffer(str,
58 -1,
59 0,
60 length,
61 length,
62 offset + index);
63 }
64
65 private StringCharBuffer(CharSequence s,
66 int mark,
67 int pos,
68 int limit,
69 int cap,
70 int offset) {
71 super(mark, pos, limit, cap, null, offset);
72 str = s;
73 this.isReadOnly = true;
74 }
75
76 public CharBuffer duplicate() {
77 return new StringCharBuffer(str, markValue(),
78 position(), limit(), capacity(), offset);
79 }
80
81 public CharBuffer asReadOnlyBuffer() {
82 return duplicate();
83 }
84
85 public final char get() {
86 return str.charAt(nextGetIndex() + offset);
87 }
88
89 public final char get(int index) {
90 return str.charAt(checkIndex(index) + offset);
91 }
92
93 char getUnchecked(int index) {
94 return str.charAt(index + offset);
95 }
96
97 // ## Override bulk get methods for better performance
98
99 public final CharBuffer put(char c) {
100 throw new ReadOnlyBufferException();
101 }
102
103 public final CharBuffer put(int index, char c) {
104 throw new ReadOnlyBufferException();
105 }
106
107 public final CharBuffer compact() {
108 throw new ReadOnlyBufferException();
109 }
110
111 public final boolean isReadOnly() {
112 return true;
113 }
114
115 final String toString(int start, int end) {
116 return str.subSequence(start + offset, end + offset).toString();
117 }
118
119 public final CharBuffer subSequence(int start, int end) {
120 try {
121 int pos = position();
122 return new StringCharBuffer(str,
123 -1,
124 pos + checkIndex(start, pos),
125 pos + checkIndex(end, pos),
126 capacity(),
127 offset);
128 } catch (IllegalArgumentException x) {
129 throw new IndexOutOfBoundsException();
130 }
131 }
132
133 public boolean isDirect() {
134 return false;
135 }
136
137 public ByteOrder order() {
138 return ByteOrder.nativeOrder();
139 }
140
141 ByteOrder charRegionOrder() {
142 return null;
143 }
144
145 public boolean equals(Object ob) {
146 if (this == ob)
147 return true;
148 if (!(ob instanceof CharBuffer))
149 return false;
150 CharBuffer that = (CharBuffer)ob;
151 if (this.remaining() != that.remaining())
152 return false;
153 return BufferMismatch.mismatch(this, this.position(),
154 that, that.position(),
155 this.remaining()) < 0;
156 }
157
158 public int compareTo(CharBuffer that) {
159 int i = BufferMismatch.mismatch(this, this.position(),
160 that, that.position(),
161 Math.min(this.remaining(), that.remaining()));
162 if (i >= 0) {
163 return Character.compare(this.get(this.position() + i), that.get(that.position() + i));
164 }
165 return this.remaining() - that.remaining();
166 }
167 }