1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 *
19 */
20 package org.apache.mina.util.byteaccess;
21
22 import java.nio.ByteOrder;
23
24 import org.apache.mina.util.byteaccess.ByteArray.Cursor;
25 import org.apache.mina.util.byteaccess.CompositeByteArray.CursorListener;
26
27 /**
28 * Provides common functionality between the
29 * <code>CompositeByteArrayRelativeReader</code> and
30 * <code>CompositeByteArrayRelativeWriter</code>.
31 *
32 * @author <a href="http://mina.apache.org">Apache MINA Project</a>
33 */
34 abstract class CompositeByteArrayRelativeBase {
35
36 /**
37 * The underlying <code>CompositeByteArray</code>.
38 */
39 protected final CompositeByteArray cba;
40
41 /**
42 * A cursor of the underlying <code>CompositeByteArray</code>. This
43 * cursor is never moved directly; its position only changes through calls
44 * to relative read or write methods.
45 */
46 protected final Cursor cursor;
47
48 /**
49 *
50 * Creates a new instance of CompositeByteArrayRelativeBase.
51 *
52 * @param cba
53 * The {@link CompositeByteArray} that will be the base for this class
54 */
55 public CompositeByteArrayRelativeBase(CompositeByteArray cba) {
56 this.cba = cba;
57 cursor = cba.cursor(cba.first(), new CursorListener() {
58
59 /**
60 * {@inheritDoc}
61 */
62 @Override
63 public void enteredFirstComponent(int componentIndex, ByteArray component) {
64 // Do nothing.
65 }
66
67 /**
68 * {@inheritDoc}
69 */
70 @Override
71 public void enteredLastComponent(int componentIndex, ByteArray component) {
72 assert false;
73 }
74
75 /**
76 * {@inheritDoc}
77 */
78 @Override
79 public void enteredNextComponent(int componentIndex, ByteArray component) {
80 cursorPassedFirstComponent();
81 }
82
83 /**
84 * {@inheritDoc}
85 */
86 @Override
87 public void enteredPreviousComponent(int componentIndex, ByteArray component) {
88 assert false;
89 }
90
91 });
92 }
93
94 /**
95 * @return The number of remaining bytes
96 */
97 public final int getRemaining() {
98 return cursor.getRemaining();
99 }
100
101 /**
102 * @return <TT>TRUE</TT> if there are some more bytes
103 */
104 public final boolean hasRemaining() {
105 return cursor.hasRemaining();
106 }
107
108 /**
109 * @return The used byte order (little of big indian)
110 */
111 public ByteOrder order() {
112 return cba.order();
113 }
114
115 /**
116 * Make a <code>ByteArray</code> available for access at the end of this object.
117 *
118 * @param ba The ByteArray to append
119 */
120 public final void append(ByteArray ba) {
121 cba.addLast(ba);
122 }
123
124 /**
125 * Free all resources associated with this object.
126 */
127 public final void free() {
128 cba.free();
129 }
130
131 /**
132 * @return the index that will be used for the next access.
133 */
134 public final int getIndex() {
135 return cursor.getIndex();
136 }
137
138 /**
139 * @return the index after the last byte that can be accessed.
140 */
141 public final int last() {
142 return cba.last();
143 }
144
145 /**
146 * Called whenever the cursor has passed from the <code>cba</code>'s
147 * first component. As the first component is no longer used, this provides
148 * a good opportunity for subclasses to perform some action on it (such as
149 * freeing it).
150 */
151 protected abstract void cursorPassedFirstComponent();
152 }