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
23 import java.nio.ByteOrder;
24
25 import org.apache.mina.util.byteaccess.ByteArray.Cursor;
26 import org.apache.mina.util.byteaccess.CompositeByteArray.CursorListener;
27
28
29 /**
30 * Provides common functionality between the
31 * <code>CompositeByteArrayRelativeReader</code> and
32 * <code>CompositeByteArrayRelativeWriter</code>.
33 *
34 * @author The Apache MINA Project (dev@mina.apache.org)
35 */
36 abstract class CompositeByteArrayRelativeBase
37 {
38
39 /**
40 * The underlying <code>CompositeByteArray</code>.
41 */
42 protected final CompositeByteArray cba;
43
44 /**
45 * A cursor of the underlying <code>CompositeByteArray</code>. This
46 * cursor is never moved directly; its position only changes through calls
47 * to relative read or write methods.
48 */
49 protected final Cursor cursor;
50
51 /**
52 *
53 * Creates a new instance of CompositeByteArrayRelativeBase.
54 *
55 * @param cba
56 * The {@link CompositeByteArray} that will be the base for this class
57 */
58 public CompositeByteArrayRelativeBase( CompositeByteArray cba )
59 {
60 this.cba = cba;
61 cursor = cba.cursor( cba.first(), new CursorListener()
62 {
63
64 public void enteredFirstComponent( int componentIndex, ByteArray component )
65 {
66 // Do nothing.
67 }
68
69
70 public void enteredLastComponent( int componentIndex, ByteArray component )
71 {
72 assert false;
73 }
74
75
76 public void enteredNextComponent( int componentIndex, ByteArray component )
77 {
78 cursorPassedFirstComponent();
79 }
80
81
82 public void enteredPreviousComponent( int componentIndex, ByteArray component )
83 {
84 assert false;
85 }
86
87 } );
88 }
89
90
91 /**
92 * @inheritDoc
93 */
94 public final int getRemaining()
95 {
96 return cursor.getRemaining();
97 }
98
99
100 /**
101 * @inheritDoc
102 */
103 public final boolean hasRemaining()
104 {
105 return cursor.hasRemaining();
106 }
107
108
109 /**
110 * @inheritDoc
111 */
112 public ByteOrder order()
113 {
114 return cba.order();
115 }
116
117
118 /**
119 * Make a <code>ByteArray</code> available for access at the end of this object.
120 */
121 public final void append( ByteArray ba )
122 {
123 cba.addLast( ba );
124 }
125
126
127 /**
128 * Free all resources associated with this object.
129 */
130 public final void free()
131 {
132 cba.free();
133 }
134
135
136 /**
137 * Get the index that will be used for the next access.
138 */
139 public final int getIndex()
140 {
141 return cursor.getIndex();
142 }
143
144
145 /**
146 * Get the index after the last byte that can be accessed.
147 */
148 public final int last()
149 {
150 return cba.last();
151 }
152
153
154 /**
155 * Called whenever the cursor has passed from the <code>cba</code>'s
156 * first component. As the first component is no longer used, this provides
157 * a good opportunity for subclasses to perform some action on it (such as
158 * freeing it).
159 */
160 protected abstract void cursorPassedFirstComponent();
161
162 }