Output.java revision bd3dba4346223593ac6033a3d2a7d8ec6f20738b 
1/*
2 * Copyright (C) 2007 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.dx.util;
18
19/**
20 * Interface for a sink for binary output. This is similar to
21 * {@code java.util.DataOutput}, but no {@code IOExceptions}
22 * are declared, and multibyte output is defined to be little-endian.
23 */
24public interface Output extends ByteOutput {
25    /**
26     * Gets the current cursor position. This is the same as the number of
27     * bytes written to this instance.
28     *
29     * @return {@code >= 0;} the cursor position
30     */
31    public int getCursor();
32
33    /**
34     * Asserts that the cursor is the given value.
35     *
36     * @param expectedCursor the expected cursor value
37     * @throws RuntimeException thrown if {@code getCursor() !=
38     * expectedCursor}
39     */
40    public void assertCursor(int expectedCursor);
41
42    /**
43     * Writes a {@code byte} to this instance.
44     *
45     * @param value the value to write; all but the low 8 bits are ignored
46     */
47    public void writeByte(int value);
48
49    /**
50     * Writes a {@code short} to this instance.
51     *
52     * @param value the value to write; all but the low 16 bits are ignored
53     */
54    public void writeShort(int value);
55
56    /**
57     * Writes an {@code int} to this instance.
58     *
59     * @param value the value to write
60     */
61    public void writeInt(int value);
62
63    /**
64     * Writes a {@code long} to this instance.
65     *
66     * @param value the value to write
67     */
68    public void writeLong(long value);
69
70    /**
71     * Writes a DWARFv3-style unsigned LEB128 integer. For details,
72     * see the "Dalvik Executable Format" document or DWARF v3 section
73     * 7.6.
74     *
75     * @param value value to write, treated as an unsigned value
76     * @return {@code 1..5;} the number of bytes actually written
77     */
78    public int writeUleb128(int value);
79
80    /**
81     * Writes a DWARFv3-style unsigned LEB128 integer. For details,
82     * see the "Dalvik Executable Format" document or DWARF v3 section
83     * 7.6.
84     *
85     * @param value value to write
86     * @return {@code 1..5;} the number of bytes actually written
87     */
88    public int writeSleb128(int value);
89
90    /**
91     * Writes a {@link ByteArray} to this instance.
92     *
93     * @param bytes {@code non-null;} the array to write
94     */
95    public void write(ByteArray bytes);
96
97    /**
98     * Writes a portion of a {@code byte[]} to this instance.
99     *
100     * @param bytes {@code non-null;} the array to write
101     * @param offset {@code >= 0;} offset into {@code bytes} for the first
102     * byte to write
103     * @param length {@code >= 0;} number of bytes to write
104     */
105    public void write(byte[] bytes, int offset, int length);
106
107    /**
108     * Writes a {@code byte[]} to this instance. This is just
109     * a convenient shorthand for {@code write(bytes, 0, bytes.length)}.
110     *
111     * @param bytes {@code non-null;} the array to write
112     */
113    public void write(byte[] bytes);
114
115    /**
116     * Writes the given number of {@code 0} bytes.
117     *
118     * @param count {@code >= 0;} the number of zeroes to write
119     */
120    public void writeZeroes(int count);
121
122    /**
123     * Adds extra bytes if necessary (with value {@code 0}) to
124     * force alignment of the output cursor as given.
125     *
126     * @param alignment {@code > 0;} the alignment; must be a power of two
127     */
128    public void alignTo(int alignment);
129}
130