1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
|
// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc. All rights reserved.
// https://developers.google.com/protocol-buffers/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
package com.google.protobuf;
/** Common methods and constants for the binary protobuf protocol. */
@ExperimentalApi
final class BinaryProtocolUtil {
private BinaryProtocolUtil() {}
private static final int TAG_TYPE_BITS = 3;
private static final int TAG_TYPE_MASK = (1 << TAG_TYPE_BITS) - 1;
static final byte WIRETYPE_VARINT = 0;
static final byte WIRETYPE_FIXED64 = 1;
static final byte WIRETYPE_LENGTH_DELIMITED = 2;
static final byte WIRETYPE_START_GROUP = 3;
static final byte WIRETYPE_END_GROUP = 4;
static final byte WIRETYPE_FIXED32 = 5;
static final byte MAX_VARINT32_SIZE = 5;
static final byte MAX_VARINT64_SIZE = 10;
static final byte FIXED32_SIZE = 4;
static final byte FIXED64_SIZE = 8;
static int tagFor(int fieldNumber, byte wireType) {
return (fieldNumber << TAG_TYPE_BITS) | wireType;
}
static int getFieldNumber(final int tag) {
return tag >>> TAG_TYPE_BITS;
}
static int getWireType(final int tag) {
return tag & TAG_TYPE_MASK;
}
/**
* Decode a ZigZag-encoded 32-bit value. ZigZag encodes signed integers into values that can be
* efficiently encoded with varint. (Otherwise, negative values must be sign-extended to 64 bits
* to be varint encoded, thus always taking 10 bytes on the wire.)
*
* @param n An unsigned 32-bit integer, stored in a signed int because Java has no explicit
* unsigned support.
* @return A signed 32-bit integer.
*/
static int decodeZigZag32(final int n) {
return (n >>> 1) ^ -(n & 1);
}
/**
* Decode a ZigZag-encoded 64-bit value. ZigZag encodes signed integers into values that can be
* efficiently encoded with varint. (Otherwise, negative values must be sign-extended to 64 bits
* to be varint encoded, thus always taking 10 bytes on the wire.)
*
* @param n An unsigned 64-bit integer, stored in a signed int because Java has no explicit
* unsigned support.
* @return A signed 64-bit integer.
*/
static long decodeZigZag64(final long n) {
return (n >>> 1) ^ -(n & 1);
}
/**
* Encode a ZigZag-encoded 32-bit value. ZigZag encodes signed integers into values that can be
* efficiently encoded with varint. (Otherwise, negative values must be sign-extended to 64 bits
* to be varint encoded, thus always taking 10 bytes on the wire.)
*
* @param n A signed 32-bit integer.
* @return An unsigned 32-bit integer, stored in a signed int because Java has no explicit
* unsigned support.
*/
static int encodeZigZag32(final int n) {
// Note: the right-shift must be arithmetic
return (n << 1) ^ (n >> 31);
}
/**
* Encode a ZigZag-encoded 64-bit value. ZigZag encodes signed integers into values that can be
* efficiently encoded with varint. (Otherwise, negative values must be sign-extended to 64 bits
* to be varint encoded, thus always taking 10 bytes on the wire.)
*
* @param n A signed 64-bit integer.
* @return An unsigned 64-bit integer, stored in a signed int because Java has no explicit
* unsigned support.
*/
static long encodeZigZag64(final long n) {
// Note: the right-shift must be arithmetic
return (n << 1) ^ (n >> 63);
}
}
|
