1 /*
2 * Copyright (C) 2016 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
17 #include <android/util/protobuf.h>
18
19 namespace android {
20 namespace util {
21
22 uint8_t
read_wire_type(uint32_t varint)23 read_wire_type(uint32_t varint)
24 {
25 return (uint8_t) (varint & WIRE_TYPE_MASK);
26 }
27
28 uint32_t
read_field_id(uint32_t varint)29 read_field_id(uint32_t varint)
30 {
31 return varint >> FIELD_ID_SHIFT;
32 }
33
34 size_t
get_varint_size(uint64_t varint)35 get_varint_size(uint64_t varint)
36 {
37 size_t size = 1;
38 while ((varint & ~0x7F)) {
39 size++;
40 varint >>= 7;
41 }
42 return size;
43 }
44
45 uint8_t*
write_raw_varint(uint8_t * buf,uint64_t val)46 write_raw_varint(uint8_t* buf, uint64_t val)
47 {
48 uint8_t* p = buf;
49 while (true) {
50 if ((val & ~0x7F) == 0) {
51 *p++ = (uint8_t)val;
52 return p;
53 } else {
54 *p++ = (uint8_t)((val & 0x7F) | 0x80);
55 val >>= 7;
56 }
57 }
58 }
59
60 uint8_t*
write_length_delimited_tag_header(uint8_t * buf,uint32_t fieldId,size_t size)61 write_length_delimited_tag_header(uint8_t* buf, uint32_t fieldId, size_t size)
62 {
63 buf = write_raw_varint(buf, (fieldId << FIELD_ID_SHIFT) | WIRE_TYPE_LENGTH_DELIMITED);
64 buf = write_raw_varint(buf, size);
65 return buf;
66 }
67
68 } // util
69 } // android
70