1 /* 2 * Copyright (C) 2017 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 #ifndef ANDROID_UTIL_PROTOBUF_H 18 #define ANDROID_UTIL_PROTOBUF_H 19 20 #include <stdint.h> 21 22 namespace android { 23 namespace util { 24 25 const int FIELD_ID_SHIFT = 3; 26 const uint8_t WIRE_TYPE_MASK = (1 << FIELD_ID_SHIFT) - 1; 27 28 const uint8_t WIRE_TYPE_VARINT = 0; 29 const uint8_t WIRE_TYPE_FIXED64 = 1; 30 const uint8_t WIRE_TYPE_LENGTH_DELIMITED = 2; 31 const uint8_t WIRE_TYPE_FIXED32 = 5; 32 33 /** 34 * Read the wire type from varint, it is the smallest 3 bits. 35 */ 36 uint8_t read_wire_type(uint32_t varint); 37 38 /** 39 * Read field id from varint, it is varint >> 3; 40 */ 41 uint32_t read_field_id(uint32_t varint); 42 43 /** 44 * Get the size of a varint. 45 */ 46 size_t get_varint_size(uint64_t varint); 47 48 /** 49 * Write a varint into the buffer. Return the next position to write at. 50 * There must be 10 bytes in the buffer. 51 */ 52 uint8_t* write_raw_varint(uint8_t* buf, uint64_t val); 53 54 /** 55 * Write a protobuf WIRE_TYPE_LENGTH_DELIMITED header. Return the next position 56 * to write at. There must be 20 bytes in the buffer. 57 */ 58 uint8_t* write_length_delimited_tag_header(uint8_t* buf, uint32_t fieldId, size_t size); 59 60 } // util 61 } // android 62 63 #endif // ANDROID_UTIL_PROTOUBUF_H 64