1 /* 2 * Copyright (C) 2023 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 INCLUDE_PERFETTO_PUBLIC_ABI_PB_DECODER_ABI_H_ 18 #define INCLUDE_PERFETTO_PUBLIC_ABI_PB_DECODER_ABI_H_ 19 20 #include <stddef.h> 21 #include <stdint.h> 22 23 #include "perfetto/public/abi/export.h" 24 25 #ifdef __cplusplus 26 extern "C" { 27 #endif 28 29 // Stores the state required to decode a protobuf message (from a continuous 30 // memory buffer). 31 struct PerfettoPbDecoder { 32 // Pointer to the beginning of the next field that should be decoded. 33 const uint8_t* read_ptr; 34 // Pointer to one past the end of the buffer. 35 const uint8_t* end_ptr; 36 }; 37 38 enum PerfettoPbDecoderStatus { 39 // A field has been decoded correctly. There is more data into the buffer, 40 // starting from an updated `read_ptr`. 41 PERFETTO_PB_DECODER_OK = 0, 42 // The last field has been decoded correctly until the end. There is no more 43 // data into the buffer. 44 PERFETTO_PB_DECODER_DONE = 1, 45 // The data starting at `read_ptr` cannot be fully decoded as a protobuf 46 // field. `read_ptr` has not been updated. 47 PERFETTO_PB_DECODER_ERROR = 2, 48 }; 49 50 // The content of a length-delimited field (wire type 2) 51 struct PerfettoPbDecoderDelimitedField { 52 const uint8_t* start; 53 size_t len; 54 }; 55 56 // A field parsed by the decoder. 57 struct PerfettoPbDecoderField { 58 // PerfettoPbDecoderStatus 59 uint32_t status; 60 // PerfettoPbWireType 61 uint32_t wire_type; 62 // The protobuf field id. 63 uint32_t id; 64 // The value of this field. 65 union { 66 // For wire type 2. 67 struct PerfettoPbDecoderDelimitedField delimited; 68 // For wire type 0 and 1. 69 uint64_t integer64; 70 // For wire type 5. 71 uint32_t integer32; 72 // For wire type 1. 73 double double_val; 74 // For wire type 5. 75 float float_val; 76 } value; 77 }; 78 79 // Parses a field and returns it. Advances `*decoder->read_ptr` to point after 80 // the field. 81 PERFETTO_SDK_EXPORT struct PerfettoPbDecoderField PerfettoPbDecoderParseField( 82 struct PerfettoPbDecoder* decoder); 83 84 // Advances `*decoder->read_ptr` to point after the current field. 85 // Returns a `PerfettoPbDecoderStatus`. 86 PERFETTO_SDK_EXPORT uint32_t 87 PerfettoPbDecoderSkipField(struct PerfettoPbDecoder* decoder); 88 89 #ifdef __cplusplus 90 } 91 #endif 92 93 #endif // INCLUDE_PERFETTO_PUBLIC_ABI_PB_DECODER_ABI_H_ 94