chromium/third_party/perfetto/src/trace_processor/util/proto_to_args_parser.h

/*
 * Copyright (C) 2021 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef SRC_TRACE_PROCESSOR_UTIL_PROTO_TO_ARGS_PARSER_H_
#define SRC_TRACE_PROCESSOR_UTIL_PROTO_TO_ARGS_PARSER_H_

#include <functional>

#include "perfetto/base/status.h"
#include "perfetto/protozero/field.h"
#include "protos/perfetto/trace/interned_data/interned_data.pbzero.h"
#include "src/trace_processor/util/descriptors.h"

namespace perfetto {
namespace trace_processor {

// TODO(altimin): Move InternedMessageView into trace_processor/util.
class InternedMessageView;
class PacketSequenceStateGeneration;

namespace util {

// ProtoToArgsParser encapsulates the process of taking an arbitrary proto and
// parsing it into key-value arg pairs. This is done by traversing
// the proto using reflection (with descriptors from |descriptor_pool|)
// and passing the parsed data to |Delegate| callbacks.
//
// E.g. given a proto like
//
// package perfetto.protos;
// message SubMessage {
//   optional int32 field = 1;
// }
// message MainMessage {
//   optional int32 field1 = 1;
//   optional string field2 = 2;
//   optional SubMessage field3 = 3;
// }
//
// We will get the args set columns "field1", "field2", "field3.field" and will
// store the values found inside as the result.
//
// Usage of this is as follows:
//
// DescriptorPool pool;
// ProtoToArgsParser parser(pool);
// pool.AddProtoFileDescriptor(
//     /* provide descriptor generated by tools/gen_binary_descriptors */);
// parser.ParseMessage(const_bytes, ".perfetto.protos.MainMessage",
//     /* fields */, /* delegate */);
class ProtoToArgsParser { … };

}  // namespace util
}  // namespace trace_processor
}  // namespace perfetto

#endif  // SRC_TRACE_PROCESSOR_UTIL_PROTO_TO_ARGS_PARSER_H_