src/ftrace_reader/event_info.h

/*
 * Copyright (C) 2017 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_FTRACE_READER_EVENT_PROTO_INFO_H_
#define SRC_FTRACE_READER_EVENT_PROTO_INFO_H_

#include <stdint.h>

#include <string>
#include <vector>

namespace perfetto {

enum ProtoFieldType {
  kProtoNumber = 1,
  kProtoString,
  kProtoInt32,
};

enum FtraceFieldType {
  kFtraceNumber = 1,
};

struct Field {
  Field() = default;
  Field(uint16_t offset, uint16_t size)
      : ftrace_offset(offset), ftrace_size(size) {}

  uint16_t ftrace_offset;
  uint16_t ftrace_size;
  FtraceFieldType ftrace_type;
  const char* ftrace_name;

  uint32_t proto_field_id;
  ProtoFieldType proto_field_type;
};

struct Event {
  Event() = default;
  Event(const char* event_name, const char* event_group)
      : name(event_name), group(event_group) {}

  const char* name;
  const char* group;
  std::vector<Field> fields;
  uint32_t ftrace_event_id;

  // Field id of the subevent proto (e.g. PrintFtraceEvent) in the FtraceEvent
  // parent proto.
  uint32_t proto_field_id;
};

// The compile time information needed to read the raw ftrace buffer.
// Specifically for each event we have a proto we fill:
//  The event name (e.g. sched_switch)
//  The event group  (e.g. sched)
//  The the proto field ID of this event in the FtraceEvent proto.
//  For each field in the proto:
//    The field name (e.g. prev_comm)
//    The proto field id for this field
//    The proto field type for this field (e.g. kProtoString or kProtoUint32)
// The other fields: ftrace_event_id, ftrace_size, ftrace_offset, ftrace_type
// are zeroed.
std::vector<Event> GetStaticEventInfo();

}  // namespace perfetto

#endif  // SRC_FTRACE_READER_EVENT_PROTO_INFO_H_