// Copyright 2021 The Pigweed Authors
//
// 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
//
//     https://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.
syntax = "proto3";

package pw.snapshot;

option java_package = "pw.snapshot.proto";
option java_outer_classname = "Snapshot";

import "pw_chrono_protos/chrono.proto";
import "pw_cpu_exception_cortex_m_protos/cpu_state.proto";
import "pw_log/proto/log.proto";
import "pw_thread_protos/thread.proto";
import "pw_snapshot_metadata_proto/snapshot_metadata.proto";

// The Snapshot proto is a list that dictates field numbers that should
// be used when serializing proto messages into a "Snapshot" that can be
// ingested by Pigweed's upstream tooling.
//
// There are various field number ranges that are marked for "upstream" use,
// and others that are marked for "pigweed users". This allows a user to
// define a parallel proto that defines product-specific messages using mutually
// exclusive field numbers:
//
//   MySnapshot {
//     // Use a project-specific logging proto format.
//     repeated MyLogFormat = 8;
//
//     // Pigweed's snapshot doesn't support my custom RTOS, so write that to
//     // a field number reserved for downstream projects.
//     MyCustomRtosInfo = 22;
//   }
//
// Writing both proto messages to the same proto encoder is valid because the
// field nubmers are mutually exclusive. This prevents collisions that would
// break a proto decode. The final message will have to be decoded twice; once
// as a pw.snapshot.Snapshot and once as the project-specific message.
message Snapshot {
  repeated pw.log.LogEntry logs = 1;

  // RESERVED FOR PIGWEED. These field numbers are reserved strictly for things
  // that are very generally useful and high in count. Downstream projects may
  // NOT write to these fields.
  // Encodes to a single byte of tag overhead.
  reserved 2 to 7;

  // RESERVED FOR USERS. These field numbers should be used for writing
  // project-specific proto messages that repeat in high quantity to reduce
  // proto encoding overhead. Pigweed must not write to these fields.
  // Encodes to a single byte of tag overhead.
  reserved 8 to 15;

  // Note: Proto tags 16-2047 encode with two bytes of overhead.
  Metadata metadata = 16;

  // Other data that should be highlighted in this crash. This field may have
  // entries added to it during a decode.
  map<string, string> tags = 17;

  repeated pw.thread.proto.Thread threads = 18;

  // If a device has multiple cores, it may be useful to collect an associated
  // snapshot for attached cores when a snapshot collection is triggered on one
  // core. By embedding one or more snapshots into a snapshot, the snapshots are
  // considered associated.
  repeated Snapshot related_snapshots = 19;

  pw.cpu_exception.cortex_m.ArmV7mCpuState armv7m_cpu_state = 20;

  // Platform-specific binary trace data region. Binary trace data is using
  // pw_trace_tokenized buffer format for stored data.
  bytes trace_data = 21;

  // Timestamps that mark when this snapshot occurred. This field is repeated
  // to accommodate wall-clock time, time since boot, and/or the raw system
  // clock value.
  repeated pw.chrono.TimePoint timestamps = 22;

  // RESERVED FOR PIGWEED. Downstream projects may NOT write to these fields.
  // Encodes to two bytes of tag overhead.
  reserved 23 to 1031;

  // RESERVED FOR USERS. Encodes to two or more bytes of tag overhead.
  reserved 1032 to max;
}