cmds/statsd/src/stats_events.proto

/*
 * 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.
 */

syntax = "proto2";

// TODO: Not the right package and class name
package android.os.statsd;
option java_package = "com.android.os";
option java_outer_classname = "StatsEventProto";

/**
 * The master event class. This message defines all of the available
 * raw stats log events from the Android system, also known as "atoms."
 *
 * This field contains a single oneof with all of the available messages.
 * The stats-log-api-gen tool runs as part of the Android build and
 * generates the android.util.StatsLog class, which contains the constants
 * and methods that Android uses to log.
 *
 * This StatsEvent class is not actually built into the Android system.
 * Instead, statsd on Android constructs these messages synthetically,
 * in the format defined here and in stats_log.proto.
 */
message StatsEvent {
    oneof event {
        ScreenStateChanged screen_state_changed = 1;
        ProcessStateChanged process_state_changed = 2;
        WakeLockChanged wakelock_changed = 3;
    }
}

/**
 * A WorkSource represents the chained attribution of applications that
 * resulted in a particular bit of work being done.
 */
message WorkSource {
    // TODO
}

/*
 * *****************************************************************************
 * Below are all of the individual atoms that are logged by Android via statsd
 * and Westworld.
 *
 * RULES:
 *   - The field ids for each atom must start at 1, and count upwards by 1.
 *     Skipping field ids is not allowed.
 *   - These form an API, so renaming, renumbering or removing fields is
 *     not allowed between android releases.  (This is not currently enforced,
 *     but there will be a tool to enforce this restriction).
 *   - The types must be built-in protocol buffer types, namely, no sub-messages
 *     are allowed (yet).  The bytes type is also not allowed.
 *   - The CamelCase name of the message type should match the
 *     underscore_separated name as defined in StatsEvent.
 *   - If an atom represents work that can be attributed to an app, there can
 *     be exactly one WorkSource field. It must be field number 1.
 *   - A field that is a uid should be a string field, tagged with the [xxx]
 *     annotation. The generated code on android will be represented by UIDs,
 *     and those UIDs will be translated in xxx to those strings.
 *
 * CONVENTIONS:
 *   - Events are past tense. e.g. ScreenStateChanged, not ScreenStateChange
 *   - If there is a UID, it goes first. Think in an object-oriented fashion.
 * *****************************************************************************
 */

/**
 * Logs when the screen state changes.
 *
 * Logged from:
 *   frameworks/base/services/core/java/com/android/server/am/BatteryStatsService.java
 */
message ScreenStateChanged {
    // TODO: Use the real screen state.
    enum State {
        STATE_UNKNOWN = 0;
        STATE_OFF = 1;
        STATE_ON = 2;
        STATE_DOZE = 3;
        STATE_DOZE_SUSPEND = 4;
        STATE_VR = 5;
    }
    // New screen state.
    optional State display_state = 1;
}

/**
 * Logs that the state of a process state, as per the activity manager has changed.
 *
 * Logged from:
 *   frameworks/base/services/core/java/com/android/server/am/BatteryStatsService.java
 */
message ProcessStateChanged {
    // TODO: Use the real (mapped) process states.
    optional int32 uid = 1; // TODO: should be a string tagged w/ uid annotation

    // The state.
    optional int32 state = 2;
}

/**
 * Logs that the state of a wakelock has changed.
 *
 * Logged from:
 *   TODO
 */
message WakeLockChanged {
    // TODO: Add attribution instead of uid.
    optional int32 uid = 1;

    // The wakelock tag (Called tag in the Java API, sometimes name elsewhere).
    optional string tag = 2;

    // TODO: Use a constant instead of boolean?
    optional bool state = 3;
}