-- Copyright 2023 The Chromium Authors
-- Use of this source code is governed by a BSD-style license that can be
-- found in the LICENSE file.
-- Finds all slices with a direct parent with the given parent_id.
CREATE PERFETTO FUNCTION _direct_children_slice(
-- Id of the parent slice.
parent_id LONG)
RETURNS TABLE(
-- Alias for `slice.id`.
id LONG,
-- Alias for `slice.type`.
type STRING,
-- Alias for `slice.ts`.
ts LONG,
-- Alias for `slice.dur`.
dur LONG,
-- Alias for `slice.category`.
category LONG,
-- Alias for `slice.name`.
name STRING,
-- Alias for `slice.track_id`.
track_id LONG,
-- Alias for `slice.depth`.
depth LONG,
-- Alias for `slice.parent_id`.
parent_id LONG,
-- Alias for `slice.arg_set_id`.
arg_set_id LONG,
-- Alias for `slice.thread_ts`.
thread_ts LONG,
-- Alias for `slice.thread_dur`.
thread_dur LONG
) AS
SELECT
slice.id,
slice.type,
slice.ts,
slice.dur,
slice.category,
slice.name,
slice.track_id,
slice.depth,
slice.parent_id,
slice.arg_set_id,
slice.thread_ts,
slice.thread_dur
FROM slice
WHERE parent_id = $parent_id;
-- Given two slice Ids A and B, find the maximum difference
-- between the durations of it's direct children with matching names
-- for example if slice A has children named (X, Y, Z) with durations of (10, 10, 5)
-- and slice B has children named (X, Y) with durations of (9, 9), the function will return
-- the slice id of the slice named Z that is A's child, as no matching slice named Z was found
-- under B, making 5 - 0 = 5 the maximum delta between both slice's direct children
CREATE PERFETTO FUNCTION chrome_get_v3_jank_cause_id(
-- The slice id of the parent slice that we want to cause among it's children.
janky_slice_id LONG,
-- The slice id of the parent slice that's the reference in comparison to
-- |janky_slice_id|.
prev_slice_id LONG
)
-- The slice id of the breakdown that has the maximum duration delta.
RETURNS LONG AS
WITH
current_breakdowns AS (
SELECT
*
FROM _direct_children_slice($janky_slice_id)
),
prev_breakdowns AS (
SELECT
*
FROM _direct_children_slice($prev_slice_id)
),
joint_breakdowns AS (
SELECT
cur.id AS breakdown_id,
(cur.dur - COALESCE(prev.dur, 0)) AS breakdown_delta
FROM current_breakdowns cur
LEFT JOIN prev_breakdowns prev ON
cur.name = prev.name
),
max_breakdown AS (
SELECT
MAX(breakdown_delta) AS breakdown_delta,
breakdown_id
FROM joint_breakdowns
)
SELECT
breakdown_id
FROM max_breakdown;