// Copyright Materialize, Inc. and contributors. All rights reserved.
//
// Use of this software is governed by the Business Source License
// included in the LICENSE file.
//
// As of the Change Date specified in that file, in accordance with
// the Business Source License, use of this software will be governed
// by the Apache License, Version 2.0.
use std::num::TryFromIntError;
use std::time::Duration;
use mz_repr::{Timestamp, TimestampManipulation};
use mz_storage_types::read_policy::ReadPolicy;
use serde::Serialize;
use timely::progress::{Antichain, Timestamp as TimelyTimestamp};
/// `DEFAULT_LOGICAL_COMPACTION_WINDOW`, in milliseconds.
/// The default is set to a second to track the default timestamp frequency for sources.
const DEFAULT_LOGICAL_COMPACTION_WINDOW_MILLIS: u64 = 1000;
pub const DEFAULT_LOGICAL_COMPACTION_WINDOW_DURATION: Duration =
Duration::from_millis(DEFAULT_LOGICAL_COMPACTION_WINDOW_MILLIS);
/// `DEFAULT_LOGICAL_COMPACTION_WINDOW` as an `EpochMillis` timestamp.
const DEFAULT_LOGICAL_COMPACTION_WINDOW_TS: Timestamp =
Timestamp::new(DEFAULT_LOGICAL_COMPACTION_WINDOW_MILLIS);
/// The value to round all `since` frontiers to.
/// We pick 1s somewhat arbitrarily, but matching historical practice.
// TODO[btv] If we want to further reduce capability chatter, we can implement the design in
// `20230322_metrics_since_granularity.md`, making it configurable.
pub const SINCE_GRANULARITY: mz_repr::Timestamp = mz_repr::Timestamp::new(1000);
// A common type (that is usable by the sql crate and also can implement various methods on types in
// storage) to express compaction windows.
#[derive(Clone, Default, Copy, Debug, Eq, Ord, PartialEq, PartialOrd, Serialize)]
pub enum CompactionWindow {
/// Unspecified by the user, use a system-provided default.
#[default]
Default,
/// Disable compaction.
DisableCompaction,
/// Create a compaction window for a specified duration.
Duration(Timestamp),
}
impl CompactionWindow {
pub fn lag_from(&self, from: Timestamp) -> Timestamp {
let lag = match self {
CompactionWindow::Default => DEFAULT_LOGICAL_COMPACTION_WINDOW_TS,
CompactionWindow::DisableCompaction => return Timestamp::minimum(),
CompactionWindow::Duration(d) => *d,
};
from.saturating_sub(lag)
}
/// Returns self as a Timestamp that can be used for comparisons.
pub fn comparable_timestamp(&self) -> Timestamp {
match self {
CompactionWindow::Default => DEFAULT_LOGICAL_COMPACTION_WINDOW_TS,
CompactionWindow::DisableCompaction => Timestamp::maximum(),
CompactionWindow::Duration(d) => *d,
}
}
}
impl From<CompactionWindow> for ReadPolicy<Timestamp> {
fn from(value: CompactionWindow) -> Self {
let time = match value {
CompactionWindow::Default => DEFAULT_LOGICAL_COMPACTION_WINDOW_TS,
CompactionWindow::Duration(time) => time,
CompactionWindow::DisableCompaction => {
return ReadPolicy::ValidFrom(Antichain::from_elem(Timestamp::minimum()))
}
};
ReadPolicy::lag_writes_by(time, SINCE_GRANULARITY)
}
}
impl TryFrom<Duration> for CompactionWindow {
type Error = TryFromIntError;
fn try_from(value: Duration) -> Result<Self, Self::Error> {
Ok(Self::Duration(value.try_into()?))
}
}