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use crate::algorithms::offline::multi_dimensional::optimal_graph_search::{
optimal_graph_search, Options as OptimalGraphSearchOptions,
};
use crate::algorithms::offline::multi_dimensional::Vertice;
use crate::algorithms::offline::Cache;
use crate::algorithms::offline::OfflineAlgorithm;
use crate::algorithms::online::{IntegralStep, Online, Step};
use crate::config::{Config, IntegralConfig};
use crate::model::data_center::DataCenterModelOutputFailure;
use crate::problem::{
DefaultGivenOnlineProblem, IntegralSmoothedLoadOptimization,
};
use crate::result::{Failure, Result};
use crate::schedule::IntegralSchedule;
use crate::utils::{assert, sample_uniform};
use is_sorted::IsSorted;
use log::debug;
use pyo3::prelude::*;
use rayon::iter::{IntoParallelIterator, ParallelIterator};
use serde_derive::{Deserialize, Serialize};
use std::cmp::max;
#[pyclass]
#[derive(Clone, Debug, Deserialize, Serialize)]
pub struct Memory {
pub lanes: Lanes,
pub horizons: Horizons,
pub gamma: f64,
cache: Option<Cache<Vertice>>,
}
impl
DefaultGivenOnlineProblem<
i32,
IntegralSmoothedLoadOptimization,
(),
DataCenterModelOutputFailure,
> for Memory
{
fn default(o: &Online<IntegralSmoothedLoadOptimization>) -> Self {
let bound: i32 = o.p.bounds.iter().sum();
Memory {
lanes: vec![0; bound as usize],
horizons: vec![0; bound as usize],
gamma: sample_gamma(),
cache: None,
}
}
}
fn sample_gamma() -> f64 {
let r = sample_uniform(0., 1.);
(r * (std::f64::consts::E - 1.) + 1.).ln()
}
pub type Lanes = Vec<i32>;
pub type Horizons = Vec<i32>;
#[pyclass]
#[derive(Clone, Default)]
pub struct Options {
pub randomized: bool,
}
#[pymethods]
impl Options {
#[new]
fn constructor(randomized: bool) -> Self {
Options { randomized }
}
}
pub fn lb(
o: Online<IntegralSmoothedLoadOptimization>,
t: i32,
_: &IntegralSchedule,
Memory {
lanes: prev_lanes,
horizons: prev_horizons,
gamma,
cache,
}: Memory,
Options { randomized }: Options,
) -> Result<IntegralStep<Memory>> {
assert(o.w == 0, Failure::UnsupportedPredictionWindow(o.w))?;
let bound = o.p.bounds.iter().sum();
debug!("starting with `m = {}`", bound);
let (optimal_lanes, new_cache) =
find_optimal_lanes(cache, o.p.clone(), bound)?;
debug!("obtained optimal lanes: {:?}", optimal_lanes);
let (lanes, horizons): (Vec<_>, Vec<_>) = (0..bound as usize)
.into_par_iter()
.map(|j| {
if prev_lanes[j] < optimal_lanes[j] || t >= prev_horizons[j] {
(
optimal_lanes[j],
t + next_time_horizon(
&o.p.hitting_cost,
&o.p.switching_cost,
optimal_lanes[j],
gamma,
randomized,
),
)
} else {
(
prev_lanes[j],
max(
prev_horizons[j],
t + next_time_horizon(
&o.p.hitting_cost,
&o.p.switching_cost,
optimal_lanes[j],
gamma,
randomized,
),
),
)
}
})
.unzip();
debug!("updated lanes from {:?} to {:?}", prev_lanes, lanes);
debug!(
"updated horizons from {:?} to {:?}",
prev_horizons, horizons
);
assert!(
IsSorted::is_sorted(&mut horizons.iter().rev()),
"horizons must be in descending order"
);
let config = collect_config(o.p.d, &lanes);
Ok(Step(
config,
Some(Memory {
lanes,
horizons,
gamma,
cache: Some(new_cache),
}),
))
}
fn next_time_horizon(
hitting_cost: &Vec<f64>,
switching_cost: &Vec<f64>,
k: i32,
gamma: f64,
randomized: bool,
) -> i32 {
if k == 0 {
0
} else {
(if randomized { gamma } else { 1. } * switching_cost[k as usize - 1]
/ hitting_cost[k as usize - 1])
.floor() as i32
}
}
fn collect_config(d: i32, lanes: &Lanes) -> IntegralConfig {
let mut config = Config::repeat(0, d);
for i in 0..lanes.len() {
if lanes[i] > 0 {
config[lanes[i] as usize - 1] += 1;
}
}
config
}
fn build_lanes(x: &IntegralConfig, d: i32, bound: i32) -> Lanes {
let mut lanes = vec![0; bound as usize];
for (k, lane) in lanes.iter_mut().enumerate() {
#[allow(clippy::int_plus_one)]
if k as i32 + 1 <= active_lanes(x, 1, d) {
for j in 1..=d {
#[allow(clippy::int_plus_one)]
if active_lanes(x, j, d) >= k as i32 + 1 {
*lane = j;
}
}
}
}
lanes
}
fn active_lanes(x: &IntegralConfig, from: i32, to: i32) -> i32 {
(from..=to).map(|k| x[k as usize - 1]).sum()
}
fn find_optimal_lanes(
cache: Option<Cache<Vertice>>,
p: IntegralSmoothedLoadOptimization,
bound: i32,
) -> Result<(Lanes, Cache<Vertice>)> {
let d = p.d;
let sblo_p = p.into_sblo();
let ssco_p = sblo_p.into_ssco();
let result = optimal_graph_search.solve(
ssco_p,
OptimalGraphSearchOptions { cache },
Default::default(),
)?;
debug!(
"obtained optimal schedule: {:?} (cost: `{}`)",
result.path.xs, result.path.cost
);
let lanes = build_lanes(&result.path.xs.now(), d, bound);
Ok((lanes, result.cache))
}