pop-launcher/service/src/recent.rs
2024-10-01 03:27:40 +02:00

103 lines
3.4 KiB
Rust

use serde::{Deserialize, Deserializer, Serialize, Serializer};
use std::collections::{hash_map::DefaultHasher, HashMap};
use std::hash::{Hash, Hasher};
const SHORTTERM_CAP: usize = 20;
const LONGTERM_CAP: usize = 100;
// Holds a long term storage that tracks how often a search
// result was activated, and a short term storage that stores
// the order of recently activated search results (higher
// vales are more recent).
// Keys for both mappings are hashes of the acvtivated result's
// command string.
#[derive(Debug, Default)]
pub struct RecentUseStorage {
long_term: HashMap<u64, usize>,
short_term: HashMap<u64, usize>,
/// used for normalizing individual scores
max_long_term: usize,
/// used for normalizing individual scores
max_short_term: usize,
}
fn hash_key<K: Hash>(key: K) -> u64 {
let mut hasher = DefaultHasher::new();
key.hash(&mut hasher);
hasher.finish()
}
impl RecentUseStorage {
pub fn add<K: Hash>(&mut self, exec: &K) {
let key = hash_key(exec);
let entry = self.long_term.entry(key).or_insert(0);
*entry += 1;
self.max_long_term = self.max_long_term.max(*entry);
let short_term_idx = self.short_term.values().max().unwrap_or(&0) + 1;
self.max_short_term = self.max_short_term.max(short_term_idx);
self.short_term.insert(key, short_term_idx);
self.trim();
}
fn trim(&mut self) {
while self.short_term.len() > SHORTTERM_CAP {
let key = *self.short_term.iter().min_by_key(|kv| kv.1).unwrap().0;
self.short_term.remove(&key);
}
while self.long_term.values().sum::<usize>() > LONGTERM_CAP {
self.max_long_term /= 2;
let mut delete_keys = Vec::new();
for (k, v) in &mut self.long_term {
*v /= 2;
if *v == 0 {
delete_keys.push(*k);
}
}
for k in delete_keys {
self.long_term.remove(&k);
}
}
}
pub fn get_recent<K: Hash>(&self, exec: &K) -> f64 {
self.short_term.get(&hash_key(exec)).copied().unwrap_or(0) as f64
/ (self.max_short_term.max(1) as f64)
}
pub fn get_freq<K: Hash>(&self, exec: &K) -> f64 {
self.long_term.get(&hash_key(exec)).copied().unwrap_or(0) as f64
/ (self.max_long_term.max(1) as f64)
}
}
impl Serialize for RecentUseStorage {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
let mut stvec: Vec<_> = self.short_term.keys().copied().collect();
stvec.sort_by_key(|k| self.short_term[k]);
(&self.long_term, stvec).serialize(serializer)
}
}
impl<'de> Deserialize<'de> for RecentUseStorage {
fn deserialize<D>(deserializer: D) -> Result<RecentUseStorage, D::Error>
where
D: Deserializer<'de>,
{
type SerType = (HashMap<u64, usize>, Vec<u64>);
let (long_term, stv) = SerType::deserialize(deserializer)?;
let short_term: HashMap<_, _> = stv.into_iter().enumerate().map(|(v, k)| (k, v)).collect();
let max_long_term = long_term.values().max().copied().unwrap_or(1);
let max_short_term = short_term.values().max().copied().unwrap_or(1);
Ok(RecentUseStorage {
long_term,
short_term,
max_long_term,
max_short_term,
})
}
}