flux_common/
cache.rs

1use std::{
2    fs::{self, File},
3    io::BufWriter,
4    path::Path,
5};
6
7use flux_config as config;
8use rustc_hash::FxHashMap;
9
10#[derive(Debug, serde::Serialize, serde::Deserialize)]
11struct QueryVal<R> {
12    constr_hash: u64,
13    result: R,
14}
15
16pub struct QueryCache<R> {
17    entries: FxHashMap<String, QueryVal<R>>,
18}
19
20impl<R> Default for QueryCache<R> {
21    fn default() -> Self {
22        Self::new()
23    }
24}
25
26impl<R> QueryCache<R> {
27    pub fn new() -> Self {
28        QueryCache { entries: FxHashMap::default() }
29    }
30
31    pub fn insert(&mut self, key: String, constr_hash: u64, result: R) {
32        let val = QueryVal { constr_hash, result };
33        self.entries.insert(key, val);
34    }
35
36    pub fn lookup(&self, key: &String, constr_hash: u64) -> Option<&R> {
37        let val = self.entries.get(key)?;
38        if val.constr_hash == constr_hash { Some(&val.result) } else { None }
39    }
40
41    /// Look up a result by key only (no hash validation).
42    pub fn lookup_by_key(&self, key: &str) -> Option<&R> {
43        self.entries.get(key).map(|e| &e.result)
44    }
45
46    /// Mutate a cached result by key only (no hash validation).
47    pub fn update_result_by_key(&mut self, key: &str, f: impl FnOnce(&mut R)) {
48        if let Some(entry) = self.entries.get_mut(key) {
49            f(&mut entry.result);
50        }
51    }
52
53    fn path() -> Result<&'static Path, std::io::Error> {
54        if let Some(path) = config::cache_path()
55            && let Some(parent) = path.parent()
56        {
57            std::fs::create_dir_all(parent)?;
58            return Ok(path);
59        }
60
61        Err(Self::no_cache_err())
62    }
63
64    fn no_cache_err() -> std::io::Error {
65        std::io::Error::other("cache not enabled")
66    }
67}
68
69impl<R: std::fmt::Debug + serde::Serialize + serde::de::DeserializeOwned> QueryCache<R> {
70    pub fn save(&self) -> Result<(), std::io::Error> {
71        let path = Self::path()?;
72        let file = File::create(path).unwrap();
73        serde_json::to_writer(BufWriter::new(file), &self.entries).unwrap();
74        Ok(())
75    }
76
77    pub fn load() -> Self {
78        let path = Self::path();
79        if let Ok(path) = path
80            && let Ok(data) = fs::read(path)
81        {
82            let entries = serde_json::from_slice(&data);
83            if let Ok(entries) = entries {
84                return QueryCache { entries };
85            }
86        }
87        Self::default()
88    }
89}
flux_common/cache.rs

flux_common/
cache.rs
