61 lines
1.6 KiB
Rust
61 lines
1.6 KiB
Rust
//! Low memory caching stuff
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use std::path::PathBuf;
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use async_trait::async_trait;
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use lru::LruCache;
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use super::{BoxedImageStream, Cache, CacheError, CacheKey, CacheStream, ImageMetadata};
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pub struct LowMemCache {
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on_disk: LruCache<CacheKey, ImageMetadata>,
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disk_path: PathBuf,
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disk_max_size: u64,
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disk_cur_size: u64,
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}
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impl LowMemCache {
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pub fn new(disk_max_size: u64, disk_path: PathBuf) -> Self {
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Self {
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on_disk: LruCache::unbounded(),
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disk_path,
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disk_max_size,
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disk_cur_size: 0,
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}
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}
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}
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// todo: schedule eviction
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#[async_trait]
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impl Cache for LowMemCache {
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async fn get(
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&mut self,
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key: &CacheKey,
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) -> Option<Result<(CacheStream, &ImageMetadata), CacheError>> {
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if let Some(metadata) = self.on_disk.get(key) {
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let path = self.disk_path.clone().join(PathBuf::from(key.clone()));
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super::fs::read_file(&path).await.map(|res| {
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res.map(|stream| (CacheStream::Fs(stream), metadata))
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.map_err(Into::into)
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})
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} else {
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None
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}
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}
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async fn put(
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&mut self,
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key: CacheKey,
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image: BoxedImageStream,
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metadata: ImageMetadata,
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) -> Result<(CacheStream, &ImageMetadata), CacheError> {
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let path = self.disk_path.clone().join(PathBuf::from(key.clone()));
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self.on_disk.put(key.clone(), metadata);
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super::fs::write_file(&path, image)
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.await
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.map(CacheStream::Fs)
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.map(move |stream| (stream, self.on_disk.get(&key).unwrap()))
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.map_err(Into::into)
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}
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}
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