new sync cache

2 files changed, 65 insertions, 0 deletions

diff --git a/cache/src/backends/filesystem.rs b/cache/src/backends/filesystem.rs
new file mode 100644
index 0000000..39fb7a2
--- /dev/null
+++ b/cache/src/backends/filesystem.rs
@@ -0,0 +1,51 @@
+/*
+    This file is part of jellything (https://codeberg.org/metamuffin/jellything)
+    which is licensed under the GNU Affero General Public License (version 3); see /COPYING.
+    Copyright (C) 2025 metamuffin <metamuffin.org>
+*/
+
+use crate::{CacheKey, Config, backends::CacheStorage};
+use anyhow::Result;
+use base64::Engine;
+use rand::random;
+use std::{
+    fs::{File, rename},
+    io::{ErrorKind, Read, Write},
+    path::PathBuf,
+};
+
+pub struct Filesystem(PathBuf);
+
+impl Filesystem {
+    pub fn new(config: &Config) -> Self {
+        Self(config.path.clone())
+    }
+    fn path(&self, key: CacheKey) -> PathBuf {
+        let filename = base64::engine::general_purpose::URL_SAFE.encode(key.0);
+        let filename = &filename[..30]; // 180 bits
+        self.0.join(filename)
+    }
+    fn temp_path(&self) -> PathBuf {
+        self.0.join(format!("temp-{:016x}", random::<u128>()))
+    }
+}
+
+impl CacheStorage for Filesystem {
+    fn store(&self, key: CacheKey, value: &[u8]) -> Result<()> {
+        let temp = self.temp_path();
+        File::create(&temp)?.write_all(value)?;
+        rename(temp, self.path(key))?;
+        Ok(())
+    }
+    fn read(&self, key: CacheKey) -> Result<Option<Vec<u8>>> {
+        match File::open(self.path(key)) {
+            Ok(mut f) => {
+                let mut data = Vec::new();
+                f.read_to_end(&mut data)?;
+                Ok(Some(data))
+            }
+            Err(e) if e.kind() == ErrorKind::NotFound => Ok(None),
+            Err(e) => Err(e.into()),
+        }
+    }
+}
diff --git a/cache/src/backends/mod.rs b/cache/src/backends/mod.rs
new file mode 100644
index 0000000..370c5ab
--- /dev/null
+++ b/cache/src/backends/mod.rs
@@ -0,0 +1,14 @@
+/*
+    This file is part of jellything (https://codeberg.org/metamuffin/jellything)
+    which is licensed under the GNU Affero General Public License (version 3); see /COPYING.
+    Copyright (C) 2025 metamuffin <metamuffin.org>
+*/
+pub mod filesystem;
+
+use crate::CacheKey;
+use anyhow::Result;
+
+pub(crate) trait CacheStorage: Send + Sync + 'static {
+    fn store(&self, key: CacheKey, value: &[u8]) -> Result<()>;
+    fn read(&self, key: CacheKey) -> Result<Option<Vec<u8>>>;
+}