1 files changed, 45 insertions, 0 deletions
diff --git a/src/cache.rs b/src/cache.rs
new file mode 100644
index 0000000..608adb5
--- /dev/null
+++ b/src/cache.rs
@@ -0,0 +1,45 @@
+use crate::{FileHash, MetricElem};
+use anyhow::Result;
+use bincode::config::standard;
+use redb::{Database, TableDefinition};
+use std::path::Path;
+
+const T_ENTRIES: TableDefinition<(&str, FileHash), &[u8]> = TableDefinition::new("entries");
+
+pub struct Cache {
+    db: Database,
+}
+impl Cache {
+    pub fn open(path: &Path) -> Result<Self> {
+        let db = Database::create(path)?;
+        let txn = db.begin_write()?;
+        txn.open_table(T_ENTRIES)?;
+        txn.commit()?;
+        Ok(Self { db })
+    }
+    pub fn get<E: MetricElem>(&self, type_name: &'static str, hash: FileHash) -> Result<Option<E>> {
+        let txn = self.db.begin_read()?;
+        let table = txn.open_table(T_ENTRIES)?;
+        if let Some(e) = table.get((type_name, hash))? {
+            Ok(Some(bincode::decode_from_slice(e.value(), standard())?.0))
+        } else {
+            Ok(None)
+        }
+    }
+    pub fn insert<E: MetricElem>(
+        &self,
+        type_name: &'static str,
+        hash: FileHash,
+        value: &E,
+    ) -> Result<()> {
+        let txn = self.db.begin_write()?;
+        let mut table = txn.open_table(T_ENTRIES)?;
+        table.insert(
+            (type_name, hash),
+            bincode::encode_to_vec(value, standard())?.as_slice(),
+        )?;
+        drop(table);
+        txn.commit()?;
+        Ok(())
+    }
+}