Add single-threaded SimpleVault

src/simple.rs

@@ -0,0 +1,45 @@
+//! A simple, single-threaded vault.
+//! 
+//! This vault may be useful if you want to re-use existing [`Action`]s and
+//! [`Migration`]s but don't need the additional guarantees and overhead of the
+//! other vaults.
+
+use rusqlite::Connection;
+
+use crate::{Action, Migration};
+
+/// A simple, single-threaded vault.
+pub struct SimpleVault(Connection);
+
+impl SimpleVault {
+    /// Create a new vault from an existing [`Connection`], applying the
+    /// migrations in the process.
+    pub fn new(conn: Connection, migrations: &[Migration]) -> rusqlite::Result<Self> {
+        Self::new_and_prepare(conn, migrations, |_| Ok(()))
+    }
+
+    /// Create a new vault from an existing [`Connection`], applying the
+    /// migrations in the process.
+    ///
+    /// The `prepare` parameter allows access to the database after all
+    /// migrations have occurred. This parameter could be replaced by executing
+    /// an [`Action`] performing the same operations.
+    pub fn new_and_prepare(
+        mut conn: Connection,
+        migrations: &[Migration],
+        prepare: impl FnOnce(&mut Connection) -> rusqlite::Result<()>,
+    ) -> rusqlite::Result<Self> {
+        crate::migrate(&mut conn, migrations)?;
+        prepare(&mut conn)?;
+        Ok(Self(conn))
+    }
+
+    /// Execute an [`Action`] and return the result.
+    pub fn execute<A>(&mut self, action: A) -> rusqlite::Result<A::Result>
+    where
+        A: Action + Send + 'static,
+        A::Result: Send,
+    {
+        action.run(&mut self.0)
+    }
+}