From 98e3bc0c0c62848ba03c18c241784a88bbef374b Mon Sep 17 00:00:00 2001
From: Pekka Enberg <penberg@iki.fi>
Date: Thu, 27 Feb 2025 10:10:07 +0200
Subject: [PATCH] bindings/rust: Make library thread-safe

---
 bindings/rust/src/lib.rs | 47 ++++++++++++++++++++++++++++++++++------
 1 file changed, 40 insertions(+), 7 deletions(-)

diff --git a/bindings/rust/src/lib.rs b/bindings/rust/src/lib.rs
index 366700a9e..0e331caf6 100644
--- a/bindings/rust/src/lib.rs
+++ b/bindings/rust/src/lib.rs
@@ -6,12 +6,14 @@ pub use params::params_from_iter;
 use crate::params::*;
 use crate::value::*;
 use std::rc::Rc;
-use std::sync::Arc;
+use std::sync::{Arc, Mutex};
 
 #[derive(Debug, thiserror::Error)]
 pub enum Error {
     #[error("SQL conversion failure: `{0}`")]
     ToSqlConversionFailure(BoxError),
+    #[error("Mutex lock error: {0}")]
+    MutexError(String),
 }
 
 impl From<limbo_core::LimboError> for Error {
@@ -51,17 +53,33 @@ pub struct Database {
     inner: Arc<limbo_core::Database>,
 }
 
+unsafe impl Send for Database {}
+unsafe impl Sync for Database {}
+
 impl Database {
     pub fn connect(&self) -> Result<Connection> {
         let conn = self.inner.connect();
-        Ok(Connection { inner: conn })
+        Ok(Connection {
+            inner: Arc::new(Mutex::new(conn)),
+        })
     }
 }
 
 pub struct Connection {
-    inner: Rc<limbo_core::Connection>,
+    inner: Arc<Mutex<Rc<limbo_core::Connection>>>,
 }
 
+impl Clone for Connection {
+    fn clone(&self) -> Self {
+        Self {
+            inner: Arc::clone(&self.inner),
+        }
+    }
+}
+
+unsafe impl Send for Connection {}
+unsafe impl Sync for Connection {}
+
 impl Connection {
     pub async fn query(&self, sql: &str, params: impl IntoParams) -> Result<Rows> {
         let mut stmt = self.prepare(sql).await?;
@@ -74,17 +92,26 @@ impl Connection {
     }
 
     pub async fn prepare(&self, sql: &str) -> Result<Statement> {
-        let stmt = self.inner.prepare(sql)?;
+        let conn = self
+            .inner
+            .lock()
+            .map_err(|e| Error::MutexError(e.to_string()))?;
+
+        let stmt = conn.prepare(sql)?;
+
         Ok(Statement {
-            _inner: Rc::new(stmt),
+            inner: Arc::new(Mutex::new(Rc::new(stmt))),
         })
     }
 }
 
 pub struct Statement {
-    _inner: Rc<limbo_core::Statement>,
+    inner: Arc<Mutex<Rc<limbo_core::Statement>>>,
 }
 
+unsafe impl Send for Statement {}
+unsafe impl Sync for Statement {}
+
 impl Statement {
     pub async fn query(&mut self, params: impl IntoParams) -> Result<Rows> {
         let _params = params.into_params()?;
@@ -110,9 +137,12 @@ pub enum Params {
 pub struct Transaction {}
 
 pub struct Rows {
-    _inner: Rc<limbo_core::Statement>,
+    inner: Arc<Mutex<Rc<limbo_core::Statement>>>,
 }
 
+unsafe impl Send for Rows {}
+unsafe impl Sync for Rows {}
+
 impl Rows {
     pub async fn next(&mut self) -> Result<Option<Row>> {
         todo!();
@@ -121,6 +151,9 @@ impl Rows {
 
 pub struct Row {}
 
+unsafe impl Send for Row {}
+unsafe impl Sync for Row {}
+
 impl Row {
     pub fn get_value(&self, _index: usize) -> Result<Value> {
         todo!();