libsql: WAL conflict detection

Author: penberg

libsql/src/errors.rs

@@ -57,6 +57,8 @@ pub enum Error {
     InvalidBlobSize(usize),
     #[error("sync error: {0}")]
     Sync(crate::BoxError),
+    #[error("WAL frame insert conflict")]
+    WalConflict,
 }
 
 #[cfg(feature = "hrana")]

libsql/src/local/connection.rs

@@ -539,20 +539,28 @@ impl Connection {
     }
 
     fn wal_insert_frame(&self, frame: &[u8]) -> Result<()> {
+        let mut conflict = 0i32;
         let rc = unsafe {
             libsql_sys::ffi::libsql_wal_insert_frame(
                 self.handle(),
                 frame.len() as u32,
                 frame.as_ptr() as *mut std::ffi::c_void,
                 0,
+                &mut conflict,
             )
         };
+
         if rc != 0 {
-            return Err(crate::errors::Error::SqliteFailure(
+            return Err(errors::Error::SqliteFailure(
                 rc as std::ffi::c_int,
-                format!("wal_insert_frame failed"),
+                "wal_insert_frame failed".to_string(),
             ));
         }
+
+        if conflict != 0 {
+            return Err(errors::Error::WalConflict);
+        }
+
         Ok(())
     }