feat: add refresh method

src/database.rs

@@ -150,12 +150,24 @@ impl<'a> Database<'a> {
 
     /// Returns true if the database is upgrading from the given version selector.
     ///
+    /// - If the database is the old version, not matching the selector the function will return `false.
+    /// - If the database is not upgrading, the function will return always `false`.
+    ///
+    /// Generally used with the method [refresh](crate::transaction::RwTransaction::refresh),
+    /// to refresh the data for the given model.
+    ///
+    /// Check [release notes](https://github.com/vincent-herlemont/native_db/releases) to know when to use this method.
+    ///
     /// # Example
     /// ```rust,ignore
     /// if db.upgrading_from_version("<0.8.0") {
     ///     // Do something that runs only when the database is upgrading from version <0.8.0.
     ///     // If the database is already at version 0.8.0, the function will return false and
     ///     // the code will not be executed.
+    ///     let rw = db.rw_transaction().unwrap();
+    ///     rw.refresh::<Item1>().unwrap();
+    ///     rw.refresh::<Item2>().unwrap();
+    ///     rw.commit().unwrap();
     /// }
     /// ```
     pub fn upgrading_from_version(&self, selector: &str) -> Result<bool> {

src/transaction/internal/rw_transaction.rs

@@ -288,4 +288,13 @@ impl<'db> InternalRwTransaction<'db> {
 
         Ok(())
     }
+
+    pub fn refresh<T: ToInput + Debug>(&self) -> Result<()> {
+        for data in self.concrete_primary_drain(T::native_db_model())? {
+            let (decoded_item, _) = native_model::decode::<T>(data.0).unwrap();
+            let decoded_item = decoded_item.native_db_input()?;
+            self.concrete_insert(T::native_db_model(), decoded_item)?;
+        }
+        Ok(())
+    }
 }

src/transaction/rw_transaction.rs

@@ -368,4 +368,11 @@ impl<'db, 'txn> RwTransaction<'db> {
     pub fn migrate<T: ToInput + Debug>(&self) -> Result<()> {
         self.internal.migrate::<T>()
     }
+
+    /// Refresh the data for the given model. Is used generally when during an database upgrade,
+    /// using the method [crate::Database::upgrading_from_version] (more details/example). Check release notes to know
+    /// when to use this method.
+    pub fn refresh<T: ToInput + Debug>(&self) -> Result<()> {
+        self.internal.refresh::<T>()
+    }
 }

tests/refresh.rs

@@ -0,0 +1,94 @@
+use native_db::*;
+use native_model::{native_model, Model};
+use serde::{Deserialize, Serialize};
+
+#[derive(Serialize, Deserialize, Eq, PartialEq, Clone, Debug)]
+#[native_model(id = 1, version = 1)]
+#[native_db]
+struct Item1 {
+    #[primary_key]
+    id: u32,
+    #[secondary_key(unique)]
+    name: String,
+}
+
+#[derive(Serialize, Deserialize, Eq, PartialEq, Clone, Debug)]
+#[native_model(id = 2, version = 1)]
+#[native_db]
+struct Item2 {
+    #[primary_key]
+    id: u32,
+    #[secondary_key(optional)]
+    id2: Option<u32>,
+    #[secondary_key]
+    name: String,
+}
+
+#[test]
+fn test_refresh() {
+    use std::path::PathBuf;
+    println!("test_refresh");
+    #[cfg(any(target_os = "android", target_os = "ios"))]
+    let database_path = { dinghy_test::test_project_path().join("tests/data/db_0_7_1") };
+
+    #[cfg(not(any(target_os = "android", target_os = "ios")))]
+    let database_path = {
+        let root_project_path = env!("CARGO_MANIFEST_DIR");
+        PathBuf::from(format!("{}/tests/data/db_0_7_1", root_project_path))
+    };
+
+    use shortcut_assert_fs::TmpFs;
+    let tmp = TmpFs::new().unwrap();
+
+    // Copy the legacy database to the temporary directory.
+    let tmp_database_path = tmp.path("db_0_7_1");
+    std::fs::copy(&database_path, &tmp_database_path).unwrap();
+
+    // Open the legacy database with the upgrade feature. This must succeed.
+    let mut models = Models::new();
+    models.define::<Item1>().unwrap();
+    models.define::<Item2>().unwrap();
+    let db = Builder::new().open(&models, &tmp_database_path).unwrap();
+    // TODO: during open, the database must be upgraded to the latest version.
+
+    tmp.display_dir_entries();
+    let stats = db.redb_stats().unwrap();
+    dbg!(&stats);
+    assert_eq!(stats.primary_tables.len(), 2);
+    assert_eq!(stats.primary_tables[0].name, "1_1_id");
+    assert_eq!(stats.primary_tables[0].n_entries, Some(1));
+    assert_eq!(stats.primary_tables[1].name, "2_1_id");
+    assert_eq!(stats.primary_tables[1].n_entries, Some(1000));
+    assert_eq!(stats.secondary_tables.len(), 3);
+    assert_eq!(stats.secondary_tables[0].name, "1_1_name");
+    assert_eq!(stats.secondary_tables[0].n_entries, Some(1));
+    assert_eq!(stats.secondary_tables[1].name, "2_1_id2");
+    assert_eq!(stats.secondary_tables[1].n_entries, Some(500));
+    assert_eq!(stats.secondary_tables[2].name, "2_1_name");
+    assert_eq!(stats.secondary_tables[2].n_entries, Some(1000));
+
+    // Is not usefull but it's generaly used with the method upgrading_from_version.
+    if db.upgrading_from_version("<0.8.0").unwrap() {
+        // Refresh the database
+        let rw = db.rw_transaction().unwrap();
+        rw.refresh::<Item1>().unwrap();
+        rw.refresh::<Item2>().unwrap();
+        rw.commit().unwrap();
+    } else {
+        assert!(false);
+    }
+
+    let stats = db.redb_stats().unwrap();
+    assert_eq!(stats.primary_tables.len(), 2);
+    assert_eq!(stats.primary_tables[0].name, "1_1_id");
+    assert_eq!(stats.primary_tables[0].n_entries, Some(1));
+    assert_eq!(stats.primary_tables[1].name, "2_1_id");
+    assert_eq!(stats.primary_tables[1].n_entries, Some(1000));
+    assert_eq!(stats.secondary_tables.len(), 3);
+    assert_eq!(stats.secondary_tables[0].name, "1_1_name");
+    assert_eq!(stats.secondary_tables[0].n_entries, Some(1));
+    assert_eq!(stats.secondary_tables[1].name, "2_1_id2");
+    assert_eq!(stats.secondary_tables[1].n_entries, Some(500));
+    assert_eq!(stats.secondary_tables[2].name, "2_1_name");
+    assert_eq!(stats.secondary_tables[2].n_entries, Some(1000));
+}