Create DB for key package rotation (#1068)

## tl;dr

- Creates database tables to track key packages for rotation

xmtp_mls/migrations/2024-09-16-221459_key_package_history/down.sql

@@ -0,0 +1,2 @@
+DROP TABLE IF EXISTS key_package_history;
+

xmtp_mls/migrations/2024-09-16-221459_key_package_history/up.sql

@@ -0,0 +1,6 @@
+CREATE TABLE key_package_history(
+    "id" integer PRIMARY KEY AUTOINCREMENT NOT NULL,
+    "key_package_hash_ref" BLOB UNIQUE NOT NULL,
+    "created_at_ns" bigint NOT NULL
+);
+

xmtp_mls/src/storage/encrypted_store/key_package_history.rs

@@ -0,0 +1,107 @@
+use diesel::prelude::*;
+
+use super::{db_connection::DbConnection, schema::key_package_history, StorageError};
+use crate::{impl_store_or_ignore, utils::time::now_ns, StoreOrIgnore};
+
+#[derive(Insertable, Debug, Clone)]
+#[diesel(table_name = key_package_history)]
+pub struct NewKeyPackageHistoryEntry {
+    pub key_package_hash_ref: Vec<u8>,
+    pub created_at_ns: i64,
+}
+
+#[derive(Queryable, Selectable, Debug, Clone)]
+#[diesel(table_name = key_package_history)]
+pub struct StoredKeyPackageHistoryEntry {
+    pub id: i32,
+    pub key_package_hash_ref: Vec<u8>,
+    pub created_at_ns: i64,
+}
+
+impl_store_or_ignore!(NewKeyPackageHistoryEntry, key_package_history);
+
+impl DbConnection {
+    pub fn store_key_package_history_entry(
+        &self,
+        key_package_hash_ref: Vec<u8>,
+    ) -> Result<StoredKeyPackageHistoryEntry, StorageError> {
+        let entry = NewKeyPackageHistoryEntry {
+            key_package_hash_ref: key_package_hash_ref.clone(),
+            created_at_ns: now_ns(),
+        };
+        entry.store_or_ignore(self)?;
+
+        self.find_key_package_history_entry_by_hash_ref(key_package_hash_ref)
+    }
+
+    pub fn find_key_package_history_entry_by_hash_ref(
+        &self,
+        hash_ref: Vec<u8>,
+    ) -> Result<StoredKeyPackageHistoryEntry, StorageError> {
+        let result = self.raw_query(|conn| {
+            key_package_history::dsl::key_package_history
+                .filter(key_package_history::dsl::key_package_hash_ref.eq(hash_ref))
+                .first::<StoredKeyPackageHistoryEntry>(conn)
+        })?;
+
+        Ok(result)
+    }
+
+    pub fn find_key_package_history_entries_before_id(
+        &self,
+        id: i32,
+    ) -> Result<Vec<StoredKeyPackageHistoryEntry>, StorageError> {
+        let result = self.raw_query(|conn| {
+            key_package_history::dsl::key_package_history
+                .filter(key_package_history::dsl::id.lt(id))
+                .load::<StoredKeyPackageHistoryEntry>(conn)
+        })?;
+
+        Ok(result)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::{storage::encrypted_store::tests::with_connection, utils::test::rand_vec};
+
+    #[test]
+    fn test_store_key_package_history_entry() {
+        with_connection(|conn| {
+            let hash_ref = rand_vec();
+            let new_entry = conn
+                .store_key_package_history_entry(hash_ref.clone())
+                .unwrap();
+            assert_eq!(new_entry.key_package_hash_ref, hash_ref);
+            assert_eq!(new_entry.id, 1);
+        })
+    }
+
+    #[test]
+    fn test_store_multiple() {
+        with_connection(|conn| {
+            let hash_ref1 = rand_vec();
+            let hash_ref2 = rand_vec();
+            let hash_ref3 = rand_vec();
+
+            conn.store_key_package_history_entry(hash_ref1.clone())
+                .unwrap();
+            conn.store_key_package_history_entry(hash_ref2.clone())
+                .unwrap();
+            let entry_3 = conn
+                .store_key_package_history_entry(hash_ref3.clone())
+                .unwrap();
+
+            let all_entries = conn
+                .find_key_package_history_entries_before_id(100)
+                .unwrap();
+
+            assert_eq!(all_entries.len(), 3);
+
+            let earlier_entries = conn
+                .find_key_package_history_entries_before_id(entry_3.id)
+                .unwrap();
+            assert_eq!(earlier_entries.len(), 2);
+        })
+    }
+}

xmtp_mls/src/storage/encrypted_store/mod.rs

@@ -18,6 +18,7 @@ pub mod group_intent;
 pub mod group_message;
 pub mod identity;
 pub mod identity_update;
+pub mod key_package_history;
 pub mod key_store_entry;
 pub mod refresh_state;
 pub mod schema;

xmtp_mls/src/storage/encrypted_store/schema.rs

@@ -74,6 +74,14 @@ diesel::table! {
     }
 }
 
+diesel::table! {
+    key_package_history (id) {
+        id -> Integer,
+        key_package_hash_ref -> Binary,
+        created_at_ns -> BigInt,
+    }
+}
+
 diesel::table! {
     openmls_key_store (key_bytes) {
         key_bytes -> Binary,
@@ -108,6 +116,7 @@ diesel::allow_tables_to_appear_in_same_query!(
     groups,
     identity,
     identity_updates,
+    key_package_history,
     openmls_key_store,
     openmls_key_value,
     refresh_state,