Make MainDB into SubstrateDB

coordinator/src/substrate/db.rs

@@ -0,0 +1,36 @@
+pub use serai_db::*;
+
+#[derive(Debug)]
+pub struct SubstrateDb<D: Db>(pub D);
+impl<D: Db> SubstrateDb<D> {
+  pub fn new(db: D) -> Self {
+    Self(db)
+  }
+
+  fn substrate_key(dst: &'static [u8], key: impl AsRef<[u8]>) -> Vec<u8> {
+    D::key(b"SUBSTRATE", dst, key)
+  }
+
+  fn block_key() -> Vec<u8> {
+    Self::substrate_key(b"block", [])
+  }
+  pub fn set_last_block(&mut self, block: u64) {
+    let mut txn = self.0.txn();
+    txn.put(Self::block_key(), block.to_le_bytes());
+    txn.commit();
+  }
+  pub fn last_block(&self) -> u64 {
+    u64::from_le_bytes(self.0.get(Self::block_key()).unwrap_or(vec![0; 8]).try_into().unwrap())
+  }
+
+  fn event_key(id: &[u8], index: u32) -> Vec<u8> {
+    Self::substrate_key(b"event", [id, index.to_le_bytes().as_ref()].concat())
+  }
+  pub fn handled_event<G: Get>(getter: &G, id: [u8; 32], index: u32) -> bool {
+    getter.get(Self::event_key(&id, index)).is_some()
+  }
+  pub fn handle_event(txn: &mut D::Transaction<'_>, id: [u8; 32], index: u32) {
+    assert!(!Self::handled_event(txn, id, index));
+    txn.put(Self::event_key(&id, index), []);
+  }
+}