Database Macro (#408)

* db_macro

* wip: converted prcessor/key_gen to use create_db macro

* wip: converted prcessor/key_gen to use create_db macro

* wip: formatting

* fix: added no_run to doc

* fix: documentation example had extra parenths

* fix: ignore doc test entirely

* Corrections from rebasing

* Misc lint

---------

Co-authored-by: Luke Parker <lukeparker5132@gmail.com>

common/db/src/create_db.rs

@@ -0,0 +1,68 @@
+#[doc(hidden)]
+pub fn serai_db_key(
+  db_dst: &'static [u8],
+  item_dst: &'static [u8],
+  key: impl AsRef<[u8]>,
+) -> Vec<u8> {
+  let db_len = u8::try_from(db_dst.len()).unwrap();
+  let dst_len = u8::try_from(item_dst.len()).unwrap();
+  [[db_len].as_ref(), db_dst, [dst_len].as_ref(), item_dst, key.as_ref()].concat()
+}
+
+/// Creates a series of structs which provide namespacing for keys
+///
+/// # Description
+///
+/// Creates a unit struct and a default implementation for the `key`, `get`, and `set`. The macro
+/// uses a syntax similar to defining a function. Parameters are concatenated to produce a key,
+/// they must be `scale` encodable. The return type is used to auto encode and decode the database
+/// value bytes using `bincode`.
+///
+/// # Arguments
+///
+/// * `db_name` - A database name
+/// * `field_name` - An item name
+/// * `args` - Comma seperated list of key arguments
+/// * `field_type` - The return type
+///
+/// # Example
+///
+/// ```ignore
+/// create_db!(
+///   TrubutariesDb {
+///     AttemptsDb: (key_bytes: &[u8], attempt_id: u32) -> u64,
+///     ExpiredDb: (genesis: [u8; 32]) -> Vec<u8>
+///   }
+/// )
+/// ```
+#[macro_export]
+macro_rules! create_db {
+  ($db_name: ident {
+    $($field_name: ident: ($($arg: ident: $arg_type: ty),*) -> $field_type: ty),*
+  }) => {
+    $(
+      #[derive(Clone, Debug)]
+      pub struct $field_name;
+      impl $field_name {
+        pub fn key($($arg: $arg_type),*) -> Vec<u8> {
+          $crate::serai_db_key(
+            stringify!($db_name).as_bytes(),
+            stringify!($field_name).as_bytes(),
+            ($($arg),*).encode()
+          )
+        }
+        #[allow(dead_code)]
+        pub fn set(txn: &mut impl DbTxn $(, $arg: $arg_type)*, data: &impl serde::Serialize) {
+          let key = $field_name::key($($arg),*);
+          txn.put(&key, bincode::serialize(data).unwrap());
+        }
+        #[allow(dead_code)]
+        pub fn get(getter: &impl Get, $($arg: $arg_type),*) -> Option<$field_type> {
+          getter.get($field_name::key($($arg),*)).map(|data| {
+            bincode::deserialize(data.as_ref()).unwrap()
+          })
+        }
+      }
+    )*
+  };
+}

common/db/src/lib.rs

@@ -1,3 +1,6 @@
+mod create_db;
+pub use create_db::*;
+
 mod mem;
 pub use mem::*;
 

processor/src/key_gen.rs

@@ -1,4 +1,3 @@
-use core::marker::PhantomData;
 use std::collections::HashMap;
 
 use zeroize::Zeroizing;
@@ -19,7 +18,7 @@ use scale::Encode;
 use serai_client::validator_sets::primitives::{ValidatorSet, KeyPair};
 use messages::key_gen::*;
 
-use crate::{Get, DbTxn, Db, networks::Network};
+use crate::{Get, DbTxn, Db, create_db, networks::Network};
 
 #[derive(Debug)]
 pub struct KeyConfirmed<C: Ciphersuite> {
@@ -27,80 +26,22 @@ pub struct KeyConfirmed<C: Ciphersuite> {
   pub network_keys: Vec<ThresholdKeys<C>>,
 }
 
-#[derive(Clone, Debug)]
+create_db!(
-struct KeyGenDb<N: Network, D: Db>(PhantomData<D>, PhantomData<N>);
+  KeyGenDb {
-impl<N: Network, D: Db> KeyGenDb<N, D> {
+    ParamsDb: (key: &ValidatorSet) -> (ThresholdParams, u16),
-  fn key_gen_key(dst: &'static [u8], key: impl AsRef<[u8]>) -> Vec<u8> {
-    D::key(b"KEY_GEN", dst, key)
-  }
-
-  fn params_key(set: &ValidatorSet) -> Vec<u8> {
-    Self::key_gen_key(b"params", set.encode())
-  }
-  fn save_params(
-    txn: &mut D::Transaction<'_>,
-    set: &ValidatorSet,
-    params: &ThresholdParams,
-    shares: u16,
-  ) {
-    txn.put(Self::params_key(set), bincode::serialize(&(params, shares)).unwrap());
-  }
-  fn params<G: Get>(getter: &G, set: &ValidatorSet) -> Option<(ThresholdParams, u16)> {
-    getter.get(Self::params_key(set)).map(|bytes| bincode::deserialize(&bytes).unwrap())
-  }
-
     // Not scoped to the set since that'd have latter attempts overwrite former
     // A former attempt may become the finalized attempt, even if it doesn't in a timely manner
     // Overwriting its commitments would be accordingly poor
-  fn commitments_key(id: &KeyGenId) -> Vec<u8> {
+    CommitmentsDb: (key: &KeyGenId) -> HashMap<Participant, Vec<u8>>,
-    Self::key_gen_key(b"commitments", id.encode())
+    GeneratedKeysDb: (set: &ValidatorSet, substrate_key: &[u8; 32], network_key: &[u8]) -> Vec<u8>,
-  }
+    KeysDb: (network_key: &[u8]) -> Vec<u8>
-  fn save_commitments(
-    txn: &mut D::Transaction<'_>,
-    id: &KeyGenId,
-    commitments: &HashMap<Participant, Vec<u8>>,
-  ) {
-    txn.put(Self::commitments_key(id), bincode::serialize(commitments).unwrap());
-  }
-  fn commitments<G: Get>(getter: &G, id: &KeyGenId) -> HashMap<Participant, Vec<u8>> {
-    bincode::deserialize::<HashMap<Participant, Vec<u8>>>(
-      &getter.get(Self::commitments_key(id)).unwrap(),
-    )
-    .unwrap()
   }
+);
 
-  fn generated_keys_key(set: ValidatorSet, key_pair: (&[u8; 32], &[u8])) -> Vec<u8> {
+impl GeneratedKeysDb {
-    Self::key_gen_key(b"generated_keys", (set, key_pair).encode())
-  }
-  fn save_keys(
-    txn: &mut D::Transaction<'_>,
-    id: &KeyGenId,
-    substrate_keys: &[ThresholdCore<Ristretto>],
-    network_keys: &[ThresholdKeys<N::Curve>],
-  ) {
-    let mut keys = Zeroizing::new(vec![]);
-    for (substrate_keys, network_keys) in substrate_keys.iter().zip(network_keys) {
-      keys.extend(substrate_keys.serialize().as_slice());
-      keys.extend(network_keys.serialize().as_slice());
-    }
-    txn.put(
-      Self::generated_keys_key(
-        id.set,
-        (
-          &substrate_keys[0].group_key().to_bytes(),
-          network_keys[0].group_key().to_bytes().as_ref(),
-        ),
-      ),
-      &keys,
-    );
-  }
-
-  fn keys_key(key: &<N::Curve as Ciphersuite>::G) -> Vec<u8> {
-    Self::key_gen_key(b"keys", key.to_bytes())
-  }
   #[allow(clippy::type_complexity)]
-  fn read_keys<G: Get>(
+  fn read_keys<N: Network>(
-    getter: &G,
+    getter: &impl Get,
     key: &[u8],
   ) -> Option<(Vec<u8>, (Vec<ThresholdKeys<Ristretto>>, Vec<ThresholdKeys<N::Curve>>))> {
     let keys_vec = getter.get(key)?;
@@ -116,13 +57,39 @@ impl<N: Network, D: Db> KeyGenDb<N, D> {
     }
     Some((keys_vec, (substrate_keys, network_keys)))
   }
-  fn confirm_keys(
+
-    txn: &mut D::Transaction<'_>,
+  fn save_keys<N: Network>(
+    txn: &mut impl DbTxn,
+    id: &KeyGenId,
+    substrate_keys: &[ThresholdCore<Ristretto>],
+    network_keys: &[ThresholdKeys<N::Curve>],
+  ) {
+    let mut keys = Zeroizing::new(vec![]);
+    for (substrate_keys, network_keys) in substrate_keys.iter().zip(network_keys) {
+      keys.extend(substrate_keys.serialize().as_slice());
+      keys.extend(network_keys.serialize().as_slice());
+    }
+    txn.put(
+      Self::key(
+        &id.set,
+        &substrate_keys[0].group_key().to_bytes(),
+        network_keys[0].group_key().to_bytes().as_ref(),
+      ),
+      keys,
+    );
+  }
+}
+
+impl KeysDb {
+  fn confirm_keys<N: Network>(
+    txn: &mut impl DbTxn,
     set: ValidatorSet,
     key_pair: KeyPair,
   ) -> (Vec<ThresholdKeys<Ristretto>>, Vec<ThresholdKeys<N::Curve>>) {
-    let (keys_vec, keys) =
+    let (keys_vec, keys) = GeneratedKeysDb::read_keys::<N>(
-      Self::read_keys(txn, &Self::generated_keys_key(set, (&key_pair.0 .0, key_pair.1.as_ref())))
+      txn,
+      &GeneratedKeysDb::key(&set, &key_pair.0 .0, key_pair.1.as_ref()),
+    )
     .unwrap();
     assert_eq!(key_pair.0 .0, keys.0[0].group_key().to_bytes());
     assert_eq!(
@@ -132,16 +99,18 @@ impl<N: Network, D: Db> KeyGenDb<N, D> {
       },
       keys.1[0].group_key().to_bytes().as_ref(),
     );
-    txn.put(Self::keys_key(&keys.1[0].group_key()), keys_vec);
+    txn.put(KeysDb::key(keys.1[0].group_key().to_bytes().as_ref()), keys_vec);
     keys
   }
+
   #[allow(clippy::type_complexity)]
-  fn keys<G: Get>(
+  fn keys<N: Network>(
-    getter: &G,
+    getter: &impl Get,
-    key: &<N::Curve as Ciphersuite>::G,
+    network_key: &<N::Curve as Ciphersuite>::G,
   ) -> Option<(Vec<ThresholdKeys<Ristretto>>, Vec<ThresholdKeys<N::Curve>>)> {
-    let res = Self::read_keys(getter, &Self::keys_key(key))?.1;
+    let res =
-    assert_eq!(&res.1[0].group_key(), key);
+      GeneratedKeysDb::read_keys::<N>(getter, &Self::key(network_key.to_bytes().as_ref()))?.1;
+    assert_eq!(&res.1[0].group_key(), network_key);
     Some(res)
   }
 }
@@ -168,7 +137,7 @@ impl<N: Network, D: Db> KeyGen<N, D> {
 
   pub fn in_set(&self, set: &ValidatorSet) -> bool {
     // We determine if we're in set using if we have the parameters for a set's key generation
-    KeyGenDb::<N, D>::params(&self.db, set).is_some()
+    ParamsDb::get(&self.db, set).is_some()
   }
 
   #[allow(clippy::type_complexity)]
@@ -177,15 +146,8 @@ impl<N: Network, D: Db> KeyGen<N, D> {
     key: &<N::Curve as Ciphersuite>::G,
   ) -> Option<(Vec<ThresholdKeys<Ristretto>>, Vec<ThresholdKeys<N::Curve>>)> {
     // This is safe, despite not having a txn, since it's a static value
-    // The only concern is it may not be set when expected, or it may be set unexpectedly
+    // It doesn't change over time/in relation to other operations
-    //
+    KeysDb::keys::<N>(&self.db, key)
-    // They're only expected to be set on boot, if confirmed. If they were confirmed yet the
-    // transaction wasn't committed, their confirmation will be re-handled
-    //
-    // The only other concern is if it's set when it's not safe to use
-    // The keys are only written on confirmation, and the transaction writing them is atomic to
-    // every associated operation
-    KeyGenDb::<N, D>::keys(&self.db, key)
   }
 
   pub async fn handle(
@@ -313,7 +275,7 @@ impl<N: Network, D: Db> KeyGen<N, D> {
           self.active_share.remove(&id.set).is_none()
         {
           // If we haven't handled this set before, save the params
-          KeyGenDb::<N, D>::save_params(txn, &id.set, &params, shares);
+          ParamsDb::set(txn, &id.set, &(params, shares));
         }
 
         let (machines, commitments) = key_gen_machines(id, params, shares);
@@ -332,7 +294,7 @@ impl<N: Network, D: Db> KeyGen<N, D> {
           panic!("commitments when already handled commitments");
         }
 
-        let (params, share_quantity) = KeyGenDb::<N, D>::params(txn, &id.set).unwrap();
+        let (params, share_quantity) = ParamsDb::get(txn, &id.set).unwrap();
 
         // Unwrap the machines, rebuilding them if we didn't have them in our cache
         // We won't if the processor rebooted
@@ -344,7 +306,7 @@ impl<N: Network, D: Db> KeyGen<N, D> {
           .remove(&id.set)
           .unwrap_or_else(|| key_gen_machines(id, params, share_quantity));
 
-        KeyGenDb::<N, D>::save_commitments(txn, &id, &commitments);
+        CommitmentsDb::set(txn, &id, &commitments);
         let (machines, shares) = secret_share_machines(id, params, prior, commitments);
 
         self.active_share.insert(id.set, (machines, shares.clone()));
@@ -355,12 +317,12 @@ impl<N: Network, D: Db> KeyGen<N, D> {
       CoordinatorMessage::Shares { id, shares } => {
         info!("Received shares for {:?}", id);
 
-        let (params, share_quantity) = KeyGenDb::<N, D>::params(txn, &id.set).unwrap();
+        let (params, share_quantity) = ParamsDb::get(txn, &id.set).unwrap();
 
         // Same commentary on inconsistency as above exists
         let (machines, our_shares) = self.active_share.remove(&id.set).unwrap_or_else(|| {
           let prior = key_gen_machines(id, params, share_quantity);
-          secret_share_machines(id, params, prior, KeyGenDb::<N, D>::commitments(txn, &id))
+          secret_share_machines(id, params, prior, CommitmentsDb::get(txn, &id).unwrap())
         });
 
         let mut rng = share_rng(id);
@@ -437,7 +399,7 @@ impl<N: Network, D: Db> KeyGen<N, D> {
           }
         }
 
-        KeyGenDb::<N, D>::save_keys(txn, &id, &substrate_keys, &network_keys);
+        GeneratedKeysDb::save_keys::<N>(txn, &id, &substrate_keys, &network_keys);
 
         ProcessorMessage::GeneratedKeyPair {
           id,
@@ -454,15 +416,15 @@ impl<N: Network, D: Db> KeyGen<N, D> {
     set: ValidatorSet,
     key_pair: KeyPair,
   ) -> KeyConfirmed<N::Curve> {
-    let (substrate_keys, network_keys) = KeyGenDb::<N, D>::confirm_keys(txn, set, key_pair.clone());
-
     info!(
       "Confirmed key pair {} {} for set {:?}",
       hex::encode(key_pair.0),
-      hex::encode(key_pair.1),
+      hex::encode(&key_pair.1),
       set,
     );
 
+    let (substrate_keys, network_keys) = KeysDb::confirm_keys::<N>(txn, set, key_pair);
+
     KeyConfirmed { substrate_keys, network_keys }
   }
 }