Ground work for preferred sequencer

examples/demo-stf/src/genesis_config.rs

@@ -45,6 +45,7 @@ pub fn create_demo_genesis_config<C: Context>(
             amount: LOCKED_AMOUNT,
             token_address,
         },
+        preferred_sequencer: None,
     };
 
     let value_setter_config = ValueSetterConfig {

module-system/module-implementations/sov-sequencer-registry/src/lib.rs

@@ -13,6 +13,7 @@ pub struct SequencerConfig<C: sov_modules_api::Context> {
     pub seq_rollup_address: C::Address,
     pub seq_da_address: Vec<u8>,
     pub coins_to_lock: sov_bank::Coins<C>,
+    pub preferred_sequencer: Option<C::Address>,
 }
 
 #[derive(ModuleInfo)]
@@ -31,6 +32,12 @@ pub struct SequencerRegistry<C: sov_modules_api::Context> {
     #[state]
     pub(crate) allowed_sequencers: StateMap<Vec<u8>, C::Address>,
 
+    /// Optional preferred sequencer
+    /// If set, batches from this sequencer will be processed first in block,
+    /// So this sequencer can guarantee soft confirmation time for transactions
+    #[state]
+    pub(crate) preferred_sequencer: StateValue<C::Address>,
+
     /// Coin's that will be slashed if the sequencer is malicious.
     /// The coins will be transferred from `self.seq_rollup_address` to `self.address`
     /// and locked forever, until sequencer decides to exit
@@ -108,4 +115,12 @@ impl<C: sov_modules_api::Context> SequencerRegistry<C> {
 
         Ok(())
     }
+
+    /// Return preferred sequencer if it was set
+    pub fn get_preferred_sequencer(
+        &self,
+        working_set: &mut WorkingSet<C::Storage>,
+    ) -> Option<C::Address> {
+        self.preferred_sequencer.get(working_set)
+    }
 }

module-system/module-implementations/sov-sequencer-registry/tests/helpers/mod.rs

@@ -94,6 +94,7 @@ pub fn create_sequencer_config(
             amount: LOCKED_AMOUNT,
             token_address,
         },
+        preferred_sequencer: None,
     }
 }