stake-contract: add config management functions

contracts/stake/src/lib.rs

@@ -94,6 +94,11 @@ unsafe fn get_version(arg_len: u32) -> u32 {
     rusk_abi::wrap_call(arg_len, |_: ()| STATE.get_version())
 }
 
+#[no_mangle]
+unsafe fn get_config(arg_len: u32) -> u32 {
+    rusk_abi::wrap_call(arg_len, |_: ()| STATE.config().clone())
+}
+
 // "Feeder" queries
 
 #[no_mangle]
@@ -116,6 +121,14 @@ unsafe fn before_state_transition(arg_len: u32) -> u32 {
     })
 }
 
+#[no_mangle]
+unsafe fn set_config(arg_len: u32) -> u32 {
+    rusk_abi::wrap_call(arg_len, |config| {
+        assert_external_caller();
+        STATE.configure(config)
+    })
+}
+
 #[no_mangle]
 unsafe fn insert_stake(arg_len: u32) -> u32 {
     rusk_abi::wrap_call(arg_len, |(pk, stake_data)| {

contracts/stake/src/state.rs

@@ -53,6 +53,14 @@ impl StakeState {
         }
     }
 
+    pub fn config(&self) -> &StakeConfig {
+        &self.conf
+    }
+
+    pub fn configure(&mut self, conf: StakeConfig) {
+        self.conf = conf;
+    }
+
     pub fn on_new_block(&mut self) {
         self.previous_block_state.clear()
     }