Account->AccountSharedData (#15691)

sdk/src/account_utils.rs

@@ -1,6 +1,7 @@
 //! useful extras for Account state
-use crate::{account::Account, instruction::InstructionError};
+use crate::{account::Account, account::AccountSharedData, instruction::InstructionError};
 use bincode::ErrorKind;
+use std::cell::Ref;
 
 /// Convenience trait to covert bincode errors to instruction errors.
 pub trait StateMut<T> {
@@ -28,20 +29,49 @@ where
     }
 }
 
+impl<T> StateMut<T> for AccountSharedData
+where
+    T: serde::Serialize + serde::de::DeserializeOwned,
+{
+    fn state(&self) -> Result<T, InstructionError> {
+        self.deserialize_data()
+            .map_err(|_| InstructionError::InvalidAccountData)
+    }
+    fn set_state(&mut self, state: &T) -> Result<(), InstructionError> {
+        self.serialize_data(state).map_err(|err| match *err {
+            ErrorKind::SizeLimit => InstructionError::AccountDataTooSmall,
+            _ => InstructionError::GenericError,
+        })
+    }
+}
+
+impl<T> StateMut<T> for Ref<'_, AccountSharedData>
+where
+    T: serde::Serialize + serde::de::DeserializeOwned,
+{
+    fn state(&self) -> Result<T, InstructionError> {
+        self.deserialize_data()
+            .map_err(|_| InstructionError::InvalidAccountData)
+    }
+    fn set_state(&mut self, _state: &T) -> Result<(), InstructionError> {
+        panic!("illegal");
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::{account::Account, pubkey::Pubkey};
+    use crate::{account::AccountSharedData, pubkey::Pubkey};
 
     #[test]
     fn test_account_state() {
         let state = 42u64;
 
-        assert!(Account::default().set_state(&state).is_err());
-        let res = Account::default().state() as Result<u64, InstructionError>;
+        assert!(AccountSharedData::default().set_state(&state).is_err());
+        let res = AccountSharedData::default().state() as Result<u64, InstructionError>;
         assert!(res.is_err());
 
-        let mut account = Account::new(0, std::mem::size_of::<u64>(), &Pubkey::default());
+        let mut account = AccountSharedData::new(0, std::mem::size_of::<u64>(), &Pubkey::default());
 
         assert!(account.set_state(&state).is_ok());
         let stored_state: u64 = account.state().unwrap();