stake: Add BorshDeserialize trait to structs (#19958)

sdk/program/src/stake/state.rs

@@ -11,6 +11,7 @@ use {
         },
         stake_history::StakeHistory,
     },
+    borsh::{maybestd::io, BorshDeserialize, BorshSchema},
     std::collections::HashSet,
 };
 
@@ -23,6 +24,29 @@ pub enum StakeState {
     RewardsPool,
 }
 
+impl BorshDeserialize for StakeState {
+    fn deserialize(buf: &mut &[u8]) -> io::Result<Self> {
+        let enum_value: u32 = BorshDeserialize::deserialize(buf)?;
+        match enum_value {
+            0 => Ok(StakeState::Uninitialized),
+            1 => {
+                let meta: Meta = BorshDeserialize::deserialize(buf)?;
+                Ok(StakeState::Initialized(meta))
+            }
+            2 => {
+                let meta: Meta = BorshDeserialize::deserialize(buf)?;
+                let stake: Stake = BorshDeserialize::deserialize(buf)?;
+                Ok(StakeState::Stake(meta, stake))
+            }
+            3 => Ok(StakeState::RewardsPool),
+            _ => Err(io::Error::new(
+                io::ErrorKind::InvalidData,
+                "Invalid enum value",
+            )),
+        }
+    }
+}
+
 impl Default for StakeState {
     fn default() -> Self {
         StakeState::Uninitialized
@@ -75,7 +99,18 @@ pub enum StakeAuthorize {
     Withdrawer,
 }
 
-#[derive(Default, Debug, Serialize, Deserialize, PartialEq, Clone, Copy, AbiExample)]
+#[derive(
+    Default,
+    Debug,
+    Serialize,
+    Deserialize,
+    PartialEq,
+    Clone,
+    Copy,
+    AbiExample,
+    BorshDeserialize,
+    BorshSchema,
+)]
 pub struct Lockup {
     /// UnixTimestamp at which this stake will allow withdrawal, unless the
     ///   transaction is signed by the custodian
@@ -97,7 +132,18 @@ impl Lockup {
     }
 }
 
-#[derive(Default, Debug, Serialize, Deserialize, PartialEq, Clone, Copy, AbiExample)]
+#[derive(
+    Default,
+    Debug,
+    Serialize,
+    Deserialize,
+    PartialEq,
+    Clone,
+    Copy,
+    AbiExample,
+    BorshDeserialize,
+    BorshSchema,
+)]
 pub struct Authorized {
     pub staker: Pubkey,
     pub withdrawer: Pubkey,
@@ -164,7 +210,18 @@ impl Authorized {
     }
 }
 
-#[derive(Default, Debug, Serialize, Deserialize, PartialEq, Clone, Copy, AbiExample)]
+#[derive(
+    Default,
+    Debug,
+    Serialize,
+    Deserialize,
+    PartialEq,
+    Clone,
+    Copy,
+    AbiExample,
+    BorshDeserialize,
+    BorshSchema,
+)]
 pub struct Meta {
     pub rent_exempt_reserve: u64,
     pub authorized: Authorized,
@@ -237,7 +294,9 @@ impl Meta {
     }
 }
 
-#[derive(Debug, Serialize, Deserialize, PartialEq, Clone, Copy, AbiExample)]
+#[derive(
+    Debug, Serialize, Deserialize, PartialEq, Clone, Copy, AbiExample, BorshDeserialize, BorshSchema,
+)]
 pub struct Delegation {
     /// to whom the stake is delegated
     pub voter_pubkey: Pubkey,
@@ -456,7 +515,18 @@ impl Delegation {
     }
 }
 
-#[derive(Debug, Default, Serialize, Deserialize, PartialEq, Clone, Copy, AbiExample)]
+#[derive(
+    Debug,
+    Default,
+    Serialize,
+    Deserialize,
+    PartialEq,
+    Clone,
+    Copy,
+    AbiExample,
+    BorshDeserialize,
+    BorshSchema,
+)]
 pub struct Stake {
     pub delegation: Delegation,
     /// credits observed is credits from vote account state when delegated or redeemed
@@ -496,3 +566,76 @@ impl Stake {
         }
     }
 }
+
+#[cfg(test)]
+mod test {
+    use {
+        super::*, crate::borsh::try_from_slice_unchecked, assert_matches::assert_matches,
+        bincode::serialize,
+    };
+
+    fn check_borsh_deserialization(stake: StakeState) {
+        let serialized = serialize(&stake).unwrap();
+        let deserialized = StakeState::try_from_slice(&serialized).unwrap();
+        assert_eq!(stake, deserialized);
+    }
+
+    #[test]
+    fn bincode_vs_borsh() {
+        check_borsh_deserialization(StakeState::Uninitialized);
+        check_borsh_deserialization(StakeState::RewardsPool);
+        check_borsh_deserialization(StakeState::Initialized(Meta {
+            rent_exempt_reserve: u64::MAX,
+            authorized: Authorized {
+                staker: Pubkey::new_unique(),
+                withdrawer: Pubkey::new_unique(),
+            },
+            lockup: Lockup::default(),
+        }));
+        check_borsh_deserialization(StakeState::Stake(
+            Meta {
+                rent_exempt_reserve: 1,
+                authorized: Authorized {
+                    staker: Pubkey::new_unique(),
+                    withdrawer: Pubkey::new_unique(),
+                },
+                lockup: Lockup::default(),
+            },
+            Stake {
+                delegation: Delegation {
+                    voter_pubkey: Pubkey::new_unique(),
+                    stake: u64::MAX,
+                    activation_epoch: Epoch::MAX,
+                    deactivation_epoch: Epoch::MAX,
+                    warmup_cooldown_rate: f64::MAX,
+                },
+                credits_observed: 1,
+            },
+        ));
+    }
+
+    #[test]
+    fn borsh_deserialization_live_data() {
+        let data = [
+            1, 0, 0, 0, 128, 213, 34, 0, 0, 0, 0, 0, 133, 0, 79, 231, 141, 29, 73, 61, 232, 35,
+            119, 124, 168, 12, 120, 216, 195, 29, 12, 166, 139, 28, 36, 182, 186, 154, 246, 149,
+            224, 109, 52, 100, 133, 0, 79, 231, 141, 29, 73, 61, 232, 35, 119, 124, 168, 12, 120,
+            216, 195, 29, 12, 166, 139, 28, 36, 182, 186, 154, 246, 149, 224, 109, 52, 100, 0, 0,
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0, 0,
+        ];
+        // As long as we get the 4-byte enum and the first field right, then
+        // we're sure the rest works out
+        let deserialized = try_from_slice_unchecked::<StakeState>(&data).unwrap();
+        assert_matches!(
+            deserialized,
+            StakeState::Initialized(Meta {
+                rent_exempt_reserve: 2282880,
+                ..
+            })
+        );
+    }
+}