Initial population of solana-program-sdk

sdk/program/src/sysvar/stake_history.rs

@@ -0,0 +1,82 @@
+//! named accounts for synthesized data accounts for bank state, etc.
+//!
+//! this account carries history about stake activations and de-activations
+//!
+pub use crate::stake_history::StakeHistory;
+
+use crate::{account::Account, sysvar::Sysvar};
+
+crate::declare_sysvar_id!("SysvarStakeHistory1111111111111111111111111", StakeHistory);
+
+impl Sysvar for StakeHistory {
+    // override
+    fn size_of() -> usize {
+        // hard-coded so that we don't have to construct an empty
+        16392 // golden, update if MAX_ENTRIES changes
+    }
+}
+
+pub fn create_account(lamports: u64, stake_history: &StakeHistory) -> Account {
+    stake_history.create_account(lamports)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::stake_history::*;
+
+    #[test]
+    fn test_size_of() {
+        let mut stake_history = StakeHistory::default();
+        for i in 0..MAX_ENTRIES as u64 {
+            stake_history.add(
+                i,
+                StakeHistoryEntry {
+                    activating: i,
+                    ..StakeHistoryEntry::default()
+                },
+            );
+        }
+
+        assert_eq!(
+            bincode::serialized_size(&stake_history).unwrap() as usize,
+            StakeHistory::size_of()
+        );
+    }
+
+    #[test]
+    fn test_create_account() {
+        let lamports = 42;
+        let account = StakeHistory::default().create_account(lamports);
+        assert_eq!(account.data.len(), StakeHistory::size_of());
+
+        let stake_history = StakeHistory::from_account(&account);
+        assert_eq!(stake_history, Some(StakeHistory::default()));
+
+        let mut stake_history = stake_history.unwrap();
+        for i in 0..MAX_ENTRIES as u64 + 1 {
+            stake_history.add(
+                i,
+                StakeHistoryEntry {
+                    activating: i,
+                    ..StakeHistoryEntry::default()
+                },
+            );
+        }
+        assert_eq!(stake_history.len(), MAX_ENTRIES);
+        assert_eq!(stake_history.iter().map(|entry| entry.0).min().unwrap(), 1);
+        assert_eq!(stake_history.get(&0), None);
+        assert_eq!(
+            stake_history.get(&1),
+            Some(&StakeHistoryEntry {
+                activating: 1,
+                ..StakeHistoryEntry::default()
+            })
+        );
+        // verify the account can hold a full instance
+        assert_eq!(
+            StakeHistory::from_account(&stake_history.create_account(lamports)),
+            Some(stake_history)
+        );
+    }
+}