solana_program_runtime/
sysvar_cache.rs

1#[expect(deprecated)]
2use solana_sysvar::{fees::Fees, recent_blockhashes::RecentBlockhashes};
3use {
4    crate::invoke_context::InvokeContext,
5    serde::{Serialize, de::DeserializeOwned},
6    solana_clock::Clock,
7    solana_epoch_rewards::EpochRewards,
8    solana_epoch_schedule::EpochSchedule,
9    solana_instruction::error::InstructionError,
10    solana_last_restart_slot::LastRestartSlot,
11    solana_pubkey::Pubkey,
12    solana_rent::Rent,
13    solana_sdk_ids::sysvar,
14    solana_slot_hashes::SlotHashes,
15    solana_stake_history::StakeHistory,
16    solana_svm_type_overrides::sync::Arc,
17    solana_sysvar_id::SysvarId,
18    solana_transaction_context::{IndexOfAccount, instruction::InstructionContext},
19};
20
21#[cfg(feature = "frozen-abi")]
22impl ::solana_frozen_abi::abi_example::AbiExample for SysvarCache {
23    fn example() -> Self {
24        // SysvarCache is not Serialize so just rely on Default.
25        SysvarCache::default()
26    }
27}
28
29#[derive(Default, Clone, Debug)]
30pub struct SysvarCache {
31    // full account data as provided by bank, including any trailing zero bytes
32    clock: Option<Vec<u8>>,
33    epoch_schedule: Option<Vec<u8>>,
34    epoch_rewards: Option<Vec<u8>>,
35    rent: Option<Vec<u8>>,
36    slot_hashes: Option<Vec<u8>>,
37    stake_history: Option<Vec<u8>>,
38    last_restart_slot: Option<Vec<u8>>,
39
40    // object representations of large sysvars for convenience
41    // these are used by the stake and vote builtin programs
42    // these should be removed once those programs are ported to bpf
43    slot_hashes_obj: Option<Arc<SlotHashes>>,
44    stake_history_obj: Option<Arc<StakeHistory>>,
45
46    // deprecated sysvars, these should be removed once practical
47    #[expect(deprecated)]
48    fees: Option<Fees>,
49    #[expect(deprecated)]
50    recent_blockhashes: Option<RecentBlockhashes>,
51}
52
53// declare_deprecated_sysvar_id doesn't support const.
54// These sysvars are going away anyway.
55const FEES_ID: Pubkey = Pubkey::from_str_const("SysvarFees111111111111111111111111111111111");
56const RECENT_BLOCKHASHES_ID: Pubkey =
57    Pubkey::from_str_const("SysvarRecentB1ockHashes11111111111111111111");
58
59impl SysvarCache {
60    /// Overwrite a sysvar. For testing purposes only.
61    #[expect(deprecated)]
62    pub fn set_sysvar_for_tests<T: Serialize + SysvarId>(&mut self, sysvar: &T) {
63        let data = bincode::serialize(sysvar).expect("Failed to serialize sysvar.");
64        let sysvar_id = T::id();
65        match sysvar_id {
66            sysvar::clock::ID => {
67                self.clock = Some(data);
68            }
69            sysvar::epoch_rewards::ID => {
70                self.epoch_rewards = Some(data);
71            }
72            sysvar::epoch_schedule::ID => {
73                self.epoch_schedule = Some(data);
74            }
75            FEES_ID => {
76                let fees: Fees =
77                    bincode::deserialize(&data).expect("Failed to deserialize Fees sysvar.");
78                self.fees = Some(fees);
79            }
80            sysvar::last_restart_slot::ID => {
81                self.last_restart_slot = Some(data);
82            }
83            RECENT_BLOCKHASHES_ID => {
84                let recent_blockhashes: RecentBlockhashes = bincode::deserialize(&data)
85                    .expect("Failed to deserialize RecentBlockhashes sysvar.");
86                self.recent_blockhashes = Some(recent_blockhashes);
87            }
88            sysvar::rent::ID => {
89                self.rent = Some(data);
90            }
91            sysvar::slot_hashes::ID => {
92                let slot_hashes: SlotHashes =
93                    wincode::deserialize(&data).expect("Failed to deserialize SlotHashes sysvar.");
94                self.slot_hashes = Some(data);
95                self.slot_hashes_obj = Some(Arc::new(slot_hashes));
96            }
97            sysvar::stake_history::ID => {
98                let stake_history: StakeHistory = bincode::deserialize(&data)
99                    .expect("Failed to deserialize StakeHistory sysvar.");
100                self.stake_history = Some(data);
101                self.stake_history_obj = Some(Arc::new(stake_history));
102            }
103            _ => panic!("Unrecognized Sysvar ID: {sysvar_id}"),
104        }
105    }
106
107    // this is exposed for SyscallGetSysvar and should not otherwise be used
108    pub fn sysvar_id_to_buffer(&self, sysvar_id: &Pubkey) -> &Option<Vec<u8>> {
109        if Clock::check_id(sysvar_id) {
110            &self.clock
111        } else if EpochSchedule::check_id(sysvar_id) {
112            &self.epoch_schedule
113        } else if EpochRewards::check_id(sysvar_id) {
114            &self.epoch_rewards
115        } else if Rent::check_id(sysvar_id) {
116            &self.rent
117        } else if SlotHashes::check_id(sysvar_id) {
118            &self.slot_hashes
119        } else if StakeHistory::check_id(sysvar_id) {
120            &self.stake_history
121        } else if LastRestartSlot::check_id(sysvar_id) {
122            &self.last_restart_slot
123        } else {
124            &None
125        }
126    }
127
128    // most if not all of the obj getter functions can be removed once builtins transition to bpf
129    // the Arc<T> wrapper is to preserve the existing public interface
130    fn get_sysvar_obj<T: DeserializeOwned>(
131        &self,
132        sysvar_id: &Pubkey,
133    ) -> Result<Arc<T>, InstructionError> {
134        if let Some(sysvar_buf) = self.sysvar_id_to_buffer(sysvar_id) {
135            bincode::deserialize(sysvar_buf)
136                .map(Arc::new)
137                .map_err(|_| InstructionError::UnsupportedSysvar)
138        } else {
139            Err(InstructionError::UnsupportedSysvar)
140        }
141    }
142
143    pub fn get_clock(&self) -> Result<Arc<Clock>, InstructionError> {
144        self.get_sysvar_obj(&Clock::id())
145    }
146
147    pub fn get_epoch_schedule(&self) -> Result<Arc<EpochSchedule>, InstructionError> {
148        self.get_sysvar_obj(&EpochSchedule::id())
149    }
150
151    pub fn get_epoch_rewards(&self) -> Result<Arc<EpochRewards>, InstructionError> {
152        self.get_sysvar_obj(&EpochRewards::id())
153    }
154
155    pub fn get_rent(&self) -> Result<Arc<Rent>, InstructionError> {
156        self.get_sysvar_obj(&Rent::id())
157    }
158
159    pub fn get_last_restart_slot(&self) -> Result<Arc<LastRestartSlot>, InstructionError> {
160        self.get_sysvar_obj(&LastRestartSlot::id())
161    }
162
163    pub fn get_stake_history(&self) -> Result<Arc<StakeHistory>, InstructionError> {
164        self.stake_history_obj
165            .clone()
166            .ok_or(InstructionError::UnsupportedSysvar)
167    }
168
169    pub fn get_slot_hashes(&self) -> Result<Arc<SlotHashes>, InstructionError> {
170        self.slot_hashes_obj
171            .clone()
172            .ok_or(InstructionError::UnsupportedSysvar)
173    }
174
175    #[deprecated]
176    #[expect(deprecated)]
177    pub fn get_fees(&self) -> Result<Arc<Fees>, InstructionError> {
178        self.fees
179            .clone()
180            .ok_or(InstructionError::UnsupportedSysvar)
181            .map(Arc::new)
182    }
183
184    #[deprecated]
185    #[expect(deprecated)]
186    pub fn get_recent_blockhashes(&self) -> Result<Arc<RecentBlockhashes>, InstructionError> {
187        self.recent_blockhashes
188            .clone()
189            .ok_or(InstructionError::UnsupportedSysvar)
190            .map(Arc::new)
191    }
192
193    pub fn fill_missing_entries<F: FnMut(&Pubkey, &mut dyn FnMut(&[u8]))>(
194        &mut self,
195        mut get_account_data: F,
196    ) {
197        if self.clock.is_none() {
198            get_account_data(&Clock::id(), &mut |data: &[u8]| {
199                if bincode::deserialize::<Clock>(data).is_ok() {
200                    self.clock = Some(data.to_vec());
201                }
202            });
203        }
204
205        if self.epoch_schedule.is_none() {
206            get_account_data(&EpochSchedule::id(), &mut |data: &[u8]| {
207                if bincode::deserialize::<EpochSchedule>(data).is_ok() {
208                    self.epoch_schedule = Some(data.to_vec());
209                }
210            });
211        }
212
213        if self.epoch_rewards.is_none() {
214            get_account_data(&EpochRewards::id(), &mut |data: &[u8]| {
215                if bincode::deserialize::<EpochRewards>(data).is_ok() {
216                    self.epoch_rewards = Some(data.to_vec());
217                }
218            });
219        }
220
221        if self.rent.is_none() {
222            get_account_data(&Rent::id(), &mut |data: &[u8]| {
223                if bincode::deserialize::<Rent>(data).is_ok() {
224                    self.rent = Some(data.to_vec());
225                }
226            });
227        }
228
229        if self.slot_hashes.is_none() {
230            get_account_data(&SlotHashes::id(), &mut |data: &[u8]| {
231                if let Ok(obj) = wincode::deserialize::<SlotHashes>(data) {
232                    self.slot_hashes = Some(data.to_vec());
233                    self.slot_hashes_obj = Some(Arc::new(obj));
234                }
235            });
236        }
237
238        if self.stake_history.is_none() {
239            get_account_data(&StakeHistory::id(), &mut |data: &[u8]| {
240                if let Ok(obj) = bincode::deserialize::<StakeHistory>(data) {
241                    self.stake_history = Some(data.to_vec());
242                    self.stake_history_obj = Some(Arc::new(obj));
243                }
244            });
245        }
246
247        if self.last_restart_slot.is_none() {
248            get_account_data(&LastRestartSlot::id(), &mut |data: &[u8]| {
249                if bincode::deserialize::<LastRestartSlot>(data).is_ok() {
250                    self.last_restart_slot = Some(data.to_vec());
251                }
252            });
253        }
254
255        #[expect(deprecated)]
256        if self.fees.is_none() {
257            get_account_data(&Fees::id(), &mut |data: &[u8]| {
258                if let Ok(fees) = bincode::deserialize(data) {
259                    self.fees = Some(fees);
260                }
261            });
262        }
263
264        #[expect(deprecated)]
265        if self.recent_blockhashes.is_none() {
266            get_account_data(&RecentBlockhashes::id(), &mut |data: &[u8]| {
267                if let Ok(recent_blockhashes) = bincode::deserialize(data) {
268                    self.recent_blockhashes = Some(recent_blockhashes);
269                }
270            });
271        }
272    }
273
274    pub fn reset(&mut self) {
275        *self = Self::default();
276    }
277}
278
279/// These methods facilitate a transition from fetching sysvars from keyed
280/// accounts to fetching from the sysvar cache without breaking consensus. In
281/// order to keep consistent behavior, they continue to enforce legacy checks
282/// despite dynamically loading them instead of deserializing from account data.
283pub mod get_sysvar_with_account_check {
284    use super::*;
285
286    fn check_sysvar_account<S: SysvarId>(
287        instruction_context: &InstructionContext,
288        instruction_account_index: IndexOfAccount,
289    ) -> Result<(), InstructionError> {
290        if !S::check_id(
291            instruction_context.get_key_of_instruction_account(instruction_account_index)?,
292        ) {
293            return Err(InstructionError::InvalidArgument);
294        }
295        Ok(())
296    }
297
298    pub fn clock(
299        invoke_context: &InvokeContext,
300        instruction_context: &InstructionContext,
301        instruction_account_index: IndexOfAccount,
302    ) -> Result<Arc<Clock>, InstructionError> {
303        check_sysvar_account::<Clock>(instruction_context, instruction_account_index)?;
304        invoke_context.environment_config.sysvar_cache().get_clock()
305    }
306
307    pub fn rent(
308        invoke_context: &InvokeContext,
309        instruction_context: &InstructionContext,
310        instruction_account_index: IndexOfAccount,
311    ) -> Result<Arc<Rent>, InstructionError> {
312        check_sysvar_account::<Rent>(instruction_context, instruction_account_index)?;
313        invoke_context.environment_config.sysvar_cache().get_rent()
314    }
315
316    pub fn slot_hashes(
317        invoke_context: &InvokeContext,
318        instruction_context: &InstructionContext,
319        instruction_account_index: IndexOfAccount,
320    ) -> Result<Arc<SlotHashes>, InstructionError> {
321        check_sysvar_account::<SlotHashes>(instruction_context, instruction_account_index)?;
322        invoke_context
323            .environment_config
324            .sysvar_cache()
325            .get_slot_hashes()
326    }
327
328    #[expect(deprecated)]
329    pub fn recent_blockhashes(
330        invoke_context: &InvokeContext,
331        instruction_context: &InstructionContext,
332        instruction_account_index: IndexOfAccount,
333    ) -> Result<Arc<RecentBlockhashes>, InstructionError> {
334        check_sysvar_account::<RecentBlockhashes>(instruction_context, instruction_account_index)?;
335        invoke_context
336            .environment_config
337            .sysvar_cache()
338            .get_recent_blockhashes()
339    }
340
341    pub fn stake_history(
342        invoke_context: &InvokeContext,
343        instruction_context: &InstructionContext,
344        instruction_account_index: IndexOfAccount,
345    ) -> Result<Arc<StakeHistory>, InstructionError> {
346        check_sysvar_account::<StakeHistory>(instruction_context, instruction_account_index)?;
347        invoke_context
348            .environment_config
349            .sysvar_cache()
350            .get_stake_history()
351    }
352
353    pub fn last_restart_slot(
354        invoke_context: &InvokeContext,
355        instruction_context: &InstructionContext,
356        instruction_account_index: IndexOfAccount,
357    ) -> Result<Arc<LastRestartSlot>, InstructionError> {
358        check_sysvar_account::<LastRestartSlot>(instruction_context, instruction_account_index)?;
359        invoke_context
360            .environment_config
361            .sysvar_cache()
362            .get_last_restart_slot()
363    }
364}
365
366#[cfg(test)]
367mod tests {
368    use {
369        super::*, solana_stake_history::SIZE as STAKE_HISTORY_ACCOUNT_SIZE, test_case::test_case,
370    };
371
372    // sysvar cache provides the full account data of a sysvar
373    // the setters MUST NOT be changed to serialize an object representation
374    // it is required that the syscall be able to access the full buffer as it exists onchain
375    // this is meant to cover the cases:
376    // * account data is larger than struct sysvar
377    // * vector sysvar has fewer than its maximum entries
378    // if at any point the data is roundtripped through bincode, the vector will shrink
379    #[test_case(Clock::default(), 40; "clock")]
380    #[test_case(EpochSchedule::default(), 33; "epoch_schedule")]
381    #[test_case(EpochRewards::default(), 81; "epoch_rewards")]
382    #[test_case(Rent::default(), 17; "rent")]
383    #[test_case(SlotHashes::default(), 20_488; "slot_hashes")]
384    #[test_case(StakeHistory::default(), STAKE_HISTORY_ACCOUNT_SIZE; "stake_history")]
385    #[test_case(LastRestartSlot::default(), 8; "last_restart_slot")]
386    fn test_sysvar_cache_preserves_bytes<T: SysvarId>(_: T, account_size: usize) {
387        let id = T::id();
388        let account_size = account_size.saturating_mul(2);
389        let in_buf = vec![0; account_size];
390
391        let mut sysvar_cache = SysvarCache::default();
392        sysvar_cache.fill_missing_entries(|pubkey, callback| {
393            if *pubkey == id {
394                callback(&in_buf)
395            }
396        });
397        let sysvar_cache = sysvar_cache;
398
399        let out_buf = sysvar_cache.sysvar_id_to_buffer(&id).clone().unwrap();
400
401        assert_eq!(out_buf, in_buf);
402    }
403}
solana_program_runtime/sysvar_cache.rs

solana_program_runtime/
sysvar_cache.rs
