soroban-rpc: preflight: Exclude temporary expired entries from Snapsh…

…otSource (#980)

* soroban-rpc: preflight: Exclude temporary expired entries from SnapshotSource

* Factor in get_including_persistent_expired

* Add specific error for expired entries and improve error check

cmd/soroban-rpc/lib/preflight/src/ledger_storage.rs

@@ -1,6 +1,6 @@
 use sha2::Digest;
 use soroban_env_host::storage::SnapshotSource;
-use soroban_env_host::xdr::ContractDataDurability::Persistent;
+use soroban_env_host::xdr::ContractDataDurability::{Persistent, Temporary};
 use soroban_env_host::xdr::{
     ConfigSettingEntry, ConfigSettingId, Error as XdrError, ExpirationEntry, Hash, LedgerEntry,
     LedgerEntryData, LedgerKey, LedgerKeyConfigSetting, LedgerKeyExpiration, ReadXdr, ScError,
@@ -28,6 +28,8 @@ extern "C" {
 pub(crate) enum Error {
     #[error("not found")]
     NotFound,
+    #[error("entry expired")]
+    EntryExpired,
     #[error("xdr processing error: {0}")]
     Xdr(#[from] XdrError),
     #[error("nul error: {0}")]
@@ -43,7 +45,9 @@ pub(crate) enum Error {
 impl From<Error> for HostError {
     fn from(value: Error) -> Self {
         match value {
-            Error::NotFound => ScError::Storage(ScErrorCode::MissingValue).into(),
+            Error::NotFound | Error::EntryExpired => {
+                ScError::Storage(ScErrorCode::MissingValue).into()
+            }
             Error::Xdr(_) => ScError::Value(ScErrorCode::InvalidInput).into(),
             _ => ScError::Context(ScErrorCode::InternalError).into(),
         }
@@ -182,7 +186,7 @@ impl LedgerStorage {
             && expiration_seq.is_some()
             && has_expired(expiration_seq.unwrap(), self.current_ledger_sequence)
         {
-            return Err(Error::NotFound);
+            return Err(Error::EntryExpired);
         }
 
         let entry = LedgerEntry::from_xdr(xdr)?;
@@ -227,28 +231,35 @@ impl LedgerStorage {
 
 impl SnapshotSource for LedgerStorage {
     fn get(&self, key: &Rc<LedgerKey>) -> Result<(Rc<LedgerEntry>, Option<u32>), HostError> {
-        let mut entry_and_expiration =
-            <LedgerStorage>::get(self, key, self.restore_tracker.is_some())?;
         if let Some(ref tracker) = self.restore_tracker {
+            let mut entry_and_expiration = self.get(key, true)?;
+            // Explicitly discard temporary expired entries
+            if let Ok(expirable_entry) =
+                TryInto::<Box<dyn ExpirableLedgerEntry>>::try_into(&entry_and_expiration)
+            {
+                if expirable_entry.durability() == Temporary
+                    && expirable_entry.has_expired(self.current_ledger_sequence)
+                {
+                    return Err(HostError::from(Error::EntryExpired));
+                }
+            }
             // If the entry expired, we modify the expiration to make it seem like it was restored
             entry_and_expiration.1 =
                 tracker.track_and_restore(self.current_ledger_sequence, key, &entry_and_expiration);
+            return Ok((entry_and_expiration.0.into(), entry_and_expiration.1));
         }
-        Ok((entry_and_expiration.0.into(), entry_and_expiration.1))
+        let entry_and_expiration =
+            <LedgerStorage>::get(self, key, false).map_err(HostError::from)?;
+        return Ok((entry_and_expiration.0.into(), entry_and_expiration.1));
     }
 
     fn has(&self, key: &Rc<LedgerKey>) -> Result<bool, HostError> {
-        let entry_and_expiration =
-            match <LedgerStorage>::get(self, key, self.restore_tracker.is_some()) {
-                Err(e) => match e {
-                    Error::NotFound => return Ok(false),
-                    _ => return Err(HostError::from(e)),
-                },
-                Ok(le) => le,
-            };
-        if let Some(ref tracker) = self.restore_tracker {
-            _ = tracker.track_and_restore(self.current_ledger_sequence, key, &entry_and_expiration);
+        let result = <dyn SnapshotSource>::get(self, key);
+        if let Err(ref host_error) = result {
+            if host_error.error.is_code(ScErrorCode::MissingValue) {
+                return Ok(false);
+            }
         }
-        Ok(true)
+        return result.map(|_| true);
     }
 }