Abstract out StoredAccountMeta as an Enum (#30478)

#### Problem
The existing StoredAccountMeta requires the file and in-memory layout of
account metadata to match StoredMeta and AccountMeta.  This limits the
flexibility to implement different accounts storage file formats.

#### Summary of Changes
This PR abstracts out StoredAccountMeta as an Enum.

runtime/src/account_storage/meta.rs

@@ -1,7 +1,7 @@
 use {
-    crate::storable_accounts::StorableAccounts,
+    crate::{append_vec::AppendVecStoredAccountMeta, storable_accounts::StorableAccounts},
     solana_sdk::{
-        account::{Account, AccountSharedData, ReadableAccount},
+        account::{AccountSharedData, ReadableAccount},
         hash::Hash,
         pubkey::Pubkey,
         stake_history::Epoch,
@@ -103,95 +103,104 @@ impl<'a: 'b, 'b, T: ReadableAccount + Sync + 'b, U: StorableAccounts<'a, T>, V:
 /// References to account data stored elsewhere. Getting an `Account` requires cloning
 /// (see `StoredAccountMeta::clone_account()`).
 #[derive(PartialEq, Eq, Debug)]
-pub struct StoredAccountMeta<'a> {
+pub enum StoredAccountMeta<'a> {
-    pub(crate) meta: &'a StoredMeta,
+    AppendVec(AppendVecStoredAccountMeta<'a>),
-    /// account data
-    pub(crate) account_meta: &'a AccountMeta,
-    pub(crate) data: &'a [u8],
-    pub(crate) offset: usize,
-    pub(crate) stored_size: usize,
-    pub(crate) hash: &'a Hash,
 }
 
 impl<'a> StoredAccountMeta<'a> {
     /// Return a new Account by copying all the data referenced by the `StoredAccountMeta`.
     pub fn clone_account(&self) -> AccountSharedData {
-        AccountSharedData::from(Account {
+        match self {
-            lamports: self.account_meta.lamports,
+            Self::AppendVec(av) => av.clone_account(),
-            owner: self.account_meta.owner,
+        }
-            executable: self.account_meta.executable,
-            rent_epoch: self.account_meta.rent_epoch,
-            data: self.data.to_vec(),
-        })
     }
 
     pub fn pubkey(&self) -> &'a Pubkey {
-        &self.meta.pubkey
+        match self {
+            Self::AppendVec(av) => av.pubkey(),
+        }
     }
 
     pub fn hash(&self) -> &'a Hash {
-        self.hash
+        match self {
+            Self::AppendVec(av) => av.hash(),
+        }
     }
 
     pub fn stored_size(&self) -> usize {
-        self.stored_size
+        match self {
+            Self::AppendVec(av) => av.stored_size(),
+        }
     }
 
     pub fn offset(&self) -> usize {
-        self.offset
+        match self {
+            Self::AppendVec(av) => av.offset(),
+        }
     }
 
     pub fn data(&self) -> &'a [u8] {
-        self.data
+        match self {
+            Self::AppendVec(av) => av.data(),
+        }
     }
 
     pub fn data_len(&self) -> u64 {
-        self.meta.data_len
+        match self {
+            Self::AppendVec(av) => av.data_len(),
+        }
     }
 
     pub fn write_version(&self) -> StoredMetaWriteVersion {
-        self.meta.write_version_obsolete
+        match self {
+            Self::AppendVec(av) => av.write_version(),
+        }
+    }
+
+    pub fn meta(&self) -> &StoredMeta {
+        match self {
+            Self::AppendVec(av) => av.meta(),
+        }
+    }
+
+    pub fn set_meta(&mut self, meta: &'a StoredMeta) {
+        match self {
+            Self::AppendVec(av) => av.set_meta(meta),
+        }
     }
 
     pub(crate) fn sanitize(&self) -> bool {
-        self.sanitize_executable() && self.sanitize_lamports()
+        match self {
+            Self::AppendVec(av) => av.sanitize(),
         }
-
-    pub(crate) fn sanitize_executable(&self) -> bool {
-        // Sanitize executable to ensure higher 7-bits are cleared correctly.
-        self.ref_executable_byte() & !1 == 0
-    }
-
-    pub(crate) fn sanitize_lamports(&self) -> bool {
-        // Sanitize 0 lamports to ensure to be same as AccountSharedData::default()
-        self.account_meta.lamports != 0 || self.clone_account() == AccountSharedData::default()
-    }
-
-    pub(crate) fn ref_executable_byte(&self) -> &'a u8 {
-        // Use extra references to avoid value silently clamped to 1 (=true) and 0 (=false)
-        // Yes, this really happens; see test_new_from_file_crafted_executable
-        let executable_bool: &bool = &self.account_meta.executable;
-        // UNSAFE: Force to interpret mmap-backed bool as u8 to really read the actual memory content
-        let executable_byte: &u8 = unsafe { &*(executable_bool as *const bool as *const u8) };
-        executable_byte
     }
 }
 
 impl<'a> ReadableAccount for StoredAccountMeta<'a> {
     fn lamports(&self) -> u64 {
-        self.account_meta.lamports
+        match self {
+            Self::AppendVec(av) => av.lamports(),
+        }
     }
     fn data(&self) -> &[u8] {
-        self.data()
+        match self {
+            Self::AppendVec(av) => av.data(),
+        }
     }
     fn owner(&self) -> &Pubkey {
-        &self.account_meta.owner
+        match self {
+            Self::AppendVec(av) => av.owner(),
+        }
     }
     fn executable(&self) -> bool {
-        self.account_meta.executable
+        match self {
+            Self::AppendVec(av) => av.executable(),
+        }
     }
     fn rent_epoch(&self) -> Epoch {
-        self.account_meta.rent_epoch
+        match self {
+            Self::AppendVec(av) => av.rent_epoch(),
+        }
     }
 }
 

runtime/src/accounts_db.rs

@@ -7976,7 +7976,7 @@ impl AccountsDb {
                 );
                 let offset = account_info.offset();
                 let account = store.accounts.get_account(offset).unwrap();
-                let stored_size = account.0.stored_size;
+                let stored_size = account.0.stored_size();
                 let count = store.remove_account(stored_size, reset_accounts);
                 if count == 0 {
                     self.dirty_stores.insert(*slot, store.clone());
@@ -9454,7 +9454,7 @@ pub mod tests {
                 tests::*, AccountIndex, AccountSecondaryIndexes,
                 AccountSecondaryIndexesIncludeExclude, ReadAccountMapEntry, RefCount,
             },
-            append_vec::test_utils::TempFile,
+            append_vec::{test_utils::TempFile, AppendVecStoredAccountMeta},
             cache_hash_data_stats::CacheHashDataStats,
             inline_spl_token,
             secondary_index::MAX_NUM_LARGEST_INDEX_KEYS_RETURNED,
@@ -9664,7 +9664,7 @@ pub mod tests {
             pubkey,
             data_len: 43,
         };
-        let account = StoredAccountMeta {
+        let account = StoredAccountMeta::AppendVec(AppendVecStoredAccountMeta {
             meta: &stored_meta,
             /// account data
             account_meta: &account_meta,
@@ -9672,7 +9672,7 @@ pub mod tests {
             offset,
             stored_size: account_size,
             hash: &hash,
-        };
+        });
         let map = vec![&account];
         let alive_total_bytes = account.stored_size();
         let to_store = AccountsToStore::new(available_bytes, &map, alive_total_bytes, slot0);
@@ -9760,38 +9760,38 @@ pub mod tests {
         let offset = 99;
         let stored_size = 101;
         let hash = Hash::new_unique();
-        let stored_account = StoredAccountMeta {
+        let stored_account = StoredAccountMeta::AppendVec(AppendVecStoredAccountMeta {
             meta: &meta,
             account_meta: &account_meta,
             data: &data,
             offset,
             stored_size,
             hash: &hash,
-        };
+        });
-        let stored_account2 = StoredAccountMeta {
+        let stored_account2 = StoredAccountMeta::AppendVec(AppendVecStoredAccountMeta {
             meta: &meta2,
             account_meta: &account_meta,
             data: &data,
             offset,
             stored_size,
             hash: &hash,
-        };
+        });
-        let stored_account3 = StoredAccountMeta {
+        let stored_account3 = StoredAccountMeta::AppendVec(AppendVecStoredAccountMeta {
             meta: &meta3,
             account_meta: &account_meta,
             data: &data,
             offset,
             stored_size,
             hash: &hash,
-        };
+        });
-        let stored_account4 = StoredAccountMeta {
+        let stored_account4 = StoredAccountMeta::AppendVec(AppendVecStoredAccountMeta {
             meta: &meta4,
             account_meta: &account_meta,
             data: &data,
             offset,
             stored_size,
             hash: &hash,
-        };
+        });
         let mut existing_ancient_pubkeys = HashSet::default();
         let accounts = [&stored_account];
         // pubkey NOT in existing_ancient_pubkeys, so do NOT unref, but add to existing_ancient_pubkeys
@@ -12382,14 +12382,14 @@ pub mod tests {
         let offset = 99;
         let stored_size = 101;
         let hash = Hash::new_unique();
-        let stored_account = StoredAccountMeta {
+        let stored_account = StoredAccountMeta::AppendVec(AppendVecStoredAccountMeta {
             meta: &meta,
             account_meta: &account_meta,
             data: &data,
             offset,
             stored_size,
             hash: &hash,
-        };
+        });
         assert!(accounts_equal(&account, &stored_account));
     }
 
@@ -12426,14 +12426,14 @@ pub mod tests {
         let (slot, meta, account_meta, data, offset, hash): InputTuple =
             unsafe { std::mem::transmute::<InputBlob, InputTuple>(blob) };
 
-        let stored_account = StoredAccountMeta {
+        let stored_account = StoredAccountMeta::AppendVec(AppendVecStoredAccountMeta {
             meta: &meta,
             account_meta: &account_meta,
             data: &data,
             offset,
             stored_size: CACHE_VIRTUAL_STORED_SIZE as usize,
             hash: &hash,
-        };
+        });
         let account = stored_account.clone_account();
 
         let expected_account_hash = if cfg!(debug_assertions) {

runtime/src/accounts_db/geyser_plugin_utils.rs

@@ -138,9 +138,9 @@ impl AccountsDb {
             // Passing 0 for everyone's write_version is sufficiently correct.
             let meta = StoredMeta {
                 write_version_obsolete: local_write_version,
-                ..*account.meta
+                ..*account.meta()
             };
-            account.meta = &meta;
+            account.set_meta(&meta);
             let mut measure_pure_notify = Measure::start("accountsdb-plugin-notifying-accounts");
             notifier.notify_account_restore_from_snapshot(slot, &account);
             measure_pure_notify.stop();

runtime/src/ancient_append_vecs.rs

@@ -770,7 +770,7 @@ pub mod tests {
                 },
                 INCLUDE_SLOT_IN_HASH_TESTS,
             },
-            append_vec::{aligned_stored_size, AppendVec},
+            append_vec::{aligned_stored_size, AppendVec, AppendVecStoredAccountMeta},
             storable_accounts::StorableAccountsBySlot,
         },
         solana_sdk::{
@@ -1618,7 +1618,7 @@ pub mod tests {
             pubkey,
             data_len: 43,
         };
-        let account = StoredAccountMeta {
+        let account = StoredAccountMeta::AppendVec(AppendVecStoredAccountMeta {
             meta: &stored_meta,
             /// account data
             account_meta: &account_meta,
@@ -1626,7 +1626,7 @@ pub mod tests {
             offset,
             stored_size: account_size,
             hash: &hash,
-        };
+        });
         let map = vec![&account];
         for (selector, available_bytes) in [
             (StorageSelector::Primary, account_size),

runtime/src/append_vec.rs

@@ -8,13 +8,19 @@ use {
     crate::{
         account_storage::meta::{
             AccountMeta, StorableAccountsWithHashesAndWriteVersions, StoredAccountInfo,
-            StoredAccountMeta, StoredMeta,
+            StoredAccountMeta, StoredMeta, StoredMetaWriteVersion,
         },
         storable_accounts::StorableAccounts,
     },
     log::*,
     memmap2::MmapMut,
-    solana_sdk::{account::ReadableAccount, clock::Slot, hash::Hash, pubkey::Pubkey},
+    solana_sdk::{
+        account::{Account, AccountSharedData, ReadableAccount},
+        clock::Slot,
+        hash::Hash,
+        pubkey::Pubkey,
+        stake_history::Epoch,
+    },
     std::{
         borrow::Borrow,
         convert::TryFrom,
@@ -89,6 +95,108 @@ pub enum MatchAccountOwnerError {
     UnableToLoad,
 }
 
+/// References to account data stored elsewhere. Getting an `Account` requires cloning
+/// (see `StoredAccountMeta::clone_account()`).
+#[derive(PartialEq, Eq, Debug)]
+pub struct AppendVecStoredAccountMeta<'a> {
+    pub meta: &'a StoredMeta,
+    /// account data
+    pub account_meta: &'a AccountMeta,
+    pub(crate) data: &'a [u8],
+    pub(crate) offset: usize,
+    pub(crate) stored_size: usize,
+    pub(crate) hash: &'a Hash,
+}
+
+impl<'a> AppendVecStoredAccountMeta<'a> {
+    pub fn clone_account(&self) -> AccountSharedData {
+        AccountSharedData::from(Account {
+            lamports: self.account_meta.lamports,
+            owner: self.account_meta.owner,
+            executable: self.account_meta.executable,
+            rent_epoch: self.account_meta.rent_epoch,
+            data: self.data.to_vec(),
+        })
+    }
+
+    pub fn pubkey(&self) -> &'a Pubkey {
+        &self.meta.pubkey
+    }
+
+    pub fn hash(&self) -> &'a Hash {
+        self.hash
+    }
+
+    pub fn stored_size(&self) -> usize {
+        self.stored_size
+    }
+
+    pub fn offset(&self) -> usize {
+        self.offset
+    }
+
+    pub fn data(&self) -> &'a [u8] {
+        self.data
+    }
+
+    pub fn data_len(&self) -> u64 {
+        self.meta.data_len
+    }
+
+    pub fn write_version(&self) -> StoredMetaWriteVersion {
+        self.meta.write_version_obsolete
+    }
+
+    pub fn meta(&self) -> &StoredMeta {
+        self.meta
+    }
+
+    pub fn set_meta(&mut self, meta: &'a StoredMeta) {
+        self.meta = meta;
+    }
+
+    pub(crate) fn sanitize(&self) -> bool {
+        self.sanitize_executable() && self.sanitize_lamports()
+    }
+
+    fn sanitize_executable(&self) -> bool {
+        // Sanitize executable to ensure higher 7-bits are cleared correctly.
+        self.ref_executable_byte() & !1 == 0
+    }
+
+    fn sanitize_lamports(&self) -> bool {
+        // Sanitize 0 lamports to ensure to be same as AccountSharedData::default()
+        self.account_meta.lamports != 0 || self.clone_account() == AccountSharedData::default()
+    }
+
+    fn ref_executable_byte(&self) -> &u8 {
+        // Use extra references to avoid value silently clamped to 1 (=true) and 0 (=false)
+        // Yes, this really happens; see test_new_from_file_crafted_executable
+        let executable_bool: &bool = &self.account_meta.executable;
+        // UNSAFE: Force to interpret mmap-backed bool as u8 to really read the actual memory content
+        let executable_byte: &u8 = unsafe { &*(executable_bool as *const bool as *const u8) };
+        executable_byte
+    }
+}
+
+impl<'a> ReadableAccount for AppendVecStoredAccountMeta<'a> {
+    fn lamports(&self) -> u64 {
+        self.account_meta.lamports
+    }
+    fn data(&self) -> &[u8] {
+        self.data()
+    }
+    fn owner(&self) -> &Pubkey {
+        &self.account_meta.owner
+    }
+    fn executable(&self) -> bool {
+        self.account_meta.executable
+    }
+    fn rent_epoch(&self) -> Epoch {
+        self.account_meta.rent_epoch
+    }
+}
+
 /// A thread-safe, file-backed block of memory used to store `Account` instances. Append operations
 /// are serialized such that only one thread updates the internal `append_lock` at a time. No
 /// restrictions are placed on reading. That is, one may read items from one thread while another
@@ -401,14 +509,14 @@ impl AppendVec {
         let (data, next) = self.get_slice(next, meta.data_len as usize)?;
         let stored_size = next - offset;
         Some((
-            StoredAccountMeta {
+            StoredAccountMeta::AppendVec(AppendVecStoredAccountMeta {
                 meta,
                 account_meta,
                 data,
                 offset,
                 stored_size,
                 hash,
-            },
+            }),
             next,
         ))
     }
@@ -450,7 +558,7 @@ impl AppendVec {
         offset: usize,
     ) -> Option<(StoredMeta, solana_sdk::account::AccountSharedData)> {
         let (stored_account, _) = self.get_account(offset)?;
-        let meta = stored_account.meta.clone();
+        let meta = stored_account.meta().clone();
         Some((meta, stored_account.clone_account()))
     }
 
@@ -593,6 +701,14 @@ pub mod tests {
     }
 
     impl<'a> StoredAccountMeta<'a> {
+        pub(crate) fn ref_executable_byte(&self) -> &u8 {
+            match self {
+                Self::AppendVec(av) => av.ref_executable_byte(),
+            }
+        }
+    }
+
+    impl<'a> AppendVecStoredAccountMeta<'a> {
         #[allow(clippy::cast_ref_to_mut)]
         fn set_data_len_unsafe(&self, new_data_len: u64) {
             // UNSAFE: cast away & (= const ref) to &mut to force to mutate append-only (=read-only) AppendVec
@@ -1071,7 +1187,7 @@ pub mod tests {
         av.append_account_test(&create_test_account(10)).unwrap();
 
         let accounts = av.accounts(0);
-        let account = accounts.first().unwrap();
+        let StoredAccountMeta::AppendVec(account) = accounts.first().unwrap();
         account.set_data_len_unsafe(crafted_data_len);
         assert_eq!(account.data_len(), crafted_data_len);
 
@@ -1098,7 +1214,7 @@ pub mod tests {
         av.append_account_test(&create_test_account(10)).unwrap();
 
         let accounts = av.accounts(0);
-        let account = accounts.first().unwrap();
+        let StoredAccountMeta::AppendVec(account) = accounts.first().unwrap();
         account.set_data_len_unsafe(too_large_data_len);
         assert_eq!(account.data_len(), too_large_data_len);
 
@@ -1133,14 +1249,14 @@ pub mod tests {
         assert_eq!(*accounts[0].ref_executable_byte(), 0);
         assert_eq!(*accounts[1].ref_executable_byte(), 1);
 
-        let account = &accounts[0];
+        let StoredAccountMeta::AppendVec(account) = &accounts[0];
         let crafted_executable = u8::max_value() - 1;
 
         account.set_executable_as_byte(crafted_executable);
 
         // reload crafted accounts
         let accounts = av.accounts(0);
-        let account = accounts.first().unwrap();
+        let StoredAccountMeta::AppendVec(account) = accounts.first().unwrap();
 
         // upper 7-bits are not 0, so sanitization should fail
         assert!(!account.sanitize_executable());

runtime/src/storable_accounts.rs

@@ -306,6 +306,7 @@ pub mod tests {
         crate::{
             account_storage::meta::{AccountMeta, StoredAccountMeta, StoredMeta},
             accounts_db::INCLUDE_SLOT_IN_HASH_TESTS,
+            append_vec::AppendVecStoredAccountMeta,
         },
         solana_sdk::{
             account::{accounts_equal, AccountSharedData, WritableAccount},
@@ -353,14 +354,14 @@ pub mod tests {
         let offset = 99;
         let stored_size = 101;
         let hash = Hash::new_unique();
-        let stored_account = StoredAccountMeta {
+        let stored_account = StoredAccountMeta::AppendVec(AppendVecStoredAccountMeta {
             meta: &meta,
             account_meta: &account_meta,
             data: &data,
             offset,
             stored_size,
             hash: &hash,
-        };
+        });
 
         let test3 = (
             slot,
@@ -411,14 +412,14 @@ pub mod tests {
                     for entry in 0..entries {
                         let offset = 99;
                         let stored_size = 101;
-                        raw2.push(StoredAccountMeta {
+                        raw2.push(StoredAccountMeta::AppendVec(AppendVecStoredAccountMeta {
                             meta: &raw[entry as usize].3,
                             account_meta: &raw[entry as usize].4,
                             data: &data,
                             offset,
                             stored_size,
                             hash: &hash,
-                        });
+                        }));
                     }
 
                     let mut two = Vec::new();
@@ -508,14 +509,14 @@ pub mod tests {
             for entry in 0..entries {
                 let offset = 99;
                 let stored_size = 101;
-                raw2.push(StoredAccountMeta {
+                raw2.push(StoredAccountMeta::AppendVec(AppendVecStoredAccountMeta {
                     meta: &raw[entry as usize].2,
                     account_meta: &raw[entry as usize].3,
                     data: &data,
                     offset,
                     stored_size,
                     hash: &hashes[entry as usize],
-                });
+                }));
             }
             let raw2_refs = raw2.iter().collect::<Vec<_>>();