Rename AppendVecId to AccountsFileId (anza-xyz#383)

#### Problem
The current AppendVecId actually refers to an accounts file id.

#### Summary of Changes
Rename AppendVecId to AccountsFileId.

#### Test Plan
Build

accounts-db/src/account_info.rs

@@ -4,7 +4,7 @@
 //! Note that AccountInfo is saved to disk buckets during runtime, but disk buckets are recreated at startup.
 use {
     crate::{
-        accounts_db::AppendVecId,
+        accounts_db::AccountsFileId,
         accounts_file::ALIGN_BOUNDARY_OFFSET,
         accounts_index::{IsCached, ZeroLamport},
     },
@@ -21,7 +21,7 @@ pub type StoredSize = u32;
 /// specify where account data is located
 #[derive(Debug, PartialEq, Eq)]
 pub enum StorageLocation {
-    AppendVec(AppendVecId, Offset),
+    AppendVec(AccountsFileId, Offset),
     Cached,
 }
 
@@ -85,7 +85,7 @@ pub struct PackedOffsetAndFlags {
 #[derive(Default, Debug, PartialEq, Eq, Clone, Copy)]
 pub struct AccountInfo {
     /// index identifying the append storage
-    store_id: AppendVecId,
+    store_id: AccountsFileId,
 
     account_offset_and_flags: AccountOffsetAndFlags,
 }
@@ -121,7 +121,7 @@ impl IsCached for StorageLocation {
 }
 
 /// We have to have SOME value for store_id when we are cached
-const CACHE_VIRTUAL_STORAGE_ID: AppendVecId = AppendVecId::MAX;
+const CACHE_VIRTUAL_STORAGE_ID: AccountsFileId = AccountsFileId::MAX;
 
 impl AccountInfo {
     pub fn new(storage_location: StorageLocation, lamports: u64) -> Self {
@@ -160,7 +160,7 @@ impl AccountInfo {
         (offset / ALIGN_BOUNDARY_OFFSET) as OffsetReduced
     }
 
-    pub fn store_id(&self) -> AppendVecId {
+    pub fn store_id(&self) -> AccountsFileId {
         // if the account is in a cached store, the store_id is meaningless
         assert!(!self.is_cached());
         self.store_id

accounts-db/src/account_storage.rs

@@ -1,7 +1,7 @@
 //! Manage the map of slot -> append vec
 
 use {
-    crate::accounts_db::{AccountStorageEntry, AppendVecId},
+    crate::accounts_db::{AccountStorageEntry, AccountsFileId},
     dashmap::DashMap,
     solana_sdk::clock::Slot,
     std::sync::Arc,
@@ -15,7 +15,7 @@ pub struct AccountStorageReference {
     pub storage: Arc<AccountStorageEntry>,
     /// id can be read from 'storage', but it is an atomic read.
     /// id will never change while a storage is held, so we store it separately here for faster runtime lookup in 'get_account_storage_entry'
-    pub id: AppendVecId,
+    pub id: AccountsFileId,
 }
 
 pub type AccountStorageMap = DashMap<Slot, AccountStorageReference>;
@@ -50,7 +50,7 @@ impl AccountStorage {
     pub(crate) fn get_account_storage_entry(
         &self,
         slot: Slot,
-        store_id: AppendVecId,
+        store_id: AccountsFileId,
     ) -> Option<Arc<AccountStorageEntry>> {
         let lookup_in_map = || {
             self.map
@@ -343,7 +343,7 @@ pub(crate) mod tests {
     }
 
     impl AccountStorage {
-        fn get_test_storage_with_id(&self, id: AppendVecId) -> Arc<AccountStorageEntry> {
+        fn get_test_storage_with_id(&self, id: AccountsFileId) -> Arc<AccountStorageEntry> {
             let slot = 0;
             // add a map store
             let common_store_path = Path::new("");

accounts-db/src/accounts_db.rs

@@ -637,7 +637,7 @@ struct StorageSizeAndCount {
     /// number of accounts in the storage including both alive and dead accounts
     pub count: usize,
 }
-type StorageSizeAndCountMap = DashMap<AppendVecId, StorageSizeAndCount>;
+type StorageSizeAndCountMap = DashMap<AccountsFileId, StorageSizeAndCount>;
 
 impl GenerateIndexTimings {
     pub fn report(&self, startup_stats: &StartupStats) {
@@ -764,8 +764,8 @@ impl<'a> MultiThreadProgress<'a> {
 }
 
 /// An offset into the AccountsDb::storage vector
-pub type AtomicAppendVecId = AtomicU32;
-pub type AppendVecId = u32;
+pub type AtomicAccountsFileId = AtomicU32;
+pub type AccountsFileId = u32;
 
 type AccountSlots = HashMap<Pubkey, HashSet<Slot>>;
 type SlotOffsets = HashMap<Slot, HashSet<usize>>;
@@ -1005,7 +1005,7 @@ struct CleanKeyTimings {
 /// Persistent storage structure holding the accounts
 #[derive(Debug)]
 pub struct AccountStorageEntry {
-    pub(crate) id: AppendVecId,
+    pub(crate) id: AccountsFileId,
 
     pub(crate) slot: Slot,
 
@@ -1031,7 +1031,7 @@ pub struct AccountStorageEntry {
 }
 
 impl AccountStorageEntry {
-    pub fn new(path: &Path, slot: Slot, id: AppendVecId, file_size: u64) -> Self {
+    pub fn new(path: &Path, slot: Slot, id: AccountsFileId, file_size: u64) -> Self {
         let tail = AccountsFile::file_name(slot, id);
         let path = Path::new(path).join(tail);
         let accounts = AccountsFile::AppendVec(AppendVec::new(&path, true, file_size as usize));
@@ -1048,7 +1048,7 @@ impl AccountStorageEntry {
 
     pub fn new_existing(
         slot: Slot,
-        id: AppendVecId,
+        id: AccountsFileId,
         accounts: AccountsFile,
         num_accounts: usize,
     ) -> Self {
@@ -1115,7 +1115,7 @@ impl AccountStorageEntry {
         self.slot
     }
 
-    pub fn append_vec_id(&self) -> AppendVecId {
+    pub fn append_vec_id(&self) -> AccountsFileId {
         self.id
     }
 
@@ -1297,7 +1297,7 @@ pub struct AccountsDb {
     read_only_accounts_cache: ReadOnlyAccountsCache,
 
     /// distribute the accounts across storage lists
-    pub next_id: AtomicAppendVecId,
+    pub next_id: AtomicAccountsFileId,
 
     /// Set of shrinkable stores organized by map of slot to append_vec_id
     pub shrink_candidate_slots: Mutex<ShrinkCandidates>,
@@ -2336,7 +2336,7 @@ impl AccountsDb {
                 READ_ONLY_CACHE_MS_TO_SKIP_LRU_UPDATE,
             ),
             uncleaned_pubkeys: DashMap::new(),
-            next_id: AtomicAppendVecId::new(0),
+            next_id: AtomicAccountsFileId::new(0),
             shrink_candidate_slots: Mutex::new(ShrinkCandidates::default()),
             write_cache_limit_bytes: None,
             write_version: AtomicU64::new(0),
@@ -2504,9 +2504,12 @@ impl AccountsDb {
         self.base_working_path.clone()
     }
 
-    fn next_id(&self) -> AppendVecId {
+    fn next_id(&self) -> AccountsFileId {
         let next_id = self.next_id.fetch_add(1, Ordering::AcqRel);
-        assert!(next_id != AppendVecId::MAX, "We've run out of storage ids!");
+        assert!(
+            next_id != AccountsFileId::MAX,
+            "We've run out of storage ids!"
+        );
         next_id
     }
 
@@ -6322,9 +6325,9 @@ impl AccountsDb {
     /// This runs prior to the storages being put in AccountsDb.storage
     pub fn combine_multiple_slots_into_one_at_startup(
         path: &Path,
-        id: AppendVecId,
+        id: AccountsFileId,
         slot: Slot,
-        slot_stores: &HashMap<AppendVecId, Arc<AccountStorageEntry>>,
+        slot_stores: &HashMap<AccountsFileId, Arc<AccountStorageEntry>>,
     ) -> Arc<AccountStorageEntry> {
         let size = slot_stores.values().map(|storage| storage.capacity()).sum();
         let storage = AccountStorageEntry::new(path, slot, id, size);
@@ -8641,7 +8644,7 @@ impl AccountsDb {
         &self,
         storage: &Arc<AccountStorageEntry>,
         slot: Slot,
-        store_id: AppendVecId,
+        store_id: AccountsFileId,
         rent_collector: &RentCollector,
         storage_info: &StorageSizeAndCountMap,
     ) -> SlotIndexGenerationInfo {
@@ -9609,7 +9612,7 @@ pub mod tests {
 
     impl CurrentAncientAppendVec {
         /// note this requires that 'slot_and_append_vec' is Some
-        fn append_vec_id(&self) -> AppendVecId {
+        fn append_vec_id(&self) -> AccountsFileId {
             self.append_vec().append_vec_id()
         }
     }
@@ -10782,7 +10785,7 @@ pub mod tests {
         write_version: StoredMetaWriteVersion,
         slot: Slot,
         pubkey: &Pubkey,
-        id: AppendVecId,
+        id: AccountsFileId,
         mark_alive: bool,
         account_data_size: Option<u64>,
         fill_percentage: u64,
@@ -10808,7 +10811,7 @@ pub mod tests {
         write_version: StoredMetaWriteVersion,
         slot: Slot,
         pubkey: &Pubkey,
-        id: AppendVecId,
+        id: AccountsFileId,
         mark_alive: bool,
         account_data_size: Option<u64>,
     ) -> Arc<AccountStorageEntry> {
@@ -13313,7 +13316,7 @@ pub mod tests {
             AccountSharedData::new(0, 0, AccountSharedData::default().owner());
 
         // set 'next' id to the max possible value
-        db.next_id.store(AppendVecId::MAX, Ordering::Release);
+        db.next_id.store(AccountsFileId::MAX, Ordering::Release);
         let slots = 3;
         let keys = (0..slots).map(|_| Pubkey::new_unique()).collect::<Vec<_>>();
         // write unique keys to successive slots
@@ -13340,7 +13343,7 @@ pub mod tests {
             AccountSharedData::new(0, 0, AccountSharedData::default().owner());
 
         // set 'next' id to the max possible value
-        db.next_id.store(AppendVecId::MAX, Ordering::Release);
+        db.next_id.store(AccountsFileId::MAX, Ordering::Release);
         let slots = 3;
         let keys = (0..slots).map(|_| Pubkey::new_unique()).collect::<Vec<_>>();
         // write unique keys to successive slots
@@ -13350,7 +13353,7 @@ pub mod tests {
             db.calculate_accounts_delta_hash(slot);
             db.add_root_and_flush_write_cache(slot);
             // reset next_id to what it was previously to cause us to re-use the same id
-            db.next_id.store(AppendVecId::MAX, Ordering::Release);
+            db.next_id.store(AccountsFileId::MAX, Ordering::Release);
         });
         let ancestors = Ancestors::default();
         keys.iter().for_each(|key| {
@@ -17236,7 +17239,7 @@ pub mod tests {
             .max()
             .unwrap_or(999);
         for (i, account_data_size) in account_data_sizes.iter().enumerate().take(num_slots) {
-            let id = starting_id + (i as AppendVecId);
+            let id = starting_id + (i as AccountsFileId);
             let pubkey1 = solana_sdk::pubkey::new_rand();
             let storage = sample_storage_with_entries_id_fill_percentage(
                 tf,
@@ -17285,7 +17288,7 @@ pub mod tests {
             .max()
             .unwrap_or(999);
         for i in 0..num_slots {
-            let id = starting_id + (i as AppendVecId);
+            let id = starting_id + (i as AccountsFileId);
             let pubkey1 = solana_sdk::pubkey::new_rand();
             let storage = sample_storage_with_entries_id(
                 tf,

accounts-db/src/accounts_file.rs

@@ -3,7 +3,7 @@ use {
         account_storage::meta::{
             StorableAccountsWithHashesAndWriteVersions, StoredAccountInfo, StoredAccountMeta,
         },
-        accounts_db::AppendVecId,
+        accounts_db::AccountsFileId,
         accounts_hash::AccountHash,
         append_vec::{AppendVec, AppendVecError},
         storable_accounts::StorableAccounts,
@@ -104,7 +104,7 @@ impl AccountsFile {
         }
     }
 
-    pub fn file_name(slot: Slot, id: AppendVecId) -> String {
+    pub fn file_name(slot: Slot, id: AccountsFileId) -> String {
         format!("{slot}.{id}")
     }
 

accounts-db/src/sorted_storages.rs

@@ -195,7 +195,7 @@ mod tests {
     use {
         super::*,
         crate::{
-            accounts_db::{AccountStorageEntry, AppendVecId},
+            accounts_db::{AccountStorageEntry, AccountsFileId},
             accounts_file::AccountsFile,
             append_vec::AppendVec,
         },
@@ -297,7 +297,7 @@ mod tests {
             assert!(
                 (slot != 2 && slot != 4)
                     ^ storage
-                        .map(|storage| storage.append_vec_id() == (slot as AppendVecId))
+                        .map(|storage| storage.append_vec_id() == (slot as AccountsFileId))
                         .unwrap_or(false),
                 "slot: {slot}, storage: {storage:?}"
             );
@@ -440,7 +440,7 @@ mod tests {
         );
     }
 
-    fn create_sample_store(id: AppendVecId) -> Arc<AccountStorageEntry> {
+    fn create_sample_store(id: AccountsFileId) -> Arc<AccountStorageEntry> {
         let tf = crate::append_vec::test_utils::get_append_vec_path("create_sample_store");
         let (_temp_dirs, paths) = crate::accounts_db::get_temp_accounts_paths(1).unwrap();
         let size: usize = 123;

docs/src/implemented-proposals/persistent-account-storage.md

@@ -19,11 +19,11 @@ The underlying memory for an AppendVec is a memory-mapped file. Memory-mapped fi
 The account index is designed to support a single index for all the currently forked Accounts.
 
 ```text
-type AppendVecId = usize;
+type AccountsFileId = usize;
 
 type Fork = u64;
 
-struct AccountMap(Hashmap<Fork, (AppendVecId, u64)>);
+struct AccountMap(Hashmap<Fork, (AccountsFileId, u64)>);
 
 type AccountIndex = HashMap<Pubkey, AccountMap>;
 ```
@@ -39,7 +39,7 @@ The index is a map of account Pubkeys to a map of Forks and the location of the
 pub fn load_slow(&self, id: Fork, pubkey: &Pubkey) -> Option<&Account>
 ```
 
-The read is satisfied by pointing to a memory-mapped location in the `AppendVecId` at the stored offset. A reference can be returned without a copy.
+The read is satisfied by pointing to a memory-mapped location in the `AccountsFileId` at the stored offset. A reference can be returned without a copy.
 
 ### Root Forks
 

runtime/src/bank/serde_snapshot.rs

@@ -14,7 +14,7 @@ mod tests {
             snapshot_bank_utils,
             snapshot_utils::{
                 self, create_tmp_accounts_dir_for_tests, get_storages_to_serialize, ArchiveFormat,
-                StorageAndNextAppendVecId, BANK_SNAPSHOT_PRE_FILENAME_EXTENSION,
+                StorageAndNextAccountsFileId, BANK_SNAPSHOT_PRE_FILENAME_EXTENSION,
             },
             status_cache::StatusCache,
         },
@@ -23,7 +23,7 @@ mod tests {
             account_storage::{AccountStorageMap, AccountStorageReference},
             accounts_db::{
                 get_temp_accounts_paths, AccountShrinkThreshold, AccountStorageEntry, AccountsDb,
-                AtomicAppendVecId,
+                AtomicAccountsFileId,
             },
             accounts_file::{AccountsFile, AccountsFileError},
             accounts_hash::{AccountsDeltaHash, AccountsHash},
@@ -53,7 +53,7 @@ mod tests {
     fn copy_append_vecs<P: AsRef<Path>>(
         accounts_db: &AccountsDb,
         output_dir: P,
-    ) -> Result<StorageAndNextAppendVecId, AccountsFileError> {
+    ) -> Result<StorageAndNextAccountsFileId, AccountsFileError> {
         let storage_entries = accounts_db.get_snapshot_storages(RangeFull).0;
         let storage: AccountStorageMap = AccountStorageMap::with_capacity(storage_entries.len());
         let mut next_append_vec_id = 0;
@@ -84,9 +84,9 @@ mod tests {
             );
         }
 
-        Ok(StorageAndNextAppendVecId {
+        Ok(StorageAndNextAccountsFileId {
             storage,
-            next_append_vec_id: AtomicAppendVecId::new(next_append_vec_id + 1),
+            next_append_vec_id: AtomicAccountsFileId::new(next_append_vec_id + 1),
         })
     }