generate_index inserts ideal initial data (#17247)

* improve insert into map initially

* rework towards single code path

* rename

* update test

runtime/src/accounts_index.rs

@@ -179,6 +179,18 @@ impl<T: 'static + Clone + IsCached> WriteAccountMapEntry<T> {
         &self.borrow_owned_entry_contents().ref_count
     }
 
+    // create an entry that is equivalent to this process:
+    // 1. new empty (refcount=0, slot_list={})
+    // 2. update(slot, account_info)
+    // This code is called when the first entry [ie. (slot,account_info)] for a pubkey is inserted into the index.
+    pub fn new_entry_after_update(slot: Slot, account_info: &T) -> AccountMapEntry<T> {
+        let ref_count = if account_info.is_cached() { 0 } else { 1 };
+        Arc::new(AccountMapEntryInner {
+            ref_count: AtomicU64::new(ref_count),
+            slot_list: RwLock::new(vec![(slot, account_info.clone())]),
+        })
+    }
+
     // Try to update an item in the slot list the given `slot` If an item for the slot
     // already exists in the list, remove the older item, add it to `reclaims`, and insert
     // the new item.
@@ -496,7 +508,7 @@ pub trait ZeroLamport {
 }
 
 type MapType<T> = AccountMap<Pubkey, AccountMapEntry<T>>;
-type ReadWriteLockMapType<'a, T> = RwLockWriteGuard<'a, AccountMap<Pubkey, AccountMapEntry<T>>>;
+type AccountMapsWriteLock<'a, T> = RwLockWriteGuard<'a, AccountMap<Pubkey, AccountMapEntry<T>>>;
 
 #[derive(Debug)]
 pub struct AccountsIndex<T> {
@@ -842,47 +854,55 @@ impl<T: 'static + Clone + IsCached + ZeroLamport> AccountsIndex<T> {
             .map(WriteAccountMapEntry::from_account_map_entry)
     }
 
-    fn new_entry() -> AccountMapEntry<T> {
-        Arc::new(AccountMapEntryInner {
-            ref_count: AtomicU64::new(0),
-            slot_list: RwLock::new(SlotList::with_capacity(1)),
-        })
-    }
-
-    fn insert_new_entry_if_missing(&self, pubkey: &Pubkey) -> (WriteAccountMapEntry<T>, bool) {
-        let new_entry = Self::new_entry();
-        let mut w_account_maps = self.get_account_maps_write_lock();
-        self.insert_new_entry_if_missing_with_lock(pubkey, &mut w_account_maps, new_entry)
+    fn insert_new_entry_if_missing(
+        &self,
+        pubkey: &Pubkey,
+        slot: Slot,
+        info: &T,
+        w_account_maps: Option<&mut AccountMapsWriteLock<T>>,
+    ) -> Option<WriteAccountMapEntry<T>> {
+        let new_entry = WriteAccountMapEntry::new_entry_after_update(slot, info);
+        match w_account_maps {
+            Some(w_account_maps) => {
+                self.insert_new_entry_if_missing_with_lock(pubkey, w_account_maps, new_entry)
+            }
+            None => {
+                let mut w_account_maps = self.get_account_maps_write_lock();
+                self.insert_new_entry_if_missing_with_lock(pubkey, &mut w_account_maps, new_entry)
+            }
+        }
     }
 
+    // return None if item was created new
+    // if entry for pubkey already existed, return Some(entry). Caller needs to call entry.update.
     fn insert_new_entry_if_missing_with_lock(
         &self,
         pubkey: &Pubkey,
-        w_account_maps: &mut ReadWriteLockMapType<T>,
+        w_account_maps: &mut AccountMapsWriteLock<T>,
         new_entry: AccountMapEntry<T>,
-    ) -> (WriteAccountMapEntry<T>, bool) {
+    ) -> Option<WriteAccountMapEntry<T>> {
         let mut is_newly_inserted = false;
         let account_entry = w_account_maps.entry(*pubkey).or_insert_with(|| {
             is_newly_inserted = true;
             new_entry
         });
-        let w_account_entry = WriteAccountMapEntry::from_account_map_entry(account_entry.clone());
-        (w_account_entry, is_newly_inserted)
+        if is_newly_inserted {
+            None
+        } else {
+            Some(WriteAccountMapEntry::from_account_map_entry(
+                account_entry.clone(),
+            ))
+        }
     }
 
     fn get_account_write_entry_else_create(
         &self,
         pubkey: &Pubkey,
-    ) -> (WriteAccountMapEntry<T>, bool) {
-        let mut w_account_entry = self.get_account_write_entry(pubkey);
-        let mut is_newly_inserted = false;
-        if w_account_entry.is_none() {
-            let entry_is_new = self.insert_new_entry_if_missing(pubkey);
-            w_account_entry = Some(entry_is_new.0);
-            is_newly_inserted = entry_is_new.1;
-        }
-
-        (w_account_entry.unwrap(), is_newly_inserted)
+        slot: Slot,
+        info: &T,
+    ) -> Option<WriteAccountMapEntry<T>> {
+        let w_account_entry = self.get_account_write_entry(pubkey);
+        w_account_entry.or_else(|| self.insert_new_entry_if_missing(pubkey, slot, info, None))
     }
 
     pub fn handle_dead_keys(
@@ -1159,7 +1179,7 @@ impl<T: 'static + Clone + IsCached + ZeroLamport> AccountsIndex<T> {
         }
     }
 
-    pub(crate) fn get_account_maps_write_lock(&self) -> ReadWriteLockMapType<T> {
+    pub(crate) fn get_account_maps_write_lock(&self) -> AccountMapsWriteLock<T> {
         self.account_maps.write().unwrap()
     }
 
@@ -1173,15 +1193,16 @@ impl<T: 'static + Clone + IsCached + ZeroLamport> AccountsIndex<T> {
         pubkey: &Pubkey,
         account_info: T,
         reclaims: &mut SlotList<T>,
-        w_account_maps: &mut ReadWriteLockMapType<T>,
+        w_account_maps: &mut AccountMapsWriteLock<T>,
     ) {
-        let new_entry = Self::new_entry();
-        let (mut w_account_entry, _is_new) =
-            self.insert_new_entry_if_missing_with_lock(pubkey, w_account_maps, new_entry);
+        let account_entry =
+            self.insert_new_entry_if_missing(pubkey, slot, &account_info, Some(w_account_maps));
         if account_info.is_zero_lamport() {
             self.zero_lamport_pubkeys.insert(*pubkey);
         }
-        w_account_entry.update(slot, account_info, reclaims);
+        if let Some(mut w_account_entry) = account_entry {
+            w_account_entry.update(slot, account_info, reclaims);
+        }
     }
 
     // Updates the given pubkey at the given slot with the new account information.
@@ -1198,8 +1219,8 @@ impl<T: 'static + Clone + IsCached + ZeroLamport> AccountsIndex<T> {
         reclaims: &mut SlotList<T>,
     ) -> bool {
         let is_newly_inserted = {
-            let (mut w_account_entry, is_newly_inserted) =
-                self.get_account_write_entry_else_create(pubkey);
+            let w_account_entry =
+                self.get_account_write_entry_else_create(pubkey, slot, &account_info);
             // We don't atomically update both primary index and secondary index together.
             // This certainly creates small time window with inconsistent state across the two indexes.
             // However, this is acceptable because:
@@ -1214,8 +1235,12 @@ impl<T: 'static + Clone + IsCached + ZeroLamport> AccountsIndex<T> {
             if account_info.is_zero_lamport() {
                 self.zero_lamport_pubkeys.insert(*pubkey);
             }
-            w_account_entry.update(slot, account_info, reclaims);
-            is_newly_inserted
+            if let Some(mut w_account_entry) = w_account_entry {
+                w_account_entry.update(slot, account_info, reclaims);
+                false
+            } else {
+                true
+            }
         };
         self.update_secondary_indexes(pubkey, account_owner, account_data, account_indexes);
         is_newly_inserted
@@ -2269,29 +2294,154 @@ pub mod tests {
         assert_eq!(num, 1);
     }
 
+    #[test]
+    fn test_new_entry() {
+        let slot = 0;
+        // account_info type that IS cached
+        let account_info = AccountInfoTest::default();
+
+        let new_entry = WriteAccountMapEntry::new_entry_after_update(slot, &account_info);
+        assert_eq!(new_entry.ref_count.load(Ordering::Relaxed), 0);
+        assert_eq!(new_entry.slot_list.read().unwrap().capacity(), 1);
+        assert_eq!(
+            new_entry.slot_list.read().unwrap().to_vec(),
+            vec![(slot, account_info)]
+        );
+
+        // account_info type that is NOT cached
+        let account_info = true;
+
+        let new_entry = WriteAccountMapEntry::new_entry_after_update(slot, &account_info);
+        assert_eq!(new_entry.ref_count.load(Ordering::Relaxed), 1);
+        assert_eq!(new_entry.slot_list.read().unwrap().capacity(), 1);
+        assert_eq!(
+            new_entry.slot_list.read().unwrap().to_vec(),
+            vec![(slot, account_info)]
+        );
+    }
+
+    fn test_new_entry_code_paths_helper<
+        T: 'static + Clone + IsCached + ZeroLamport + std::cmp::PartialEq + std::fmt::Debug,
+    >(
+        account_infos: [T; 2],
+        is_cached: bool,
+        upsert: bool,
+    ) {
+        let slot0 = 0;
+        let slot1 = 1;
+        let key = Keypair::new().pubkey();
+
+        let index = AccountsIndex::<T>::default();
+        let mut gc = Vec::new();
+
+        if upsert {
+            // insert first entry for pubkey. This will use new_entry_after_update and not call update.
+            index.upsert(
+                slot0,
+                &key,
+                &Pubkey::default(),
+                &[],
+                &AccountSecondaryIndexes::default(),
+                account_infos[0].clone(),
+                &mut gc,
+            );
+        } else {
+            let mut lock = index.get_account_maps_write_lock();
+            index.insert_new_if_missing_into_primary_index(
+                slot0,
+                &key,
+                account_infos[0].clone(),
+                &mut gc,
+                &mut lock,
+            );
+        }
+        assert!(gc.is_empty());
+
+        // verify the added entry matches expected
+        {
+            let entry = index.get_account_read_entry(&key).unwrap();
+            assert_eq!(
+                entry.ref_count().load(Ordering::Relaxed),
+                if is_cached { 0 } else { 1 }
+            );
+            let expected = vec![(slot0, account_infos[0].clone())];
+            assert_eq!(entry.slot_list().to_vec(), expected);
+            let new_entry = WriteAccountMapEntry::new_entry_after_update(slot0, &account_infos[0]);
+            assert_eq!(
+                entry.slot_list().to_vec(),
+                new_entry.slot_list.read().unwrap().to_vec(),
+            );
+        }
+
+        // insert second entry for pubkey. This will use update and NOT use new_entry_after_update.
+        if upsert {
+            index.upsert(
+                slot1,
+                &key,
+                &Pubkey::default(),
+                &[],
+                &AccountSecondaryIndexes::default(),
+                account_infos[1].clone(),
+                &mut gc,
+            );
+        } else {
+            let mut lock = index.get_account_maps_write_lock();
+            index.insert_new_if_missing_into_primary_index(
+                slot1,
+                &key,
+                account_infos[1].clone(),
+                &mut gc,
+                &mut lock,
+            );
+        }
+        assert!(gc.is_empty());
+
+        {
+            let entry = index.get_account_read_entry(&key).unwrap();
+            assert_eq!(
+                entry.ref_count().load(Ordering::Relaxed),
+                if is_cached { 0 } else { 2 }
+            );
+            assert_eq!(
+                entry.slot_list().to_vec(),
+                vec![
+                    (slot0, account_infos[0].clone()),
+                    (slot1, account_infos[1].clone())
+                ]
+            );
+
+            let new_entry = WriteAccountMapEntry::new_entry_after_update(slot1, &account_infos[1]);
+            assert_eq!(entry.slot_list()[1], new_entry.slot_list.read().unwrap()[0],);
+        }
+    }
+
+    #[test]
+    fn test_new_entry_and_update_code_paths() {
+        for is_upsert in &[false, true] {
+            // account_info type that IS cached
+            test_new_entry_code_paths_helper([1.0, 2.0], true, *is_upsert);
+
+            // account_info type that is NOT cached
+            test_new_entry_code_paths_helper([true, false], false, *is_upsert);
+        }
+    }
+
     #[test]
     fn test_insert_with_lock_no_ancestors() {
         let key = Keypair::new();
         let index = AccountsIndex::<bool>::default();
-        let mut gc = Vec::new();
         let slot = 0;
+        let account_info = true;
 
-        let new_entry = AccountsIndex::new_entry();
-        assert_eq!(new_entry.ref_count.load(Ordering::Relaxed), 0);
-        assert!(new_entry.slot_list.read().unwrap().is_empty());
-        assert_eq!(new_entry.slot_list.read().unwrap().capacity(), 1);
+        let new_entry = WriteAccountMapEntry::new_entry_after_update(slot, &account_info);
         let mut w_account_maps = index.get_account_maps_write_lock();
-        let (mut write, insert) = index.insert_new_entry_if_missing_with_lock(
+        let write = index.insert_new_entry_if_missing_with_lock(
             &key.pubkey(),
             &mut w_account_maps,
             new_entry,
         );
-        assert!(insert);
+        assert!(write.is_none());
         drop(w_account_maps);
-        let account_info = true;
-        write.update(slot, account_info, &mut gc);
-        assert!(gc.is_empty());
-        drop(write);
 
         let mut ancestors = Ancestors::default();
         assert!(index.get(&key.pubkey(), Some(&ancestors), None).is_none());