[TieredStorage] Implement HotStorageReader::accounts()

accounts-db/src/tiered_storage/hot.rs

@@ -458,6 +458,20 @@ impl HotStorageReader {
             index_offset.0.saturating_add(1) as usize,
         )))
     }
+
+    /// Return a vector of account metadata for each account, starting from
+    /// `index_offset`
+    pub fn accounts(
+        &self,
+        mut index_offset: IndexOffset,
+    ) -> TieredStorageResult<Vec<StoredAccountMeta>> {
+        let mut accounts = vec![];
+        while let Some((account, next)) = self.get_account(index_offset)? {
+            accounts.push(account);
+            index_offset = IndexOffset(next as u32);
+        }
+        Ok(accounts)
+    }
 }
 
 fn write_optional_fields(
@@ -1403,5 +1417,21 @@ pub mod tests {
                 storable_accounts.get(stored_info.offset);
             verify_account(&stored_meta, account, address, account_hash);
         }
+
+        // verify get_accounts
+        let accounts = hot_storage.accounts(IndexOffset(0)).unwrap();
+
+        // first, we verify everything
+        for (i, stored_meta) in accounts.iter().enumerate() {
+            let (account, address, account_hash, _write_version) = storable_accounts.get(i);
+            verify_account(&stored_meta, account, address, account_hash);
+        }
+
+        // second, we verify various initial position
+        let total_stored_accounts = accounts.len();
+        for i in 0..total_stored_accounts {
+            let partial_accounts = hot_storage.accounts(IndexOffset(i as u32)).unwrap();
+            assert_eq!(&partial_accounts, &accounts[i..]);
+        }
     }
 }

accounts-db/src/tiered_storage/readable.rs

@@ -1,9 +1,11 @@
 use {
     crate::{
+        account_storage::meta::StoredAccountMeta,
         accounts_hash::AccountHash,
         tiered_storage::{
             footer::{AccountMetaFormat, TieredStorageFooter},
             hot::HotStorageReader,
+            index::IndexOffset,
             meta::TieredAccountMeta,
             TieredStorageResult,
         },
@@ -111,4 +113,15 @@ impl TieredStorageReader {
             Self::Hot(hot) => hot.num_accounts(),
         }
     }
+
+    /// Return a vector of account metadata for each account, starting from
+    /// `index_offset`
+    pub fn accounts(
+        &self,
+        index_offset: IndexOffset,
+    ) -> TieredStorageResult<Vec<StoredAccountMeta>> {
+        match self {
+            Self::Hot(hot) => hot.accounts(index_offset),
+        }
+    }
 }