diff options
Diffstat (limited to 'src/table/data.rs')
| -rw-r--r-- | src/table/data.rs | 27 |
1 files changed, 18 insertions, 9 deletions
diff --git a/src/table/data.rs b/src/table/data.rs index 7af5f552..d7787b6b 100644 --- a/src/table/data.rs +++ b/src/table/data.rs @@ -130,22 +130,31 @@ where let tree_key = self.tree_key(update.partition_key(), update.sort_key()); let changed = (&self.store, &self.merkle_todo).transaction(|(store, mkl_todo)| { - let (old_entry, new_entry) = match store.get(&tree_key)? { - Some(prev_bytes) => { + let (old_entry, old_bytes, new_entry) = match store.get(&tree_key)? { + Some(old_bytes) => { let old_entry = self - .decode_entry(&prev_bytes) + .decode_entry(&old_bytes) .map_err(sled::transaction::ConflictableTransactionError::Abort)?; let mut new_entry = old_entry.clone(); new_entry.merge(&update); - (Some(old_entry), new_entry) + (Some(old_entry), Some(old_bytes), new_entry) } - None => (None, update.clone()), + None => (None, None, update.clone()), }; - if Some(&new_entry) != old_entry.as_ref() { - let new_bytes = rmp_to_vec_all_named(&new_entry) - .map_err(Error::RmpEncode) - .map_err(sled::transaction::ConflictableTransactionError::Abort)?; + // Scenario 1: the value changed, so of course there is a change + let value_changed = Some(&new_entry) != old_entry.as_ref(); + + // Scenario 2: the value didn't change but due to a migration in the + // data format, the messagepack encoding changed. In this case + // we have to write the migrated value in the table and update + // the associated Merkle tree entry. + let new_bytes = rmp_to_vec_all_named(&new_entry) + .map_err(Error::RmpEncode) + .map_err(sled::transaction::ConflictableTransactionError::Abort)?; + let encoding_changed = Some(&new_bytes[..]) != old_bytes.as_ref().map(|x| &x[..]); + + if value_changed || encoding_changed { let new_bytes_hash = blake2sum(&new_bytes[..]); mkl_todo.insert(tree_key.clone(), new_bytes_hash.as_slice())?; store.insert(tree_key.clone(), new_bytes)?; |