This PR contains a small portion of the full pbss PR, namely
Remove the tracer from trie (and comitter), and instead using an accessList.
Related changes to the Nodeset.
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Co-authored-by: Gary Rong <garyrong0905@gmail.com>
This PR fixes an error in trie commit. If the trie.root is nil, it can be two possible scenarios:
- The trie was empty, and no change happens
- The trie was non-empty and all nodes are dropped
For the latter one, we should collect the deletions and apply them into database(e.g. in PBSS).
Trie tracer is an auxiliary tool to capture all deleted nodes
which can't be captured by trie.Committer. The deleted nodes
can be removed from the disk later.