Since it not explicit in #520 that the archiver should also keep a "for-ever" growing set of L1 -> L2 messages that are in the "non-pending" set to make it easy for RPC's to fetch data for consuming messages. Add an explicit store of these messages.
Consider storing a mapping from entryKeys => L1ToL2Message and simply store the entryKeys in the pending set as you can always lookup the data from the ever-growing set.
Since it not explicit in #520 that the archiver should also keep a "for-ever" growing set of L1 -> L2 messages that are in the "non-pending" set to make it easy for RPC's to fetch data for consuming messages. Add an explicit store of these messages.
Consider storing a mapping from entryKeys => L1ToL2Message and simply store the entryKeys in the pending set as you can always lookup the data from the ever-growing set.