Blockchain backend fetch MMR nodes #1918
Conversation
…ckends to enable downloading of the Kernel, UTXO and Range Proof MMRs. - Added chain backend tests for testing the lmdb and memory backend implementations of the fetch_mmr_nodes and fetch_mmr_node_count functions for the Kernel, UTXO and Range Proof MMRs. - Added a pruned mode test for downloading of blocks when the node is running in pruned mode.
| { | ||
| node_count += cp.nodes_added().len() as u32; | ||
| } | ||
| } |
There was a problem hiding this comment.
Remote nodes require the ability to determine the total number of added leaf nodes at a specific chain height, adding of UTXOs requires the same ability but at the tip of the chain. Currently, this calculation is expensive as all the checkpoints need to be traversed. A possible solution is to store the total accumulated added node count with each checkpoint to allow efficient retrieval. It could be implemented as a separate db for each checkpoint set, but then special care needs to be taken to ensure it is kept consistent during reorgs and rewinds. Another possibility is to make use of the existing checkpoint dbs, this will ensure no reorg and rewind logic need to be added but will break backwards compatibility.
Description
Added fetch_mmr_nodes and fetch_mmr_node_count to the blockchain backends to enable downloading of the Kernel, UTXO and Range Proof MMRs when syncing using Pruned mode.
Motivation and Context
The MMR state should be retrievable to allow sharing between nodes that are running in pruned mode.
How Has This Been Tested?
Types of changes
Checklist:
developmentbranch.cargo-fmt --allbefore pushing.