Making persistent and incremental merkle trees

[QEDK]

It is not possible to create a 32-depth incremental tree sadly, due to RAM constraints. It would be great if there was persistence through RocksDB, it would also be a great alternative to https://docs.rs/monotree/latest/monotree imo.

[rkdud007]

thank you for opening issue - i agree to have an option of persistent storage is needed. I'll try to refactor storage in near future.

just to confirm, you need it for the case of this below right? :

 let tree = IncrementalMerkleTree::<32>::new();

[QEDK]

thank you for opening issue - i agree to have an option of persistent storage is needed. I'll try to refactor storage in near future.

for your context, you need it for the case of this below right? :

 let tree = IncrementalMerkleTree::<32>::new();

That is correct, it seems that the proof generation is too slow - takes around 12s for depth 20 and depth 32 is unattainable on a M2 Pro machine.