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Storage Layout of zkBNB

storage-layout

Table​

  • Account: record account related information
  • Account History: record the historical change information of the account
  • Asset: record Asset related information
  • Block Witness: record the information about the generated Witness
  • L1 Rollup Tx: record transaction information from L1
  • L1 Synced Block: record block information from L1
  • Compressed Block: record other information of L2 block
  • Block: record L2 block information
  • Pool Tx: record pending and executed but not packed Tx messages
  • L2 NFT: record NFT related information
  • L2 NFT History: record the historical status change information of NFT
  • Priority Request: record Priority Request information from L1
  • Proof: record the Proof information generated by the circuit
  • Sys Config: store system variables
  • Tx: record transaction information on L2
  • Tx Detail: record detailed transaction information on L2

L2Block

Tree​

There are 4 types of trees in the system.

  • Account Tree
  • Account Asset Tree
  • NFT Tree

Account Tree​

The AccountNameHash, PublicKey, Nonce, CollectionNonce, AccountAssetTree.Root() of each Account will be calculated as a hash and written into the tree corresponding to the AccountID. Used to record and save account status under each block height.

Account Asset Tree​

Each Account will maintain an Asset tree, the Balance, LpAmount, and OfferCanceledOrFinalized of each Asset will be calculated as a hash and written into the tree corresponding to the AssetID.

NFT Tree​

The CreatorAccountIndex, OwnerAccountIndex, NftContentHash, NftL1Address, NftL1TokenId, CreatorTreasuryRate, and CollectionId of each nft resource will be calculated as a hash and written into the tree corresponding to the NftIndex. Used to record and save nft status under each block height.

Physical Storage​

The Tree in ZkBNB uses the Sparse Merkle Tree (SMT) structure. In order to optimize the storage space as much as possible, we have implemented a SMT library, compressing the four-layer tree structure into one layer, reducing the depth of the tree and achieving a higher level. storage space usage.

Find More: https://github.com/bnb-chain/zkbnb-smt/blob/master/docs/design.md