MerkleTreeWithHistory

A Merkle tree with history for storing and managing commitments in the privacy system.This structure implements a sparse Merkle tree that maintains a history of recent roots to enable privacy-preserving transaction verification while preventing double-spending. # Components - levels: The depth of the Merkle tree (number of levels) - filled_subtrees: Intermediate hashes of subtree roots at each level - roots: Historical Merkle roots for verification - current_root_index: Index of the current active root - next_index: Next available index for inserting new leaves - zeros: Precomputed zero hashes for empty nodes at each level # Privacy Features - Maintains commitment history without revealing individual transactions - Enables zero-knowledge proof verification against recent state - Prevents double-spending through nullifier tracking

Fully qualified path: obscura::structs::MerkleTreeWithHistory

#[starknet::storage_node]
pub struct MerkleTreeWithHistory {
    pub levels: u32,
    pub filled_subtrees: Vec<u256>,
    pub roots: Vec<u256>,
    pub current_root_index: u32,
    pub next_index: u32,
    pub zeros: Vec<u256>,
}

Members

levels

The depth of the Merkle tree (number of levels). Determines the maximum number of commitments that can be stored.

Fully qualified path: obscura::structs::MerkleTreeWithHistory::levels

pub levels: u32

filled_subtrees

Stores intermediate hashes of subtree roots at each level. Used for efficient Merkle tree updates and proof generation.

Fully qualified path: obscura::structs::MerkleTreeWithHistory::filled_subtrees

pub filled_subtrees: Vec<u256>

roots

Stores the historical Merkle roots for transaction verification. Allows verification against recent state while maintaining privacy.

Fully qualified path: obscura::structs::MerkleTreeWithHistory::roots

pub roots: Vec<u256>

current_root_index

Tracks the index of the current Merkle root in the circular buffer. Used for efficient root rotation and history management.

Fully qualified path: obscura::structs::MerkleTreeWithHistory::current_root_index

pub current_root_index: u32

next_index

Tracks the next available index for inserting a new leaf. Ensures sequential insertion and proper tree structure.

Fully qualified path: obscura::structs::MerkleTreeWithHistory::next_index

pub next_index: u32

zeros

Precomputed zero hashes for empty nodes at each level. Optimizes Merkle tree operations by avoiding repeated hash calculations.

Fully qualified path: obscura::structs::MerkleTreeWithHistory::zeros

pub zeros: Vec<u256>