/**
 * Minimum surface a backend exposes to drive a MerkleTree. Sync
 * everywhere: the merkle layer is synchronous and consumers that need
 * async IO wrap externally.
 *
 * Storage records only perfect aligned subtree hashes. Roots of
 * partial right-edge subtrees are recomputed on demand by the tree.
 */
export interface MerkleStorage {
    /** Number of leaves appended so far. */
    size(): number;
    /** Record a leaf hash at the given index. The implementation must reject out-of-order indices. */
    appendLeaf(leafIndex: number, leafHash: Uint8Array): void;
    /** Read the leaf hash at index. Throws if absent. */
    getLeaf(leafIndex: number): Uint8Array;
    /** Record an internal node hash at the given (level, index). */
    putNode(level: number, index: number, hash: Uint8Array): void;
    /** Read an internal-node hash. Throws if absent. */
    getNode(level: number, index: number): Uint8Array;
    /** Probe an internal-node slot without throwing. */
    hasNode(level: number, index: number): boolean;
}
/**
 * In-process storage backed by a Map keyed on `${level}:${index}`. Sync.
 * Suitable for tests, witnesses without persistent storage, and the
 * MerkleVerifier short-lived flow. Production logs that need durability
 * implement MerkleStorage over a file or DB and feed it to a
 * MerkleTree the same way.
 */
export declare class MemoryStorage implements MerkleStorage {
    private leafCount;
    private readonly nodes;
    private static key;
    size(): number;
    appendLeaf(leafIndex: number, leafHash: Uint8Array): void;
    getLeaf(leafIndex: number): Uint8Array;
    putNode(level: number, index: number, hash: Uint8Array): void;
    getNode(level: number, index: number): Uint8Array;
    hasNode(level: number, index: number): boolean;
}