// Copyright (c) The Libra Core Contributors
// SPDX-License-Identifier: Apache-2.0

syntax = "proto3";

package types;

import "transaction_info.proto";

message AccumulatorProof {
  // The bitmap indicating which siblings are default. 1 means non-default and
  // 0 means default. The LSB corresponds to the sibling at the bottom of the
  // accumulator. The leftmost 1-bit corresponds to the sibling at the level
  // just below root level in the accumulator, since this one is always
  // non-default.
  uint64 bitmap = 1;

  // The non-default siblings. The ones near the root are at the beginning of
  // the list.
  repeated bytes non_default_siblings = 2;
}

message SparseMerkleProof {
  // This proof can be used to authenticate whether a given leaf exists in the
  // tree or not. In Rust:
  //   - If this is `Some(HashValue, HashValue)`
  //     - If the first `HashValue` equals requested key, this is an inclusion
  //       proof and the second `HashValue` equals the hash of the
  //       corresponding account blob.
  //     - Otherwise this is a non-inclusion proof. The first `HashValue` is
  //       the only key that exists in the subtree and the second `HashValue`
  //       equals the hash of the corresponding account blob.
  //   - If this is `None`, this is also a non-inclusion proof which indicates
  //     the subtree is empty.
  //
  // In protobuf, this leaf field should either be
  //   - empty, which corresponds to None in the Rust structure.
  //   - exactly 64 bytes, which corresponds to Some<(HashValue, HashValue)>
  //     in the Rust structure.
  bytes leaf = 1;

  // The bitmap indicating which siblings are default. 1 means non-default and
  // 0 means default. The MSB of the first byte corresponds to the sibling at
  // the top of the Sparse Merkle Tree. The rightmost 1-bit of the last byte
  // corresponds to the sibling at the bottom, since this one is always
  // non-default.
  bytes bitmap = 2;

  // The non-default siblings. The ones near the root are at the beginning of
  // the list.
  repeated bytes non_default_siblings = 3;
}

message AccumulatorConsistencyProof {
  // The root hashes of the frozen subtrees that form the small accumulator.
  // Note that none of these hashes should be default hash.
  repeated bytes frozen_subtree_roots = 1;

  // The total number of siblings.
  uint32 num_siblings = 2;

  // The non-default siblings. Note that the entire list of siblings always
  // start of zero or more non-default siblings, followed by zero of more
  // default siblings. So given the total number of siblings and the non-default
  // siblings we should be able to construct the entire sibling list.
  repeated bytes non_default_siblings = 3;
}

// The complete proof used to authenticate a signed transaction.
message SignedTransactionProof {
  AccumulatorProof ledger_info_to_transaction_info_proof = 1;
  TransactionInfo transaction_info = 2;
}

// The complete proof used to authenticate an account state.
message AccountStateProof {
  AccumulatorProof ledger_info_to_transaction_info_proof = 1;
  TransactionInfo transaction_info = 2;
  SparseMerkleProof transaction_info_to_account_proof = 3;
}

// The complete proof used to authenticate an event.
message EventProof {
  AccumulatorProof ledger_info_to_transaction_info_proof = 1;
  TransactionInfo transaction_info = 2;
  AccumulatorProof transaction_info_to_event_proof = 3;
}