Repository: bitcoin/bitcoin
File: src/node/utxo_snapshot.h (C/C++)

Code before:
// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2022 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#ifndef BITCOIN_NODE_UTXO_SNAPSHOT_H
#define BITCOIN_NODE_UTXO_SNAPSHOT_H

#include <kernel/cs_main.h>
#include <serialize.h>
#include <sync.h>
#include <uint256.h>
#include <util/fs.h>

#include <cstdint>
#include <optional>
#include <string_view>

class Chainstate;

namespace node {
//! Metadata describing a serialized version of a UTXO set from which an
//! assumeutxo Chainstate can be constructed.
class SnapshotMetadata
{
public:
    //! The hash of the block that reflects the tip of the chain for the
    //! UTXO set contained in this snapshot.
    uint256 m_base_blockhash;

    //! The number of coins in the UTXO set contained in this snapshot. Used
    //! during snapshot load to estimate progress of UTXO set reconstruction.
    uint64_t m_coins_count = 0;

    SnapshotMetadata() { }
    SnapshotMetadata(
        const uint256& base_blockhash,
        uint64_t coins_count) :
            m_base_blockhash(base_blockhash),
            m_coins_count(coins_count) { }

    SERIALIZE_METHODS(SnapshotMetadata, obj) { READWRITE(obj.m_base_blockhash, obj.m_coins_count); }
};

//! The file in the snapshot chainstate dir which stores the base blockhash. This is
//! needed to reconstruct snapshot chainstates on init.
//!

Review comment (suggestion):
nit: could use `std::array`, and use its methods (`.begin()`, `.end()`, `.size()`) in `Unserialize` below to avoid magic numbers
```suggestion
static constexpr std::array<uint8_t, 5> SNAPSHOT_MAGIC_BYTES = {'u', 't', 'x', 'o', 0xff};
```

Code after:
// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2022 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#ifndef BITCOIN_NODE_UTXO_SNAPSHOT_H
#define BITCOIN_NODE_UTXO_SNAPSHOT_H

#include <chainparams.h>
#include <kernel/chainparams.h>
#include <kernel/cs_main.h>
#include <serialize.h>
#include <sync.h>
#include <uint256.h>
#include <util/chaintype.h>
#include <util/fs.h>

#include <cstdint>
#include <optional>
#include <string_view>

// UTXO set snapshot magic bytes
static constexpr std::array<uint8_t, 5> SNAPSHOT_MAGIC_BYTES = {'u', 't', 'x', 'o', 0xff};

class Chainstate;

namespace node {
//! Metadata describing a serialized version of a UTXO set from which an
//! assumeutxo Chainstate can be constructed.
class SnapshotMetadata
{
    const uint16_t m_version{1};
    const std::set<uint16_t> m_supported_versions{1};
public:
    //! The hash of the block that reflects the tip of the chain for the
    //! UTXO set contained in this snapshot.
    uint256 m_base_blockhash;
    uint32_t m_base_blockheight;


    //! The number of coins in the UTXO set contained in this snapshot. Used
    //! during snapshot load to estimate progress of UTXO set reconstruction.
    uint64_t m_coins_count = 0;

    SnapshotMetadata() { }
    SnapshotMetadata(
        const uint256& base_blockhash,