From 35f73ce4b2efd7341fe55f77b334f27ad8aad090 Mon Sep 17 00:00:00 2001 From: Carl Dong Date: Wed, 16 Feb 2022 15:31:02 -0500 Subject: coinstats: Move hasher codepath to kernel/coinstats As mentioned in a previous commit, the hashing codepath can now be moved to a separate file. This decouples callers that only rely on the hashing codepath from the indexing one. This is key for libbitcoinkernel, which needs to have the CoinsStats hashing codepath for AssumeUTXO, but does not wish to be coupled with indexes. Note that only the .cpp file is split in this commit, the header files will be split in a subsequent commit and the #includes to node/coinstats.h will be adjusted to only #include the necessary headers. --- src/kernel/coinstats.cpp | 187 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 187 insertions(+) create mode 100644 src/kernel/coinstats.cpp (limited to 'src/kernel') diff --git a/src/kernel/coinstats.cpp b/src/kernel/coinstats.cpp new file mode 100644 index 0000000000..15d5c3fbe6 --- /dev/null +++ b/src/kernel/coinstats.cpp @@ -0,0 +1,187 @@ +// Copyright (c) 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. + +#include + +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +namespace node { + +CCoinsStats::CCoinsStats(int block_height, const uint256& block_hash) + : nHeight(block_height), + hashBlock(block_hash) {} + +// Database-independent metric indicating the UTXO set size +uint64_t GetBogoSize(const CScript& script_pub_key) +{ + return 32 /* txid */ + + 4 /* vout index */ + + 4 /* height + coinbase */ + + 8 /* amount */ + + 2 /* scriptPubKey len */ + + script_pub_key.size() /* scriptPubKey */; +} + +CDataStream TxOutSer(const COutPoint& outpoint, const Coin& coin) { + CDataStream ss(SER_DISK, PROTOCOL_VERSION); + ss << outpoint; + ss << static_cast(coin.nHeight * 2 + coin.fCoinBase); + ss << coin.out; + return ss; +} + +//! Warning: be very careful when changing this! assumeutxo and UTXO snapshot +//! validation commitments are reliant on the hash constructed by this +//! function. +//! +//! If the construction of this hash is changed, it will invalidate +//! existing UTXO snapshots. This will not result in any kind of consensus +//! failure, but it will force clients that were expecting to make use of +//! assumeutxo to do traditional IBD instead. +//! +//! It is also possible, though very unlikely, that a change in this +//! construction could cause a previously invalid (and potentially malicious) +//! UTXO snapshot to be considered valid. +static void ApplyHash(CHashWriter& ss, const uint256& hash, const std::map& outputs) +{ + for (auto it = outputs.begin(); it != outputs.end(); ++it) { + if (it == outputs.begin()) { + ss << hash; + ss << VARINT(it->second.nHeight * 2 + it->second.fCoinBase ? 1u : 0u); + } + + ss << VARINT(it->first + 1); + ss << it->second.out.scriptPubKey; + ss << VARINT_MODE(it->second.out.nValue, VarIntMode::NONNEGATIVE_SIGNED); + + if (it == std::prev(outputs.end())) { + ss << VARINT(0u); + } + } +} + +static void ApplyHash(std::nullptr_t, const uint256& hash, const std::map& outputs) {} + +static void ApplyHash(MuHash3072& muhash, const uint256& hash, const std::map& outputs) +{ + for (auto it = outputs.begin(); it != outputs.end(); ++it) { + COutPoint outpoint = COutPoint(hash, it->first); + Coin coin = it->second; + muhash.Insert(MakeUCharSpan(TxOutSer(outpoint, coin))); + } +} + +static void ApplyStats(CCoinsStats& stats, const uint256& hash, const std::map& outputs) +{ + assert(!outputs.empty()); + stats.nTransactions++; + for (auto it = outputs.begin(); it != outputs.end(); ++it) { + stats.nTransactionOutputs++; + if (stats.total_amount.has_value()) { + stats.total_amount = CheckedAdd(*stats.total_amount, it->second.out.nValue); + } + stats.nBogoSize += GetBogoSize(it->second.out.scriptPubKey); + } +} + +//! Calculate statistics about the unspent transaction output set +template +static bool ComputeUTXOStats(CCoinsView* view, CCoinsStats& stats, T hash_obj, const std::function& interruption_point) +{ + std::unique_ptr pcursor(view->Cursor()); + assert(pcursor); + + PrepareHash(hash_obj, stats); + + uint256 prevkey; + std::map outputs; + while (pcursor->Valid()) { + interruption_point(); + COutPoint key; + Coin coin; + if (pcursor->GetKey(key) && pcursor->GetValue(coin)) { + if (!outputs.empty() && key.hash != prevkey) { + ApplyStats(stats, prevkey, outputs); + ApplyHash(hash_obj, prevkey, outputs); + outputs.clear(); + } + prevkey = key.hash; + outputs[key.n] = std::move(coin); + stats.coins_count++; + } else { + return error("%s: unable to read value", __func__); + } + pcursor->Next(); + } + if (!outputs.empty()) { + ApplyStats(stats, prevkey, outputs); + ApplyHash(hash_obj, prevkey, outputs); + } + + FinalizeHash(hash_obj, stats); + + stats.nDiskSize = view->EstimateSize(); + + return true; +} + +std::optional ComputeUTXOStats(CoinStatsHashType hash_type, CCoinsView* view, BlockManager& blockman, const std::function& interruption_point) +{ + CBlockIndex* pindex = WITH_LOCK(::cs_main, return blockman.LookupBlockIndex(view->GetBestBlock())); + CCoinsStats stats{Assert(pindex)->nHeight, pindex->GetBlockHash()}; + + bool success = [&]() -> bool { + switch (hash_type) { + case(CoinStatsHashType::HASH_SERIALIZED): { + CHashWriter ss(SER_GETHASH, PROTOCOL_VERSION); + return ComputeUTXOStats(view, stats, ss, interruption_point); + } + case(CoinStatsHashType::MUHASH): { + MuHash3072 muhash; + return ComputeUTXOStats(view, stats, muhash, interruption_point); + } + case(CoinStatsHashType::NONE): { + return ComputeUTXOStats(view, stats, nullptr, interruption_point); + } + } // no default case, so the compiler can warn about missing cases + assert(false); + }(); + + if (!success) { + return std::nullopt; + } + return stats; +} + +// The legacy hash serializes the hashBlock +static void PrepareHash(CHashWriter& ss, const CCoinsStats& stats) +{ + ss << stats.hashBlock; +} +// MuHash does not need the prepare step +static void PrepareHash(MuHash3072& muhash, CCoinsStats& stats) {} +static void PrepareHash(std::nullptr_t, CCoinsStats& stats) {} + +static void FinalizeHash(CHashWriter& ss, CCoinsStats& stats) +{ + stats.hashSerialized = ss.GetHash(); +} +static void FinalizeHash(MuHash3072& muhash, CCoinsStats& stats) +{ + uint256 out; + muhash.Finalize(out); + stats.hashSerialized = out; +} +static void FinalizeHash(std::nullptr_t, CCoinsStats& stats) {} + +} // namespace node -- cgit v1.2.3