fuzz coverage

// Copyright (c) 2023-present 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 <kernel/disconnected_transactions.h>

#include <cassert>

#include <core_memusage.h>

#include <memusage.h>

#include <primitives/transaction.h>

#include <util/hasher.h>

#include <memory>

#include <utility>

// It's almost certainly a logic bug if we don't clear out queuedTx before

// destruction, as we add to it while disconnecting blocks, and then we

// need to re-process remaining transactions to ensure mempool consistency.

// For now, assert() that we've emptied out this object on destruction.

// This assert() can always be removed if the reorg-processing code were

// to be refactored such that this assumption is no longer true (for

// instance if there was some other way we cleaned up the mempool after a

// reorg, besides draining this object).

DisconnectedBlockTransactions::~DisconnectedBlockTransactions()

{

    assert(queuedTx.empty());

    assert(iters_by_txid.empty());

    assert(cachedInnerUsage == 0);

}

std::vector<CTransactionRef> DisconnectedBlockTransactions::LimitMemoryUsage()

{

    std::vector<CTransactionRef> evicted;

    while (!queuedTx.empty() && DynamicMemoryUsage() > m_max_mem_usage) {

        evicted.emplace_back(queuedTx.front());

        cachedInnerUsage -= RecursiveDynamicUsage(queuedTx.front());

        iters_by_txid.erase(queuedTx.front()->GetHash());

        queuedTx.pop_front();

    }

    return evicted;

}

size_t DisconnectedBlockTransactions::DynamicMemoryUsage() const

{

    return cachedInnerUsage + memusage::DynamicUsage(iters_by_txid) + memusage::DynamicUsage(queuedTx);

}

[[nodiscard]] std::vector<CTransactionRef> DisconnectedBlockTransactions::AddTransactionsFromBlock(const std::vector<CTransactionRef>& vtx)

{

    iters_by_txid.reserve(iters_by_txid.size() + vtx.size());

    for (auto block_it = vtx.rbegin(); block_it != vtx.rend(); 
++block_it78
) {

        auto it = queuedTx.insert(queuedTx.end(), *block_it);

        auto [_, inserted] = iters_by_txid.emplace((*block_it)->GetHash(), it);

        assert(inserted); // callers may never pass multiple transactions with the same txid

        cachedInnerUsage += RecursiveDynamicUsage(*block_it);

    }

    return LimitMemoryUsage();

}

void DisconnectedBlockTransactions::removeForBlock(const std::vector<CTransactionRef>& vtx)

{

    // Short-circuit in the common case of a block being added to the tip

    if (queuedTx.empty()) {

        return;

    }

    
for (const auto& tx : vtx)156
 {

        auto iter = iters_by_txid.find(tx->GetHash());

        if (iter != iters_by_txid.end()) {

            auto list_iter = iter->second;

            iters_by_txid.erase(iter);

            cachedInnerUsage -= RecursiveDynamicUsage(*list_iter);

            queuedTx.erase(list_iter);

        }

    }

}

void DisconnectedBlockTransactions::clear()

{

    cachedInnerUsage = 0;

    iters_by_txid.clear();

    queuedTx.clear();

}

std::list<CTransactionRef> DisconnectedBlockTransactions::take()

{

    std::list<CTransactionRef> ret = std::move(queuedTx);

    clear();

    return ret;

}