1// Copyright (c) 2023-present The Bitcoin Core developers
2// Distributed under the MIT software license, see the accompanying
3// file COPYING or http://www.opensource.org/licenses/mit-license.php.
4
5#include <kernel/disconnected_transactions.h>
6
7#include <cassert>
8#include <core_memusage.h>
9#include <memusage.h>
10#include <primitives/transaction.h>
11#include <util/hasher.h>
12
13#include <memory>
14#include <utility>
15
16// It's almost certainly a logic bug if we don't clear out queuedTx before
17// destruction, as we add to it while disconnecting blocks, and then we
18// need to re-process remaining transactions to ensure mempool consistency.
19// For now, assert() that we've emptied out this object on destruction.
20// This assert() can always be removed if the reorg-processing code were
21// to be refactored such that this assumption is no longer true (for
22// instance if there was some other way we cleaned up the mempool after a
23// reorg, besides draining this object).
24DisconnectedBlockTransactions::~DisconnectedBlockTransactions()
25{
26    assert(queuedTx.empty());
27    assert(iters_by_txid.empty());
28    assert(cachedInnerUsage == 0);
29}
30
31std::vector<CTransactionRef> DisconnectedBlockTransactions::LimitMemoryUsage()
32{
33    std::vector<CTransactionRef> evicted;
34
35    while (!queuedTx.empty() && DynamicMemoryUsage() > m_max_mem_usage) {
36        evicted.emplace_back(queuedTx.front());
37        cachedInnerUsage -= RecursiveDynamicUsage(queuedTx.front());
38        iters_by_txid.erase(queuedTx.front()->GetHash());
39        queuedTx.pop_front();
40    }
41    return evicted;
42}
43
44size_t DisconnectedBlockTransactions::DynamicMemoryUsage() const
45{
46    return cachedInnerUsage + memusage::DynamicUsage(iters_by_txid) + memusage::DynamicUsage(queuedTx);
47}
48
49[[nodiscard]] std::vector<CTransactionRef> DisconnectedBlockTransactions::AddTransactionsFromBlock(const std::vector<CTransactionRef>& vtx)
50{
51    iters_by_txid.reserve(iters_by_txid.size() + vtx.size());
52    for (auto block_it = vtx.rbegin(); block_it != vtx.rend(); ++block_it) {
53        auto it = queuedTx.insert(queuedTx.end(), *block_it);
54        auto [_, inserted] = iters_by_txid.emplace((*block_it)->GetHash(), it);
55        assert(inserted); // callers may never pass multiple transactions with the same txid
56        cachedInnerUsage += RecursiveDynamicUsage(*block_it);
57    }
58    return LimitMemoryUsage();
59}
60
61void DisconnectedBlockTransactions::removeForBlock(const std::vector<CTransactionRef>& vtx)
62{
63    // Short-circuit in the common case of a block being added to the tip
64    if (queuedTx.empty()) {
65        return;
66    }
67    for (const auto& tx : vtx) {
68        auto iter = iters_by_txid.find(tx->GetHash());
69        if (iter != iters_by_txid.end()) {
70            auto list_iter = iter->second;
71            iters_by_txid.erase(iter);
72            cachedInnerUsage -= RecursiveDynamicUsage(*list_iter);
73            queuedTx.erase(list_iter);
74        }
75    }
76}
77
78void DisconnectedBlockTransactions::clear()
79{
80    cachedInnerUsage = 0;
81    iters_by_txid.clear();
82    queuedTx.clear();
83}
84
85std::list<CTransactionRef> DisconnectedBlockTransactions::take()
86{
87    std::list<CTransactionRef> ret = std::move(queuedTx);
88    clear();
89    return ret;
90}
91