Function FUZZ_TARGET

src/test/fuzz/txgraph.cpp:306–1397

} // namespace

FUZZ_TARGET(txgraph)
{
    // This is a big simulation test for TxGraph, which performs a fuzz-derived sequence of valid
    // operations on a TxGraph instance, as well as on a simpler (mostly) reimplementation (see
    // SimTxGraph above), comparing the outcome of functions that return a result, and finally
    // performing a full comparison between the two.

    SeedRandomStateForTest(SeedRand::ZEROS);
    FuzzedDataProvider provider(buffer.data(), buffer.size());

    /** Internal test RNG, used only for decisions which would require significant amount of data
     *  to be read from the provider, without realistically impacting test sensitivity, and for
     *  specialized test cases that are hard to perform more generically. */
    InsecureRandomContext rng(provider.ConsumeIntegral<uint64_t>());

    /** Variable used whenever an empty SimTxObject is needed. */
    SimTxObject empty_ref;

    /** The maximum number of transactions per (non-oversized) cluster we will use in this
     *  simulation. */
    auto max_cluster_count = provider.ConsumeIntegralInRange<DepGraphIndex>(1, MAX_CLUSTER_COUNT_LIMIT);
    /** The maximum total size of transactions in a (non-oversized) cluster. */
    auto max_cluster_size = provider.ConsumeIntegralInRange<uint64_t>(1, 0x3fffff * MAX_CLUSTER_COUNT_LIMIT);
    /** The amount of work to consider a cluster acceptably linearized. */
    auto acceptable_cost = provider.ConsumeIntegralInRange<uint64_t>(0, 10000);

    /** The set of uint64_t "txid"s that have been assigned before. */
    std::set<uint64_t> assigned_txids;

    // Construct a real graph, and a vector of simulated graphs (main, and possibly staging).
    auto fallback_order = [&](const TxGraph::Ref& a, const TxGraph::Ref& b) noexcept {
        uint64_t txid_a = static_cast<const SimTxObject&>(a).m_txid;
        uint64_t txid_b = static_cast<const SimTxObject&>(b).m_txid;
        assert(assigned_txids.contains(txid_a));
        assert(assigned_txids.contains(txid_b));
        return txid_a <=> txid_b;
    };
    auto real = MakeTxGraph(
        /*max_cluster_count=*/max_cluster_count,
        /*max_cluster_size=*/max_cluster_size,
        /*acceptable_cost=*/acceptable_cost,
        /*fallback_order=*/fallback_order);

    std::vector<SimTxGraph> sims;
    sims.reserve(2);
    sims.emplace_back(max_cluster_count, max_cluster_size);

    /** Struct encapsulating information about a BlockBuilder that's currently live. */
    struct BlockBuilderData
    {
        /** BlockBuilder object from real. */
        std::unique_ptr<TxGraph::BlockBuilder> builder;
        /** The set of transactions marked as included in *builder. */
        SimTxGraph::SetType included;
        /** The set of transactions marked as included or skipped in *builder. */
        SimTxGraph::SetType done;
        /** The last chunk feerate returned by *builder. IsEmpty() if none yet. */
        FeePerWeight last_feerate;