monero/tests/unit_tests/curve_trees.h

// Copyright (c) 2014, The Monero Project
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#pragma once

#include "fcmp_pp/curve_trees.h"
#include "fcmp_pp/tower_cycle.h"

using Helios       = fcmp_pp::curve_trees::Helios;
using Selene       = fcmp_pp::curve_trees::Selene;
using CurveTreesV1 = fcmp_pp::curve_trees::CurveTreesV1;

// Helper class to read/write a global tree in memory. It's only used in testing because normally the tree isn't kept
// in memory (it's stored in the db)
class CurveTreesGlobalTree
{
public:
    CurveTreesGlobalTree(CurveTreesV1 &curve_trees): m_curve_trees(curve_trees) {};

//member structs
public:
    template<typename C>
    using Layer = std::vector<typename C::Point>;

    // A complete tree, useful for testing (don't want to keep the whole tree in memory during normal operation)
    struct Tree final
    {
        std::vector<CurveTreesV1::LeafTuple> leaves;
        std::vector<Layer<Helios>> c1_layers;
        std::vector<Layer<Selene>> c2_layers;
    };

//public member functions
public:
    // Read the in-memory tree and get the number of leaf tuples
    std::size_t get_num_leaf_tuples() const;

    // Read the in-memory tree and get the last hashes from each layer in the tree
    CurveTreesV1::LastHashes get_last_hashes() const;

    // Use the tree extension to extend the in-memory tree
    void extend_tree(const CurveTreesV1::TreeExtension &tree_extension);

    // Use the tree reduction to reduce the in-memory tree
    void reduce_tree(const CurveTreesV1::TreeReduction &tree_reduction);

    // Trim the provided number of leaf tuples from the tree
    void trim_tree(const std::size_t trim_n_leaf_tuples);

    // Validate the in-memory tree by re-hashing every layer, starting from root and working down to leaf layer
    bool audit_tree(const std::size_t expected_n_leaf_tuples);

    // logging helpers
    void log_last_hashes(const CurveTreesV1::LastHashes &last_hashes);
    void log_tree_extension(const CurveTreesV1::TreeExtension &tree_extension);
    void log_tree();

    // Read the in-memory tree and get data from what will be the last chunks after trimming the tree to the provided
    // number of leaves
    // - This function is useful to collect all tree data necessary to perform the actual trim operation
    // - This function can return elems from each last chunk that will need to be trimmed
    CurveTreesV1::LastHashes get_last_hashes_to_trim(
        const std::vector<fcmp_pp::curve_trees::TrimLayerInstructions> &trim_instructions) const;

    CurveTreesV1::LastChunkChildrenToTrim get_all_last_chunk_children_to_trim(
        const std::vector<fcmp_pp::curve_trees::TrimLayerInstructions> &trim_instructions);

private:
    CurveTreesV1 &m_curve_trees;
    Tree m_tree = Tree{};
};