SHAMapNodeID.h

#pragma once
 
#include <xrpl/basics/CountedObject.h>
#include <xrpl/basics/base_uint.h>
 
#include <compare>
#include <cstddef>
#include <optional>
#include <ostream>
#include <string>
#include <string_view>
#include <tuple>
 
namespace xrpl {

class SHAMapNodeID : public CountedObject<SHAMapNodeID>
{
private:
    UInt256 id_;
    unsigned int depth_ = 0;
 
public:
    SHAMapNodeID() = default;
    SHAMapNodeID(SHAMapNodeID const& other) = default;
    SHAMapNodeID(unsigned int depth, UInt256 const& hash);
 
    SHAMapNodeID&
    operator=(SHAMapNodeID const& other) = default;
 
    [[nodiscard]] bool
    isRoot() const
    {
        return depth_ == 0;
    }
 
    // Get the wire format (256-bit nodeID, 1-byte depth)
    [[nodiscard]] std::string
    getRawString() const;
 
    [[nodiscard]] unsigned int
    getDepth() const
    {
        return depth_;
    }
 
    [[nodiscard]] UInt256 const&
    getNodeID() const
    {
        return id_;
    }
 
    [[nodiscard]] SHAMapNodeID
    getChildNodeID(unsigned int branch) const;

    [[nodiscard]] bool
    isPrefixOf(UInt256 const& key) const;

    static SHAMapNodeID
    createID(unsigned int depth, UInt256 const& key);

    std::strong_ordering
    operator<=>(SHAMapNodeID const& n) const
    {
        return std::tie(depth_, id_) <=> std::tie(n.depth_, n.id_);
    }

    bool
    operator==(SHAMapNodeID const& n) const
    {
        return (depth_ == n.depth_) && (id_ == n.id_);
    }
};
 
inline std::string
to_string(SHAMapNodeID const& node)
{
    if (node.isRoot())
        return "NodeID(root)";
 
    return "NodeID(" + std::to_string(node.getDepth()) + "," + to_string(node.getNodeID()) + ")";
}
 
inline std::ostream&
operator<<(std::ostream& out, SHAMapNodeID const& node)
{
    return out << to_string(node);
}

[[nodiscard]] std::optional<SHAMapNodeID>
deserializeSHAMapNodeID(void const* data, std::size_t size);
 
[[nodiscard]] inline std::optional<SHAMapNodeID>
deserializeSHAMapNodeID(std::string_view s)
{
    return deserializeSHAMapNodeID(s.data(), s.size());
}


[[nodiscard]] unsigned int
selectBranch(SHAMapNodeID const& id, UInt256 const& hash);
 
}  // namespace xrpl