LedgerNodeHelpers.cpp

#include <xrpld/app/ledger/LedgerNodeHelpers.h>
 
#include <xrpl/basics/Slice.h>
#include <xrpl/beast/utility/instrumentation.h>
#include <xrpl/shamap/SHAMap.h>
#include <xrpl/shamap/SHAMapLeafNode.h>
#include <xrpl/shamap/SHAMapNodeID.h>
#include <xrpl/shamap/SHAMapTreeNode.h>
 
#include <xrpl.pb.h>
 
#include <exception>
#include <optional>
#include <string_view>
 
namespace xrpl {
 
SHAMapTreeNodePtr
getTreeNode(std::string_view data)
{
    auto const slice = makeSlice(data);
    try
    {
        return SHAMapTreeNode::makeFromWire(slice);
    }
    catch (std::exception const&)
    {
        return {};
    }
}
 
std::optional<SHAMapNodeID>
getSHAMapNodeID(protocol::TMLedgerNode const& ledgerNode, SHAMapTreeNode const& treeNode)
{
    if (ledgerNode.has_id() || ledgerNode.has_depth())
    {
        // Reject ambiguous messages that mix the legacy and new reference fields.
        if (ledgerNode.has_nodeid())
            return std::nullopt;
 
        if (treeNode.isInner())
        {
            if (!ledgerNode.has_id())
                return std::nullopt;
 
            REACHABLE("xrpl::getSHAMapNodeID : inner node ID from id field");
            return deserializeSHAMapNodeID(ledgerNode.id());
        }
 
        if (treeNode.isLeaf())
        {
            SOMETIMES(
                ledgerNode.has_depth() && ledgerNode.depth() > SHAMap::kLeafDepth,
                "xrpl::getSHAMapNodeID : leaf depth exceeds max");
            if (!ledgerNode.has_depth() || ledgerNode.depth() > SHAMap::kLeafDepth)
                return std::nullopt;
 
            auto const key = leafKey(treeNode);
            REACHABLE("xrpl::getSHAMapNodeID : leaf node ID reconstructed from depth");
            return SHAMapNodeID::createID(ledgerNode.depth(), key);
        }
        // LCOV_EXCL_START
        UNREACHABLE("xrpl::getSHAMapNodeID : tree node is neither inner nor leaf");
        return std::nullopt;
        // LCOV_EXCL_STOP
    }
 
    if (!ledgerNode.has_nodeid())
        return std::nullopt;
 
    auto nodeID = deserializeSHAMapNodeID(ledgerNode.nodeid());
    if (!nodeID.has_value())
        return std::nullopt;
 
    if (treeNode.isLeaf())
    {
        auto const key = leafKey(treeNode);
        SOMETIMES(
            !nodeID->isPrefixOf(key),
            "xrpl::getSHAMapNodeID : legacy leaf ID inconsistent with key");
        if (!nodeID->isPrefixOf(key))
            return std::nullopt;
    }
 
    return nodeID;
}
 
}  // namespace xrpl