SHAMapNodeID.h

//------------------------------------------------------------------------------
/*
    This file is part of rippled: https://github.com/ripple/rippled
    Copyright (c) 2012, 2013 Ripple Labs Inc.

    Permission to use, copy, modify, and/or distribute this software for any
    purpose  with  or without fee is hereby granted, provided that the above
    copyright notice and this permission notice appear in all copies.

    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================

#ifndef RIPPLE_SHAMAP_SHAMAPNODEID_H_INCLUDED
#define RIPPLE_SHAMAP_SHAMAPNODEID_H_INCLUDED

#include <ripple/protocol/Serializer.h>
#include <ripple/basics/base_uint.h>
#include <ripple/beast/utility/Journal.h>
#include <ostream>
#include <string>
#include <tuple>

namespace ripple {

// Identifies a node in a half-SHA512 (256 bit) hash map
class SHAMapNodeID
{
private:
    uint256 mNodeID;
    int mDepth;

public:
    SHAMapNodeID ();
    SHAMapNodeID (int depth, uint256 const& hash);
    SHAMapNodeID (void const* ptr, int len);

    bool isValid () const;
    bool isRoot () const;

    // Convert to/from wire format (256-bit nodeID, 1-byte depth)
    void addIDRaw (Serializer& s) const;
    std::string getRawString () const;

    bool operator== (const SHAMapNodeID& n) const;
    bool operator!= (const SHAMapNodeID& n) const;

    bool operator< (const SHAMapNodeID& n) const;
    bool operator> (const SHAMapNodeID& n) const;
    bool operator<= (const SHAMapNodeID& n) const;
    bool operator>= (const SHAMapNodeID& n) const;

    std::string getString () const;
    void dump (beast::Journal journal) const;

// Only used by SHAMap and SHAMapTreeNode

    uint256 const& getNodeID ()  const;
    SHAMapNodeID getChildNodeID (int m) const;
    int selectBranch (uint256 const& hash) const;
    int getDepth () const;
    bool has_common_prefix(SHAMapNodeID const& other) const;

private:
    static uint256 const& Masks (int depth);

    friend std::ostream& operator<< (std::ostream& out, SHAMapNodeID const& node);

private:  // Currently unused
    SHAMapNodeID getParentNodeID () const;
};

//------------------------------------------------------------------------------

inline
SHAMapNodeID::SHAMapNodeID ()
    : mDepth (0)
{
}

inline
int
SHAMapNodeID::getDepth () const
{
    return mDepth;
}

inline
uint256 const&
SHAMapNodeID::getNodeID ()  const
{
    return mNodeID;
}

inline
bool
SHAMapNodeID::isValid () const
{
    return (mDepth >= 0) && (mDepth <= 64);
}

inline
bool
SHAMapNodeID::isRoot () const
{
    return mDepth == 0;
}

inline
SHAMapNodeID
SHAMapNodeID::getParentNodeID () const
{
    assert (mDepth);
    return SHAMapNodeID (mDepth - 1,
        mNodeID & Masks (mDepth - 1));
}

inline
bool
SHAMapNodeID::operator< (const SHAMapNodeID& n) const
{
    return std::tie(mDepth, mNodeID) < std::tie(n.mDepth, n.mNodeID);
}

inline
bool
SHAMapNodeID::operator> (const SHAMapNodeID& n) const
{
    return n < *this;
}

inline
bool
SHAMapNodeID::operator<= (const SHAMapNodeID& n) const
{
    return !(n < *this);
}

inline
bool
SHAMapNodeID::operator>= (const SHAMapNodeID& n) const
{
    return !(*this < n);
}

inline
bool
SHAMapNodeID::operator== (const SHAMapNodeID& n) const
{
    return (mDepth == n.mDepth) && (mNodeID == n.mNodeID);
}

inline
bool
SHAMapNodeID::operator!= (const SHAMapNodeID& n) const
{
    return !(*this == n);
}

inline std::ostream& operator<< (std::ostream& out, SHAMapNodeID const& node)
{
    return out << node.getString ();
}

} // ripple

#endif