SHAMapTreeNode.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_SHAMAPTREENODE_H_INCLUDED
#define RIPPLE_SHAMAP_SHAMAPTREENODE_H_INCLUDED
 
#include <ripple/basics/CountedObject.h>
#include <ripple/basics/TaggedCache.h>
#include <ripple/beast/utility/Journal.h>
#include <ripple/shamap/SHAMapItem.h>
#include <ripple/shamap/SHAMapNodeID.h>
 
#include <cstdint>
#include <memory>
#include <mutex>
#include <string>
 
namespace ripple {
 
// These are wire-protocol identifiers used during serialization to encode the
// type of a node. They should not be arbitrarily be changed.
static constexpr unsigned char const wireTypeTransaction = 0;
static constexpr unsigned char const wireTypeAccountState = 1;
static constexpr unsigned char const wireTypeInner = 2;
static constexpr unsigned char const wireTypeCompressedInner = 3;
static constexpr unsigned char const wireTypeTransactionWithMeta = 4;
 
// A SHAMapHash is the hash of a node in a SHAMap, and also the
// type of the hash of the entire SHAMap.
 
class SHAMapHash
{
    uint256 hash_;
 
public:
    SHAMapHash() = default;
    explicit SHAMapHash(uint256 const& hash) : hash_(hash)
    {
    }
 
    uint256 const&
    as_uint256() const
    {
        return hash_;
    }
    uint256&
    as_uint256()
    {
        return hash_;
    }
    bool
    isZero() const
    {
        return hash_.isZero();
    }
    bool
    isNonZero() const
    {
        return hash_.isNonZero();
    }
    int
    signum() const
    {
        return hash_.signum();
    }
    void
    zero()
    {
        hash_.zero();
    }
 
    friend bool
    operator==(SHAMapHash const& x, SHAMapHash const& y)
    {
        return x.hash_ == y.hash_;
    }
 
    friend bool
    operator<(SHAMapHash const& x, SHAMapHash const& y)
    {
        return x.hash_ < y.hash_;
    }
 
    friend std::ostream&
    operator<<(std::ostream& os, SHAMapHash const& x)
    {
        return os << x.hash_;
    }
 
    friend std::string
    to_string(SHAMapHash const& x)
    {
        return to_string(x.hash_);
    }
 
    template <class H>
    friend void
    hash_append(H& h, SHAMapHash const& x)
    {
        hash_append(h, x.hash_);
    }
};
 
inline bool
operator!=(SHAMapHash const& x, SHAMapHash const& y)
{
    return !(x == y);
}
 
enum class SHAMapNodeType {
    tnINNER = 1,
    tnTRANSACTION_NM = 2,  // transaction, no metadata
    tnTRANSACTION_MD = 3,  // transaction, with metadata
    tnACCOUNT_STATE = 4
};
 
class SHAMapTreeNode
{
protected:
    SHAMapHash hash_;
 
    std::uint32_t cowid_;
 
protected:
    SHAMapTreeNode(SHAMapTreeNode const&) = delete;
    SHAMapTreeNode&
    operator=(SHAMapTreeNode const&) = delete;
 
    explicit SHAMapTreeNode(std::uint32_t cowid) noexcept : cowid_(cowid)
    {
    }
 
    explicit SHAMapTreeNode(
        std::uint32_t cowid,
        SHAMapHash const& hash) noexcept
        : hash_(hash), cowid_(cowid)
    {
    }
public:
    virtual ~SHAMapTreeNode() noexcept = default;
 
    std::uint32_t
    cowid() const
    {
        return cowid_;
    }
 
    void
    unshare()
    {
        cowid_ = 0;
    }
 
    virtual std::shared_ptr<SHAMapTreeNode>
    clone(std::uint32_t cowid) const = 0;
    virtual void
    updateHash() = 0;
 
    SHAMapHash const&
    getHash() const
    {
        return hash_;
    }
 
    virtual SHAMapNodeType
    getType() const = 0;
 
    virtual bool
    isLeaf() const = 0;
 
    virtual bool
    isInner() const = 0;
 
    virtual void
    serializeForWire(Serializer&) const = 0;
 
    virtual void
    serializeWithPrefix(Serializer&) const = 0;
 
    virtual std::string
    getString(SHAMapNodeID const&) const;
 
    virtual void
    invariants(bool is_root = false) const = 0;
 
    static std::shared_ptr<SHAMapTreeNode>
    makeFromPrefix(Slice rawNode, SHAMapHash const& hash);
 
    static std::shared_ptr<SHAMapTreeNode>
    makeFromWire(Slice rawNode);
 
private:
    static std::shared_ptr<SHAMapTreeNode>
    makeTransaction(Slice data, SHAMapHash const& hash, bool hashValid);
 
    static std::shared_ptr<SHAMapTreeNode>
    makeAccountState(Slice data, SHAMapHash const& hash, bool hashValid);
 
    static std::shared_ptr<SHAMapTreeNode>
    makeTransactionWithMeta(Slice data, SHAMapHash const& hash, bool hashValid);
};
 
}  // namespace ripple
 
#endif