merkleblock.h

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// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-present The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#ifndef BITCOIN_MERKLEBLOCK_H
#define BITCOIN_MERKLEBLOCK_H

#include <common/bloom.h>
#include <primitives/block.h>
#include <primitives/transaction_identifier.h>
#include <serialize.h>
#include <uint256.h>

#include <set>
#include <vector>

// Helper functions for serialization.
std::vector<unsigned char> BitsToBytes(const std::vector<bool>& bits);
std::vector<bool> BytesToBits(const std::vector<unsigned char>& bytes);

class CPartialMerkleTree
{
protected:
    unsigned int nTransactions;

    std::vector<bool> vBits;

    std::vector<uint256> vHash;

    bool fBad;

    unsigned int CalcTreeWidth(int height) const {
        return (nTransactions+(1 << height)-1) >> height;
    }

    uint256 CalcHash(int height, unsigned int pos, const std::vector<Txid> &vTxid);

    void TraverseAndBuild(int height, unsigned int pos, const std::vector<Txid> &vTxid, const std::vector<bool> &vMatch);

    uint256 TraverseAndExtract(int height, unsigned int pos, unsigned int &nBitsUsed, unsigned int &nHashUsed, std::vector<Txid> &vMatch, std::vector<unsigned int> &vnIndex);

public:

    SERIALIZE_METHODS(CPartialMerkleTree, obj)
    {
        READWRITE(obj.nTransactions, obj.vHash);
        std::vector<unsigned char> bytes;
        SER_WRITE(obj, bytes = BitsToBytes(obj.vBits));
        READWRITE(bytes);
        SER_READ(obj, obj.vBits = BytesToBits(bytes));
        SER_READ(obj, obj.fBad = false);
    }

    CPartialMerkleTree(const std::vector<Txid> &vTxid, const std::vector<bool> &vMatch);

    CPartialMerkleTree();

    uint256 ExtractMatches(std::vector<Txid> &vMatch, std::vector<unsigned int> &vnIndex);

    unsigned int GetNumTransactions() const { return nTransactions; };

};


class CMerkleBlock
{
public:
    CBlockHeader header;
    CPartialMerkleTree txn;

    std::vector<std::pair<unsigned int, Txid> > vMatchedTxn;

    CMerkleBlock(const CBlock& block, CBloomFilter& filter) : CMerkleBlock(block, &filter, nullptr) { }

    // Create from a CBlock, matching the txids in the set
    CMerkleBlock(const CBlock& block, const std::set<Txid>& txids) : CMerkleBlock{block, nullptr, &txids} {}

    CMerkleBlock() = default;

    SERIALIZE_METHODS(CMerkleBlock, obj) { READWRITE(obj.header, obj.txn); }

private:
    // Combined constructor to consolidate code
    CMerkleBlock(const CBlock& block, CBloomFilter* filter, const std::set<Txid>* txids);
};

#endif // BITCOIN_MERKLEBLOCK_H