aboutsummaryrefslogtreecommitdiff
path: root/src/blockencodings.h
blob: 326db1b4a7c4745b146477e52982d741dfe09cbc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
// Copyright (c) 2016-2020 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_BLOCKENCODINGS_H
#define BITCOIN_BLOCKENCODINGS_H

#include <primitives/block.h>


class CTxMemPool;

// Transaction compression schemes for compact block relay can be introduced by writing
// an actual formatter here.
using TransactionCompression = DefaultFormatter;

class DifferenceFormatter
{
    uint64_t m_shift = 0;

public:
    template<typename Stream, typename I>
    void Ser(Stream& s, I v)
    {
        if (v < m_shift || v >= std::numeric_limits<uint64_t>::max()) throw std::ios_base::failure("differential value overflow");
        WriteCompactSize(s, v - m_shift);
        m_shift = uint64_t(v) + 1;
    }
    template<typename Stream, typename I>
    void Unser(Stream& s, I& v)
    {
        uint64_t n = ReadCompactSize(s);
        m_shift += n;
        if (m_shift < n || m_shift >= std::numeric_limits<uint64_t>::max() || m_shift < std::numeric_limits<I>::min() || m_shift > std::numeric_limits<I>::max()) throw std::ios_base::failure("differential value overflow");
        v = I(m_shift++);
    }
};

class BlockTransactionsRequest {
public:
    // A BlockTransactionsRequest message
    uint256 blockhash;
    std::vector<uint16_t> indexes;

    SERIALIZE_METHODS(BlockTransactionsRequest, obj)
    {
        READWRITE(obj.blockhash, Using<VectorFormatter<DifferenceFormatter>>(obj.indexes));
    }
};

class BlockTransactions {
public:
    // A BlockTransactions message
    uint256 blockhash;
    std::vector<CTransactionRef> txn;

    BlockTransactions() {}
    explicit BlockTransactions(const BlockTransactionsRequest& req) :
        blockhash(req.blockhash), txn(req.indexes.size()) {}

    SERIALIZE_METHODS(BlockTransactions, obj)
    {
        READWRITE(obj.blockhash, Using<VectorFormatter<TransactionCompression>>(obj.txn));
    }
};

// Dumb serialization/storage-helper for CBlockHeaderAndShortTxIDs and PartiallyDownloadedBlock
struct PrefilledTransaction {
    // Used as an offset since last prefilled tx in CBlockHeaderAndShortTxIDs,
    // as a proper transaction-in-block-index in PartiallyDownloadedBlock
    uint16_t index;
    CTransactionRef tx;

    SERIALIZE_METHODS(PrefilledTransaction, obj) { READWRITE(COMPACTSIZE(obj.index), Using<TransactionCompression>(obj.tx)); }
};

typedef enum ReadStatus_t
{
    READ_STATUS_OK,
    READ_STATUS_INVALID, // Invalid object, peer is sending bogus crap
    READ_STATUS_FAILED, // Failed to process object
    READ_STATUS_CHECKBLOCK_FAILED, // Used only by FillBlock to indicate a
                                   // failure in CheckBlock.
} ReadStatus;

class CBlockHeaderAndShortTxIDs {
private:
    mutable uint64_t shorttxidk0, shorttxidk1;
    uint64_t nonce;

    void FillShortTxIDSelector() const;

    friend class PartiallyDownloadedBlock;

protected:
    std::vector<uint64_t> shorttxids;
    std::vector<PrefilledTransaction> prefilledtxn;

public:
    static constexpr int SHORTTXIDS_LENGTH = 6;

    CBlockHeader header;

    // Dummy for deserialization
    CBlockHeaderAndShortTxIDs() {}

    CBlockHeaderAndShortTxIDs(const CBlock& block, bool fUseWTXID);

    uint64_t GetShortID(const uint256& txhash) const;

    size_t BlockTxCount() const { return shorttxids.size() + prefilledtxn.size(); }

    SERIALIZE_METHODS(CBlockHeaderAndShortTxIDs, obj)
    {
        READWRITE(obj.header, obj.nonce, Using<VectorFormatter<CustomUintFormatter<SHORTTXIDS_LENGTH>>>(obj.shorttxids), obj.prefilledtxn);
        if (ser_action.ForRead()) {
            if (obj.BlockTxCount() > std::numeric_limits<uint16_t>::max()) {
                throw std::ios_base::failure("indexes overflowed 16 bits");
            }
            obj.FillShortTxIDSelector();
        }
    }
};

class PartiallyDownloadedBlock {
protected:
    std::vector<CTransactionRef> txn_available;
    size_t prefilled_count = 0, mempool_count = 0, extra_count = 0;
    const CTxMemPool* pool;
public:
    CBlockHeader header;
    explicit PartiallyDownloadedBlock(CTxMemPool* poolIn) : pool(poolIn) {}

    // extra_txn is a list of extra transactions to look at, in <witness hash, reference> form
    ReadStatus InitData(const CBlockHeaderAndShortTxIDs& cmpctblock, const std::vector<std::pair<uint256, CTransactionRef>>& extra_txn);
    bool IsTxAvailable(size_t index) const;
    ReadStatus FillBlock(CBlock& block, const std::vector<CTransactionRef>& vtx_missing);
};

#endif // BITCOIN_BLOCKENCODINGS_H