Bitcoin ABC 0.30.7
P2P Digital Currency
headerssync.h
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1// Copyright (c) 2022 The Bitcoin Core developers
2// Distributed under the MIT software license, see the accompanying
3// file COPYING or http://www.opensource.org/licenses/mit-license.php.
4
5#ifndef BITCOIN_HEADERSSYNC_H
6#define BITCOIN_HEADERSSYNC_H
7
8#include <arith_uint256.h>
9#include <chain.h>
10#include <consensus/params.h>
11#include <net.h> // For NodeId
12#include <primitives/block.h>
13#include <uint256.h>
14#include <util/bitdeque.h>
15#include <util/hasher.h>
16
17#include <deque>
18#include <vector>
19
20// A compressed CBlockHeader, which leaves out the prevhash
22 // header
23 int32_t nVersion{0};
25 uint32_t nTime{0};
26 uint32_t nBits{0};
27 uint32_t nNonce{0};
28
30
32 nVersion = header.nVersion;
34 nTime = header.nTime;
35 nBits = header.nBits;
36 nNonce = header.nNonce;
37 }
38
39 CBlockHeader GetFullHeader(const BlockHash &hash_prev_block) {
40 CBlockHeader ret;
41 ret.nVersion = nVersion;
42 ret.hashPrevBlock = hash_prev_block;
44 ret.nTime = nTime;
45 ret.nBits = nBits;
46 ret.nNonce = nNonce;
47 return ret;
48 };
49};
50
99public:
101
102 enum class State {
108 PRESYNC,
114 REDOWNLOAD,
119 FINAL
120 };
121
123 State GetState() const { return m_download_state; }
124
126 int64_t GetPresyncHeight() const { return m_current_height; }
127
132 uint32_t GetPresyncTime() const { return m_last_header_received.nTime; }
133
139
149 HeadersSyncState(NodeId id, const Consensus::Params &consensus_params,
150 const CBlockIndex *chain_start,
151 const arith_uint256 &minimum_required_work);
152
155 std::vector<CBlockHeader> pow_validated_headers;
156 bool success{false};
157 bool request_more{false};
158 };
159
183 ProcessingResult
184 ProcessNextHeaders(const std::vector<CBlockHeader> &received_headers,
185 bool full_headers_message);
186
194
195private:
200 void Finalize();
201
210 const std::vector<CBlockHeader> &headers);
211
213 bool ValidateAndProcessSingleHeader(const CBlockHeader &current);
214
220
222 std::vector<CBlockHeader> PopHeadersReadyForAcceptance();
223
224private:
227
230
235 const CBlockIndex *m_chain_start{nullptr};
236
239
242
248
254
261 const unsigned m_commit_offset;
262
270 uint64_t m_max_commitments{0};
271
277
280
286 std::deque<CompressedHeader> m_redownloaded_headers;
287
290
297
304
307
314
317};
318
319#endif // BITCOIN_HEADERSSYNC_H
Nodes collect new transactions into a block, hash them into a hash tree, and scan through nonce value...
Definition: block.h:23
uint32_t nNonce
Definition: block.h:31
uint32_t nBits
Definition: block.h:30
uint32_t nTime
Definition: block.h:29
BlockHash hashPrevBlock
Definition: block.h:27
int32_t nVersion
Definition: block.h:26
uint256 hashMerkleRoot
Definition: block.h:28
The block chain is a tree shaped structure starting with the genesis block at the root,...
Definition: blockindex.h:25
HeadersSyncState:
Definition: headerssync.h:98
arith_uint256 GetPresyncWork() const
Return the amount of work in the chain received during the PRESYNC phase.
Definition: headerssync.h:138
uint64_t m_max_commitments
m_max_commitments is a bound we calculate on how long an honest peer's chain could be,...
Definition: headerssync.h:270
HeadersSyncState(NodeId id, const Consensus::Params &consensus_params, const CBlockIndex *chain_start, const arith_uint256 &minimum_required_work)
Construct a HeadersSyncState object representing a headers sync via this download-twice mechanism).
Definition: headerssync.cpp:27
arith_uint256 m_redownload_chain_work
The accumulated work on the redownloaded chain.
Definition: headerssync.h:306
@ PRESYNC
PRESYNC means the peer has not yet demonstrated their chain has sufficient work and we're only buildi...
CBlockHeader m_last_header_received
Store the latest header received while in PRESYNC (initialized to m_chain_start)
Definition: headerssync.h:276
BlockHash m_redownload_buffer_last_hash
Hash of last header in m_redownloaded_headers (initialized to m_chain_start).
Definition: headerssync.h:296
arith_uint256 m_current_chain_work
Work that we've seen so far on the peer's chain.
Definition: headerssync.h:241
int64_t m_current_height
Height of m_last_header_received.
Definition: headerssync.h:279
const unsigned m_commit_offset
The (secret) offset on the heights for which to create commitments.
Definition: headerssync.h:261
uint32_t GetPresyncTime() const
Return the block timestamp of the last header received during the PRESYNC phase.
Definition: headerssync.h:132
const arith_uint256 m_minimum_required_work
Minimum work that we're looking for on this chain.
Definition: headerssync.h:238
std::vector< CBlockHeader > PopHeadersReadyForAcceptance()
Return a set of headers that satisfy our proof-of-work threshold.
bool ValidateAndStoreHeadersCommitments(const std::vector< CBlockHeader > &headers)
Only called in PRESYNC.
const Consensus::Params & m_consensus_params
We use the consensus params in our anti-DoS calculations.
Definition: headerssync.h:229
bool ValidateAndProcessSingleHeader(const CBlockHeader &current)
In PRESYNC, process and update state for a single header.
State m_download_state
Current state of our headers sync.
Definition: headerssync.h:316
bool ValidateAndStoreRedownloadedHeader(const CBlockHeader &header)
In REDOWNLOAD, check a header's commitment (if applicable) and add to buffer for later processing.
bitdeque m_header_commitments
A queue of commitment bits, created during the 1st phase, and verified during the 2nd.
Definition: headerssync.h:253
BlockHash m_redownload_buffer_first_prev_hash
The hashPrevBlock entry for the first header in m_redownloaded_headers We need this to reconstruct th...
Definition: headerssync.h:303
const NodeId m_id
NodeId of the peer (used for log messages)
Definition: headerssync.h:226
int64_t m_redownload_buffer_last_height
Height of last header in m_redownloaded_headers.
Definition: headerssync.h:289
std::deque< CompressedHeader > m_redownloaded_headers
During phase 2 (REDOWNLOAD), we buffer redownloaded headers in memory until enough commitments have b...
Definition: headerssync.h:286
const SaltedBlockHashHasher m_hasher
m_hasher is a salted hasher for making our 1-bit commitments to headers we've seen.
Definition: headerssync.h:247
ProcessingResult ProcessNextHeaders(const std::vector< CBlockHeader > &received_headers, bool full_headers_message)
Process a batch of headers, once a sync via this mechanism has started.
Definition: headerssync.cpp:84
State GetState() const
Return the current state of our download.
Definition: headerssync.h:123
bool m_process_all_remaining_headers
Set this to true once we encounter the target blockheader during phase 2 (REDOWNLOAD).
Definition: headerssync.h:313
void Finalize()
Clear out all download state that might be in progress (freeing any used memory), and mark this objec...
Definition: headerssync.cpp:66
const CBlockIndex * m_chain_start
Store the last block in our block index that the peer's chain builds from.
Definition: headerssync.h:235
int64_t GetPresyncHeight() const
Return the height reached during the PRESYNC phase.
Definition: headerssync.h:126
CBlockLocator NextHeadersRequestLocator() const
Issue the next GETHEADERS message to our peer.
256-bit unsigned big integer.
void SetNull()
Definition: uint256.h:41
Class that mimics std::deque<bool>, but with std::vector<bool>'s bit packing.
Definition: bitdeque.h:22
256-bit opaque blob.
Definition: uint256.h:129
int64_t NodeId
Definition: nodeid.h:10
A BlockHash is a unqiue identifier for a block.
Definition: blockhash.h:13
Describes a place in the block chain to another node such that if the other node doesn't have the sam...
Definition: block.h:105
uint32_t nBits
Definition: headerssync.h:26
uint32_t nTime
Definition: headerssync.h:25
uint32_t nNonce
Definition: headerssync.h:27
uint256 hashMerkleRoot
Definition: headerssync.h:24
CBlockHeader GetFullHeader(const BlockHash &hash_prev_block)
Definition: headerssync.h:39
int32_t nVersion
Definition: headerssync.h:23
CompressedHeader(const CBlockHeader &header)
Definition: headerssync.h:31
Parameters that influence chain consensus.
Definition: params.h:34
Result data structure for ProcessNextHeaders.
Definition: headerssync.h:154
std::vector< CBlockHeader > pow_validated_headers
Definition: headerssync.h:155