Bitcoin Core  26.99.0
P2P Digital Currency
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TxReconciliationTracker Class Reference

Transaction reconciliation is a way for nodes to efficiently announce transactions. More...

#include <txreconciliation.h>

Classes

class  Impl
 Actual implementation for TxReconciliationTracker's data structure. More...
 

Public Member Functions

 TxReconciliationTracker (uint32_t recon_version)
 
 ~TxReconciliationTracker ()
 
uint64_t PreRegisterPeer (NodeId peer_id)
 Step 0. More...
 
ReconciliationRegisterResult RegisterPeer (NodeId peer_id, bool is_peer_inbound, uint32_t peer_recon_version, uint64_t remote_salt)
 Step 0. More...
 
void ForgetPeer (NodeId peer_id)
 Attempts to forget txreconciliation-related state of the peer (if we previously stored any). More...
 
bool IsPeerRegistered (NodeId peer_id) const
 Check if a peer is registered to reconcile transactions with us. More...
 

Private Attributes

const std::unique_ptr< Implm_impl
 

Detailed Description

Transaction reconciliation is a way for nodes to efficiently announce transactions.

This object keeps track of all txreconciliation-related communications with the peers. The high-level protocol is: 0. Txreconciliation protocol handshake.

  1. Once we receive a new transaction, add it to the set instead of announcing immediately.
  2. At regular intervals, a txreconciliation initiator requests a sketch from a peer, where a sketch is a compressed representation of short form IDs of the transactions in their set.
  3. Once the initiator received a sketch from the peer, the initiator computes a local sketch, and combines the two sketches to attempt finding the difference in sets. 4a. If the difference was not larger than estimated, see SUCCESS below. 4b. If the difference was larger than estimated, initial txreconciliation fails. The initiator requests a larger sketch via an extension round (allowed only once).
    • If extension succeeds (a larger sketch is sufficient), see SUCCESS below.
    • If extension fails (a larger sketch is insufficient), see FAILURE below.

SUCCESS. The initiator knows full symmetrical difference and can request what the initiator is missing and announce to the peer what the peer is missing.

FAILURE. The initiator notifies the peer about the failure and announces all transactions from the corresponding set. Once the peer received the failure notification, the peer announces all transactions from their set.

This is a modification of the Erlay protocol (https://arxiv.org/abs/1905.10518) with two changes (sketch extensions instead of bisections, and an extra INV exchange round), both are motivated in BIP-330.

Definition at line 51 of file txreconciliation.h.

Constructor & Destructor Documentation

◆ TxReconciliationTracker()

TxReconciliationTracker::TxReconciliationTracker ( uint32_t  recon_version)
explicit

Definition at line 147 of file txreconciliation.cpp.

◆ ~TxReconciliationTracker()

TxReconciliationTracker::~TxReconciliationTracker ( )
default

Member Function Documentation

◆ ForgetPeer()

void TxReconciliationTracker::ForgetPeer ( NodeId  peer_id)

Attempts to forget txreconciliation-related state of the peer (if we previously stored any).

After this, we won't be able to reconcile transactions with the peer.

Definition at line 162 of file txreconciliation.cpp.

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◆ IsPeerRegistered()

bool TxReconciliationTracker::IsPeerRegistered ( NodeId  peer_id) const

Check if a peer is registered to reconcile transactions with us.

Definition at line 167 of file txreconciliation.cpp.

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◆ PreRegisterPeer()

uint64_t TxReconciliationTracker::PreRegisterPeer ( NodeId  peer_id)

Step 0.

Generates initial part of the state (salt) required to reconcile txs with the peer. The salt is used for short ID computation required for txreconciliation. The function returns the salt. A peer can't participate in future txreconciliations without this call. This function must be called only once per peer.

Definition at line 151 of file txreconciliation.cpp.

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◆ RegisterPeer()

ReconciliationRegisterResult TxReconciliationTracker::RegisterPeer ( NodeId  peer_id,
bool  is_peer_inbound,
uint32_t  peer_recon_version,
uint64_t  remote_salt 
)

Step 0.

Once the peer agreed to reconcile txs with us, generate the state required to track ongoing reconciliations. Must be called only after pre-registering the peer and only once.

Definition at line 156 of file txreconciliation.cpp.

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Member Data Documentation

◆ m_impl

const std::unique_ptr<Impl> TxReconciliationTracker::m_impl
private

Definition at line 55 of file txreconciliation.h.


The documentation for this class was generated from the following files: