CTxMemPool::EpochGuard Class Reference

EpochGuard: RAII-style guard for using epoch-based graph traversal algorithms. More...

#include <txmempool.h>

Collaboration diagram for CTxMemPool::EpochGuard:

Public Member Functions
	EpochGuard (const CTxMemPool &in)
	~EpochGuard ()

Private Attributes
const CTxMemPool &	pool

Detailed Description

EpochGuard: RAII-style guard for using epoch-based graph traversal algorithms.

When walking ancestors or descendants, we generally want to avoid visiting the same transactions twice. Some traversal algorithms use std::set (or setEntries) to deduplicate the transaction we visit. However, use of std::set is algorithmically undesirable because it both adds an asymptotic factor of O(log n) to traverals cost and triggers O(n) more dynamic memory allocations. In many algorithms we can replace std::set with an internal mempool counter to track the time (or, "epoch") that we began a traversal, and check + update a per-transaction epoch for each transaction we look at to determine if that transaction has not yet been visited during the current traversal's epoch. Algorithms using std::set can be replaced on a one by one basis. Both techniques are not fundamentally incompatible across the codebase. Generally speaking, however, the remaining use of std::set for mempool traversal should be viewed as a TODO for replacement with an epoch based traversal, rather than a preference for std::set over epochs in that algorithm.

Definition at line 849 of file txmempool.h.

Constructor & Destructor Documentation

EpochGuard()

CTxMemPool::EpochGuard::EpochGuard ( const CTxMemPool &  in )

explicit

Definition at line 1128 of file txmempool.cpp.

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~EpochGuard()

CTxMemPool::EpochGuard::~EpochGuard

(

)

Definition at line 1135 of file txmempool.cpp.

Member Data Documentation

pool

const CTxMemPool& CTxMemPool::EpochGuard::pool

private

Definition at line 850 of file txmempool.h.

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

• src/txmempool.h
• src/txmempool.cpp