#include <hasher.h>

Public Member Functions
	SaltedOutpointHasher (bool deterministic=false)

size_t	operator() (const COutPoint &outpoint) const noexcept
	Having the hash noexcept allows libstdc++'s unordered_map to recalculate the hash during rehash, so it does not have to cache the value.

Private Attributes
const uint64_t	k0
	Salt.

const uint64_t	k1

Detailed Description

Definition at line 43 of file hasher.h.

Constructor & Destructor Documentation

◆ SaltedOutpointHasher()

SaltedOutpointHasher::SaltedOutpointHasher ( bool deterministic = false )

Definition at line 13 of file hasher.cpp.

Member Function Documentation

◆ operator()()

size_t SaltedOutpointHasher::operator() ( const COutPoint & outpoint ) const

inlinenoexcept

Having the hash noexcept allows libstdc++'s unordered_map to recalculate the hash during rehash, so it does not have to cache the value.

This reduces node's memory by sizeof(size_t). The required recalculation has a slight performance penalty (around 1.6%), but this is compensated by memory savings of about 9% which allow for a larger dbcache setting.

See also: https://gcc.gnu.org/onlinedocs/gcc-9.2.0/libstdc++/manual/manual/unordered_associative.html

Definition at line 61 of file hasher.h.

Here is the call graph for this function:

Member Data Documentation

◆ k0

const uint64_t SaltedOutpointHasher::k0

private

Salt.

Definition at line 46 of file hasher.h.

◆ k1

const uint64_t SaltedOutpointHasher::k1