[#SaltedOutpointHasher]
= SaltedOutpointHasher
:mrdocs:

Hashes a transaction outpoint (COutPoint) with a per‐instance random salt.

== Synopsis

Declared in `<util/hasher.h>`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
class SaltedOutpointHasher;
----

== Member Functions

[cols="1,4"]
|===
| Name| Description
| xref:SaltedOutpointHasher/2constructor.adoc[`SaltedOutpointHasher`]         [.small]#[constructor]#
| Construct the hasher with a fresh random salt.
| xref:SaltedOutpointHasher/operator_call.adoc[`operator()`] 
| 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.
|===



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