mirrors/dragonfly
1
0
Fork 0
mirror of https://github.com/dragonflydb/dragonfly.git synced 2025-05-10 18:05:44 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions 5

chore: add Dash::Prefetch function (#4476)

Browse source 
* chore: add Dash::Prefetch function

It's not being used at this time.

* chore: fixes
This commit is contained in:
Roman Gershman 2025-01-19 20:07:22 +02:00 • committed by GitHub
parent 6265f52bff
commit a936dfe8a5
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
2 changed files with 21 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

11
src/core/dash.h
View file

@ -149,6 +149,9 @@ class DashTable : public detail::DashTableBase {
template <typename U> const_iterator Find(U&& key) const;
template <typename U> iterator Find(U&& key);
// Prefetches the memory where the key would resize into the cache.
template <typename U> void Prefetch(U&& key) const;
// Find first entry with given key hash that evaulates to true on pred.
// Pred accepts either (const key&) or (const key&, const value&)
template <typename Pred> iterator FindFirst(uint64_t key_hash, Pred&& pred);
@ -699,6 +702,14 @@ auto DashTable<_Key, _Value, Policy>::Find(U&& key) -> iterator {
return FindFirst(DoHash(key), EqPred(key));
}
template <typename _Key, typename _Value, typename Policy>
template <typename U>
void DashTable<_Key, _Value, Policy>::Prefetch(U&& key) const {
uint64_t key_hash = DoHash(key);
uint32_t seg_id = SegmentId(key_hash);
segment_[seg_id]->Prefetch(key_hash);
}
template <typename _Key, typename _Value, typename Policy>
template <typename Pred>
auto DashTable<_Key, _Value, Policy>::FindFirst(uint64_t key_hash, Pred&& pred) -> iterator {

10
src/core/dash_internal.h
View file

@ -502,6 +502,7 @@ template <typename _Key, typename _Value, typename Policy = DefaultSegmentPolicy
// Find item with given key hash and truthy predicate
template <typename Pred> Iterator FindIt(Hash_t key_hash, Pred&& pred) const;
void Prefetch(Hash_t key_hash) const;
// Returns valid iterator if succeeded or invalid if not (it's full).
// Requires: key should be not present in the segment.
@ -1188,6 +1189,15 @@ auto Segment<Key, Value, Policy>::FindIt(Hash_t key_hash, Pred&& pred) const ->
return Iterator{};
}
template <typename Key, typename Value, typename Policy>
void Segment<Key, Value, Policy>::Prefetch(Hash_t key_hash) const {
uint8_t bidx = BucketIndex(key_hash);
const Bucket& target = bucket_[bidx];
// Prefetch the home bucket that might hold the key with high probability.
__builtin_prefetch(&target, 0, 1);
}
template <typename Key, typename Value, typename Policy>
template <typename Cb>
void Segment<Key, Value, Policy>::TraverseAll(Cb&& cb) const {