Documentation
¶
Overview ¶
Package ring is a specialized adaption of `container/ring` for use in LIRS.
Index ¶
- type Metadata
- type Ring
- func (r *Ring[Key, Value]) Do(yield func(Value) bool)
- func (r *Ring[Key, Value]) Iter() iter.Seq[*Ring[Key, Value]]
- func (r *Ring[Key, Value]) Len() int
- func (r *Ring[Key, Value]) Link(s *Ring[Key, Value]) *Ring[Key, Value]
- func (r *Ring[Key, Value]) Move(n int) *Ring[Key, Value]
- func (r *Ring[Key, Value]) Next() *Ring[Key, Value]
- func (r *Ring[Key, Value]) Prev() *Ring[Key, Value]
- func (r *Ring[Key, Value]) Unlink(n int) *Ring[Key, Value]
Constants ¶
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Variables ¶
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Functions ¶
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Types ¶
type Metadata ¶
type Metadata[Key comparable] struct { // Name is the identifier of the data this metadata is bound to. Name Key // LIR (Low Inter-Reference Recency) is true // if the page is frequently accessed relative to other pages, // to be spared from eviction because of its short "reuse distance". // See LIRS algorithm for more detail. LIR bool // Resident is true if the data this metadata // is associated with, is to be considered valid. // I.e. true if the data is still stored in memory // and has not been nullified via eviction. Resident bool // Demoted is true if the page has been moved // to the test/ghost list (HIR non-resident). Demoted bool // Referenced is true if the page was // accessed since the last sweep. Referenced bool // Stacked is true if the page is currently in the LRU/LIRS stack. Stacked bool }
Metadata stores LIRS (Low Inter‑Reference Recency Set) state of a cache page. It is used by CLOCK‑Pro and related eviction algorithms.
type Ring ¶
type Ring[Key comparable, Value any] struct { Value Value Metadata[Key] // contains filtered or unexported fields }
A Ring is an element of a circular list, or ring. Rings do not have a beginning or end; a pointer to any ring element serves as reference to the entire ring. Empty rings are represented as nil Ring pointers. The zero value for a Ring is a one-element ring with a nil Value.
func New ¶
func New[Key comparable, Value any](n int) *Ring[Key, Value]
New creates a ring of n elements.
func (*Ring[Key, Value]) Do ¶
Do calls function f on each element of the ring, in forward order, stopping early if yield returns false. The behavior of Do is undefined if f changes *r.
func (*Ring[Key, Value]) Len ¶
Len computes the number of elements in ring r. It executes in time proportional to the number of elements.
func (*Ring[Key, Value]) Link ¶
Link connects ring r with ring s such that r.Next() becomes s and returns the original value for r.Next(). r must not be empty.
If r and s point to the same ring, linking them removes the elements between r and s from the ring. The removed elements form a subring and the result is a reference to that subring (if no elements were removed, the result is still the original value for r.Next(), and not nil).
If r and s point to different rings, linking them creates a single ring with the elements of s inserted after r. The result points to the element following the last element of s after insertion.
func (*Ring[Key, Value]) Move ¶
Move moves n % r.Len() elements backward (n < 0) or forward (n >= 0) in the ring and returns that ring element. r must not be empty.
Source Files