Documentation
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Overview ¶
package hamap provides a collision-safe hashmap implementation which is more efficient than Go's native map for small datasets and allows allocation-free reseting efficiently reusing memory. Allocations are made only in case of rare hash collisions. Any custom hasher can be provided during initialization. By default, XXH3 from github.com/zeebo/xxh3 is used with seed 0. On an Apple M1 Max machine the efficiency breaking point compared to Go's native map is at around 192 items.
Index ¶
- type Hasher
- type HasherXXH3
- type KeyInterface
- type Map
- func (m *Map[K, V]) Delete(key K)
- func (m *Map[K, V]) Equal(mm *Map[K, V]) bool
- func (m *Map[K, V]) Get(key K) (value V, ok bool)
- func (m *Map[K, V]) GetFn(key K, fn func(*V)) (ok bool)
- func (m *Map[K, V]) Len() int
- func (m *Map[K, V]) Reset()
- func (m *Map[K, V]) Set(key K, value V)
- func (m *Map[K, V]) SetFn(key K, fn func(*V) V)
- func (m *Map[K, V]) Values() (values []V)
- func (m *Map[K, V]) Visit(fn func(key K, value V) (stop bool))
- func (m *Map[K, V]) VisitAll(fn func(key K, value V))
- type Pair
Constants ¶
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Variables ¶
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Functions ¶
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Types ¶
type Hasher ¶
type Hasher[K KeyInterface] interface{ Hash(K) uint64 }
type HasherXXH3 ¶
type HasherXXH3[K KeyInterface] struct { Seed uint64 }
HasherXXH3 can be used to provide custom seeds during initialization.
func (*HasherXXH3[K]) Hash ¶
func (h *HasherXXH3[K]) Hash(k K) uint64
Hash hashes k to a 64-bit hash value.
type KeyInterface ¶
type Map ¶
type Map[K KeyInterface, V any] struct { // contains filtered or unexported fields }
Map is backed by a slice and utilizes binary search.
WARNING: In case of []byte typed keys the keys will be aliased and must remain immutable until the map is reset!
func New ¶
func New[K KeyInterface, V any]( capacity int, hasher Hasher[K], ) *Map[K, V]
New creates a new map instance.
func (*Map[K, V]) Delete ¶
func (m *Map[K, V]) Delete(key K)
Delete deletes the key if it exists. Noop if the key doesn't exist.
func (*Map[K, V]) Get ¶
Get returns (value, true) if key exists, otherwise returns (zeroValue, false).
func (*Map[K, V]) GetFn ¶
GetFn calls fn providing a pointer to the value and returns true if key exists, otherwise calls fn providing nil and returns false.
func (*Map[K, V]) Set ¶
func (m *Map[K, V]) Set(key K, value V)
Set associates key with value overwriting any existing associations.
WARNING: In case of []byte typed keys the map will alias keys! Make sure key remains immutable during the life-time of the map or until the map is reset.
func (*Map[K, V]) SetFn ¶
func (m *Map[K, V]) SetFn(key K, fn func(*V) V)
SetFn calls fn(nil) if the key doesn't exist yet and associates the value returned by fn with the key. If the key already exists then fn is passed a pointer to the value already associated with the key.
WARNING: In case of []byte typed keys the map will alias keys! Make sure key remains immutable during the life-time of the map or until the map is reset.
Source Files