https://github.com/brentp/intintmap
fast int64-int64 map for go
https://github.com/brentp/intintmap
Last synced: about 1 month ago
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fast int64-int64 map for go
- Host: GitHub
- URL: https://github.com/brentp/intintmap
- Owner: brentp
- License: bsd-2-clause
- Created: 2016-05-16T16:09:19.000Z (about 9 years ago)
- Default Branch: master
- Last Pushed: 2023-01-08T03:46:00.000Z (over 2 years ago)
- Last Synced: 2025-03-31T17:54:27.793Z (3 months ago)
- Language: Go
- Size: 14.6 KB
- Stars: 95
- Watchers: 6
- Forks: 22
- Open Issues: 3
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
Fast int64 -> int64 hash in golang.
[](https://godoc.org/github.com/brentp/intintmap)
[](https://goreportcard.com/report/github.com/brentp/intintmap)
# intintmap
import "github.com/brentp/intintmap"
Package intintmap is a fast int64 key -> int64 value map.
It is copied nearly verbatim from
http://java-performance.info/implementing-world-fastest-java-int-to-int-hash-map/ .
It interleaves keys and values in the same underlying array to improve locality.
It is 2-5X faster than the builtin map:
```
BenchmarkIntIntMapFill 10 158436598 ns/op
BenchmarkStdMapFill 5 312135474 ns/op
BenchmarkIntIntMapGet10PercentHitRate 5000 243108 ns/op
BenchmarkStdMapGet10PercentHitRate 5000 268927 ns/op
BenchmarkIntIntMapGet100PercentHitRate 500 2249349 ns/op
BenchmarkStdMapGet100PercentHitRate 100 10258929 ns/op
```
## Usage
```go
m := intintmap.New(32768, 0.6)
m.Put(int64(1234), int64(-222))
m.Put(int64(123), int64(33))
v, ok := m.Get(int64(222))
v, ok := m.Get(int64(333))
m.Del(int64(222))
m.Del(int64(333))
fmt.Println(m.Size())
for k := range m.Keys() {
fmt.Printf("key: %d\n", k)
}
for kv := range m.Items() {
fmt.Printf("key: %d, value: %d\n", kv[0], kv[1])
}
```
#### type Map
```go
type Map struct {
}
```
Map is a map-like data-structure for int64s
#### func New
```go
func New(size int, fillFactor float64) *Map
```
New returns a map initialized with n spaces and uses the stated fillFactor. The
map will grow as needed.
#### func (*Map) Get
```go
func (m *Map) Get(key int64) (int64, bool)
```
Get returns the value if the key is found.
#### func (*Map) Put
```go
func (m *Map) Put(key int64, val int64)
```
Put adds or updates key with value val.
#### func (*Map) Del
```go
func (m *Map) Del(key int64)
```
Del deletes a key and its value.
#### func (*Map) Keys
```go
func (m *Map) Keys() chan int64
```
Keys returns a channel for iterating all keys.
#### func (*Map) Items
```go
func (m *Map) Items() chan [2]int64
```
Items returns a channel for iterating all key-value pairs.
#### func (*Map) Size
```go
func (m *Map) Size() int
```
Size returns size of the map.