# go-cache
```
[](https://github.com/num30/go-cache/actions/workflows/test.yaml)
[](https://codecov.io/gh/num30/go-cache)
[](https://goreportcard.com/report/github.com/num30/go-cache)
[](https://pkg.go.dev/github.com/num30/go-cache)
```
[](https://ci.sg.caj.me/caj/go-cache)
ℹ️ go-cache is a port of great [go-cache](https://github.com/patrickmn/go-cache) library that was written by @patrickmn. The main defference is that it relies on generics instead of reflection.
go-cache is a in-memory key:value store/cache similar to memcached that is
suitable for applications running on a single machine. Its major advantage is
that, being essentially a thread-safe `map[string][T]` with expiration
times, it doesn't need to serialize or transmit its contents over the network.
Any object can be stored, for a given duration or forever, and the cache can be
safely used by multiple goroutines.
Although go-cache isn't meant to be used as a persistent datastore, the entire
cache can be saved to and loaded from a file (using `c.Items()` to retrieve the
items map to serialize, and `NewFrom()` to create a cache from a deserialized
one) to recover from downtime quickly. (See the docs for `NewFrom()` for caveats.)
### Installation
`go get github.com/num30/go-cache`
### Usage
```go
import (
"fmt"
"github.com/num30/go-cache"
"time"
)
func main() {
// Create a cache with a default expiration time of 5 minutes, and which
// purges expired items every 10 minutes
c := cache.New[string](5*time.Minute, 10*time.Minute)
// Set the value of the key "foo" to "bar", with the default expiration time
c.Set("foo", "bar", cache.DefaultExpiration)
// Set the value of the key "baz" to "lightning", with no expiration time
// (the item won't be removed until it is re-set, or removed using
// c.Delete("baz")
c.Set("baz", "lightning", cache.NoExpiration)
// Get the string associated with the key "foo" from the cache
foo, found := c.Get("foo")
if found {
fmt.Println(foo)
}
// Want performance? Store pointers!
structCache := cache.New[MyStruct](5*time.Minute, 10*time.Minute)
structCache.Set("foo", &MyStruct, cache.DefaultExpiration)
if x, found := c.Get("foo"); found {
fmt.Println(")
}
}
```
Run this example with `go run examples/main.go`.
## Performance Comparison
Comparison of performance with original [go-cache](https://github.com/patrickmn/go-cache) implementation.
Spoiler alert! The difference is insignificant.
| Test | [Non generic](https://github.com/patrickmn/go-cache) | | This version | |
|----------------------------------------------|-----------|-------------|-----------|---------------|
| BenchmarkCacheGetStringExpiring-8 | 29884011 | 41.45 ns/op | 28318041 | 43.31 ns/op |
| BenchmarkCacheGetStringNotExpiring-8 | 91891774 | 14.20 ns/op | 72259294 | 14.02 ns/op |
| BenchmarkCacheGetConcurrentExpiring-8 | 26299849 | 42.58 ns/op | 30129078 | 39.53 ns/op |
| BenchmarkCacheGetConcurrentNotExpiring-8 | 28991383 | 41.25 ns/op | 30760544 | 38.09 ns/op |
| BenchmarkCacheGetManyConcurrentExpiring-8 | 55589712 | 44.90 ns/op | 56991110 | 38.86 ns/op |
| BenchmarkCacheGetManyConcurrentNotExpiring-8 | 30105078 | 43.98 ns/op | 46270045 | 41.54 ns/op |
| BenchmarkCacheSetStringExpiring-8 | 18392893 | 63.41 ns/op | 17788724 | 61.42 ns/op |
| BenchmarkCacheSetStringNotExpiring-8 | 46400654 | 28.45 ns/op | 40226074 | 27.41 ns/op |
| BenchmarkCacheSetDelete-8 | 18703620 | 60.75 ns/op | 18270448 | 59.90 ns/op |
| BenchmarkCacheSetDeleteSingleLock-8 | 32633755 | 39.34 ns/op | 32415156 | 36.96 ns/op |
| BenchmarkCacheGetStructExpiring-8 | 30487856 | 41.60 ns/op | 26925226 | 40.55 ns/op |
| BenchmarkCacheGetStructNotExpiring-8 | 91921044 | 13.94 ns/op | 96379750 | 13.08 ns/op |
| BenchmarkCacheSetStructExpiring-8 | 13977464 | 86.44 ns/op | 13364509 | 87.69 ns/op |
| BenchmarkCacheSetStructNotExpiring-8 | 22749384 | 54.14 ns/op | 23207397 | 52.58 ns/op |
| BenchmarkCacheSetFatStructExpiring-8 | 11718718 | 103.3 ns/op | 12051895 | 102.3 ns/op |
| BenchmarkCacheGetFatStructNotExpiring-8 | 88695709 | 13.92 ns/op | 83220014 | 13.76 ns/op |