|
|
|
@ -8,81 +8,83 @@ be saved to and loaded from a file (or any io.Reader/Writer) to recover from
|
|
|
|
|
downtime quickly.
|
|
|
|
|
|
|
|
|
|
== Installation
|
|
|
|
|
goinstall github.com/pmylund/go-cache
|
|
|
|
|
|
|
|
|
|
goinstall github.com/pmylund/go-cache
|
|
|
|
|
|
|
|
|
|
== Usage
|
|
|
|
|
import "github.com/pmylund/go-cache"
|
|
|
|
|
|
|
|
|
|
// Create a cache with a default expiration time of 5 minutes, and which
|
|
|
|
|
// purges expired items every 30 seconds
|
|
|
|
|
c := cache.New(5*time.Minute, 30*time.Second)
|
|
|
|
|
import "github.com/pmylund/go-cache"
|
|
|
|
|
|
|
|
|
|
// Create a cache with a default expiration time of 5 minutes, and which
|
|
|
|
|
// purges expired items every 30 seconds
|
|
|
|
|
c := cache.New(5*time.Minute, 30*time.Second)
|
|
|
|
|
|
|
|
|
|
// Set the value of the key "foo" to "bar", with the default expiration time
|
|
|
|
|
c.Set("foo", "bar", 0)
|
|
|
|
|
// Set the value of the key "foo" to "bar", with the default expiration time
|
|
|
|
|
c.Set("foo", "bar", 0)
|
|
|
|
|
|
|
|
|
|
// Set the value of the key "baz" to "yes", with no expiration time
|
|
|
|
|
// (the item won't be removed until it is re-set, or removed using
|
|
|
|
|
// c.Delete("baz")
|
|
|
|
|
c.Set("baz", "yes", -1)
|
|
|
|
|
// Set the value of the key "baz" to "yes", with no expiration time
|
|
|
|
|
// (the item won't be removed until it is re-set, or removed using
|
|
|
|
|
// c.Delete("baz")
|
|
|
|
|
c.Set("baz", "yes", -1)
|
|
|
|
|
|
|
|
|
|
// Get the string associated with the key "foo" from the cache
|
|
|
|
|
foo, found := c.Get("foo")
|
|
|
|
|
if found {
|
|
|
|
|
// Get the string associated with the key "foo" from the cache
|
|
|
|
|
foo, found := c.Get("foo")
|
|
|
|
|
if found {
|
|
|
|
|
fmt.Println(foo)
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
// Since Go is statically typed, and cache values can be anything, type
|
|
|
|
|
// assertion is needed when values are being passed to functions that don't
|
|
|
|
|
// take arbitrary types, (i.e. interface{}). The simplest way to do this for
|
|
|
|
|
// values which will only be used once--e.g. for passing to another
|
|
|
|
|
// function--is:
|
|
|
|
|
foo, found := c.Get("foo")
|
|
|
|
|
if found {
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
// Since Go is statically typed, and cache values can be anything, type
|
|
|
|
|
// assertion is needed when values are being passed to functions that don't
|
|
|
|
|
// take arbitrary types, (i.e. interface{}). The simplest way to do this for
|
|
|
|
|
// values which will only be used once--e.g. for passing to another
|
|
|
|
|
// function--is:
|
|
|
|
|
foo, found := c.Get("foo")
|
|
|
|
|
if found {
|
|
|
|
|
MyFunction(foo.(string))
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
// This gets tedious if the value is used several times in the same function.
|
|
|
|
|
// You might do either of the following instead:
|
|
|
|
|
if x, found := c.Get("foo"); found {
|
|
|
|
|
// This gets tedious if the value is used several times in the same function.
|
|
|
|
|
// You might do either of the following instead:
|
|
|
|
|
if x, found := c.Get("foo"); found {
|
|
|
|
|
foo := x.(string)
|
|
|
|
|
...
|
|
|
|
|
}
|
|
|
|
|
// or
|
|
|
|
|
var foo string
|
|
|
|
|
if x, found := c.Get("foo"); found {
|
|
|
|
|
}
|
|
|
|
|
// or
|
|
|
|
|
var foo string
|
|
|
|
|
if x, found := c.Get("foo"); found {
|
|
|
|
|
foo = x.(string)
|
|
|
|
|
}
|
|
|
|
|
...
|
|
|
|
|
// foo can then be passed around freely as a string
|
|
|
|
|
}
|
|
|
|
|
...
|
|
|
|
|
// foo can then be passed around freely as a string
|
|
|
|
|
|
|
|
|
|
// Want performance? Store pointers!
|
|
|
|
|
c.Set("foo", &MyStruct, 0)
|
|
|
|
|
if x, found := c.Get("foo"); found {
|
|
|
|
|
// Want performance? Store pointers!
|
|
|
|
|
c.Set("foo", &MyStruct, 0)
|
|
|
|
|
if x, found := c.Get("foo"); found {
|
|
|
|
|
foo := x.(*MyStruct)
|
|
|
|
|
...
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
// If you store a reference type like a pointer, slice, map or channel, you
|
|
|
|
|
// do not need to run Set if you modify the underlying data. The cached
|
|
|
|
|
// reference points to the same memory, so if you modify a struct whose
|
|
|
|
|
// pointer you've stored in the cache, retrieving that pointer with Get will
|
|
|
|
|
// point you to the same data:
|
|
|
|
|
foo := &MyStruct{Num: 1}
|
|
|
|
|
c.Set("foo", foo, 0)
|
|
|
|
|
...
|
|
|
|
|
x, _ := c.Get("foo")
|
|
|
|
|
foo := x.(*MyStruct)
|
|
|
|
|
fmt.Println(foo.Num)
|
|
|
|
|
...
|
|
|
|
|
foo.Num++
|
|
|
|
|
...
|
|
|
|
|
x, _ := c.Get("foo")
|
|
|
|
|
foo := x.(*MyStruct)
|
|
|
|
|
foo.Println(foo.Num)
|
|
|
|
|
|
|
|
|
|
// will print:
|
|
|
|
|
1
|
|
|
|
|
2
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
// If you store a reference type like a pointer, slice, map or channel, you
|
|
|
|
|
// do not need to run Set if you modify the underlying data. The cached
|
|
|
|
|
// reference points to the same memory, so if you modify a struct whose
|
|
|
|
|
// pointer you've stored in the cache, retrieving that pointer with Get will
|
|
|
|
|
// point you to the same data:
|
|
|
|
|
foo := &MyStruct{Num: 1}
|
|
|
|
|
c.Set("foo", foo, 0)
|
|
|
|
|
...
|
|
|
|
|
x, _ := c.Get("foo")
|
|
|
|
|
foo := x.(*MyStruct)
|
|
|
|
|
fmt.Println(foo.Num)
|
|
|
|
|
...
|
|
|
|
|
foo.Num++
|
|
|
|
|
...
|
|
|
|
|
x, _ := c.Get("foo")
|
|
|
|
|
foo := x.(*MyStruct)
|
|
|
|
|
foo.Println(foo.Num)
|
|
|
|
|
|
|
|
|
|
// will print:
|
|
|
|
|
1
|
|
|
|
|
2
|
|
|
|
|
|
|
|
|
|
== Reference
|
|
|
|
|
|
|
|
|
|