turboezh/heapcache

# heapcache
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This cache implementation is based on priority queue (see [Heap](https://golang.org/pkg/container/heap/)).
It uses user-defined comparator to evaluate priorities of cached items. Items with lowest priorities will be evicted first.
 
Features:
 - simple standard data structure;
 - no write locks on get operations;
 - capacity may be changed at any time.
 
# Requirements
Go >= 1.11
 
# Documentation
https://godoc.org/github.com/turboezh/heapcache
 
# Examples
 
## Cache
```go
type Foo struct {
    Value int
    Timestamp time.Time
}
 
item1 := Foo{10, time.Now()}
item2 := Foo{20, time.Now().Add(time.Second)}
 
cache := New(10, func(a, b interface{}) bool {
    return a.(*Foo).Timestamp.Before(b.(*Foo).Timestamp)
})
```
 
## Add item
```go
cache.Add("one", &item1)
cache.Add("two", &item2)
 
```
 
## Get item
```go
item, exists := cache.Get("one")
if !exists {
    // `foo` doesn't exists in cache
    // `item` is nil
}
// cache returns `interface{}` so we need to assert type (if need so)
item = item.(*Foo) // = &item1
```
 
## Check item
```go
// check if cache contain all keys 
ok := cache.All("one", "two")
 
// check if cache contain any of keys 
ok := cache.Any("one", "two")
```
 
## Remove item
```go
// Remove returns false if there is no item in cache
wasRemoved := cache.Remove("one")
```
 
## Support on Beerpay
Hey dude! Help me out for a couple of :beers:!
 
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