README
¶
Cache wrapper for web applications.
The primary goal is to simplify caching of responses.
Adds guava-style loading cache and support of scopes for partial flushes.
Provides in-memory NewMemoryCache on top of hashicorp/golang-lru and
defines basic interface for other implementations.
In addition to Get and Flush methods, memory cache also support limits for a single value size, number of keys and total memory utilization. PostFlushFn adds ability to call a function on flush completion.
Install and update
go get -u github.com/go-pkgz/rest/cache
Technical details
- Cache keeps data in a simple key:value format.
- Key is a type, created with
Key(site_id)wheresite_idrepresents independent bucket in the cache. For simple cases can be set to an empty string. - Particular key set by
Key.ID(string) - Key may contain optional scopes (list of string). They not affect retrieval and used for partial (scoped) invalidation only.
- Cache is safe for concurrent use.
- Value is []byte.
Getmethod returns from the cache if the key already in. Overwise executes passed function and saves results.- Special fake implementation
cache.NopsatisfiesLoadingCacheinterface and can be used to disable any caching
Usage
// create in-memory cache with max keys=50, total (max) size=2000 and max cached size of a record = 200
lc, err := cache.NewMemoryCache(cache.MaxKeys(50), cacheMaxCacheSize(2000), cache.MaxValSize(200))
if err != nil {
panic(err)
}
...
// load cached value for key1. Call func if not cached yet or evicted
res, err = lc.Get(cache.NewKey("site1").ID("key1").Scopes("scope1"), func() ([]byte, error) {
return []byte("1234567890"), nil
})
lc.Flush("scope1") // invalidate cache for scope1
Documentation
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Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type FlusherRequest ¶
type FlusherRequest struct {
// contains filtered or unexported fields
}
FlusherRequest used as input for cache.Flush
func Flusher ¶
func Flusher(siteID string) FlusherRequest
Flusher makes new FlusherRequest with empty scopes
func (FlusherRequest) Scopes ¶
func (f FlusherRequest) Scopes(scopes ...string) FlusherRequest
Scopes adds scopes to FlusherRequest
type Key ¶
type Key struct {
// contains filtered or unexported fields
}
Key for cache
func ParseKey ¶
ParseKey gets compound key created by Key func and split it to the actual key and scopes
type LoadingCache ¶
type LoadingCache interface {
Get(key Key, fn func() ([]byte, error)) (data []byte, err error)
Flush(req FlusherRequest)
}
LoadingCache defines interface for caching
func NewMemoryCache ¶
func NewMemoryCache(options ...Option) (LoadingCache, error)
NewMemoryCache makes memoryCache implementation
type Option ¶
type Option func(lc cacheWithOpts) error
Option func type
func MaxCacheSize ¶
MaxCacheSize functional option defines the total size of cached data. By default it is 0, which means unlimited.
func MaxKeys ¶
MaxKeys functional option defines how many keys to keep. By default it is 0, which means unlimited.
func MaxValSize ¶
MaxValSize functional option defines the largest value's size allowed to be cached By default it is 0, which means unlimited.
func PostFlushFn ¶
func PostFlushFn(postFlushFn func()) Option
PostFlushFn functional option defines how callback function called after each Flush.
Source Files