open-consul/vendor/github.com/gregjones/httpcache/diskcache/diskcache.go
2018-09-05 14:59:02 -07:00

62 lines
1.4 KiB
Go

// Package diskcache provides an implementation of httpcache.Cache that uses the diskv package
// to supplement an in-memory map with persistent storage
//
package diskcache
import (
"bytes"
"crypto/md5"
"encoding/hex"
"github.com/peterbourgon/diskv"
"io"
)
// Cache is an implementation of httpcache.Cache that supplements the in-memory map with persistent storage
type Cache struct {
d *diskv.Diskv
}
// Get returns the response corresponding to key if present
func (c *Cache) Get(key string) (resp []byte, ok bool) {
key = keyToFilename(key)
resp, err := c.d.Read(key)
if err != nil {
return []byte{}, false
}
return resp, true
}
// Set saves a response to the cache as key
func (c *Cache) Set(key string, resp []byte) {
key = keyToFilename(key)
c.d.WriteStream(key, bytes.NewReader(resp), true)
}
// Delete removes the response with key from the cache
func (c *Cache) Delete(key string) {
key = keyToFilename(key)
c.d.Erase(key)
}
func keyToFilename(key string) string {
h := md5.New()
io.WriteString(h, key)
return hex.EncodeToString(h.Sum(nil))
}
// New returns a new Cache that will store files in basePath
func New(basePath string) *Cache {
return &Cache{
d: diskv.New(diskv.Options{
BasePath: basePath,
CacheSizeMax: 100 * 1024 * 1024, // 100MB
}),
}
}
// NewWithDiskv returns a new Cache using the provided Diskv as underlying
// storage.
func NewWithDiskv(d *diskv.Diskv) *Cache {
return &Cache{d}
}