rclone/cmd/serve/restic/cache.go
Nick Craig-Wood ceeac84cfe serve restic: implement object cache
This caches all the objects returned from the List call. This makes
opening them much quicker so speeds up prune and restores. It also
uses fewer transactions. It can be disabled with
`--cache-objects=false`.

This was discovered when using the B2 backend when the budget was
being blown on list object calls which can avoided with a bit of
caching.

For typical 1 million file backup for a latop or server this will only
use a small amount more memory.
2020-11-12 17:58:46 +00:00

76 lines
1.2 KiB
Go

package restic
import (
"strings"
"sync"
"github.com/rclone/rclone/fs"
)
// cache implements a simple object cache
type cache struct {
mu sync.RWMutex // protects the cache
items map[string]fs.Object // cache of objects
}
// create a new cache
func newCache() *cache {
return &cache{
items: map[string]fs.Object{},
}
}
// find the object at remote or return nil
func (c *cache) find(remote string) fs.Object {
if !cacheObjects {
return nil
}
c.mu.RLock()
o := c.items[remote]
c.mu.RUnlock()
return o
}
// add the object to the cache
func (c *cache) add(remote string, o fs.Object) {
if !cacheObjects {
return
}
c.mu.Lock()
c.items[remote] = o
c.mu.Unlock()
}
// remove the object from the cache
func (c *cache) remove(remote string) {
if !cacheObjects {
return
}
c.mu.Lock()
delete(c.items, remote)
c.mu.Unlock()
}
// remove all the items with prefix from the cache
func (c *cache) removePrefix(prefix string) {
if !cacheObjects {
return
}
c.mu.Lock()
defer c.mu.Unlock()
if !strings.HasSuffix(prefix, "/") {
prefix += "/"
}
if prefix == "/" {
c.items = map[string]fs.Object{}
return
}
for key := range c.items {
if strings.HasPrefix(key, prefix) {
delete(c.items, key)
}
}
}