130 lines
3.1 KiB
Go
130 lines
3.1 KiB
Go
package store
|
|
|
|
import (
|
|
"github.com/lbryio/lbry.go/v2/extras/errors"
|
|
"github.com/lbryio/lbry.go/v2/stream"
|
|
"github.com/lbryio/reflector.go/internal/metrics"
|
|
|
|
golru "github.com/hashicorp/golang-lru"
|
|
"github.com/sirupsen/logrus"
|
|
)
|
|
|
|
// LRUStore adds a max cache size and LRU eviction to a BlobStore
|
|
type LRUStore struct {
|
|
// underlying store
|
|
store BlobStore
|
|
// lru implementation
|
|
lru *golru.Cache
|
|
}
|
|
|
|
// NewLRUStore initialize a new LRUStore
|
|
func NewLRUStore(component string, store BlobStore, maxItems int) *LRUStore {
|
|
l := &LRUStore{
|
|
store: store,
|
|
}
|
|
|
|
lru, err := golru.NewWithEvict(maxItems, func(key interface{}, value interface{}) {
|
|
metrics.CacheLRUEvictCount.With(metrics.CacheLabels(l.Name(), component)).Inc()
|
|
_ = store.Delete(key.(string)) // TODO: log this error. may happen if underlying entry is gone but cache entry still there
|
|
})
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
|
|
l.lru = lru
|
|
|
|
go func() {
|
|
if lstr, ok := store.(lister); ok {
|
|
err = l.loadExisting(lstr, maxItems)
|
|
if err != nil {
|
|
panic(err) // TODO: what should happen here? panic? return nil? just keep going?
|
|
}
|
|
}
|
|
}()
|
|
|
|
return l
|
|
}
|
|
|
|
// Name is the cache type name
|
|
func (l *LRUStore) Name() string {
|
|
return "lru_" + l.store.Name()
|
|
}
|
|
|
|
// Has returns whether the blob is in the store, without updating the recent-ness.
|
|
func (l *LRUStore) Has(hash string) (bool, error) {
|
|
return l.lru.Contains(hash), nil
|
|
}
|
|
|
|
// Get returns the blob or an error if the blob doesn't exist.
|
|
func (l *LRUStore) Get(hash string) (stream.Blob, error) {
|
|
_, has := l.lru.Get(hash)
|
|
if !has {
|
|
return nil, errors.Err(ErrBlobNotFound)
|
|
}
|
|
blob, err := l.store.Get(hash)
|
|
if errors.Is(err, ErrBlobNotFound) {
|
|
// Blob disappeared from underlying store
|
|
l.lru.Remove(hash)
|
|
}
|
|
return blob, err
|
|
}
|
|
|
|
// Put stores the blob
|
|
func (l *LRUStore) Put(hash string, blob stream.Blob) error {
|
|
err := l.store.Put(hash, blob)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
l.lru.Add(hash, true)
|
|
return nil
|
|
}
|
|
|
|
// PutSD stores the sd blob
|
|
func (l *LRUStore) PutSD(hash string, blob stream.Blob) error {
|
|
err := l.store.PutSD(hash, blob)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
l.lru.Add(hash, true)
|
|
return nil
|
|
}
|
|
|
|
// Delete deletes the blob from the store
|
|
func (l *LRUStore) Delete(hash string) error {
|
|
err := l.store.Delete(hash)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
// This must come after store.Delete()
|
|
// Remove triggers onEvict function, which also tries to delete blob from store
|
|
// We need to delete it manually first so any errors can be propagated up
|
|
l.lru.Remove(hash)
|
|
return nil
|
|
}
|
|
|
|
// loadExisting imports existing blobs from the underlying store into the LRU cache
|
|
func (l *LRUStore) loadExisting(store lister, maxItems int) error {
|
|
logrus.Infof("loading at most %d items", maxItems)
|
|
existing, err := store.list()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
logrus.Infof("read %d files from disk", len(existing))
|
|
added := 0
|
|
for _, h := range existing {
|
|
l.lru.Add(h, true)
|
|
added++
|
|
if maxItems > 0 && added >= maxItems { // underlying cache is bigger than LRU cache
|
|
break
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// Shutdown shuts down the store gracefully
|
|
func (l *LRUStore) Shutdown() {
|
|
return
|
|
}
|