reflector.go/store/disk.go
2021-07-24 01:03:47 +02:00

157 lines
3.3 KiB
Go

package store
import (
"io/ioutil"
"os"
"path"
"time"
"github.com/lbryio/lbry.go/v2/extras/errors"
"github.com/lbryio/lbry.go/v2/stream"
"github.com/lbryio/reflector.go/shared"
"github.com/lbryio/reflector.go/store/speedwalk"
)
// DiskStore stores blobs on a local disk
type DiskStore struct {
// the location of blobs on disk
blobDir string
// store files in subdirectories based on the first N chars in the filename. 0 = don't create subdirectories.
prefixLength int
// true if initOnce ran, false otherwise
initialized bool
}
// NewDiskStore returns an initialized file disk store pointer.
func NewDiskStore(dir string, prefixLength int) *DiskStore {
return &DiskStore{
blobDir: dir,
prefixLength: prefixLength,
}
}
const nameDisk = "disk"
// Name is the cache type name
func (d *DiskStore) Name() string { return nameDisk }
// Has returns T/F or Error if it the blob stored already. It will error with any IO disk error.
func (d *DiskStore) Has(hash string) (bool, error) {
err := d.initOnce()
if err != nil {
return false, err
}
_, err = os.Stat(d.path(hash))
if err != nil {
if os.IsNotExist(err) {
return false, nil
}
return false, errors.Err(err)
}
return true, nil
}
// Get returns the blob or an error if the blob doesn't exist.
func (d *DiskStore) Get(hash string) (stream.Blob, shared.BlobTrace, error) {
start := time.Now()
err := d.initOnce()
if err != nil {
return nil, shared.NewBlobTrace(time.Since(start), d.Name()), err
}
blob, err := ioutil.ReadFile(d.path(hash))
if err != nil {
if os.IsNotExist(err) {
return nil, shared.NewBlobTrace(time.Since(start), d.Name()), errors.Err(ErrBlobNotFound)
}
return nil, shared.NewBlobTrace(time.Since(start), d.Name()), errors.Err(err)
}
return blob, shared.NewBlobTrace(time.Since(start), d.Name()), nil
}
// Put stores the blob on disk
func (d *DiskStore) Put(hash string, blob stream.Blob) error {
err := d.initOnce()
if err != nil {
return err
}
err = d.ensureDirExists(d.dir(hash))
if err != nil {
return err
}
err = ioutil.WriteFile(d.path(hash), blob, 0644)
return errors.Err(err)
}
// PutSD stores the sd blob on the disk
func (d *DiskStore) PutSD(hash string, blob stream.Blob) error {
return d.Put(hash, blob)
}
// Delete deletes the blob from the store
func (d *DiskStore) Delete(hash string) error {
err := d.initOnce()
if err != nil {
return err
}
has, err := d.Has(hash)
if err != nil {
return err
}
if !has {
return nil
}
err = os.Remove(d.path(hash))
return errors.Err(err)
}
// list returns the hashes of blobs that already exist in the blobDir
func (d *DiskStore) list() ([]string, error) {
err := d.initOnce()
if err != nil {
return nil, err
}
return speedwalk.AllFiles(d.blobDir, true)
}
func (d *DiskStore) dir(hash string) string {
if d.prefixLength <= 0 || len(hash) < d.prefixLength {
return d.blobDir
}
return path.Join(d.blobDir, hash[:d.prefixLength])
}
func (d *DiskStore) path(hash string) string {
return path.Join(d.dir(hash), hash)
}
func (d *DiskStore) ensureDirExists(dir string) error {
return errors.Err(os.MkdirAll(dir, 0755))
}
func (d *DiskStore) initOnce() error {
if d.initialized {
return nil
}
err := d.ensureDirExists(d.blobDir)
if err != nil {
return err
}
d.initialized = true
return nil
}
// Shutdown shuts down the store gracefully
func (d *DiskStore) Shutdown() {
return
}