reflector.go/store/disk.go
2019-10-03 16:34:57 -04:00

127 lines
2.5 KiB
Go

package store
import (
"io/ioutil"
"os"
"path"
"github.com/lbryio/lbry.go/extras/errors"
"github.com/lbryio/lbry.go/stream"
)
// DiskBlobStore stores blobs on a local disk
type DiskBlobStore 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
initialized bool
}
// NewDiskBlobStore returns an initialized file disk store pointer.
func NewDiskBlobStore(dir string, prefixLength int) *DiskBlobStore {
return &DiskBlobStore{blobDir: dir, prefixLength: prefixLength}
}
func (d *DiskBlobStore) 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 *DiskBlobStore) path(hash string) string {
return path.Join(d.dir(hash), hash)
}
func (d *DiskBlobStore) ensureDirExists(dir string) error {
return errors.Err(os.MkdirAll(dir, 0755))
}
func (d *DiskBlobStore) initOnce() error {
if d.initialized {
return nil
}
err := d.ensureDirExists(d.blobDir)
if err != nil {
return err
}
d.initialized = true
return nil
}
// Has returns T/F or Error if it the blob stored already. It will error with any IO disk error.
func (d *DiskBlobStore) 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, err
}
return true, nil
}
// Get returns the blob or an error if the blob doesn't exist.
func (d *DiskBlobStore) Get(hash string) (stream.Blob, error) {
err := d.initOnce()
if err != nil {
return nil, err
}
file, err := os.Open(d.path(hash))
if err != nil {
if os.IsNotExist(err) {
return nil, errors.Err(ErrBlobNotFound)
}
return nil, err
}
return ioutil.ReadAll(file)
}
// Put stores the blob on disk
func (d *DiskBlobStore) 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
}
return ioutil.WriteFile(d.path(hash), blob, 0644)
}
// PutSD stores the sd blob on the disk
func (d *DiskBlobStore) PutSD(hash string, blob stream.Blob) error {
return d.Put(hash, blob)
}
// Delete deletes the blob from the store
func (d *DiskBlobStore) 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
}
return os.Remove(d.path(hash))
}