reflector.go/store/file.go

127 lines
2.5 KiB
Go

package store
import (
"io/ioutil"
"os"
"path"
"github.com/lbryio/lbry.go/extras/errors"
)
// FileBlobStore is a local disk store.
type FileBlobStore 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
}
// NewFileBlobStore returns an initialized file disk store pointer.
func NewFileBlobStore(dir string, prefixLength int) *FileBlobStore {
return &FileBlobStore{blobDir: dir, prefixLength: prefixLength}
}
func (f *FileBlobStore) dir(hash string) string {
if f.prefixLength <= 0 || len(hash) < f.prefixLength {
return f.blobDir
}
return path.Join(f.blobDir, hash[:f.prefixLength])
}
func (f *FileBlobStore) path(hash string) string {
return path.Join(f.dir(hash), hash)
}
func (f *FileBlobStore) ensureDirExists(dir string) error {
return errors.Err(os.MkdirAll(dir, 0755))
}
func (f *FileBlobStore) initOnce() error {
if f.initialized {
return nil
}
err := f.ensureDirExists(f.blobDir)
if err != nil {
return err
}
f.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 (f *FileBlobStore) Has(hash string) (bool, error) {
err := f.initOnce()
if err != nil {
return false, err
}
_, err = os.Stat(f.path(hash))
if err != nil {
if os.IsNotExist(err) {
return false, nil
}
return false, err
}
return true, nil
}
// Get returns the byte slice of the blob stored or will error if the blob doesn't exist.
func (f *FileBlobStore) Get(hash string) ([]byte, error) {
err := f.initOnce()
if err != nil {
return nil, err
}
file, err := os.Open(f.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 (f *FileBlobStore) Put(hash string, blob []byte) error {
err := f.initOnce()
if err != nil {
return err
}
err = f.ensureDirExists(f.dir(hash))
if err != nil {
return err
}
return ioutil.WriteFile(f.path(hash), blob, 0644)
}
// PutSD stores the sd blob on the disk
func (f *FileBlobStore) PutSD(hash string, blob []byte) error {
return f.Put(hash, blob)
}
// Delete deletes the blob from the store
func (f *FileBlobStore) Delete(hash string) error {
err := f.initOnce()
if err != nil {
return err
}
has, err := f.Has(hash)
if err != nil {
return err
}
if !has {
return nil
}
return os.Remove(f.path(hash))
}