gitea/modules/lfs/content_store.go

100 lines
2.7 KiB
Go

// Copyright 2020 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package lfs
import (
"crypto/sha256"
"encoding/hex"
"errors"
"io"
"os"
"code.gitea.io/gitea/models"
"code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/storage"
)
var (
errHashMismatch = errors.New("Content hash does not match OID")
errSizeMismatch = errors.New("Content size does not match")
)
// ContentStore provides a simple file system based storage.
type ContentStore struct {
storage.ObjectStorage
}
// Get takes a Meta object and retrieves the content from the store, returning
// it as an io.Reader. If fromByte > 0, the reader starts from that byte
func (s *ContentStore) Get(meta *models.LFSMetaObject, fromByte int64) (io.ReadCloser, error) {
f, err := s.Open(meta.RelativePath())
if err != nil {
log.Error("Whilst trying to read LFS OID[%s]: Unable to open Error: %v", meta.Oid, err)
return nil, err
}
if fromByte > 0 {
_, err = f.Seek(fromByte, os.SEEK_CUR)
if err != nil {
log.Error("Whilst trying to read LFS OID[%s]: Unable to seek to %d Error: %v", meta.Oid, fromByte, err)
}
}
return f, err
}
// Put takes a Meta object and an io.Reader and writes the content to the store.
func (s *ContentStore) Put(meta *models.LFSMetaObject, r io.Reader) error {
hash := sha256.New()
rd := io.TeeReader(r, hash)
p := meta.RelativePath()
written, err := s.Save(p, rd)
if err != nil {
log.Error("Whilst putting LFS OID[%s]: Failed to copy to tmpPath: %s Error: %v", meta.Oid, p, err)
return err
}
if written != meta.Size {
if err := s.Delete(p); err != nil {
log.Error("Cleaning the LFS OID[%s] failed: %v", meta.Oid, err)
}
return errSizeMismatch
}
shaStr := hex.EncodeToString(hash.Sum(nil))
if shaStr != meta.Oid {
if err := s.Delete(p); err != nil {
log.Error("Cleaning the LFS OID[%s] failed: %v", meta.Oid, err)
}
return errHashMismatch
}
return nil
}
// Exists returns true if the object exists in the content store.
func (s *ContentStore) Exists(meta *models.LFSMetaObject) (bool, error) {
_, err := s.ObjectStorage.Stat(meta.RelativePath())
if err != nil {
if os.IsNotExist(err) {
return false, nil
}
return false, err
}
return true, nil
}
// Verify returns true if the object exists in the content store and size is correct.
func (s *ContentStore) Verify(meta *models.LFSMetaObject) (bool, error) {
p := meta.RelativePath()
fi, err := s.ObjectStorage.Stat(p)
if os.IsNotExist(err) || (err == nil && fi.Size() != meta.Size) {
return false, nil
} else if err != nil {
log.Error("Unable stat file: %s for LFS OID[%s] Error: %v", p, meta.Oid, err)
return false, err
}
return true, nil
}