1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
|
// Copyright 2020 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package lfs
import (
"crypto/sha256"
"encoding/hex"
"errors"
"hash"
"io"
"os"
"code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/storage"
)
var (
// ErrHashMismatch occurs if the content has does not match OID
ErrHashMismatch = errors.New("content hash does not match OID")
// ErrSizeMismatch occurs if the content size does not match
ErrSizeMismatch = errors.New("content size does not match")
)
// ContentStore provides a simple file system based storage.
type ContentStore struct {
storage.ObjectStorage
}
// NewContentStore creates the default ContentStore
func NewContentStore() *ContentStore {
contentStore := &ContentStore{ObjectStorage: storage.LFS}
return contentStore
}
// Get takes a Meta object and retrieves the content from the store, returning
// it as an io.ReadSeekCloser.
func (s *ContentStore) Get(pointer Pointer) (storage.Object, error) {
f, err := s.Open(pointer.RelativePath())
if err != nil {
log.Error("Whilst trying to read LFS OID[%s]: Unable to open Error: %v", pointer.Oid, err)
return nil, err
}
return f, err
}
// Put takes a Meta object and an io.Reader and writes the content to the store.
func (s *ContentStore) Put(pointer Pointer, r io.Reader) error {
p := pointer.RelativePath()
// Wrap the provided reader with an inline hashing and size checker
wrappedRd := newHashingReader(pointer.Size, pointer.Oid, r)
// now pass the wrapped reader to Save - if there is a size mismatch or hash mismatch then
// the errors returned by the newHashingReader should percolate up to here
written, err := s.Save(p, wrappedRd, pointer.Size)
if err != nil {
log.Error("Whilst putting LFS OID[%s]: Failed to copy to tmpPath: %s Error: %v", pointer.Oid, p, err)
return err
}
// check again whether there is any error during the Save operation
// because some errors might be ignored by the Reader's caller
if wrappedRd.lastError != nil && !errors.Is(wrappedRd.lastError, io.EOF) {
err = wrappedRd.lastError
} else if written != pointer.Size {
err = ErrSizeMismatch
}
// if the upload failed, try to delete the file
if err != nil {
if errDel := s.Delete(p); errDel != nil {
log.Error("Cleaning the LFS OID[%s] failed: %v", pointer.Oid, errDel)
}
}
return err
}
// Exists returns true if the object exists in the content store.
func (s *ContentStore) Exists(pointer Pointer) (bool, error) {
_, err := s.ObjectStorage.Stat(pointer.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(pointer Pointer) (bool, error) {
p := pointer.RelativePath()
fi, err := s.ObjectStorage.Stat(p)
if os.IsNotExist(err) || (err == nil && fi.Size() != pointer.Size) {
return false, nil
} else if err != nil {
log.Error("Unable stat file: %s for LFS OID[%s] Error: %v", p, pointer.Oid, err)
return false, err
}
return true, nil
}
// ReadMetaObject will read a git_model.LFSMetaObject and return a reader
func ReadMetaObject(pointer Pointer) (io.ReadSeekCloser, error) {
contentStore := NewContentStore()
return contentStore.Get(pointer)
}
type hashingReader struct {
internal io.Reader
currentSize int64
expectedSize int64
hash hash.Hash
expectedHash string
lastError error
}
// recordError records the last error during the Save operation
// Some callers of the Reader doesn't respect the returned "err"
// For example, MinIO's Put will ignore errors if the written size could equal to expected size
// So we must remember the error by ourselves,
// and later check again whether ErrSizeMismatch or ErrHashMismatch occurs during the Save operation
func (r *hashingReader) recordError(err error) error {
r.lastError = err
return err
}
func (r *hashingReader) Read(b []byte) (int, error) {
n, err := r.internal.Read(b)
if n > 0 {
r.currentSize += int64(n)
wn, werr := r.hash.Write(b[:n])
if wn != n || werr != nil {
return n, r.recordError(werr)
}
}
if errors.Is(err, io.EOF) || r.currentSize >= r.expectedSize {
if r.currentSize != r.expectedSize {
return n, r.recordError(ErrSizeMismatch)
}
shaStr := hex.EncodeToString(r.hash.Sum(nil))
if shaStr != r.expectedHash {
return n, r.recordError(ErrHashMismatch)
}
}
return n, r.recordError(err)
}
func newHashingReader(expectedSize int64, expectedHash string, reader io.Reader) *hashingReader {
return &hashingReader{
internal: reader,
expectedSize: expectedSize,
expectedHash: expectedHash,
hash: sha256.New(),
}
}
|
