forked from hashicorp/vault
-
Notifications
You must be signed in to change notification settings - Fork 0
/
storagepacker.go
355 lines (295 loc) · 9.07 KB
/
storagepacker.go
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
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
package storagepacker
import (
"context"
"crypto/md5"
"encoding/hex"
"fmt"
"strconv"
"strings"
"github.com/golang/protobuf/proto"
"github.com/hashicorp/errwrap"
log "github.com/hashicorp/go-hclog"
"github.com/hashicorp/vault/helper/compressutil"
"github.com/hashicorp/vault/helper/locksutil"
"github.com/hashicorp/vault/logical"
)
const (
bucketCount = 256
StoragePackerBucketsPrefix = "packer/buckets/"
)
// StoragePacker packs the objects into a specific number of buckets by hashing
// its ID and indexing it. Currently this supports only 256 bucket entries and
// hence relies on the first byte of the hash value for indexing. The items
// that gets inserted into the packer should implement StorageBucketItem
// interface.
type StoragePacker struct {
view logical.Storage
logger log.Logger
storageLocks []*locksutil.LockEntry
viewPrefix string
}
// BucketPath returns the storage entry key for a given bucket key
func (s *StoragePacker) BucketPath(bucketKey string) string {
return s.viewPrefix + bucketKey
}
// BucketKeyHash returns the MD5 hash of the bucket storage key in which
// the item will be stored. The choice of MD5 is only for hash performance
// reasons since its value is not used for any security sensitive operation.
func (s *StoragePacker) BucketKeyHashByItemID(itemID string) string {
return s.BucketKeyHashByKey(s.BucketPath(s.BucketKey(itemID)))
}
// BucketKeyHashByKey returns the MD5 hash of the bucket storage key
func (s *StoragePacker) BucketKeyHashByKey(bucketKey string) string {
hf := md5.New()
hf.Write([]byte(bucketKey))
return hex.EncodeToString(hf.Sum(nil))
}
// View returns the storage view configured to be used by the packer
func (s *StoragePacker) View() logical.Storage {
return s.view
}
// Get returns a bucket for a given key
func (s *StoragePacker) GetBucket(key string) (*Bucket, error) {
if key == "" {
return nil, fmt.Errorf("missing bucket key")
}
lock := locksutil.LockForKey(s.storageLocks, key)
lock.RLock()
defer lock.RUnlock()
// Read from the underlying view
storageEntry, err := s.view.Get(context.Background(), key)
if err != nil {
return nil, errwrap.Wrapf("failed to read packed storage entry: {{err}}", err)
}
if storageEntry == nil {
return nil, nil
}
uncompressedData, notCompressed, err := compressutil.Decompress(storageEntry.Value)
if err != nil {
return nil, errwrap.Wrapf("failed to decompress packed storage entry: {{err}}", err)
}
if notCompressed {
uncompressedData = storageEntry.Value
}
var bucket Bucket
err = proto.Unmarshal(uncompressedData, &bucket)
if err != nil {
return nil, errwrap.Wrapf("failed to decode packed storage entry: {{err}}", err)
}
return &bucket, nil
}
// upsert either inserts a new item into the bucket or updates an existing one
// if an item with a matching key is already present.
func (s *Bucket) upsert(item *Item) error {
if s == nil {
return fmt.Errorf("nil storage bucket")
}
if item == nil {
return fmt.Errorf("nil item")
}
if item.ID == "" {
return fmt.Errorf("missing item ID")
}
// Look for an item with matching key and don't modify the collection
// while iterating
foundIdx := -1
for itemIdx, bucketItems := range s.Items {
if bucketItems.ID == item.ID {
foundIdx = itemIdx
break
}
}
// If there is no match, append the item, otherwise update it
if foundIdx == -1 {
s.Items = append(s.Items, item)
} else {
s.Items[foundIdx] = item
}
return nil
}
// BucketIndex returns the bucket key index for a given storage key
func (s *StoragePacker) BucketIndex(key string) uint8 {
hf := md5.New()
hf.Write([]byte(key))
return uint8(hf.Sum(nil)[0])
}
// BucketKey returns the bucket key for a given item ID
func (s *StoragePacker) BucketKey(itemID string) string {
return strconv.Itoa(int(s.BucketIndex(itemID)))
}
// DeleteItem removes the storage entry which the given key refers to from its
// corresponding bucket.
func (s *StoragePacker) DeleteItem(itemID string) error {
if itemID == "" {
return fmt.Errorf("empty item ID")
}
// Get the bucket key
bucketKey := s.BucketKey(itemID)
// Prepend the view prefix
bucketPath := s.BucketPath(bucketKey)
// Read from underlying view
storageEntry, err := s.view.Get(context.Background(), bucketPath)
if err != nil {
return errwrap.Wrapf("failed to read packed storage value: {{err}}", err)
}
if storageEntry == nil {
return nil
}
uncompressedData, notCompressed, err := compressutil.Decompress(storageEntry.Value)
if err != nil {
return errwrap.Wrapf("failed to decompress packed storage value: {{err}}", err)
}
if notCompressed {
uncompressedData = storageEntry.Value
}
var bucket Bucket
err = proto.Unmarshal(uncompressedData, &bucket)
if err != nil {
return errwrap.Wrapf("failed decoding packed storage entry: {{err}}", err)
}
// Look for a matching storage entry
foundIdx := -1
for itemIdx, item := range bucket.Items {
if item.ID == itemID {
foundIdx = itemIdx
break
}
}
// If there is a match, remove it from the collection and persist the
// resulting collection
if foundIdx != -1 {
bucket.Items = append(bucket.Items[:foundIdx], bucket.Items[foundIdx+1:]...)
// Persist bucket entry only if there is an update
err = s.PutBucket(&bucket)
if err != nil {
return err
}
}
return nil
}
// Put stores a packed bucket entry
func (s *StoragePacker) PutBucket(bucket *Bucket) error {
if bucket == nil {
return fmt.Errorf("nil bucket entry")
}
if bucket.Key == "" {
return fmt.Errorf("missing key")
}
if !strings.HasPrefix(bucket.Key, s.viewPrefix) {
return fmt.Errorf("incorrect prefix; bucket entry key should have %q prefix", s.viewPrefix)
}
marshaledBucket, err := proto.Marshal(bucket)
if err != nil {
return errwrap.Wrapf("failed to marshal bucket: {{err}}", err)
}
compressedBucket, err := compressutil.Compress(marshaledBucket, &compressutil.CompressionConfig{
Type: compressutil.CompressionTypeSnappy,
})
if err != nil {
return errwrap.Wrapf("failed to compress packed bucket: {{err}}", err)
}
// Store the compressed value
err = s.view.Put(context.Background(), &logical.StorageEntry{
Key: bucket.Key,
Value: compressedBucket,
})
if err != nil {
return errwrap.Wrapf("failed to persist packed storage entry: {{err}}", err)
}
return nil
}
// GetItem fetches the storage entry for a given key from its corresponding
// bucket.
func (s *StoragePacker) GetItem(itemID string) (*Item, error) {
if itemID == "" {
return nil, fmt.Errorf("empty item ID")
}
bucketKey := s.BucketKey(itemID)
bucketPath := s.BucketPath(bucketKey)
// Fetch the bucket entry
bucket, err := s.GetBucket(bucketPath)
if err != nil {
return nil, errwrap.Wrapf("failed to read packed storage item: {{err}}", err)
}
if bucket == nil {
return nil, nil
}
// Look for a matching storage entry in the bucket items
for _, item := range bucket.Items {
if item.ID == itemID {
return item, nil
}
}
return nil, nil
}
// PutItem stores a storage entry in its corresponding bucket
func (s *StoragePacker) PutItem(item *Item) error {
if item == nil {
return fmt.Errorf("nil item")
}
if item.ID == "" {
return fmt.Errorf("missing ID in item")
}
var err error
bucketKey := s.BucketKey(item.ID)
bucketPath := s.BucketPath(bucketKey)
bucket := &Bucket{
Key: bucketPath,
}
// In this case, we persist the storage entry regardless of the read
// storageEntry below is nil or not. Hence, directly acquire write lock
// even to read the entry.
lock := locksutil.LockForKey(s.storageLocks, bucketPath)
lock.Lock()
defer lock.Unlock()
// Check if there is an existing bucket for a given key
storageEntry, err := s.view.Get(context.Background(), bucketPath)
if err != nil {
return errwrap.Wrapf("failed to read packed storage bucket entry: {{err}}", err)
}
if storageEntry == nil {
// If the bucket entry does not exist, this will be the only item the
// bucket that is going to be persisted.
bucket.Items = []*Item{
item,
}
} else {
uncompressedData, notCompressed, err := compressutil.Decompress(storageEntry.Value)
if err != nil {
return errwrap.Wrapf("failed to decompress packed storage entry: {{err}}", err)
}
if notCompressed {
uncompressedData = storageEntry.Value
}
err = proto.Unmarshal(uncompressedData, bucket)
if err != nil {
return errwrap.Wrapf("failed to decode packed storage entry: {{err}}", err)
}
err = bucket.upsert(item)
if err != nil {
return errwrap.Wrapf("failed to update entry in packed storage entry: {{err}}", err)
}
}
// Persist the result
return s.PutBucket(bucket)
}
// NewStoragePacker creates a new storage packer for a given view
func NewStoragePacker(view logical.Storage, logger log.Logger, viewPrefix string) (*StoragePacker, error) {
if view == nil {
return nil, fmt.Errorf("nil view")
}
if viewPrefix == "" {
viewPrefix = StoragePackerBucketsPrefix
}
if !strings.HasSuffix(viewPrefix, "/") {
viewPrefix = viewPrefix + "/"
}
// Create a new packer object for the given view
packer := &StoragePacker{
view: view,
viewPrefix: viewPrefix,
logger: logger,
storageLocks: locksutil.CreateLocks(),
}
return packer, nil
}