/usr/share/gocode/src/github.com/docker/libkv/store/boltdb/boltdb.go is in golang-github-docker-libkv-dev 0.1.0-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 | package boltdb
import (
"bytes"
"encoding/binary"
"errors"
"os"
"path/filepath"
"sync"
"sync/atomic"
"time"
"github.com/boltdb/bolt"
"github.com/docker/libkv"
"github.com/docker/libkv/store"
)
var (
// ErrMultipleEndpointsUnsupported is thrown when multiple endpoints specified for
// BoltDB. Endpoint has to be a local file path
ErrMultipleEndpointsUnsupported = errors.New("boltdb supports one endpoint and should be a file path")
// ErrBoltBucketNotFound is thrown when specified BoltBD bucket doesn't exist in the DB
ErrBoltBucketNotFound = errors.New("boltdb bucket doesn't exist")
// ErrBoltBucketOptionMissing is thrown when boltBcuket config option is missing
ErrBoltBucketOptionMissing = errors.New("boltBucket config option missing")
)
const (
filePerm os.FileMode = 0644
)
//BoltDB type implements the Store interface
type BoltDB struct {
client *bolt.DB
boltBucket []byte
dbIndex uint64
path string
timeout time.Duration
// By default libkv opens and closes the bolt DB connection for every
// get/put operation. This allows multiple apps to use a Bolt DB at the
// same time.
// PersistConnection flag provides an option to override ths behavior.
// ie: open the connection in New and use it till Close is called.
PersistConnection bool
sync.Mutex
}
const (
libkvmetadatalen = 8
transientTimeout = time.Duration(10) * time.Second
)
// Register registers boltdb to libkv
func Register() {
libkv.AddStore(store.BOLTDB, New)
}
// New opens a new BoltDB connection to the specified path and bucket
func New(endpoints []string, options *store.Config) (store.Store, error) {
var (
db *bolt.DB
err error
boltOptions *bolt.Options
)
if len(endpoints) > 1 {
return nil, ErrMultipleEndpointsUnsupported
}
if (options == nil) || (len(options.Bucket) == 0) {
return nil, ErrBoltBucketOptionMissing
}
dir, _ := filepath.Split(endpoints[0])
if err = os.MkdirAll(dir, 0750); err != nil {
return nil, err
}
if options.PersistConnection {
boltOptions = &bolt.Options{Timeout: options.ConnectionTimeout}
db, err = bolt.Open(endpoints[0], filePerm, boltOptions)
if err != nil {
return nil, err
}
}
b := &BoltDB{
client: db,
path: endpoints[0],
boltBucket: []byte(options.Bucket),
timeout: transientTimeout,
PersistConnection: options.PersistConnection,
}
return b, nil
}
func (b *BoltDB) reset() {
b.path = ""
b.boltBucket = []byte{}
}
func (b *BoltDB) getDBhandle() (*bolt.DB, error) {
var (
db *bolt.DB
err error
)
if !b.PersistConnection {
boltOptions := &bolt.Options{Timeout: b.timeout}
if db, err = bolt.Open(b.path, filePerm, boltOptions); err != nil {
return nil, err
}
b.client = db
}
return b.client, nil
}
func (b *BoltDB) releaseDBhandle() {
if !b.PersistConnection {
b.client.Close()
}
}
// Get the value at "key". BoltDB doesn't provide an inbuilt last modified index with every kv pair. Its implemented by
// by a atomic counter maintained by the libkv and appened to the value passed by the client.
func (b *BoltDB) Get(key string) (*store.KVPair, error) {
var (
val []byte
db *bolt.DB
err error
)
b.Lock()
defer b.Unlock()
if db, err = b.getDBhandle(); err != nil {
return nil, err
}
defer b.releaseDBhandle()
err = db.View(func(tx *bolt.Tx) error {
bucket := tx.Bucket(b.boltBucket)
if bucket == nil {
return ErrBoltBucketNotFound
}
v := bucket.Get([]byte(key))
val = make([]byte, len(v))
copy(val, v)
return nil
})
if len(val) == 0 {
return nil, store.ErrKeyNotFound
}
if err != nil {
return nil, err
}
dbIndex := binary.LittleEndian.Uint64(val[:libkvmetadatalen])
val = val[libkvmetadatalen:]
return &store.KVPair{Key: key, Value: val, LastIndex: (dbIndex)}, nil
}
//Put the key, value pair. index number metadata is prepended to the value
func (b *BoltDB) Put(key string, value []byte, opts *store.WriteOptions) error {
var (
dbIndex uint64
db *bolt.DB
err error
)
b.Lock()
defer b.Unlock()
dbval := make([]byte, libkvmetadatalen)
if db, err = b.getDBhandle(); err != nil {
return err
}
defer b.releaseDBhandle()
err = db.Update(func(tx *bolt.Tx) error {
bucket, err := tx.CreateBucketIfNotExists(b.boltBucket)
if err != nil {
return err
}
dbIndex = atomic.AddUint64(&b.dbIndex, 1)
binary.LittleEndian.PutUint64(dbval, dbIndex)
dbval = append(dbval, value...)
err = bucket.Put([]byte(key), dbval)
if err != nil {
return err
}
return nil
})
return err
}
//Delete the value for the given key.
func (b *BoltDB) Delete(key string) error {
var (
db *bolt.DB
err error
)
b.Lock()
defer b.Unlock()
if db, err = b.getDBhandle(); err != nil {
return err
}
defer b.releaseDBhandle()
err = db.Update(func(tx *bolt.Tx) error {
bucket := tx.Bucket(b.boltBucket)
if bucket == nil {
return ErrBoltBucketNotFound
}
err := bucket.Delete([]byte(key))
return err
})
return err
}
// Exists checks if the key exists inside the store
func (b *BoltDB) Exists(key string) (bool, error) {
var (
val []byte
db *bolt.DB
err error
)
b.Lock()
defer b.Unlock()
if db, err = b.getDBhandle(); err != nil {
return false, err
}
defer b.releaseDBhandle()
err = db.View(func(tx *bolt.Tx) error {
bucket := tx.Bucket(b.boltBucket)
if bucket == nil {
return ErrBoltBucketNotFound
}
val = bucket.Get([]byte(key))
return nil
})
if len(val) == 0 {
return false, err
}
return true, err
}
// List returns the range of keys starting with the passed in prefix
func (b *BoltDB) List(keyPrefix string) ([]*store.KVPair, error) {
var (
db *bolt.DB
err error
)
b.Lock()
defer b.Unlock()
kv := []*store.KVPair{}
if db, err = b.getDBhandle(); err != nil {
return nil, err
}
defer b.releaseDBhandle()
err = db.View(func(tx *bolt.Tx) error {
bucket := tx.Bucket(b.boltBucket)
if bucket == nil {
return ErrBoltBucketNotFound
}
cursor := bucket.Cursor()
prefix := []byte(keyPrefix)
for key, v := cursor.Seek(prefix); bytes.HasPrefix(key, prefix); key, v = cursor.Next() {
dbIndex := binary.LittleEndian.Uint64(v[:libkvmetadatalen])
v = v[libkvmetadatalen:]
val := make([]byte, len(v))
copy(val, v)
kv = append(kv, &store.KVPair{
Key: string(key),
Value: val,
LastIndex: dbIndex,
})
}
return nil
})
if len(kv) == 0 {
return nil, store.ErrKeyNotFound
}
return kv, err
}
// AtomicDelete deletes a value at "key" if the key
// has not been modified in the meantime, throws an
// error if this is the case
func (b *BoltDB) AtomicDelete(key string, previous *store.KVPair) (bool, error) {
var (
val []byte
db *bolt.DB
err error
)
b.Lock()
defer b.Unlock()
if previous == nil {
return false, store.ErrPreviousNotSpecified
}
if db, err = b.getDBhandle(); err != nil {
return false, err
}
defer b.releaseDBhandle()
err = db.Update(func(tx *bolt.Tx) error {
bucket := tx.Bucket(b.boltBucket)
if bucket == nil {
return ErrBoltBucketNotFound
}
val = bucket.Get([]byte(key))
if val == nil {
return store.ErrKeyNotFound
}
dbIndex := binary.LittleEndian.Uint64(val[:libkvmetadatalen])
if dbIndex != previous.LastIndex {
return store.ErrKeyModified
}
err := bucket.Delete([]byte(key))
return err
})
if err != nil {
return false, err
}
return true, err
}
// AtomicPut puts a value at "key" if the key has not been
// modified since the last Put, throws an error if this is the case
func (b *BoltDB) AtomicPut(key string, value []byte, previous *store.KVPair, options *store.WriteOptions) (bool, *store.KVPair, error) {
var (
val []byte
dbIndex uint64
db *bolt.DB
err error
)
b.Lock()
defer b.Unlock()
dbval := make([]byte, libkvmetadatalen)
if db, err = b.getDBhandle(); err != nil {
return false, nil, err
}
defer b.releaseDBhandle()
err = db.Update(func(tx *bolt.Tx) error {
var err error
bucket := tx.Bucket(b.boltBucket)
if bucket == nil {
if previous != nil {
return ErrBoltBucketNotFound
}
bucket, err = tx.CreateBucket(b.boltBucket)
if err != nil {
return err
}
}
// AtomicPut is equivalent to Put if previous is nil and the Ky
// doesn't exist in the DB.
val = bucket.Get([]byte(key))
if previous == nil && len(val) != 0 {
return store.ErrKeyExists
}
if previous != nil {
if len(val) == 0 {
return store.ErrKeyNotFound
}
dbIndex = binary.LittleEndian.Uint64(val[:libkvmetadatalen])
if dbIndex != previous.LastIndex {
return store.ErrKeyModified
}
}
dbIndex = atomic.AddUint64(&b.dbIndex, 1)
binary.LittleEndian.PutUint64(dbval, b.dbIndex)
dbval = append(dbval, value...)
return (bucket.Put([]byte(key), dbval))
})
if err != nil {
return false, nil, err
}
updated := &store.KVPair{
Key: key,
Value: value,
LastIndex: dbIndex,
}
return true, updated, nil
}
// Close the db connection to the BoltDB
func (b *BoltDB) Close() {
b.Lock()
defer b.Unlock()
if !b.PersistConnection {
b.reset()
} else {
b.client.Close()
}
return
}
// DeleteTree deletes a range of keys with a given prefix
func (b *BoltDB) DeleteTree(keyPrefix string) error {
var (
db *bolt.DB
err error
)
b.Lock()
defer b.Unlock()
if db, err = b.getDBhandle(); err != nil {
return err
}
defer b.releaseDBhandle()
err = db.Update(func(tx *bolt.Tx) error {
bucket := tx.Bucket(b.boltBucket)
if bucket == nil {
return ErrBoltBucketNotFound
}
cursor := bucket.Cursor()
prefix := []byte(keyPrefix)
for key, _ := cursor.Seek(prefix); bytes.HasPrefix(key, prefix); key, _ = cursor.Next() {
_ = bucket.Delete([]byte(key))
}
return nil
})
return err
}
// NewLock has to implemented at the library level since its not supported by BoltDB
func (b *BoltDB) NewLock(key string, options *store.LockOptions) (store.Locker, error) {
return nil, store.ErrCallNotSupported
}
// Watch has to implemented at the library level since its not supported by BoltDB
func (b *BoltDB) Watch(key string, stopCh <-chan struct{}) (<-chan *store.KVPair, error) {
return nil, store.ErrCallNotSupported
}
// WatchTree has to implemented at the library level since its not supported by BoltDB
func (b *BoltDB) WatchTree(directory string, stopCh <-chan struct{}) (<-chan []*store.KVPair, error) {
return nil, store.ErrCallNotSupported
}
|