/usr/share/gocode/src/github.com/jacobsa/gcloud/gcs/gcsfake/bucket.go is in golang-github-jacobsa-gcloud-dev 0.0~git20150709-1.
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 | // Copyright 2015 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package gcsfake
import (
"bytes"
"crypto/md5"
"encoding/hex"
"errors"
"fmt"
"hash/crc32"
"io"
"io/ioutil"
"sort"
"strings"
"unicode/utf8"
"github.com/jacobsa/gcloud/gcs"
"github.com/jacobsa/syncutil"
"github.com/jacobsa/timeutil"
"golang.org/x/net/context"
)
var crc32cTable = crc32.MakeTable(crc32.Castagnoli)
// Equivalent to NewConn(clock).GetBucket(name).
func NewFakeBucket(clock timeutil.Clock, name string) gcs.Bucket {
b := &bucket{clock: clock, name: name}
b.mu = syncutil.NewInvariantMutex(b.checkInvariants)
return b
}
////////////////////////////////////////////////////////////////////////
// Helper types
////////////////////////////////////////////////////////////////////////
type fakeObject struct {
metadata gcs.Object
data []byte
}
// A slice of objects compared by name.
type fakeObjectSlice []fakeObject
func (s fakeObjectSlice) Len() int {
return len(s)
}
func (s fakeObjectSlice) Less(i, j int) bool {
return s[i].metadata.Name < s[j].metadata.Name
}
func (s fakeObjectSlice) Swap(i, j int) {
s[i], s[j] = s[j], s[i]
}
// Return the smallest i such that s[i].metadata.Name >= name, or len(s) if
// there is no such i.
func (s fakeObjectSlice) lowerBound(name string) int {
pred := func(i int) bool {
return s[i].metadata.Name >= name
}
return sort.Search(len(s), pred)
}
// Return the smallest i such that s[i].metadata.Name == name, or len(s) if
// there is no such i.
func (s fakeObjectSlice) find(name string) int {
lb := s.lowerBound(name)
if lb < len(s) && s[lb].metadata.Name == name {
return lb
}
return len(s)
}
// Return the smallest string that is lexicographically larger than prefix and
// does not have prefix as a prefix. For the sole case where this is not
// possible (all strings consisting solely of 0xff bytes, including the empty
// string), return the empty string.
func prefixSuccessor(prefix string) string {
// Attempt to increment the last byte. If that is a 0xff byte, erase it and
// recurse. If we hit an empty string, then we know our task is impossible.
limit := []byte(prefix)
for len(limit) > 0 {
b := limit[len(limit)-1]
if b != 0xff {
limit[len(limit)-1]++
break
}
limit = limit[:len(limit)-1]
}
return string(limit)
}
// Return the smallest i such that prefix < s[i].metadata.Name and
// !strings.HasPrefix(s[i].metadata.Name, prefix).
func (s fakeObjectSlice) prefixUpperBound(prefix string) int {
successor := prefixSuccessor(prefix)
if successor == "" {
return len(s)
}
return s.lowerBound(successor)
}
////////////////////////////////////////////////////////////////////////
// Helpers
////////////////////////////////////////////////////////////////////////
type bucket struct {
clock timeutil.Clock
name string
mu syncutil.InvariantMutex
// The set of extant objects.
//
// INVARIANT: Strictly increasing.
objects fakeObjectSlice // GUARDED_BY(mu)
// The most recent generation number that was minted. The next object will
// receive generation prevGeneration + 1.
//
// INVARIANT: This is an upper bound for generation numbers in objects.
prevGeneration int64 // GUARDED_BY(mu)
}
func checkName(name string) (err error) {
if len(name) == 0 || len(name) > 1024 {
err = errors.New("Invalid object name: length must be in [1, 1024]")
return
}
if !utf8.ValidString(name) {
err = errors.New("Invalid object name: not valid UTF-8")
return
}
for _, r := range name {
if r == 0x0a || r == 0x0d {
err = errors.New("Invalid object name: must not contain CR or LF")
return
}
}
return
}
// LOCKS_REQUIRED(b.mu)
func (b *bucket) checkInvariants() {
// Make sure 'objects' is strictly increasing.
for i := 1; i < len(b.objects); i++ {
objA := b.objects[i-1]
objB := b.objects[i]
if !(objA.metadata.Name < objB.metadata.Name) {
panic(
fmt.Sprintf(
"Object names are not strictly increasing: %v vs. %v",
objA.metadata.Name,
objB.metadata.Name))
}
}
// Make sure prevGeneration is an upper bound for object generation numbers.
for _, o := range b.objects {
if !(o.metadata.Generation <= b.prevGeneration) {
panic(
fmt.Sprintf(
"Object generation %v exceeds %v",
o.metadata.Generation,
b.prevGeneration))
}
}
}
// Create an object struct for the given attributes and contents.
//
// LOCKS_REQUIRED(b.mu)
func (b *bucket) mintObject(
req *gcs.CreateObjectRequest,
contents []byte) (o fakeObject) {
md5Sum := md5.Sum(contents)
// Set up basic info.
b.prevGeneration++
o.metadata = gcs.Object{
Name: req.Name,
ContentType: req.ContentType,
ContentLanguage: req.ContentLanguage,
CacheControl: req.CacheControl,
Owner: "user-fake",
Size: uint64(len(contents)),
ContentEncoding: req.ContentEncoding,
ComponentCount: 1,
MD5: &md5Sum,
CRC32C: crc32.Checksum(contents, crc32cTable),
MediaLink: "http://localhost/download/storage/fake/" + req.Name,
Metadata: req.Metadata,
Generation: b.prevGeneration,
MetaGeneration: 1,
StorageClass: "STANDARD",
Updated: b.clock.Now(),
}
// Set up data.
o.data = contents
// Support the same default content type as GCS.
if o.metadata.ContentType == "" {
o.metadata.ContentType = "application/octet-stream"
}
return
}
// LOCKS_REQUIRED(b.mu)
func (b *bucket) createObjectLocked(
req *gcs.CreateObjectRequest) (o *gcs.Object, err error) {
// Check that the name is legal.
err = checkName(req.Name)
if err != nil {
return
}
// Snarf the contents.
contents, err := ioutil.ReadAll(req.Contents)
if err != nil {
err = fmt.Errorf("ReadAll: %v", err)
return
}
// Find any existing record for this name.
existingIndex := b.objects.find(req.Name)
var existingRecord *fakeObject
if existingIndex < len(b.objects) {
existingRecord = &b.objects[existingIndex]
}
// Check the provided checksum, if any.
if req.CRC32C != nil {
actual := crc32.Checksum(contents, crc32cTable)
if actual != *req.CRC32C {
err = fmt.Errorf(
"CRC32C mismatch: got 0x%08x, expected 0x%08x",
actual,
*req.CRC32C)
return
}
}
// Check the provided hash, if any.
if req.MD5 != nil {
actual := md5.Sum(contents)
if actual != *req.MD5 {
err = fmt.Errorf(
"MD5 mismatch: got %s, expected %s",
hex.EncodeToString(actual[:]),
hex.EncodeToString(req.MD5[:]))
return
}
}
// Check preconditions.
if req.GenerationPrecondition != nil {
if *req.GenerationPrecondition == 0 && existingRecord != nil {
err = &gcs.PreconditionError{
Err: errors.New("Precondition failed: object exists"),
}
return
}
if *req.GenerationPrecondition > 0 {
if existingRecord == nil {
err = &gcs.PreconditionError{
Err: errors.New("Precondition failed: object doesn't exist"),
}
return
}
existingGen := existingRecord.metadata.Generation
if existingGen != *req.GenerationPrecondition {
err = &gcs.PreconditionError{
Err: fmt.Errorf(
"Precondition failed: object has generation %v",
existingGen),
}
return
}
}
}
// Create an object record from the given attributes.
var fo fakeObject = b.mintObject(req, contents)
o = &fo.metadata
// Replace an entry in or add an entry to our list of objects.
if existingIndex < len(b.objects) {
b.objects[existingIndex] = fo
} else {
b.objects = append(b.objects, fo)
sort.Sort(b.objects)
}
return
}
// Create a reader based on the supplied request, also returning the index
// within b.objects of the entry for the requested generation.
//
// LOCKS_REQUIRED(b.mu)
func (b *bucket) newReaderLocked(
req *gcs.ReadObjectRequest) (r io.Reader, index int, err error) {
// Find the object with the requested name.
index = b.objects.find(req.Name)
if index == len(b.objects) {
err = &gcs.NotFoundError{
Err: fmt.Errorf("Object %s not found", req.Name),
}
return
}
o := b.objects[index]
// Does the generation match?
if req.Generation != 0 && req.Generation != o.metadata.Generation {
err = &gcs.NotFoundError{
Err: fmt.Errorf(
"Object %s generation %v not found", req.Name, req.Generation),
}
return
}
// Extract the requested range.
result := o.data
if req.Range != nil {
start := req.Range.Start
limit := req.Range.Limit
l := uint64(len(result))
if start > limit {
start = 0
limit = 0
}
if start > l {
start = 0
limit = 0
}
if limit > l {
limit = l
}
result = result[start:limit]
}
r = bytes.NewReader(result)
return
}
func minInt(a, b int) int {
if a < b {
return a
}
return b
}
////////////////////////////////////////////////////////////////////////
// Public interface
////////////////////////////////////////////////////////////////////////
func (b *bucket) Name() string {
return b.name
}
// LOCKS_EXCLUDED(b.mu)
func (b *bucket) ListObjects(
ctx context.Context,
req *gcs.ListObjectsRequest) (listing *gcs.Listing, err error) {
b.mu.Lock()
defer b.mu.Unlock()
// Set up the result object.
listing = new(gcs.Listing)
// Handle defaults.
maxResults := req.MaxResults
if maxResults == 0 {
maxResults = 1000
}
// Find where in the space of object names to start.
nameStart := req.Prefix
if req.ContinuationToken != "" && req.ContinuationToken > nameStart {
nameStart = req.ContinuationToken
}
// Find the range of indexes within the array to scan.
indexStart := b.objects.lowerBound(nameStart)
prefixLimit := b.objects.prefixUpperBound(req.Prefix)
indexLimit := minInt(indexStart+maxResults, prefixLimit)
// Scan the array.
var lastResultWasPrefix bool
for i := indexStart; i < indexLimit; i++ {
var o fakeObject = b.objects[i]
name := o.metadata.Name
// Search for a delimiter if necessary.
if req.Delimiter != "" {
// Search only in the part after the prefix.
nameMinusQueryPrefix := name[len(req.Prefix):]
delimiterIndex := strings.Index(nameMinusQueryPrefix, req.Delimiter)
if delimiterIndex >= 0 {
resultPrefixLimit := delimiterIndex
// Transform to an index within name.
resultPrefixLimit += len(req.Prefix)
// Include the delimiter in the result.
resultPrefixLimit += len(req.Delimiter)
// Save the result, but only if it's not a duplicate.
resultPrefix := name[:resultPrefixLimit]
if len(listing.CollapsedRuns) == 0 ||
listing.CollapsedRuns[len(listing.CollapsedRuns)-1] != resultPrefix {
listing.CollapsedRuns = append(listing.CollapsedRuns, resultPrefix)
}
lastResultWasPrefix = true
continue
}
}
lastResultWasPrefix = false
// Otherwise, return as an object result. Make a copy to avoid handing back
// internal state.
var oCopy gcs.Object = o.metadata
listing.Objects = append(listing.Objects, &oCopy)
}
// Set up a cursor for where to start the next scan if we didn't exhaust the
// results.
if indexLimit < prefixLimit {
// If the final object we visited was returned as an element in
// listing.CollapsedRuns, we want to skip all other objects that would
// result in the same so we don't return duplicate elements in
// listing.CollapsedRuns accross requests.
if lastResultWasPrefix {
lastResultPrefix := listing.CollapsedRuns[len(listing.CollapsedRuns)-1]
listing.ContinuationToken = prefixSuccessor(lastResultPrefix)
// Check an assumption: prefixSuccessor cannot result in the empty string
// above because object names must be non-empty UTF-8 strings, and there
// is no valid non-empty UTF-8 string that consists of entirely 0xff
// bytes.
if listing.ContinuationToken == "" {
err = errors.New("Unexpected empty string from prefixSuccessor")
return
}
} else {
// Otherwise, we'll start scanning at the next object.
listing.ContinuationToken = b.objects[indexLimit].metadata.Name
}
}
return
}
// LOCKS_EXCLUDED(b.mu)
func (b *bucket) NewReader(
ctx context.Context,
req *gcs.ReadObjectRequest) (rc io.ReadCloser, err error) {
b.mu.Lock()
defer b.mu.Unlock()
r, _, err := b.newReaderLocked(req)
if err != nil {
return
}
rc = ioutil.NopCloser(r)
return
}
// LOCKS_EXCLUDED(b.mu)
func (b *bucket) CreateObject(
ctx context.Context,
req *gcs.CreateObjectRequest) (o *gcs.Object, err error) {
b.mu.Lock()
defer b.mu.Unlock()
o, err = b.createObjectLocked(req)
return
}
// LOCKS_EXCLUDED(b.mu)
func (b *bucket) CopyObject(
ctx context.Context,
req *gcs.CopyObjectRequest) (o *gcs.Object, err error) {
b.mu.Lock()
defer b.mu.Unlock()
// Check that the destination name is legal.
err = checkName(req.DstName)
if err != nil {
return
}
// Does the object exist?
srcIndex := b.objects.find(req.SrcName)
if srcIndex == len(b.objects) {
err = &gcs.NotFoundError{
Err: fmt.Errorf("Object %q not found", req.SrcName),
}
return
}
// Does it have the correct generation?
if req.SrcGeneration != 0 &&
b.objects[srcIndex].metadata.Generation != req.SrcGeneration {
err = &gcs.NotFoundError{
Err: fmt.Errorf(
"Object %s generation %d not found", req.SrcName, req.SrcGeneration),
}
return
}
// Copy it and assign a new generation number, to ensure that the generation
// number for the destination name is strictly increasing.
dst := b.objects[srcIndex]
dst.metadata.Name = req.DstName
dst.metadata.MediaLink = "http://localhost/download/storage/fake/" + req.DstName
b.prevGeneration++
dst.metadata.Generation = b.prevGeneration
// Insert into our array.
existingIndex := b.objects.find(req.DstName)
if existingIndex < len(b.objects) {
b.objects[existingIndex] = dst
} else {
b.objects = append(b.objects, dst)
sort.Sort(b.objects)
}
o = &dst.metadata
return
}
// LOCKS_EXCLUDED(b.mu)
func (b *bucket) ComposeObjects(
ctx context.Context,
req *gcs.ComposeObjectsRequest) (o *gcs.Object, err error) {
b.mu.Lock()
defer b.mu.Unlock()
// GCS doesn't like too few or too many sources.
if len(req.Sources) < 2 {
err = errors.New("You must provide at least two source components")
return
}
if len(req.Sources) > gcs.MaxSourcesPerComposeRequest {
err = errors.New("You have provided too many source components")
return
}
// Find readers for all of the source objects, also computing the sum of
// their component counts.
var srcReaders []io.Reader
var dstComponentCount int64
for _, src := range req.Sources {
var r io.Reader
var srcIndex int
r, srcIndex, err = b.newReaderLocked(&gcs.ReadObjectRequest{
Name: src.Name,
Generation: src.Generation,
})
if err != nil {
return
}
srcReaders = append(srcReaders, r)
dstComponentCount += b.objects[srcIndex].metadata.ComponentCount
}
// GCS doesn't like the component count to go too high.
if dstComponentCount > gcs.MaxComponentCount {
err = errors.New("Result would have too many components")
return
}
// Create the new object.
createReq := &gcs.CreateObjectRequest{
Name: req.DstName,
GenerationPrecondition: req.DstGenerationPrecondition,
Contents: io.MultiReader(srcReaders...),
}
_, err = b.createObjectLocked(createReq)
if err != nil {
return
}
dstIndex := b.objects.find(req.DstName)
metadata := &b.objects[dstIndex].metadata
// Touchup: fix the component count.
metadata.ComponentCount = dstComponentCount
// Touchup: emulate the real GCS behavior of not exporting an MD5 hash for
// composite objects.
metadata.MD5 = nil
oCopy := *metadata
o = &oCopy
return
}
// LOCKS_EXCLUDED(b.mu)
func (b *bucket) StatObject(
ctx context.Context,
req *gcs.StatObjectRequest) (o *gcs.Object, err error) {
b.mu.Lock()
defer b.mu.Unlock()
// Does the object exist?
index := b.objects.find(req.Name)
if index == len(b.objects) {
err = &gcs.NotFoundError{
Err: fmt.Errorf("Object %s not found", req.Name),
}
return
}
// Make a copy to avoid handing back internal state.
var objCopy gcs.Object = b.objects[index].metadata
o = &objCopy
return
}
// LOCKS_EXCLUDED(b.mu)
func (b *bucket) UpdateObject(
ctx context.Context,
req *gcs.UpdateObjectRequest) (o *gcs.Object, err error) {
b.mu.Lock()
defer b.mu.Unlock()
// Match real GCS in not allowing the removal of ContentType.
if req.ContentType != nil && *req.ContentType == "" {
err = errors.New("The ContentType field is required and cannot be removed.")
return
}
// Does the object exist?
index := b.objects.find(req.Name)
if index == len(b.objects) {
err = &gcs.NotFoundError{
Err: fmt.Errorf("Object %s not found", req.Name),
}
return
}
var obj *gcs.Object = &b.objects[index].metadata
// Update the entry's basic fields according to the request.
if req.ContentType != nil {
obj.ContentType = *req.ContentType
}
if req.ContentEncoding != nil {
obj.ContentEncoding = *req.ContentEncoding
}
if req.ContentLanguage != nil {
obj.ContentLanguage = *req.ContentLanguage
}
if req.CacheControl != nil {
obj.CacheControl = *req.CacheControl
}
// Update the user metadata if necessary.
if len(req.Metadata) > 0 {
if obj.Metadata == nil {
obj.Metadata = make(map[string]string)
}
for k, v := range req.Metadata {
if v == nil {
delete(obj.Metadata, k)
continue
}
obj.Metadata[k] = *v
}
}
// Bump up the entry generation number.
obj.MetaGeneration++
// Make a copy to avoid handing back internal state.
var objCopy gcs.Object = *obj
o = &objCopy
return
}
// LOCKS_EXCLUDED(b.mu)
func (b *bucket) DeleteObject(
ctx context.Context,
req *gcs.DeleteObjectRequest) (err error) {
b.mu.Lock()
defer b.mu.Unlock()
// Do we possess the object with the given name?
index := b.objects.find(req.Name)
if index == len(b.objects) {
return
}
// Don't do anything if the generation is wrong.
if req.Generation != 0 &&
b.objects[index].metadata.Generation != req.Generation {
return
}
// Remove the object.
b.objects = append(b.objects[:index], b.objects[index+1:]...)
return
}
|