summaryrefslogtreecommitdiffstats
path: root/vendor/github.com/minio/minio-go/api-list.go
blob: 795de6183e44c68e4a099a78df8411e95c815d4c (plain)
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
/*
 * Minio Go Library for Amazon S3 Compatible Cloud Storage (C) 2015, 2016 Minio, Inc.
 *
 * 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 minio

import (
	"fmt"
	"net/http"
	"net/url"
	"strings"
)

// ListBuckets list all buckets owned by this authenticated user.
//
// This call requires explicit authentication, no anonymous requests are
// allowed for listing buckets.
//
//   api := client.New(....)
//   for message := range api.ListBuckets() {
//       fmt.Println(message)
//   }
//
func (c Client) ListBuckets() ([]BucketInfo, error) {
	// Execute GET on service.
	resp, err := c.executeMethod("GET", requestMetadata{})
	defer closeResponse(resp)
	if err != nil {
		return nil, err
	}
	if resp != nil {
		if resp.StatusCode != http.StatusOK {
			return nil, httpRespToErrorResponse(resp, "", "")
		}
	}
	listAllMyBucketsResult := listAllMyBucketsResult{}
	err = xmlDecoder(resp.Body, &listAllMyBucketsResult)
	if err != nil {
		return nil, err
	}
	return listAllMyBucketsResult.Buckets.Bucket, nil
}

/// Bucket Read Operations.

// ListObjectsV2 lists all objects matching the objectPrefix from
// the specified bucket. If recursion is enabled it would list
// all subdirectories and all its contents.
//
// Your input parameters are just bucketName, objectPrefix, recursive
// and a done channel for pro-actively closing the internal go
// routine. If you enable recursive as 'true' this function will
// return back all the objects in a given bucket name and object
// prefix.
//
//   api := client.New(....)
//   // Create a done channel.
//   doneCh := make(chan struct{})
//   defer close(doneCh)
//   // Recurively list all objects in 'mytestbucket'
//   recursive := true
//   for message := range api.ListObjectsV2("mytestbucket", "starthere", recursive, doneCh) {
//       fmt.Println(message)
//   }
//
func (c Client) ListObjectsV2(bucketName, objectPrefix string, recursive bool, doneCh <-chan struct{}) <-chan ObjectInfo {
	// Allocate new list objects channel.
	objectStatCh := make(chan ObjectInfo, 1)
	// Default listing is delimited at "/"
	delimiter := "/"
	if recursive {
		// If recursive we do not delimit.
		delimiter = ""
	}
	// Return object owner information by default
	fetchOwner := true
	// Validate bucket name.
	if err := isValidBucketName(bucketName); err != nil {
		defer close(objectStatCh)
		objectStatCh <- ObjectInfo{
			Err: err,
		}
		return objectStatCh
	}
	// Validate incoming object prefix.
	if err := isValidObjectPrefix(objectPrefix); err != nil {
		defer close(objectStatCh)
		objectStatCh <- ObjectInfo{
			Err: err,
		}
		return objectStatCh
	}

	// Initiate list objects goroutine here.
	go func(objectStatCh chan<- ObjectInfo) {
		defer close(objectStatCh)
		// Save continuationToken for next request.
		var continuationToken string
		for {
			// Get list of objects a maximum of 1000 per request.
			result, err := c.listObjectsV2Query(bucketName, objectPrefix, continuationToken, fetchOwner, delimiter, 1000)
			if err != nil {
				objectStatCh <- ObjectInfo{
					Err: err,
				}
				return
			}

			// If contents are available loop through and send over channel.
			for _, object := range result.Contents {
				// Save the marker.
				select {
				// Send object content.
				case objectStatCh <- object:
				// If receives done from the caller, return here.
				case <-doneCh:
					return
				}
			}

			// Send all common prefixes if any.
			// NOTE: prefixes are only present if the request is delimited.
			for _, obj := range result.CommonPrefixes {
				object := ObjectInfo{}
				object.Key = obj.Prefix
				object.Size = 0
				select {
				// Send object prefixes.
				case objectStatCh <- object:
				// If receives done from the caller, return here.
				case <-doneCh:
					return
				}
			}

			// If continuation token present, save it for next request.
			if result.NextContinuationToken != "" {
				continuationToken = result.NextContinuationToken
			}

			// Listing ends result is not truncated, return right here.
			if !result.IsTruncated {
				return
			}
		}
	}(objectStatCh)
	return objectStatCh
}

// listObjectsV2Query - (List Objects V2) - List some or all (up to 1000) of the objects in a bucket.
//
// You can use the request parameters as selection criteria to return a subset of the objects in a bucket.
// request parameters :-
// ---------
// ?continuation-token - Specifies the key to start with when listing objects in a bucket.
// ?delimiter - A delimiter is a character you use to group keys.
// ?prefix - Limits the response to keys that begin with the specified prefix.
// ?max-keys - Sets the maximum number of keys returned in the response body.
func (c Client) listObjectsV2Query(bucketName, objectPrefix, continuationToken string, fetchOwner bool, delimiter string, maxkeys int) (listBucketV2Result, error) {
	// Validate bucket name.
	if err := isValidBucketName(bucketName); err != nil {
		return listBucketV2Result{}, err
	}
	// Validate object prefix.
	if err := isValidObjectPrefix(objectPrefix); err != nil {
		return listBucketV2Result{}, err
	}
	// Get resources properly escaped and lined up before
	// using them in http request.
	urlValues := make(url.Values)

	// Always set list-type in ListObjects V2
	urlValues.Set("list-type", "2")

	// Set object prefix.
	if objectPrefix != "" {
		urlValues.Set("prefix", objectPrefix)
	}
	// Set continuation token
	if continuationToken != "" {
		urlValues.Set("continuation-token", continuationToken)
	}
	// Set delimiter.
	if delimiter != "" {
		urlValues.Set("delimiter", delimiter)
	}

	// Fetch owner when listing
	if fetchOwner {
		urlValues.Set("fetch-owner", "true")
	}

	// maxkeys should default to 1000 or less.
	if maxkeys == 0 || maxkeys > 1000 {
		maxkeys = 1000
	}
	// Set max keys.
	urlValues.Set("max-keys", fmt.Sprintf("%d", maxkeys))

	// Execute GET on bucket to list objects.
	resp, err := c.executeMethod("GET", requestMetadata{
		bucketName:  bucketName,
		queryValues: urlValues,
	})
	defer closeResponse(resp)
	if err != nil {
		return listBucketV2Result{}, err
	}
	if resp != nil {
		if resp.StatusCode != http.StatusOK {
			return listBucketV2Result{}, httpRespToErrorResponse(resp, bucketName, "")
		}
	}

	// Decode listBuckets XML.
	listBucketResult := listBucketV2Result{}
	err = xmlDecoder(resp.Body, &listBucketResult)
	if err != nil {
		return listBucketResult, err
	}
	return listBucketResult, nil
}

// ListObjects - (List Objects) - List some objects or all recursively.
//
// ListObjects lists all objects matching the objectPrefix from
// the specified bucket. If recursion is enabled it would list
// all subdirectories and all its contents.
//
// Your input parameters are just bucketName, objectPrefix, recursive
// and a done channel for pro-actively closing the internal go
// routine. If you enable recursive as 'true' this function will
// return back all the objects in a given bucket name and object
// prefix.
//
//   api := client.New(....)
//   // Create a done channel.
//   doneCh := make(chan struct{})
//   defer close(doneCh)
//   // Recurively list all objects in 'mytestbucket'
//   recursive := true
//   for message := range api.ListObjects("mytestbucket", "starthere", recursive, doneCh) {
//       fmt.Println(message)
//   }
//
func (c Client) ListObjects(bucketName, objectPrefix string, recursive bool, doneCh <-chan struct{}) <-chan ObjectInfo {
	// Allocate new list objects channel.
	objectStatCh := make(chan ObjectInfo, 1)
	// Default listing is delimited at "/"
	delimiter := "/"
	if recursive {
		// If recursive we do not delimit.
		delimiter = ""
	}
	// Validate bucket name.
	if err := isValidBucketName(bucketName); err != nil {
		defer close(objectStatCh)
		objectStatCh <- ObjectInfo{
			Err: err,
		}
		return objectStatCh
	}
	// Validate incoming object prefix.
	if err := isValidObjectPrefix(objectPrefix); err != nil {
		defer close(objectStatCh)
		objectStatCh <- ObjectInfo{
			Err: err,
		}
		return objectStatCh
	}

	// Initiate list objects goroutine here.
	go func(objectStatCh chan<- ObjectInfo) {
		defer close(objectStatCh)
		// Save marker for next request.
		var marker string
		for {
			// Get list of objects a maximum of 1000 per request.
			result, err := c.listObjectsQuery(bucketName, objectPrefix, marker, delimiter, 1000)
			if err != nil {
				objectStatCh <- ObjectInfo{
					Err: err,
				}
				return
			}

			// If contents are available loop through and send over channel.
			for _, object := range result.Contents {
				// Save the marker.
				marker = object.Key
				select {
				// Send object content.
				case objectStatCh <- object:
				// If receives done from the caller, return here.
				case <-doneCh:
					return
				}
			}

			// Send all common prefixes if any.
			// NOTE: prefixes are only present if the request is delimited.
			for _, obj := range result.CommonPrefixes {
				object := ObjectInfo{}
				object.Key = obj.Prefix
				object.Size = 0
				select {
				// Send object prefixes.
				case objectStatCh <- object:
				// If receives done from the caller, return here.
				case <-doneCh:
					return
				}
			}

			// If next marker present, save it for next request.
			if result.NextMarker != "" {
				marker = result.NextMarker
			}

			// Listing ends result is not truncated, return right here.
			if !result.IsTruncated {
				return
			}
		}
	}(objectStatCh)
	return objectStatCh
}

// listObjects - (List Objects) - List some or all (up to 1000) of the objects in a bucket.
//
// You can use the request parameters as selection criteria to return a subset of the objects in a bucket.
// request parameters :-
// ---------
// ?marker - Specifies the key to start with when listing objects in a bucket.
// ?delimiter - A delimiter is a character you use to group keys.
// ?prefix - Limits the response to keys that begin with the specified prefix.
// ?max-keys - Sets the maximum number of keys returned in the response body.
func (c Client) listObjectsQuery(bucketName, objectPrefix, objectMarker, delimiter string, maxkeys int) (listBucketResult, error) {
	// Validate bucket name.
	if err := isValidBucketName(bucketName); err != nil {
		return listBucketResult{}, err
	}
	// Validate object prefix.
	if err := isValidObjectPrefix(objectPrefix); err != nil {
		return listBucketResult{}, err
	}
	// Get resources properly escaped and lined up before
	// using them in http request.
	urlValues := make(url.Values)
	// Set object prefix.
	if objectPrefix != "" {
		urlValues.Set("prefix", objectPrefix)
	}
	// Set object marker.
	if objectMarker != "" {
		urlValues.Set("marker", objectMarker)
	}
	// Set delimiter.
	if delimiter != "" {
		urlValues.Set("delimiter", delimiter)
	}

	// maxkeys should default to 1000 or less.
	if maxkeys == 0 || maxkeys > 1000 {
		maxkeys = 1000
	}
	// Set max keys.
	urlValues.Set("max-keys", fmt.Sprintf("%d", maxkeys))

	// Execute GET on bucket to list objects.
	resp, err := c.executeMethod("GET", requestMetadata{
		bucketName:  bucketName,
		queryValues: urlValues,
	})
	defer closeResponse(resp)
	if err != nil {
		return listBucketResult{}, err
	}
	if resp != nil {
		if resp.StatusCode != http.StatusOK {
			return listBucketResult{}, httpRespToErrorResponse(resp, bucketName, "")
		}
	}
	// Decode listBuckets XML.
	listBucketResult := listBucketResult{}
	err = xmlDecoder(resp.Body, &listBucketResult)
	if err != nil {
		return listBucketResult, err
	}
	return listBucketResult, nil
}

// ListIncompleteUploads - List incompletely uploaded multipart objects.
//
// ListIncompleteUploads lists all incompleted objects matching the
// objectPrefix from the specified bucket. If recursion is enabled
// it would list all subdirectories and all its contents.
//
// Your input parameters are just bucketName, objectPrefix, recursive
// and a done channel to pro-actively close the internal go routine.
// If you enable recursive as 'true' this function will return back all
// the multipart objects in a given bucket name.
//
//   api := client.New(....)
//   // Create a done channel.
//   doneCh := make(chan struct{})
//   defer close(doneCh)
//   // Recurively list all objects in 'mytestbucket'
//   recursive := true
//   for message := range api.ListIncompleteUploads("mytestbucket", "starthere", recursive) {
//       fmt.Println(message)
//   }
//
func (c Client) ListIncompleteUploads(bucketName, objectPrefix string, recursive bool, doneCh <-chan struct{}) <-chan ObjectMultipartInfo {
	// Turn on size aggregation of individual parts.
	isAggregateSize := true
	return c.listIncompleteUploads(bucketName, objectPrefix, recursive, isAggregateSize, doneCh)
}

// listIncompleteUploads lists all incomplete uploads.
func (c Client) listIncompleteUploads(bucketName, objectPrefix string, recursive, aggregateSize bool, doneCh <-chan struct{}) <-chan ObjectMultipartInfo {
	// Allocate channel for multipart uploads.
	objectMultipartStatCh := make(chan ObjectMultipartInfo, 1)
	// Delimiter is set to "/" by default.
	delimiter := "/"
	if recursive {
		// If recursive do not delimit.
		delimiter = ""
	}
	// Validate bucket name.
	if err := isValidBucketName(bucketName); err != nil {
		defer close(objectMultipartStatCh)
		objectMultipartStatCh <- ObjectMultipartInfo{
			Err: err,
		}
		return objectMultipartStatCh
	}
	// Validate incoming object prefix.
	if err := isValidObjectPrefix(objectPrefix); err != nil {
		defer close(objectMultipartStatCh)
		objectMultipartStatCh <- ObjectMultipartInfo{
			Err: err,
		}
		return objectMultipartStatCh
	}
	go func(objectMultipartStatCh chan<- ObjectMultipartInfo) {
		defer close(objectMultipartStatCh)
		// object and upload ID marker for future requests.
		var objectMarker string
		var uploadIDMarker string
		for {
			// list all multipart uploads.
			result, err := c.listMultipartUploadsQuery(bucketName, objectMarker, uploadIDMarker, objectPrefix, delimiter, 1000)
			if err != nil {
				objectMultipartStatCh <- ObjectMultipartInfo{
					Err: err,
				}
				return
			}
			// Save objectMarker and uploadIDMarker for next request.
			objectMarker = result.NextKeyMarker
			uploadIDMarker = result.NextUploadIDMarker
			// Send all multipart uploads.
			for _, obj := range result.Uploads {
				// Calculate total size of the uploaded parts if 'aggregateSize' is enabled.
				if aggregateSize {
					// Get total multipart size.
					obj.Size, err = c.getTotalMultipartSize(bucketName, obj.Key, obj.UploadID)
					if err != nil {
						objectMultipartStatCh <- ObjectMultipartInfo{
							Err: err,
						}
					}
				}
				select {
				// Send individual uploads here.
				case objectMultipartStatCh <- obj:
				// If done channel return here.
				case <-doneCh:
					return
				}
			}
			// Send all common prefixes if any.
			// NOTE: prefixes are only present if the request is delimited.
			for _, obj := range result.CommonPrefixes {
				object := ObjectMultipartInfo{}
				object.Key = obj.Prefix
				object.Size = 0
				select {
				// Send delimited prefixes here.
				case objectMultipartStatCh <- object:
				// If done channel return here.
				case <-doneCh:
					return
				}
			}
			// Listing ends if result not truncated, return right here.
			if !result.IsTruncated {
				return
			}
		}
	}(objectMultipartStatCh)
	// return.
	return objectMultipartStatCh
}

// listMultipartUploads - (List Multipart Uploads).
//   - Lists some or all (up to 1000) in-progress multipart uploads in a bucket.
//
// You can use the request parameters as selection criteria to return a subset of the uploads in a bucket.
// request parameters. :-
// ---------
// ?key-marker - Specifies the multipart upload after which listing should begin.
// ?upload-id-marker - Together with key-marker specifies the multipart upload after which listing should begin.
// ?delimiter - A delimiter is a character you use to group keys.
// ?prefix - Limits the response to keys that begin with the specified prefix.
// ?max-uploads - Sets the maximum number of multipart uploads returned in the response body.
func (c Client) listMultipartUploadsQuery(bucketName, keyMarker, uploadIDMarker, prefix, delimiter string, maxUploads int) (listMultipartUploadsResult, error) {
	// Get resources properly escaped and lined up before using them in http request.
	urlValues := make(url.Values)
	// Set uploads.
	urlValues.Set("uploads", "")
	// Set object key marker.
	if keyMarker != "" {
		urlValues.Set("key-marker", keyMarker)
	}
	// Set upload id marker.
	if uploadIDMarker != "" {
		urlValues.Set("upload-id-marker", uploadIDMarker)
	}
	// Set prefix marker.
	if prefix != "" {
		urlValues.Set("prefix", prefix)
	}
	// Set delimiter.
	if delimiter != "" {
		urlValues.Set("delimiter", delimiter)
	}

	// maxUploads should be 1000 or less.
	if maxUploads == 0 || maxUploads > 1000 {
		maxUploads = 1000
	}
	// Set max-uploads.
	urlValues.Set("max-uploads", fmt.Sprintf("%d", maxUploads))

	// Execute GET on bucketName to list multipart uploads.
	resp, err := c.executeMethod("GET", requestMetadata{
		bucketName:  bucketName,
		queryValues: urlValues,
	})
	defer closeResponse(resp)
	if err != nil {
		return listMultipartUploadsResult{}, err
	}
	if resp != nil {
		if resp.StatusCode != http.StatusOK {
			return listMultipartUploadsResult{}, httpRespToErrorResponse(resp, bucketName, "")
		}
	}
	// Decode response body.
	listMultipartUploadsResult := listMultipartUploadsResult{}
	err = xmlDecoder(resp.Body, &listMultipartUploadsResult)
	if err != nil {
		return listMultipartUploadsResult, err
	}
	return listMultipartUploadsResult, nil
}

// listObjectParts list all object parts recursively.
func (c Client) listObjectParts(bucketName, objectName, uploadID string) (partsInfo map[int]objectPart, err error) {
	// Part number marker for the next batch of request.
	var nextPartNumberMarker int
	partsInfo = make(map[int]objectPart)
	for {
		// Get list of uploaded parts a maximum of 1000 per request.
		listObjPartsResult, err := c.listObjectPartsQuery(bucketName, objectName, uploadID, nextPartNumberMarker, 1000)
		if err != nil {
			return nil, err
		}
		// Append to parts info.
		for _, part := range listObjPartsResult.ObjectParts {
			// Trim off the odd double quotes from ETag in the beginning and end.
			part.ETag = strings.TrimPrefix(part.ETag, "\"")
			part.ETag = strings.TrimSuffix(part.ETag, "\"")
			partsInfo[part.PartNumber] = part
		}
		// Keep part number marker, for the next iteration.
		nextPartNumberMarker = listObjPartsResult.NextPartNumberMarker
		// Listing ends result is not truncated, return right here.
		if !listObjPartsResult.IsTruncated {
			break
		}
	}

	// Return all the parts.
	return partsInfo, nil
}

// findUploadID lists all incomplete uploads and finds the uploadID of the matching object name.
func (c Client) findUploadID(bucketName, objectName string) (uploadID string, err error) {
	// Make list incomplete uploads recursive.
	isRecursive := true
	// Turn off size aggregation of individual parts, in this request.
	isAggregateSize := false
	// latestUpload to track the latest multipart info for objectName.
	var latestUpload ObjectMultipartInfo
	// Create done channel to cleanup the routine.
	doneCh := make(chan struct{})
	defer close(doneCh)
	// List all incomplete uploads.
	for mpUpload := range c.listIncompleteUploads(bucketName, objectName, isRecursive, isAggregateSize, doneCh) {
		if mpUpload.Err != nil {
			return "", mpUpload.Err
		}
		if objectName == mpUpload.Key {
			if mpUpload.Initiated.Sub(latestUpload.Initiated) > 0 {
				latestUpload = mpUpload
			}
		}
	}
	// Return the latest upload id.
	return latestUpload.UploadID, nil
}

// getTotalMultipartSize - calculate total uploaded size for the a given multipart object.
func (c Client) getTotalMultipartSize(bucketName, objectName, uploadID string) (size int64, err error) {
	// Iterate over all parts and aggregate the size.
	partsInfo, err := c.listObjectParts(bucketName, objectName, uploadID)
	if err != nil {
		return 0, err
	}
	for _, partInfo := range partsInfo {
		size += partInfo.Size
	}
	return size, nil
}

// listObjectPartsQuery (List Parts query)
//     - lists some or all (up to 1000) parts that have been uploaded
//     for a specific multipart upload
//
// You can use the request parameters as selection criteria to return
// a subset of the uploads in a bucket, request parameters :-
// ---------
// ?part-number-marker - Specifies the part after which listing should
// begin.
// ?max-parts - Maximum parts to be listed per request.
func (c Client) listObjectPartsQuery(bucketName, objectName, uploadID string, partNumberMarker, maxParts int) (listObjectPartsResult, error) {
	// Get resources properly escaped and lined up before using them in http request.
	urlValues := make(url.Values)
	// Set part number marker.
	urlValues.Set("part-number-marker", fmt.Sprintf("%d", partNumberMarker))
	// Set upload id.
	urlValues.Set("uploadId", uploadID)

	// maxParts should be 1000 or less.
	if maxParts == 0 || maxParts > 1000 {
		maxParts = 1000
	}
	// Set max parts.
	urlValues.Set("max-parts", fmt.Sprintf("%d", maxParts))

	// Execute GET on objectName to get list of parts.
	resp, err := c.executeMethod("GET", requestMetadata{
		bucketName:  bucketName,
		objectName:  objectName,
		queryValues: urlValues,
	})
	defer closeResponse(resp)
	if err != nil {
		return listObjectPartsResult{}, err
	}
	if resp != nil {
		if resp.StatusCode != http.StatusOK {
			return listObjectPartsResult{}, httpRespToErrorResponse(resp, bucketName, objectName)
		}
	}
	// Decode list object parts XML.
	listObjectPartsResult := listObjectPartsResult{}
	err = xmlDecoder(resp.Body, &listObjectPartsResult)
	if err != nil {
		return listObjectPartsResult, err
	}
	return listObjectPartsResult, nil
}