forked from pdfcpu/pdfcpu
/
xreftable.go
881 lines (671 loc) · 22.6 KB
/
xreftable.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
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
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
package types
import (
"fmt"
"sort"
"strings"
"github.com/pkg/errors"
)
// IntSet is a set of integers.
type IntSet map[int]bool
// XRefTableEntry represents an entry in the PDF cross reference table.
//
// This may be a free object, a compressed object or any in use PDF object:
//
// PDFDict, PDFStreamDict, PDFObjectStreamDict, PDFXRefStreamDict,
// PDFArray, PDFInteger, PDFFloat, PDFName, PDFStringLiteral, PDFHexLiteral, PDFBoolean
type XRefTableEntry struct {
Free bool
Offset *int64
Generation *int
Object interface{}
Compressed bool
ObjectStream *int
ObjectStreamInd *int
}
// NewXRefTableEntryGen0 creates a cross reference table entry for an object with generation 0.
func NewXRefTableEntryGen0() *XRefTableEntry {
zero := 0
return &XRefTableEntry{Generation: &zero}
}
// XRefTable represents a PDF cross reference table plus stats for a PDF file.
type XRefTable struct {
Table map[int]*XRefTableEntry
Size *int // Object count from PDF trailer dict.
PageCount int // Number of pages.
Root *PDFIndirectRef // Catalog (reference to root object).
// PDF Version
HeaderVersion *PDFVersion // The PDF version the source is claiming to us as per its header.
RootVersion *PDFVersion // Optional PDF version taking precedence over the header version.
// Document information section
Info *PDFIndirectRef // Infodict (reference to info dict object)
ID *PDFArray // from info dict (or trailer?)
Author string
Creator string
Producer string
// Linearization section (not yet supported)
OffsetPrimaryHintTable *int64
OffsetOverflowHintTable *int64
LinearizationObjs IntSet
// Offspec section
AdditionalStreams []PDFIndirectRef //trailer :e.g., Oasis "Open Doc"
// Statistics
Stats PDFStats
Tagged bool // File is using tags. This is important for ???
// Validation
Valid bool // true means successful validated against ISO 32000.
ValidationMode int // see Configuration
Optimized bool
}
// NewXRefTable creates a new XRefTable.
func newXRefTable(validationMode int) (xRefTable *XRefTable) {
return &XRefTable{
Table: map[int]*XRefTableEntry{},
LinearizationObjs: IntSet{},
Stats: NewPDFStats(),
ValidationMode: validationMode,
}
}
// Version returns the PDF version of the PDF writer that created this file.
// Before V1.4 this is the header version.
// Since V1.4 the catalog may contain a Version entry which takes precedence over the header version.
func (xRefTable *XRefTable) Version() PDFVersion {
if xRefTable.RootVersion != nil {
return *xRefTable.RootVersion
}
return *xRefTable.HeaderVersion
}
// VersionString return a string representation for this PDF files PDF version.
func (xRefTable *XRefTable) VersionString() string {
return VersionString(xRefTable.Version())
}
// ParseRootVersion returns a string representation for an optional Version entry in the root object.
func (xRefTable *XRefTable) ParseRootVersion() (*string, error) {
// Look in the catalog/root for a name entry "Version"
// this should be the PDFVersion of this file.
rootDict, err := xRefTable.Catalog()
if err != nil {
return nil, err
}
// Optional
if _, ok := rootDict.Find("Version"); !ok {
return nil, nil
}
v := rootDict.PDFNameEntry("Version")
if v != nil {
s := v.String()
return &s, nil
}
indirectRef := rootDict.IndirectRefEntry("Version")
if indirectRef == nil {
return nil, errors.New("ParseRootVersion: corrupt \"Version\" in root")
}
pdfObject, err := xRefTable.object(indirectRef)
if err != nil {
return nil, err
}
name, ok := pdfObject.(PDFName)
if !ok {
return nil, errors.New("ParseRootVersion: corrupt \"Version\" in root")
}
s := name.String()
return &s, nil
}
// IsLinearizationObject returns true if object #i is a a linearization object.
func (xRefTable *XRefTable) IsLinearizationObject(i int) bool {
return xRefTable.LinearizationObjs[i]
}
// LinearizationObjsString returns a formatted string and the number of objs.
func (xRefTable *XRefTable) LinearizationObjsString() (int, string) {
var objs []int
for k := range xRefTable.LinearizationObjs {
if xRefTable.LinearizationObjs[k] {
objs = append(objs, k)
}
}
sort.Ints(objs)
var linObj []string
for _, i := range objs {
linObj = append(linObj, fmt.Sprintf("%d", i))
}
return len(linObj), strings.Join(linObj, ",")
}
// Exists returns true if xRefTable contains an entry for objNumber.
func (xRefTable *XRefTable) Exists(objNumber int) bool {
_, found := xRefTable.Table[objNumber]
return found
}
// Find returns the XRefTable entry for given object number.
func (xRefTable *XRefTable) Find(objNumber int) (*XRefTableEntry, bool) {
e, found := xRefTable.Table[objNumber]
if !found {
return nil, false
}
return e, true
}
// Free returns the cross ref table entry for given number of a free object.
func (xRefTable *XRefTable) Free(objNumber int) (entry *XRefTableEntry, err error) {
entry, found := xRefTable.Find(objNumber)
if !found {
err = errors.Errorf("GetFree: object #%d not found.", objNumber)
return
}
if !entry.Free {
err = errors.Errorf("GetFree: object #%d found, but not free.", objNumber)
}
return
}
// NextForFree returns the number of the object the free object with objNumber links to.
// This is the successor of this free object in the free list.
func (xRefTable *XRefTable) NextForFree(objNumber int) (next int, err error) {
entry, err := xRefTable.Free(objNumber)
if err != nil {
return
}
next = int(*entry.Offset)
return
}
// FindTableEntryLight returns the XRefTable entry for given object number.
func (xRefTable *XRefTable) FindTableEntryLight(objNumber int) (*XRefTableEntry, bool) {
return xRefTable.Find(objNumber)
}
// FindTableEntry returns the XRefTable entry for given object and generation numbers.
func (xRefTable *XRefTable) FindTableEntry(objNumber int, generationNumber int) (*XRefTableEntry, bool) {
entry, found := xRefTable.Find(objNumber)
if found && *entry.Generation == generationNumber {
return entry, found
}
return nil, false
}
// FindTableEntryForIndRef returns the XRefTable entry for given indirect reference.
func (xRefTable *XRefTable) FindTableEntryForIndRef(indRef *PDFIndirectRef) (*XRefTableEntry, bool) {
if indRef == nil {
logErrorTypes.Println("FindTableEntryForIndRef: returning false on absent indRef")
return nil, false
}
return xRefTable.FindTableEntry(indRef.ObjectNumber.Value(), indRef.GenerationNumber.Value())
}
// Insert adds given xRefTableEntry at given index objNumber into the cross reference table.
// Gets called when reading in a PDF file and generating its xRefTable in memory.
func (xRefTable *XRefTable) Insert(objNumber int, xRefTableEntry XRefTableEntry) bool {
xRefTable.Table[objNumber] = &xRefTableEntry
return true
}
// InsertNew adds given xRefTableEntry at next new objNumber into the cross reference table.
// Only to be called once an xRefTable has been generated completely and all trailer dicts have been processed.
// xRefTable.Size is the size entry of the first trailer dict processed.
// Called on creation of new object streams.
// Called by InsertAndUseRecycled.
func (xRefTable *XRefTable) InsertNew(xRefTableEntry XRefTableEntry) (objNumber int, ok bool) {
objNumber = *xRefTable.Size
ok = xRefTable.Insert(objNumber, xRefTableEntry)
*xRefTable.Size++
return
}
// InsertAndUseRecycled adds given xRefTableEntry into the cross reference table utilizing the freelist.
// Called on creation of new xref stream only.
func (xRefTable *XRefTable) InsertAndUseRecycled(xRefTableEntry XRefTableEntry) (objNumber int, err error) {
// see 7.5.4 Cross-Reference Table
logDebugTypes.Println("InsertAndUseRecycled: begin")
// Get Next free object from freelist.
freeListHeadEntry, err := xRefTable.Free(0)
if err != nil {
return
}
// If none available, add new object & return.
if *freeListHeadEntry.Offset == 0 {
i, ok := xRefTable.InsertNew(xRefTableEntry)
if !ok {
err = errors.Errorf("InsertAndRecycle: Problem inserting entry for %d", i)
return
}
objNumber = i
logInfoTypes.Printf("InsertAndUseRecycled: end, new objNr=%d\n", objNumber)
return
}
// Recycle free object, update free list & return.
objNumber = int(*freeListHeadEntry.Offset)
entry, found := xRefTable.FindTableEntryLight(objNumber)
if !found {
err = errors.Errorf("InsertAndRecycle: no entry for obj #%d\n", objNumber)
return
}
// The new free list head entry becomes the old head entry's successor.
freeListHeadEntry.Offset = entry.Offset
// The old head entry becomes garbage.
entry.Free = false
entry.Offset = nil
// Create a new entry for the recycled object.
if !xRefTable.Insert(objNumber, xRefTableEntry) {
err = errors.Errorf("InsertAndRecycle: Problem inserting entry for %d", objNumber)
}
logInfoTypes.Printf("InsertAndUseRecycled: end, recycled objNr=%d\n", objNumber)
return
}
// EnsureValidFreeList ensures the integrity of the free list associated with the recorded free objects.
// See 7.5.4 Cross-Reference Table
func (xRefTable *XRefTable) EnsureValidFreeList() (err error) {
logDebugTypes.Println("EnsureValidFreeList begin")
m := IntSet{}
for k, v := range xRefTable.Table {
if v.Free && k > 0 {
m[k] = true
}
}
// Verify free object 0 as free list head.
head, err := xRefTable.Free(0)
if err != nil {
return err
}
// verify generation of 56535
if *head.Generation != FreeHeadGeneration {
// Fix generation for obj 0.
*head.Generation = FreeHeadGeneration
}
if len(m) == 0 {
// no free object other than 0.
// repair if necessary
if *head.Offset != 0 {
*head.Offset = 0
}
logInfoTypes.Println("EnsureValidFreeList: empty free list.")
return
}
f := int(*head.Offset)
// until we have found the last free object which should point to obj 0.
for f != 0 {
logDebugTypes.Printf("EnsureValidFreeList: validating obj #%d %v\n", f, m)
// verify if obj f is one of the free objects recorded.
if !m[f] {
return errors.New("EnsureValidFreeList: freelist corrupted")
}
delete(m, f)
f, err = xRefTable.NextForFree(f)
if err != nil {
return err
}
}
if len(m) == 0 {
logInfoTypes.Println("EnsureValidFreeList: end, regular linked list")
return
}
// insert remaining free objects into verified linked list
// unless they are forever deleted with generation 65535.
// In that case they have to point to obj 0.
for i := range m {
entry, found := xRefTable.FindTableEntryLight(i)
if !found {
return errors.Errorf("EnsureValidFreeList: no xref entry found for obj #%d\n", i)
}
if !entry.Free {
return errors.Errorf("EnsureValidFreeList: xref entry is not free for obj #%d\n", i)
}
if *entry.Generation == FreeHeadGeneration {
zero := int64(0)
entry.Offset = &zero
continue
}
entry.Offset = head.Offset
next := int64(i)
head.Offset = &next
}
logInfoTypes.Println("EnsureValidFreeList: end, linked list plus some dangling free objects.")
return
}
// DeleteObject marks an object as free and inserts it into the free list right after the head.
func (xRefTable *XRefTable) DeleteObject(objectNumber int) (err error) {
// see 7.5.4 Cross-Reference Table
logDebugTypes.Printf("DeleteObject: begin %d\n", objectNumber)
freeListHeadEntry, err := xRefTable.Free(0)
if err != nil {
return
}
entry, found := xRefTable.FindTableEntryLight(objectNumber)
if !found {
err = errors.Errorf("DeleteObject: no entry for obj #%d\n", objectNumber)
return
}
*entry.Generation++
entry.Free = true
entry.Compressed = false
entry.Offset = freeListHeadEntry.Offset
entry.Object = nil
next := int64(objectNumber)
freeListHeadEntry.Offset = &next
logInfoTypes.Printf("DeleteObject: end %d\n", objectNumber)
return
}
// UndeleteObject ensures an object is not recorded in the free list.
// e.g. sometimes caused by indirect references to free objects in the original PDF file.
func (xRefTable *XRefTable) UndeleteObject(objectNumber int) (err error) {
logDebugTypes.Printf("UndeleteObject: begin %d\n", objectNumber)
var f, entry *XRefTableEntry
f, err = xRefTable.Free(0)
if err != nil {
return
}
// until we have found the last free object which should point to obj 0.
for *f.Offset != 0 {
objNr := int(*f.Offset)
entry, err = xRefTable.Free(objNr)
if err != nil {
return
}
if objNr == objectNumber {
logDebugTypes.Printf("UndeleteObject end: undeleting obj#%d\n", objectNumber)
*f.Offset = *entry.Offset
entry.Offset = nil
entry.Free = false
return
}
f = entry
}
logDebugTypes.Printf("UndeleteObject: end: obj#%d not in free list.\n", objectNumber)
return
}
// getObject dereferences an indirect object from the xRefTable and returns the result.
func (xRefTable *XRefTable) object(indObjRef *PDFIndirectRef) (interface{}, error) {
logDebugTypes.Printf("getObject: begin")
if indObjRef == nil {
return nil, errors.New("getObject: input argument is nil")
}
logDebugTypes.Printf("getObject: != nil")
objectNumber := indObjRef.ObjectNumber.Value()
generationNumber := indObjRef.GenerationNumber.Value()
entry, found := xRefTable.FindTableEntry(objectNumber, generationNumber)
if !found {
return nil, errors.Errorf("getObject(obj#%d, gen#%d): xref table entry not found", objectNumber, generationNumber)
}
logDebugTypes.Printf("getObject: found xRefTable entry")
if entry.Free {
logDebugTypes.Printf("getObject(obj#%d, gen#%d): entry is free", objectNumber, generationNumber)
return nil, nil
}
if entry.Object == nil {
logDebugTypes.Printf("getObject(obj#%d, gen#%d): entry.Object is nil", objectNumber, generationNumber)
return nil, nil
}
logDebugTypes.Printf("getObject: end")
// return dereferenced object
return entry.Object, nil
}
// Dereference resolves an indirect object and returns the resulting PDF object.
func (xRefTable *XRefTable) Dereference(obj interface{}) (interface{}, error) {
indRef, ok := obj.(PDFIndirectRef)
if !ok {
// Nothing do dereference.
return obj, nil
}
return xRefTable.object(&indRef)
}
// DereferenceInteger resolves and validates an integer object, which may be an indirect reference.
func (xRefTable *XRefTable) DereferenceInteger(obj interface{}) (ip *PDFInteger, err error) {
obj, err = xRefTable.Dereference(obj)
if err != nil || obj == nil {
return
}
i, ok := obj.(PDFInteger)
if !ok {
err = errors.Errorf("ValidateInteger: wrong type <%v>", obj)
}
ip = &i
return
}
// DereferenceName resolves and validates a name object, which may be an indirect reference.
func (xRefTable *XRefTable) DereferenceName(obj interface{}, sinceVersion PDFVersion, validate func(string) bool) (n PDFName, err error) {
obj, err = xRefTable.Dereference(obj)
if err != nil || obj == nil {
return
}
n, ok := obj.(PDFName)
if !ok {
err = errors.Errorf("ValidateName: wrong type <%v>", obj)
return
}
// Version check
if xRefTable.Version() < sinceVersion {
err = errors.Errorf("ValidateName: unsupported in version %s", xRefTable.VersionString())
return
}
// Validation
if validate != nil && !validate(n.Value()) {
err = errors.Errorf("ValidateName: invalid <%s>", n.Value())
return
}
return
}
// DereferenceStringLiteral resolves and validates a string literal object, which may be an indirect reference.
func (xRefTable *XRefTable) DereferenceStringLiteral(obj interface{}, sinceVersion PDFVersion, validate func(string) bool) (s PDFStringLiteral, err error) {
obj, err = xRefTable.Dereference(obj)
if err != nil || obj == nil {
return
}
s, ok := obj.(PDFStringLiteral)
if !ok {
err = errors.Errorf("ValidateStringLiteral: wrong type <%v>", obj)
return
}
// Ensure UTF16 correctness.
s1, err := StringLiteralToString(s.Value())
if err != nil {
return
}
// Version check
if xRefTable.Version() < sinceVersion {
err = errors.Errorf("ValidateStringLiteral: unsupported in version %s", xRefTable.VersionString())
return
}
// Validation
if validate != nil && !validate(s1) {
err = errors.Errorf("ValidateStringLiteral: invalid <%s>", s1)
return
}
return
}
// DereferenceStringOrHexLiteral resolves and validates a string or hex literal object, which may be an indirect reference.
func (xRefTable *XRefTable) DereferenceStringOrHexLiteral(obj interface{}, sinceVersion PDFVersion, validate func(string) bool) (o interface{}, err error) {
o, err = xRefTable.Dereference(obj)
if err != nil || o == nil {
return
}
var s string
switch str := o.(type) {
case PDFStringLiteral:
// Ensure UTF16 correctness.
s, err = StringLiteralToString(str.Value())
if err != nil {
return
}
case PDFHexLiteral:
// Ensure UTF16 correctness.
s, err = HexLiteralToString(str.Value())
if err != nil {
return
}
default:
err = errors.Errorf("ValidateStringOrHexLiteral: wrong type <%v>", obj)
return
}
// Version check
if xRefTable.Version() < sinceVersion {
err = errors.Errorf("ValidateStringLiteral: unsupported in version %s", xRefTable.VersionString())
return
}
// Validation
if validate != nil && !validate(s) {
err = errors.Errorf("ValidateStringLiteral: invalid <%s>", s)
return
}
return
}
// DereferenceArray resolves an indirect object that points to a PDFArray.
func (xRefTable *XRefTable) DereferenceArray(obj interface{}) (arrp *PDFArray, err error) {
obj, err = xRefTable.Dereference(obj)
if err != nil || obj == nil {
return
}
arr, ok := obj.(PDFArray)
if !ok {
err = errors.Errorf("DereferenceArray: wrong type <%v>", obj)
}
arrp = &arr
return
}
// DereferenceDict resolves an indirect object that points to a PDFDict.
func (xRefTable *XRefTable) DereferenceDict(obj interface{}) (dictp *PDFDict, err error) {
obj, err = xRefTable.Dereference(obj)
if err != nil || obj == nil {
return
}
dict, ok := obj.(PDFDict)
if !ok {
err = errors.Errorf("DereferenceDict: wrong type %T <%v>", obj, obj)
}
dictp = &dict
return
}
// DereferenceStreamDict resolves an indirect object that points to a PDFStreamDict.
func (xRefTable *XRefTable) DereferenceStreamDict(obj interface{}) (streamDictp *PDFStreamDict, err error) {
obj, err = xRefTable.Dereference(obj)
if err != nil || obj == nil {
return
}
streamDict, ok := obj.(PDFStreamDict)
if !ok {
err = errors.Errorf("DereferenceStreamDict: wrong type <%v>", obj)
}
streamDictp = &streamDict
return
}
// Catalog returns a pointer to the root object / catalog.
func (xRefTable *XRefTable) Catalog() (*PDFDict, error) {
pdfObject, err := xRefTable.object(xRefTable.Root)
if err != nil {
return nil, err
}
pdfDict, ok := pdfObject.(PDFDict)
if !ok {
return nil, errors.New("Catalog: corrupt root catalog")
}
return &pdfDict, nil
}
// CatalogHasPieceInfo returns true if the root has an entry for \"PieceInfo\".
func (xRefTable *XRefTable) CatalogHasPieceInfo() (bool, error) {
rootDict, err := xRefTable.Catalog()
if err != nil {
return false, err
}
obj, hasPieceInfo := rootDict.Find("PieceInfo")
return hasPieceInfo && obj != nil, nil
}
// Pages returns the Pages reference contained in the catalog.
func (xRefTable *XRefTable) Pages() (*PDFIndirectRef, error) {
rootDict, err := xRefTable.Catalog()
if err != nil {
return nil, err
}
return rootDict.IndirectRefEntry("Pages"), nil
}
// MissingObjects returns the number of objects that were not written
// plus the corresponding comma separated string representation.
func (xRefTable *XRefTable) MissingObjects() (int, *string) {
var missing []string
for i := 0; i < *xRefTable.Size; i++ {
if !xRefTable.Exists(i) {
missing = append(missing, fmt.Sprintf("%d", i))
}
}
var s *string
if len(missing) > 0 {
joined := strings.Join(missing, ",")
s = &joined
}
return len(missing), s
}
func (xRefTable *XRefTable) list(logStr []string) []string {
var keys []int
for k := range xRefTable.Table {
keys = append(keys, k)
}
sort.Ints(keys)
// Print list of XRefTable entries to logString.
for _, k := range keys {
entry := xRefTable.Table[k]
var str string
if entry.Free {
str = fmt.Sprintf("%5d: f next=%8d generation=%d\n", k, *entry.Offset, *entry.Generation)
} else if entry.Compressed {
str = fmt.Sprintf("%5d: c => obj:%d[%d] generation=%d \n%s\n", k, *entry.ObjectStream, *entry.ObjectStreamInd, *entry.Generation, entry.Object)
} else {
if entry.Object != nil {
typeStr := fmt.Sprintf("%T", entry.Object)
pdfDict, ok := entry.Object.(PDFDict)
if ok {
if pdfDict.Type() != nil {
typeStr += fmt.Sprintf(" type=%s", *pdfDict.Type())
}
if pdfDict.Subtype() != nil {
typeStr += fmt.Sprintf(" subType=%s", *pdfDict.Subtype())
}
}
if entry.ObjectStream != nil {
// was compressed, offset is nil.
str = fmt.Sprintf("%5d: was compressed %d[%d] generation=%d %s \n%s\n",
k, *entry.ObjectStream, *entry.ObjectStreamInd, *entry.Generation, typeStr, entry.Object)
} else {
// regular in use object with offset.
if entry.Offset != nil {
str = fmt.Sprintf("%5d: offset=%8d generation=%d %s \n%s\n",
k, *entry.Offset, *entry.Generation, typeStr, entry.Object)
} else {
str = fmt.Sprintf("%5d: offset=nil generation=%d %s \n%s\n",
k, *entry.Generation, typeStr, entry.Object)
}
}
if typeStr == "types.PDFStreamDict" {
pdfStreamDict, _ := entry.Object.(PDFStreamDict)
str += fmt.Sprintf("stream content length = %d\n", len(pdfStreamDict.Content))
if pdfStreamDict.IsPageContent {
str += fmt.Sprintf("content: <%s>\n", pdfStreamDict.Content)
}
}
if typeStr == "types.PDFObjectStreamDict" {
pdfObjectStreamDict, _ := entry.Object.(PDFObjectStreamDict)
str += fmt.Sprintf("object stream count:%d size of objectarray:%d\n", pdfObjectStreamDict.ObjCount, len(pdfObjectStreamDict.ObjArray))
}
} else {
str = fmt.Sprintf("%5d: offset=%8d generation=%d nil\n", k, *entry.Offset, *entry.Generation)
}
}
logStr = append(logStr, str)
}
return logStr
}
// Dump the free list to logStr.
// At this point the free list is assumed to be a linked list with its last node linked to the beginning.
func (xRefTable *XRefTable) freeList(logStr []string) ([]string, error) {
logDebugTypes.Printf("freeList begin")
head, err := xRefTable.Free(0)
if err != nil {
return nil, err
}
if *head.Offset == 0 {
return append(logStr, "\nEmpty free list.\n"), nil
}
f := int(*head.Offset)
logStr = append(logStr, "\nfree list:\n obj next generation\n")
logStr = append(logStr, fmt.Sprintf("%5d %5d %5d\n", 0, f, FreeHeadGeneration))
for f != 0 {
logDebugTypes.Printf("freeList validating free object %d\n", f)
entry, err := xRefTable.Free(f)
if err != nil {
return nil, err
}
next := int(*entry.Offset)
generation := *entry.Generation
s := fmt.Sprintf("%5d %5d %5d\n", f, next, generation)
logStr = append(logStr, s)
logDebugTypes.Printf("freeList: %s", s)
f = next
}
return logStr, nil
}