summaryrefslogtreecommitdiff
path: root/writerperfect/source/common/WPXSvInputStream.cxx
blob: 54204cf607686ac376db01b2739c8207152e6c69 (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
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
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

#include <WPXSvInputStream.hxx>

#include <com/sun/star/packages/zip/XZipFileAccess2.hpp>

#include <comphelper/processfactory.hxx>
#include <comphelper/seekableinput.hxx>

#include <rtl/string.hxx>

#include <sot/storage.hxx>

#include <tools/stream.hxx>
#include <unotools/streamwrap.hxx>
#include <unotools/ucbstreamhelper.hxx>

#include <climits>
#include <limits>
#include <memory>
#include <unordered_map>
#include <vector>

namespace writerperfect
{

using namespace ::com::sun::star::uno;
using namespace ::com::sun::star::io;

namespace container = com::sun::star::container;
namespace packages = com::sun::star::packages;

namespace
{

class PositionHolder
{
public:
    explicit PositionHolder(const Reference<XSeekable> &rxSeekable);
    ~PositionHolder();
    PositionHolder(const PositionHolder &) = delete;
    PositionHolder &operator=(const PositionHolder &) = delete;

private:
    const Reference<XSeekable> mxSeekable;
    const sal_uInt64 mnPosition;
};

PositionHolder::PositionHolder(const Reference<XSeekable> &rxSeekable)
    : mxSeekable(rxSeekable)
    , mnPosition(rxSeekable->getPosition())
{
}

PositionHolder::~PositionHolder()
{
    try
    {
        mxSeekable->seek(mnPosition);
    }
    catch (...) {}
}

} // anonymous namespace

typedef struct
{
    tools::SvRef<SotStorage> ref;
} SotStorageRefWrapper;

typedef struct
{
    tools::SvRef<SotStorageStream> ref;
} SotStorageStreamRefWrapper;

namespace
{

rtl::OUString lcl_normalizeSubStreamPath(const rtl::OUString &rPath)
{
    // accept paths which begin by '/'
    // TODO: maybe this should to a full normalization
    if (rPath.startsWith("/") && rPath.getLength() >= 2)
        return rPath.copy(1);
    return rPath;
}

}

namespace
{

const rtl::OUString concatPath(const rtl::OUString &lhs, const rtl::OUString &rhs)
{
    if (lhs.isEmpty())
        return rhs;
    return lhs + "/" + rhs;
}

struct OLEStreamData
{
    OLEStreamData(const rtl::OString &rName, const rtl::OString &rvngName);

    SotStorageStreamRefWrapper stream;

    /** Name of the stream.
      *
      * This is not @c rtl::OUString, because we need to be able to
      * produce const char* from it.
      */
    rtl::OString name;
    /** librevenge name of the stream.
      *
      * This is not @c rtl::OUString, because we need to be able to
      * produce const char* from it.
      */
    rtl::OString RVNGname;
};

typedef std::unordered_map<rtl::OUString, std::size_t, rtl::OUStringHash> NameMap_t;
typedef std::unordered_map<rtl::OUString, SotStorageRefWrapper, rtl::OUStringHash> OLEStorageMap_t;

/** Representation of an OLE2 storage.
  *
  * This class tries to bring a bit of sanity to use of SotStorage with
  * respect to the needs of @c librevenge::RVNGInputStream API. It
  * holds all nested storages for the whole lifetime (more precisely,
  * since initialization, which is performed by calling @c
  * initialize()), thus ensuring that no created stream is destroyed
  * just because its parent storage went out of scope. It also holds a
  * bidirectional map of stream names to their indexes (index of a
  * stream is determined by deep-first traversal), which is also
  * populated during initialization (member variables @c maStreams and
  * @c maNameMap).
  *
  * Streams are created on demand (and saved, for the same reason as
  * storages).
  */
struct OLEStorageImpl
{
    OLEStorageImpl();

    void initialize(SvStream *pStream);

    tools::SvRef<SotStorageStream> getStream(const rtl::OUString &rPath);
    tools::SvRef<SotStorageStream> const &getStream(std::size_t nId);

private:
    void traverse(const tools::SvRef<SotStorage> &rStorage, const rtl::OUString &rPath);

    tools::SvRef<SotStorageStream> createStream(const rtl::OUString &rPath);

public:
    SotStorageRefWrapper mxRootStorage; //< root storage of the OLE2
    OLEStorageMap_t maStorageMap; //< map of all sub storages by name
    ::std::vector< OLEStreamData > maStreams; //< list of streams and their names
    NameMap_t maNameMap; //< map of stream names to indexes (into @c maStreams)
    bool mbInitialized;
};

OLEStreamData::OLEStreamData(const rtl::OString &rName, const rtl::OString &rvngName)
    : stream()
    , name(rName)
    , RVNGname(rvngName)
{
}

OLEStorageImpl::OLEStorageImpl()
    : mxRootStorage()
    , maStorageMap()
    , maStreams()
    , maNameMap()
    , mbInitialized(false)
{
}

void OLEStorageImpl::initialize(SvStream *const pStream)
{
    if (!pStream)
        return;

    mxRootStorage.ref = new SotStorage(pStream, true);

    traverse(mxRootStorage.ref, "");

    mbInitialized = true;
}

tools::SvRef<SotStorageStream> OLEStorageImpl::getStream(const rtl::OUString &rPath)
{
    const rtl::OUString aPath(lcl_normalizeSubStreamPath(rPath));
    NameMap_t::iterator aIt = maNameMap.find(aPath);

    // For the while don't return stream in this situation.
    // Later, given how libcdr's zip stream implementation behaves,
    // return the first stream in the storage if there is one.
    if (maNameMap.end() == aIt)
        return tools::SvRef<SotStorageStream>();

    if (!maStreams[aIt->second].stream.ref.is())
        maStreams[aIt->second].stream.ref = createStream(rtl::OStringToOUString(maStreams[aIt->second].name, RTL_TEXTENCODING_UTF8));

    return maStreams[aIt->second].stream.ref;
}

tools::SvRef<SotStorageStream> const &OLEStorageImpl::getStream(const std::size_t nId)
{
    if (!maStreams[nId].stream.ref.is())
        maStreams[nId].stream.ref = createStream(rtl::OStringToOUString(maStreams[nId].name, RTL_TEXTENCODING_UTF8));

    return maStreams[nId].stream.ref;
}

void OLEStorageImpl::traverse(const tools::SvRef<SotStorage> &rStorage, const rtl::OUString &rPath)
{
    SvStorageInfoList infos;

    rStorage->FillInfoList(&infos);

    for (SvStorageInfoList::const_iterator aIt = infos.begin(); infos.end() != aIt; ++aIt)
    {
        if (aIt->IsStream())
        {
            rtl::OUString baseName=aIt->GetName(), rvngName=baseName;
            // librevenge::RVNGOLEStream ignores the first character when is a control code, so ...
            if (!rvngName.isEmpty() && rvngName.toChar()<32)
                rvngName=rvngName.copy(1);
            maStreams.push_back(OLEStreamData(rtl::OUStringToOString(concatPath(rPath, baseName), RTL_TEXTENCODING_UTF8),
                                              rtl::OUStringToOString(concatPath(rPath, rvngName), RTL_TEXTENCODING_UTF8)));
            maNameMap[concatPath(rPath, rvngName)] = maStreams.size() - 1;
        }
        else if (aIt->IsStorage())
        {
            const rtl::OUString aPath = concatPath(rPath, aIt->GetName());
            SotStorageRefWrapper aStorage;
            aStorage.ref = rStorage->OpenSotStorage(aIt->GetName(), StreamMode::STD_READ);
            maStorageMap[aPath] = aStorage;

            // deep-first traversal
            traverse(aStorage.ref, aPath);
        }
        else
        {
            SAL_WARN("writerperfect", "OLEStorageImpl::traverse: invalid storage entry, neither stream nor file");
        }
    }
}

tools::SvRef<SotStorageStream> OLEStorageImpl::createStream(const rtl::OUString &rPath)
{
    const sal_Int32 nDelim = rPath.lastIndexOf(u'/');

    if (-1 == nDelim)
        return mxRootStorage.ref->OpenSotStream(rPath, StreamMode::STD_READ);

    const rtl::OUString aDir = rPath.copy(0, nDelim);
    const rtl::OUString aName = rPath.copy(nDelim + 1);

    const OLEStorageMap_t::const_iterator aIt = maStorageMap.find(aDir);

    if (maStorageMap.end() == aIt)
        return nullptr;

    return aIt->second.ref->OpenSotStream(aName, StreamMode::STD_READ);
}

}

namespace
{

struct ZipStreamData
{
    explicit ZipStreamData(const rtl::OString &rName);

    Reference<XInputStream> xStream;

    /** Name of the stream.
      *
      * This is not @c rtl::OUString, because we need to be able to
      * produce const char* from it.
      */
    rtl::OString aName;
};

/** Representation of a Zip storage.
  *
  * This is quite similar to OLEStorageImpl, except that we do not need
  * to keep all storages (folders) open.
  */
struct ZipStorageImpl
{
    explicit ZipStorageImpl(const Reference<container::XNameAccess> &rxContainer);

    /** Initialize for access.
      *
      * This creates a bidirectional map of stream names to their
      * indexes (index of a stream is determined by deep-first
      * traversal).
      */
    void initialize();

    Reference<XInputStream> getStream(const rtl::OUString &rPath);
    Reference<XInputStream> getStream(std::size_t nId);

private:
    void traverse(const Reference<container::XNameAccess> &rxEnum);

    Reference<XInputStream> createStream(const rtl::OUString &rPath);

public:
    Reference<container::XNameAccess> mxContainer; //< root of the Zip
    ::std::vector< ZipStreamData > maStreams; //< list of streams and their names
    NameMap_t maNameMap; //< map of stream names to indexes (into @c maStreams)
    bool mbInitialized;
};

ZipStreamData::ZipStreamData(const rtl::OString &rName)
    : xStream()
    , aName(rName)
{
}

ZipStorageImpl::ZipStorageImpl(const Reference<container::XNameAccess> &rxContainer)
    : mxContainer(rxContainer)
    , maStreams()
    , maNameMap()
    , mbInitialized(false)
{
    assert(mxContainer.is());
}

void ZipStorageImpl::initialize()
{
    traverse(mxContainer);

    mbInitialized = true;
}

Reference<XInputStream> ZipStorageImpl::getStream(const rtl::OUString &rPath)
{
    const rtl::OUString aPath(lcl_normalizeSubStreamPath(rPath));
    NameMap_t::iterator aIt = maNameMap.find(aPath);

    // For the while don't return stream in this situation.
    // Later, given how libcdr's zip stream implementation behaves,
    // return the first stream in the storage if there is one.
    if (maNameMap.end() == aIt)
        return Reference<XInputStream>();

    if (!maStreams[aIt->second].xStream.is())
        maStreams[aIt->second].xStream = createStream(aPath);

    return maStreams[aIt->second].xStream;
}

Reference<XInputStream> ZipStorageImpl::getStream(const std::size_t nId)
{
    if (!maStreams[nId].xStream.is())
        maStreams[nId].xStream = createStream(rtl::OStringToOUString(maStreams[nId].aName, RTL_TEXTENCODING_UTF8));

    return maStreams[nId].xStream;
}

void ZipStorageImpl::traverse(const Reference<container::XNameAccess> &rxContainer)
{
    const Sequence<rtl::OUString> lNames = rxContainer->getElementNames();

    maStreams.reserve(lNames.getLength());

    for (sal_Int32 n = 0; n < lNames.getLength(); ++n)
    {
        if (!lNames[n].endsWith("/")) // skip dirs
        {
            maStreams.push_back(ZipStreamData(rtl::OUStringToOString(lNames[n], RTL_TEXTENCODING_UTF8)));
            maNameMap[lNames[n]] = maStreams.size() - 1;
        }
    }
}

Reference<XInputStream> ZipStorageImpl::createStream(const rtl::OUString &rPath)
{
    Reference<XInputStream> xStream;

    try
    {
        const Reference<XInputStream> xInputStream(mxContainer->getByName(rPath), UNO_QUERY_THROW);
        const Reference<XSeekable> xSeekable(xInputStream, UNO_QUERY);

        if (xSeekable.is())
            xStream = xInputStream;
        else
            xStream.set(new comphelper::OSeekableInputWrapper(xInputStream, comphelper::getProcessComponentContext()));
    }
    catch (const Exception &)
    {
        // nothing needed
    }

    return xStream;
}

}

class WPXSvInputStreamImpl
{
public:
    explicit WPXSvInputStreamImpl(css::uno::Reference<
                                  css::io::XInputStream > const &xStream);

    bool isStructured();
    unsigned subStreamCount();
    const char *subStreamName(unsigned id);
    bool existsSubStream(const char *name);
    librevenge::RVNGInputStream *getSubStreamByName(const char *name);
    librevenge::RVNGInputStream *getSubStreamById(unsigned id);

    const unsigned char *read(unsigned long numBytes, unsigned long &numBytesRead);
    int seek(long offset);
    long tell();
    bool isEnd();

    void invalidateReadBuffer();

private:
    bool isOLE();
    void ensureOLEIsInitialized();

    bool isZip();
    void ensureZipIsInitialized();

    static librevenge::RVNGInputStream *createWPXStream(const tools::SvRef<SotStorageStream> &rxStorage);
    static librevenge::RVNGInputStream *createWPXStream(const Reference<XInputStream> &rxStream);

private:
    css::uno::Reference< css::io::XInputStream > mxStream;
    css::uno::Reference< css::io::XSeekable > mxSeekable;
    css::uno::Sequence< sal_Int8 > maData;
    std::unique_ptr< OLEStorageImpl > mpOLEStorage;
    std::unique_ptr< ZipStorageImpl > mpZipStorage;
    bool mbCheckedOLE;
    bool mbCheckedZip;
public:
    sal_Int64 mnLength;
    const unsigned char *mpReadBuffer;
    unsigned long mnReadBufferLength;
    unsigned long mnReadBufferPos;
};

WPXSvInputStreamImpl::WPXSvInputStreamImpl(Reference< XInputStream > const &xStream) :
    mxStream(xStream),
    mxSeekable(xStream, UNO_QUERY),
    maData(0),
    mpOLEStorage(nullptr),
    mpZipStorage(nullptr),
    mbCheckedOLE(false),
    mbCheckedZip(false),
    mnLength(0),
    mpReadBuffer(nullptr),
    mnReadBufferLength(0),
    mnReadBufferPos(0)
{
    if (!xStream.is() || !mxStream.is())
        mnLength = 0;
    else
    {
        if (!mxSeekable.is())
            mnLength = 0;
        else
        {
            try
            {
                mnLength = mxSeekable->getLength();
                if (0 < mxSeekable->getPosition())
                    mxSeekable->seek(0);
            }
            catch (...)
            {
                SAL_WARN("writerperfect", "mnLength = mxSeekable->getLength() threw exception");
                mnLength = 0;
            }
        }
    }
}

const unsigned char *WPXSvInputStreamImpl::read(unsigned long numBytes, unsigned long &numBytesRead)
{
    numBytesRead = 0;

    if (numBytes == 0 || isEnd())
        return nullptr;

    numBytesRead = mxStream->readSomeBytes(maData, numBytes);
    if (numBytesRead == 0)
        return nullptr;

    return reinterpret_cast<const unsigned char *>(maData.getConstArray());
}

long WPXSvInputStreamImpl::tell()
{
    if ((mnLength == 0) || !mxStream.is() || !mxSeekable.is())
        return -1L;
    else
    {
        sal_Int64 tmpPosition = mxSeekable->getPosition();
        if ((tmpPosition < 0) || (tmpPosition > LONG_MAX))
            return -1L;
        return (long)tmpPosition;
    }
}

int WPXSvInputStreamImpl::seek(long offset)
{
    if ((mnLength == 0) || !mxStream.is() || !mxSeekable.is())
        return -1;

    sal_Int64 tmpPosition = mxSeekable->getPosition();
    if ((tmpPosition < 0) || (tmpPosition > LONG_MAX))
        return -1;

    try
    {
        mxSeekable->seek(offset);
        return 0;
    }
    catch (...)
    {
        SAL_WARN("writerperfect", "mxSeekable->seek(offset) threw exception");
        return -1;
    }
}

bool WPXSvInputStreamImpl::isEnd()
{
    if ((mnLength == 0) || !mxStream.is() || !mxSeekable.is())
        return true;
    return (mxSeekable->getPosition() >= mnLength);
}

bool WPXSvInputStreamImpl::isStructured()
{
    if ((mnLength == 0) || !mxStream.is() || !mxSeekable.is())
        return false;

    PositionHolder pos(mxSeekable);
    mxSeekable->seek(0);

    if (isOLE())
        return true;

    mxSeekable->seek(0);

    return isZip();
}

unsigned WPXSvInputStreamImpl::subStreamCount()
{
    if ((mnLength == 0) || !mxStream.is() || !mxSeekable.is())
        return 0;

    PositionHolder pos(mxSeekable);
    mxSeekable->seek(0);

    if (isOLE())
    {
        ensureOLEIsInitialized();

        return mpOLEStorage->maStreams.size();
    }

    mxSeekable->seek(0);

    if (isZip())
    {
        ensureZipIsInitialized();

        return mpZipStorage->maStreams.size();
    }

    return 0;
}

const char *WPXSvInputStreamImpl::subStreamName(const unsigned id)
{
    if ((mnLength == 0) || !mxStream.is() || !mxSeekable.is())
        return nullptr;

    PositionHolder pos(mxSeekable);
    mxSeekable->seek(0);

    if (isOLE())
    {
        ensureOLEIsInitialized();

        if (mpOLEStorage->maStreams.size() <= id)
            return nullptr;

        return mpOLEStorage->maStreams[id].RVNGname.getStr();
    }

    mxSeekable->seek(0);

    if (isZip())
    {
        ensureZipIsInitialized();

        if (mpZipStorage->maStreams.size() <= id)
            return nullptr;

        return mpZipStorage->maStreams[id].aName.getStr();
    }

    return nullptr;
}

bool WPXSvInputStreamImpl::existsSubStream(const char *const name)
{
    if (!name)
        return false;

    if ((mnLength == 0) || !mxStream.is() || !mxSeekable.is())
        return false;

    PositionHolder pos(mxSeekable);
    mxSeekable->seek(0);

    const rtl::OUString aName(rtl::OStringToOUString(rtl::OString(name), RTL_TEXTENCODING_UTF8));

    if (isOLE())
    {
        ensureOLEIsInitialized();
        return mpOLEStorage->maNameMap.end() != mpOLEStorage->maNameMap.find(aName);
    }

    mxSeekable->seek(0);

    if (isZip())
    {
        ensureZipIsInitialized();
        return mpZipStorage->maNameMap.end() != mpZipStorage->maNameMap.find(aName);
    }

    return false;
}

librevenge::RVNGInputStream *WPXSvInputStreamImpl::getSubStreamByName(const char *const name)
{
    if (!name)
        return nullptr;

    if ((mnLength == 0) || !mxStream.is() || !mxSeekable.is())
        return nullptr;

    PositionHolder pos(mxSeekable);
    mxSeekable->seek(0);

    const rtl::OUString aName(rtl::OStringToOUString(rtl::OString(name), RTL_TEXTENCODING_UTF8));

    if (isOLE())
    {
        ensureOLEIsInitialized();
        return createWPXStream(mpOLEStorage->getStream(aName));
    }

    mxSeekable->seek(0);

    if (isZip())
    {
        ensureZipIsInitialized();

        try
        {
            return createWPXStream(mpZipStorage->getStream(aName));
        }
        catch (const Exception &)
        {
            // nothing needed
        }
    }

    return nullptr;
}

librevenge::RVNGInputStream *WPXSvInputStreamImpl::getSubStreamById(const unsigned id)
{
    if ((mnLength == 0) || !mxStream.is() || !mxSeekable.is())
        return nullptr;

    PositionHolder pos(mxSeekable);
    mxSeekable->seek(0);

    if (isOLE())
    {
        ensureOLEIsInitialized();

        if (mpOLEStorage->maStreams.size() <= id)
            return nullptr;

        return createWPXStream(mpOLEStorage->getStream(id));
    }

    mxSeekable->seek(0);

    if (isZip())
    {
        ensureZipIsInitialized();

        if (mpZipStorage->maStreams.size() <= id)
            return nullptr;

        try
        {
            return createWPXStream(mpZipStorage->getStream(id));
        }
        catch (const Exception &)
        {
            // nothing needed
        }
    }
    return nullptr;
}

void WPXSvInputStreamImpl::invalidateReadBuffer()
{
    if (mpReadBuffer)
    {
        seek(tell() + (long)mnReadBufferPos - (long)mnReadBufferLength);
        mpReadBuffer = nullptr;
        mnReadBufferPos = 0;
        mnReadBufferLength = 0;
    }
}

librevenge::RVNGInputStream *WPXSvInputStreamImpl::createWPXStream(const tools::SvRef<SotStorageStream> &rxStorage)
{
    if (rxStorage.is())
    {
        Reference < XInputStream > xContents(new utl::OSeekableInputStreamWrapper(rxStorage.get()));
        return new WPXSvInputStream(xContents);
    }
    return nullptr;
}

librevenge::RVNGInputStream *WPXSvInputStreamImpl::createWPXStream(const Reference<XInputStream> &rxStream)
{
    if (rxStream.is())
        return new WPXSvInputStream(rxStream);
    else
        return nullptr;
}

bool WPXSvInputStreamImpl::isOLE()
{
    if (!mbCheckedOLE)
    {
        assert(0 == mxSeekable->getPosition());

        std::unique_ptr<SvStream> pStream(utl::UcbStreamHelper::CreateStream(mxStream));
        if (pStream && SotStorage::IsOLEStorage(pStream.get()))
            mpOLEStorage.reset(new OLEStorageImpl());

        mbCheckedOLE = true;
    }

    return bool(mpOLEStorage);
}

bool WPXSvInputStreamImpl::isZip()
{
    if (!mbCheckedZip)
    {
        assert(0 == mxSeekable->getPosition());

        try
        {
            Sequence<Any> aArgs(1);
            aArgs[0] <<= mxStream;

            const Reference<XComponentContext> xContext(comphelper::getProcessComponentContext(), UNO_QUERY_THROW);
            const Reference<packages::zip::XZipFileAccess2> xZip(
                xContext->getServiceManager()->createInstanceWithArgumentsAndContext("com.sun.star.packages.zip.ZipFileAccess", aArgs, xContext),
                UNO_QUERY_THROW);
            mpZipStorage.reset(new ZipStorageImpl(xZip));
        }
        catch (const Exception &)
        {
            // ignore
        }

        mbCheckedZip = true;
    }

    return bool(mpZipStorage);
}

void WPXSvInputStreamImpl::ensureOLEIsInitialized()
{
    assert(mpOLEStorage);

    if (!mpOLEStorage->mbInitialized)
        mpOLEStorage->initialize(utl::UcbStreamHelper::CreateStream(mxStream));
}

void WPXSvInputStreamImpl::ensureZipIsInitialized()
{
    assert(mpZipStorage);

    if (!mpZipStorage->mbInitialized)
        mpZipStorage->initialize();
}

WPXSvInputStream::WPXSvInputStream(Reference< XInputStream > const &xStream) :
    mpImpl(new WPXSvInputStreamImpl(xStream))
{
}

WPXSvInputStream::~WPXSvInputStream()
{
}

#define BUFFER_MAX 65536

const unsigned char *WPXSvInputStream::read(unsigned long numBytes, unsigned long &numBytesRead)
{
    numBytesRead = 0;

    if (numBytes == 0 || numBytes > (std::numeric_limits<unsigned long>::max)()/2)
        return nullptr;

    if (mpImpl->mpReadBuffer)
    {
        if ((mpImpl->mnReadBufferPos + numBytes > mpImpl->mnReadBufferPos) && (mpImpl->mnReadBufferPos + numBytes <= mpImpl->mnReadBufferLength))
        {
            const unsigned char *pTmp = mpImpl->mpReadBuffer + mpImpl->mnReadBufferPos;
            mpImpl->mnReadBufferPos += numBytes;
            numBytesRead = numBytes;
            return pTmp;
        }

        mpImpl->invalidateReadBuffer();
    }

    unsigned long curpos = (unsigned long) mpImpl->tell();
    if (curpos == (unsigned long)-1)  // returned ERROR
        return nullptr;

    if ((curpos + numBytes < curpos) /*overflow*/ ||
            (curpos + numBytes >= (sal_uInt64)mpImpl->mnLength))  /*reading more than available*/
    {
        numBytes = mpImpl->mnLength - curpos;
    }

    if (numBytes < BUFFER_MAX)
    {
        if (BUFFER_MAX < mpImpl->mnLength - curpos)
            mpImpl->mnReadBufferLength = BUFFER_MAX;
        else /* BUFFER_MAX >= mpImpl->mnLength - curpos */
            mpImpl->mnReadBufferLength = mpImpl->mnLength - curpos;
    }
    else
        mpImpl->mnReadBufferLength = numBytes;

    unsigned long tmpNumBytes(0);
    mpImpl->mpReadBuffer = mpImpl->read(mpImpl->mnReadBufferLength, tmpNumBytes);
    if (tmpNumBytes != mpImpl->mnReadBufferLength)
        mpImpl->mnReadBufferLength = tmpNumBytes;

    mpImpl->mnReadBufferPos = 0;
    if (!mpImpl->mnReadBufferLength)
        return nullptr;

    if (numBytes <= mpImpl->mnReadBufferLength)
        numBytesRead = numBytes;
    else
        numBytesRead = mpImpl->mnReadBufferLength;

    mpImpl->mnReadBufferPos += numBytesRead;
    return mpImpl->mpReadBuffer;
}

long WPXSvInputStream::tell()
{
    long retVal = mpImpl->tell();
    return retVal - (long)mpImpl->mnReadBufferLength + (long)mpImpl->mnReadBufferPos;
}

int WPXSvInputStream::seek(long offset, librevenge::RVNG_SEEK_TYPE seekType)
{
    sal_Int64 tmpOffset = offset;
    if (seekType == librevenge::RVNG_SEEK_CUR)
        tmpOffset += tell();
    if (seekType == librevenge::RVNG_SEEK_END)
        tmpOffset += mpImpl->mnLength;

    int retVal = 0;
    if (tmpOffset < 0)
    {
        tmpOffset = 0;
        retVal = -1;
    }
    if (tmpOffset > mpImpl->mnLength)
    {
        tmpOffset = mpImpl->mnLength;
        retVal = -1;
    }

    if (tmpOffset < mpImpl->tell() && (unsigned long)tmpOffset >= (unsigned long)mpImpl->tell() - mpImpl->mnReadBufferLength)
    {
        mpImpl->mnReadBufferPos = (unsigned long)(tmpOffset + (long) mpImpl->mnReadBufferLength - mpImpl->tell());
        return retVal;
    }

    mpImpl->invalidateReadBuffer();

    if (mpImpl->seek(tmpOffset))
        return -1;
    return retVal;
}

bool WPXSvInputStream::isEnd()
{
    return mpImpl->isEnd() && mpImpl->mnReadBufferPos == mpImpl->mnReadBufferLength;
}

bool WPXSvInputStream::isStructured()
{
    mpImpl->invalidateReadBuffer();
    return mpImpl->isStructured();
}

unsigned WPXSvInputStream::subStreamCount()
{
    mpImpl->invalidateReadBuffer();
    return mpImpl->subStreamCount();
}

const char *WPXSvInputStream::subStreamName(const unsigned id)
{
    mpImpl->invalidateReadBuffer();
    return mpImpl->subStreamName(id);
}

bool WPXSvInputStream::existsSubStream(const char *const name)
{
    mpImpl->invalidateReadBuffer();
    return mpImpl->existsSubStream(name);
}

librevenge::RVNGInputStream *WPXSvInputStream::getSubStreamByName(const char *name)
{
    mpImpl->invalidateReadBuffer();
    return mpImpl->getSubStreamByName(name);
}

librevenge::RVNGInputStream *WPXSvInputStream::getSubStreamById(const unsigned id)
{
    mpImpl->invalidateReadBuffer();
    return mpImpl->getSubStreamById(id);
}

}

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */