vcl/source/graphic/BinaryDataContainer.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  */
  10
  11 #include <vcl/BinaryDataContainer.hxx>
  12 #include <o3tl/hash_combine.hxx>
  13 #include <unotools/tempfile.hxx>
  14 #include <comphelper/lok.hxx>
  15 #include <comphelper/seqstream.hxx>
  16 #include <sal/log.hxx>
  17
  18 struct BinaryDataContainer::Impl
  19 {
  20     // temp file to store the data out of RAM if necessary
  21     std::unique_ptr<utl::TempFileNamed> mpFile;
  22     // the binary data
  23     std::shared_ptr<std::vector<sal_uInt8>> mpData;
  24
  25     Impl(SvStream& stream, size_t size) { readData(stream, size); }
  26
  27     /// Populate mpData from the stream
  28     void readData(SvStream& stream, size_t size)
  29     {
  30         auto pData = std::make_shared<std::vector<sal_uInt8>>(size);
  31         if (stream.ReadBytes(pData->data(), pData->size()) == size)
  32             mpData = std::move(pData);
  33     }
  34
  35     /// ensure the data is in-RAM
  36     void ensureSwappedIn()
  37     {
  38         if (mpData || !mpFile)
  39             return;
  40
  41         auto pStream = mpFile->GetStream(StreamMode::READ);
  42         pStream->Seek(0);
  43         readData(*pStream, pStream->remainingSize());
  44
  45         // Horrifying data loss ...
  46         SAL_WARN_IF(pStream->GetError(), "vcl",
  47                     "Inconsistent system - failed to swap image back in");
  48         SAL_DEBUG("Swap in: " << pStream->GetError());
  49     }
  50
  51     void swapOut()
  52     {
  53         if (mpFile)
  54         {
  55             // we already have it swapped out.
  56             mpData.reset();
  57             return;
  58         }
  59
  60         if (!mpData || mpData->empty())
  61             return;
  62
  63         mpFile.reset(new utl::TempFileNamed());
  64         auto pStream = mpFile->GetStream(StreamMode::READWRITE);
  65
  66         pStream->WriteBytes(mpData->data(), mpData->size());
  67
  68         mpData.reset();
  69     }
  70 };
  71
  72 BinaryDataContainer::BinaryDataContainer(SvStream& stream, size_t size)
  73     : mpImpl(new Impl(stream, size))
  74 {
  75 }
  76
  77 size_t BinaryDataContainer::calculateHash() const
  78 {
  79     size_t nSeed = 0;
  80     if (mpImpl && mpImpl->mpData && !mpImpl->mpData->empty())
  81     {
  82         o3tl::hash_combine(nSeed, getSize());
  83         for (sal_uInt8 const& rByte : *mpImpl->mpData)
  84             o3tl::hash_combine(nSeed, rByte);
  85     }
  86     return nSeed;
  87 }
  88
  89 css::uno::Sequence<sal_Int8> BinaryDataContainer::getCopyAsByteSequence() const
  90 {
  91     if (isEmpty())
  92         return css::uno::Sequence<sal_Int8>();
  93     assert(mpImpl);
  94
  95     css::uno::Sequence<sal_Int8> aData(getSize());
  96
  97     std::copy(mpImpl->mpData->cbegin(), mpImpl->mpData->cend(), aData.getArray());
  98
  99     return aData;
 100 }
 101
 102 namespace
 103 {
 104 /*
 105  * Hold a reference on the internal state in case we swap out
 106  * and free the vector while someone holds an SvStream pointer.
 107  */
 108 class ReferencedMemoryStream : public SvMemoryStream
 109 {
 110     std::shared_ptr<std::vector<sal_uInt8>> mpData;
 111
 112 public:
 113     ReferencedMemoryStream(const std::shared_ptr<std::vector<sal_uInt8>>& pData)
 114         : SvMemoryStream(pData->data(), pData->size(), StreamMode::READ)
 115         , mpData(pData)
 116     {
 117     }
 118 };
 119
 120 class ReferencedXInputStream : public comphelper::MemoryInputStream
 121 {
 122     std::shared_ptr<std::vector<sal_uInt8>> mpData;
 123
 124 public:
 125     ReferencedXInputStream(const std::shared_ptr<std::vector<sal_uInt8>>& pData)
 126         : comphelper::MemoryInputStream(reinterpret_cast<const sal_Int8*>(pData->data()),
 127                                         pData->size())
 128         , mpData(pData)
 129     {
 130     }
 131 };
 132 }
 133
 134 std::shared_ptr<SvStream> BinaryDataContainer::getAsStream()
 135 {
 136     ensureSwappedIn(); // TODO: transfer in streamed chunks
 137     return std::make_shared<ReferencedMemoryStream>(mpImpl->mpData);
 138 }
 139
 140 css::uno::Reference<css::io::XInputStream> BinaryDataContainer::getAsXInputStream()
 141 {
 142     ensureSwappedIn(); // TODO: transfer in streamed chunks
 143     return new ReferencedXInputStream(mpImpl->mpData);
 144 }
 145
 146 std::size_t BinaryDataContainer::writeToStream(SvStream& rStream) const
 147 {
 148     ensureSwappedIn(); // TODO: transfer in streamed chunks
 149     return rStream.WriteBytes(getData(), getSize());
 150 }
 151
 152 size_t BinaryDataContainer::getSize() const
 153 {
 154     ensureSwappedIn();
 155     return mpImpl && mpImpl->mpData ? mpImpl->mpData->size() : 0;
 156 }
 157
 158 size_t BinaryDataContainer::getSizeBytes() const
 159 {
 160     return mpImpl && mpImpl->mpData ? mpImpl->mpData->size() : 0;
 161 }
 162
 163 bool BinaryDataContainer::isEmpty() const
 164 {
 165     ensureSwappedIn();
 166     return !mpImpl || !mpImpl->mpData || mpImpl->mpData->empty();
 167 }
 168
 169 const sal_uInt8* BinaryDataContainer::getData() const
 170 {
 171     ensureSwappedIn();
 172     return mpImpl && mpImpl->mpData ? mpImpl->mpData->data() : nullptr;
 173 }
 174
 175 void BinaryDataContainer::ensureSwappedIn() const
 176 {
 177     if (mpImpl)
 178         mpImpl->ensureSwappedIn();
 179 }
 180
 181 void BinaryDataContainer::swapOut() const
 182 {
 183     // Only bother reducing memory footprint in kit mode - for mobile/online etc.
 184     if (!mpImpl || !comphelper::LibreOfficeKit::isActive())
 185         return;
 186
 187     mpImpl->swapOut();
 188 }
 189
 190 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */