File indexing completed on 2024-09-15 04:36:24

 /*
     SPDX-FileCopyrightText: 2020 Daniel Vrátil <dvratil@kde.org>
 
     SPDX-License-Identifier: LGPL-2.0-or-later
 */
 
 #include "akonadiprivate_debug.h"
 #include "compressionstream_p.h"
 
 #include <QByteArray>
 
 #include <lzma.h>
 
 #include <array>
 
 using namespace Akonadi;
 
 namespace
 {
 class LZMAErrorCategory : public std::error_category
 {
 public:
     const char *name() const noexcept override
     {
         return "lzma";
     }
     std::string message(int ev) const noexcept override
     {
         switch (static_cast<lzma_ret>(ev)) {
         case LZMA_OK:
             return "Operation completed successfully";
         case LZMA_STREAM_END:
             return "End of stream was reached";
         case LZMA_NO_CHECK:
             return "Input stream has no integrity check";
         case LZMA_UNSUPPORTED_CHECK:
             return "Cannot calculate the integrity check";
         case LZMA_GET_CHECK:
             return "Integrity check type is now available";
         case LZMA_MEM_ERROR:
             return "Cannot allocate memory";
         case LZMA_MEMLIMIT_ERROR:
             return "Memory usage limit was reached";
         case LZMA_FORMAT_ERROR:
             return "File format not recognized";
         case LZMA_OPTIONS_ERROR:
             return "Invalid or unsupported options";
         case LZMA_DATA_ERROR:
             return "Data is corrupt";
         case LZMA_BUF_ERROR:
             return "No progress is possible";
         case LZMA_PROG_ERROR:
             return "Programming error";
         }
 
         Q_UNREACHABLE();
     }
 };
 
 const LZMAErrorCategory &lzmaErrorCategory()
 {
     static const LZMAErrorCategory lzmaErrorCategory{};
     return lzmaErrorCategory;
 }
 
 } // namespace
 
 namespace std
 {
 template<>
 struct is_error_code_enum<lzma_ret> : std::true_type {
 };
 
 std::error_condition make_error_condition(lzma_ret ret)
 {
     return std::error_condition(static_cast<int>(ret), lzmaErrorCategory());
 }
 
 } // namespace std
 
 std::error_code make_error_code(lzma_ret e)
 {
     return {static_cast<int>(e), lzmaErrorCategory()};
 }
 
 class Akonadi::Compressor
 {
 public:
     std::error_code initialize(QIODevice::OpenMode openMode)
     {
         if (openMode == QIODevice::ReadOnly) {
             return lzma_auto_decoder(&mStream, 100 * 1024 * 1024 /* 100 MiB */, 0);
         } else {
             return lzma_easy_encoder(&mStream, LZMA_PRESET_DEFAULT, LZMA_CHECK_CRC32);
         }
     }
 
     void setInputBuffer(const char *data, qint64 size)
     {
         mStream.next_in = reinterpret_cast<const uint8_t *>(data);
         mStream.avail_in = size;
     }
 
     void setOutputBuffer(char *data, qint64 maxSize)
     {
         mStream.next_out = reinterpret_cast<uint8_t *>(data);
         mStream.avail_out = maxSize;
     }
 
     size_t inputBufferAvailable() const
     {
         return mStream.avail_in;
     }
 
     size_t outputBufferAvailable() const
     {
         return mStream.avail_out;
     }
 
     std::error_code finalize()
     {
         lzma_end(&mStream);
         return LZMA_OK;
     }
 
     std::error_code inflate()
     {
         return lzma_code(&mStream, LZMA_RUN);
     }
 
     std::error_code deflate(bool finish)
     {
         return lzma_code(&mStream, finish ? LZMA_FINISH : LZMA_RUN);
     }
 
 protected:
     lzma_stream mStream = LZMA_STREAM_INIT;
 };
 
 CompressionStream::CompressionStream(QIODevice *stream, QObject *parent)
     : QIODevice(parent)
     , mStream(stream)
     , mResult(LZMA_OK)
 {
 }
 
 CompressionStream::~CompressionStream()
 {
     CompressionStream::close();
 }
 
 bool CompressionStream::isSequential() const
 {
     return true;
 }
 
 bool CompressionStream::open(OpenMode mode)
 {
     if ((mode & QIODevice::ReadOnly) && (mode & QIODevice::WriteOnly)) {
         qCWarning(AKONADIPRIVATE_LOG) << "Invalid open mode for CompressionStream.";
         return false;
     }
 
     mCompressor = std::make_unique<Compressor>();
     if (const auto err = mCompressor->initialize(mode & QIODevice::ReadOnly ? QIODevice::ReadOnly : QIODevice::WriteOnly); err != LZMA_OK) {
         qCWarning(AKONADIPRIVATE_LOG) << "Failed to initialize LZMA stream coder:" << err.message();
         return false;
     }
 
     if (mode & QIODevice::WriteOnly) {
         mBuffer.resize(BUFSIZ);
         mCompressor->setOutputBuffer(mBuffer.data(), mBuffer.size());
     }
 
     return QIODevice::open(mode);
 }
 
 void CompressionStream::close()
 {
     if (!isOpen()) {
         return;
     }
 
     if (openMode() & QIODevice::WriteOnly && mResult == LZMA_OK) {
         write(nullptr, 0);
     }
 
     mResult = mCompressor->finalize();
 
     setOpenMode(QIODevice::NotOpen);
 }
 
 std::error_code CompressionStream::error() const
 {
     return mResult == LZMA_STREAM_END ? LZMA_OK : mResult;
 }
 
 bool CompressionStream::atEnd() const
 {
     return mResult == LZMA_STREAM_END && QIODevice::atEnd() && mStream->atEnd();
 }
 
 qint64 CompressionStream::readData(char *data, qint64 dataSize)
 {
     qint64 dataRead = 0;
 
     if (mResult == LZMA_STREAM_END) {
         return 0;
     } else if (mResult != LZMA_OK) {
         return -1;
     }
 
     mCompressor->setOutputBuffer(data, dataSize);
 
     while (dataSize > 0) {
         if (mCompressor->inputBufferAvailable() == 0) {
             mBuffer.resize(BUFSIZ);
             const auto compressedDataRead = mStream->read(mBuffer.data(), mBuffer.size());
 
             if (compressedDataRead > 0) {
                 mCompressor->setInputBuffer(mBuffer.data(), compressedDataRead);
             } else {
                 break;
             }
         }
 
         mResult = mCompressor->inflate();
 
         if (mResult != LZMA_OK && mResult != LZMA_STREAM_END) {
             qCWarning(AKONADIPRIVATE_LOG) << "Error while decompressing LZMA stream:" << mResult.message();
             break;
         }
 
         const auto decompressedDataRead = dataSize - mCompressor->outputBufferAvailable();
         dataRead += decompressedDataRead;
         dataSize -= decompressedDataRead;
 
         if (mResult == LZMA_STREAM_END) {
             if (mStream->atEnd()) {
                 break;
             }
         }
 
         mCompressor->setOutputBuffer(data + dataRead, dataSize);
     }
 
     return dataRead;
 }
 
 qint64 CompressionStream::writeData(const char *data, qint64 dataSize)
 {
     if (mResult != LZMA_OK) {
         return 0;
     }
 
     bool finish = (data == nullptr);
     if (!finish) {
         mCompressor->setInputBuffer(data, dataSize);
     }
 
     size_t dataWritten = 0;
 
     while (dataSize > 0 || finish) {
         mResult = mCompressor->deflate(finish);
 
         if (mResult != LZMA_OK && mResult != LZMA_STREAM_END) {
             qCWarning(AKONADIPRIVATE_LOG) << "Error while compressing LZMA stream:" << mResult.message();
             break;
         }
 
         if (mCompressor->inputBufferAvailable() == 0 || (mResult == LZMA_STREAM_END)) {
             const auto wrote = dataSize - mCompressor->inputBufferAvailable();
 
             dataWritten += wrote;
             dataSize -= wrote;
 
             if (dataSize > 0) {
                 mCompressor->setInputBuffer(data + dataWritten, dataSize);
             }
         }
 
         if (mCompressor->outputBufferAvailable() == 0 || (mResult == LZMA_STREAM_END) || finish) {
             const auto toWrite = mBuffer.size() - mCompressor->outputBufferAvailable();
             if (toWrite > 0) {
                 const auto writtenSize = mStream->write(mBuffer.constData(), toWrite);
                 if (writtenSize != toWrite) {
                     qCWarning(AKONADIPRIVATE_LOG) << "Failed to write compressed data to output device:" << mStream->errorString();
                     setErrorString(QStringLiteral("Failed to write compressed data to output device."));
                     return 0;
                 }
             }
 
             if (mResult == LZMA_STREAM_END) {
                 Q_ASSERT(finish);
                 break;
             }
             mBuffer.resize(BUFSIZ);
             mCompressor->setOutputBuffer(mBuffer.data(), mBuffer.size());
         }
     }
 
     return dataWritten;
 }
 
 bool CompressionStream::isCompressed(QIODevice *data)
 {
     constexpr std::array<uchar, 6> magic = {0xfd, 0x37, 0x7a, 0x58, 0x5a, 0x00};
 
     if (!data->isOpen() && !data->isReadable()) {
         return false;
     }
 
     char buf[6] = {};
     if (data->peek(buf, sizeof(buf)) != sizeof(buf)) {
         return false;
     }
 
     return memcmp(magic.data(), buf, sizeof(buf)) == 0;
 }
 
 #include "moc_compressionstream_p.cpp"