BufferedProjectBlobStream Class Reference

Inheritance diagram for BufferedProjectBlobStream:

Collaboration diagram for BufferedProjectBlobStream:

Public Member Functions
	BufferedProjectBlobStream (sqlite3 *db, const char *schema, const char *table, int64_t rowID)
Public Member Functions inherited from BufferedStreamReader
	BufferedStreamReader (size_t bufferSize=4096)
size_t	Read (void *buffer, size_t maxBytes)
	Read up to maxBytes into the buffer. Returns the number of bytes read. More...

Static Public Attributes
static constexpr std::array< const char *, 2 >	Columns = { "dict", "doc" }
Static Public Attributes inherited from BufferedStreamReader
static constexpr size_t	RequiredAlignment = 8

Protected Member Functions
bool	HasMoreData () const override
size_t	ReadData (void *buffer, size_t maxBytes) override

Private Member Functions
bool	OpenBlob (size_t index)

Private Attributes
std::optional< SQLiteBlobStream >	mBlobStream
size_t	mNextBlobIndex { 0 }
sqlite3 *	mDB
const char *	mSchema
const char *	mTable
const int64_t	mRowID

Additional Inherited Members
Public Attributes inherited from BufferedStreamReader
template<typename ValueType >
std::enable_if_t< sizeof(ValueType)<=RequiredAlignment, bool > ReadValue(ValueType &value) { constexpr size_t valueSize=sizeof(ValueType);const size_t availableBytes=mCurrentBytes - mCurrentIndex;if(availableBytes< valueSize) return valueSize==Read(&value, valueSize);if constexpr(valueSize==1) value=mBufferStart[mCurrentIndex];else value=UncheckedRead< ValueType >();mCurrentIndex+=valueSize;return true;} bool Eof() const ;int GetC();protected:virtual bool HasMoreData() const=0;virtual size_t ReadData(void *buffer, size_t maxBytes)=0;private:bool HandleUnderflow();template< typename T > T UncheckedRead() noexcept { T result;if((mCurrentIndex % sizeof(T))==0) { const void *ptr=mBufferStart+mCurrentIndex;result=*static_cast< const T * >(ptr);} else { const uint8_t *begin=mBufferStart+mCurrentIndex;const uint8_t *end=begin+sizeof(T);void *out=&result;std::copy(begin, end, static_cast< uint8_t * >(out));} return result;} std::vector< uint8_t >	mBufferData
	Read a single value of ValueType, where sizeof(ValueType) <= 8 and value is aligned to the size boundary. More...
uint8_t *	mBufferStart
size_t	mBufferSize
size_t	mCurrentIndex { 0 }
size_t	mCurrentBytes { 0 }

Detailed Description

Definition at line 293 of file ProjectFileIO.cpp.

Constructor & Destructor Documentation

BufferedProjectBlobStream()

BufferedProjectBlobStream::BufferedProjectBlobStream ( sqlite3 *  db, const char *  schema, const char *  table, int64_t  rowID  )

inline

Definition at line 298 of file ProjectFileIO.cpp.

       : BufferedStreamReader(32 * 1024)
       , mDB(db)
       , mSchema(schema)
       , mTable(table)
       , mRowID(rowID)
   {
   }

Member Function Documentation

HasMoreData()

bool BufferedProjectBlobStream::HasMoreData ( ) const

inlineoverrideprotected

Definition at line 338 of file ProjectFileIO.cpp.

   {
      return mBlobStream.has_value() || mNextBlobIndex < Columns.size();
   }

References Columns, mBlobStream, and mNextBlobIndex.

OpenBlob()

bool BufferedProjectBlobStream::OpenBlob ( size_t  index )

inlineprivate

Definition at line 315 of file ProjectFileIO.cpp.

   {
      if (index >= Columns.size())
      {
         mBlobStream.reset();
         return false;
      }
 
      mBlobStream = SQLiteBlobStream::Open(
         mDB, mSchema, mTable, Columns[index], mRowID, true);
 
      return mBlobStream.has_value();
   }

References Columns, mBlobStream, mDB, mRowID, mSchema, mTable, and SQLiteBlobStream::Open().

Referenced by ReadData().

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ReadData()

size_t BufferedProjectBlobStream::ReadData ( void *  buffer, size_t  maxBytes  )

inlineoverrideprotected

Definition at line 343 of file ProjectFileIO.cpp.

   {
      if (!mBlobStream || mBlobStream->IsEof())
      {
         if (!OpenBlob(mNextBlobIndex++))
            return {};
      }
 
      // Do not allow reading more then 2GB at a time (O_o)
      maxBytes = std::min<size_t>(maxBytes, std::numeric_limits<int>::max());
      auto bytesRead = static_cast<int>(maxBytes);
 
      if (SQLITE_OK != mBlobStream->Read(buffer, bytesRead))
      {
         // Reading has failed, close the stream and do not allow opening
         // the next one
         mBlobStream = {};
         mNextBlobIndex = Columns.size();
 
         return 0;
      }
      else if (bytesRead == 0)
      {
         mBlobStream = {};
      }
 
      return static_cast<size_t>(bytesRead);
   }

References Columns, mBlobStream, mNextBlobIndex, and OpenBlob().

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Member Data Documentation

Columns

constexpr std::array< const char *, 2 > BufferedProjectBlobStream::Columns = { "dict", "doc" }

staticconstexpr

Definition at line 296 of file ProjectFileIO.cpp.

Referenced by HasMoreData(), OpenBlob(), and ReadData().

mBlobStream

std::optional<SQLiteBlobStream> BufferedProjectBlobStream::mBlobStream

private

Definition at line 329 of file ProjectFileIO.cpp.

Referenced by HasMoreData(), OpenBlob(), and ReadData().

mDB

sqlite3* BufferedProjectBlobStream::mDB

private

Definition at line 332 of file ProjectFileIO.cpp.

Referenced by OpenBlob().

mNextBlobIndex

size_t BufferedProjectBlobStream::mNextBlobIndex { 0 }

private

Definition at line 330 of file ProjectFileIO.cpp.

Referenced by HasMoreData(), and ReadData().

mRowID

const int64_t BufferedProjectBlobStream::mRowID

private

Definition at line 335 of file ProjectFileIO.cpp.

Referenced by OpenBlob().

mSchema

const char* BufferedProjectBlobStream::mSchema

private

Definition at line 333 of file ProjectFileIO.cpp.

Referenced by OpenBlob().

mTable

const char* BufferedProjectBlobStream::mTable

private

Definition at line 334 of file ProjectFileIO.cpp.

Referenced by OpenBlob().

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The documentation for this class was generated from the following file:

• ProjectFileIO.cpp