openMSX
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openmsx::MemBuffer< T, ALIGNMENT > Class Template Reference

This class manages the lifetime of a block of memory. More...

#include <MemBuffer.hh>

Inheritance diagram for openmsx::MemBuffer< T, ALIGNMENT >:
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Public Member Functions

 MemBuffer ()
 Construct an empty MemBuffer, no memory is allocated. More...
 
 MemBuffer (size_t size)
 Construct a (uninitialized) memory buffer of given size. More...
 
 MemBuffer (MemBuffer &&other) noexcept
 Move constructor. More...
 
MemBufferoperator= (MemBuffer &&other) noexcept
 Move assignment. More...
 
 ~MemBuffer ()
 Free the memory buffer. More...
 
const T * data () const
 Returns pointer to the start of the memory buffer. More...
 
T * data ()
 
const T & operator[] (size_t i) const
 Access elements in the memory buffer. More...
 
T & operator[] (size_t i)
 
bool empty () const
 No memory allocated? More...
 
void resize (size_t size)
 Grow or shrink the memory block. More...
 
void clear ()
 Free the allocated memory block and set the current size to 0. More...
 
void swap (MemBuffer &other) noexcept
 Swap the managed memory block of two MemBuffers. More...
 

Detailed Description

template<typename T, size_t ALIGNMENT = 0>
class openmsx::MemBuffer< T, ALIGNMENT >

This class manages the lifetime of a block of memory.

Its two main use cases are: 1) As a safer alternative for new[] / delete[]. Using this class makes sure the memory block is always properly cleaned up. Also in case of exceptions. 2) As an alternative for vector<byte> ('byte' or other primitive types). The main difference with vector is that the allocated block is left uninitialized. This can be a bit more efficient if the block will anyway soon be overwritten.

Like vector this buffer can dynamically grow or shrink. But it's not optimized for this case (it doesn't keep track of extra capacity). If you need frequent resizing prefer to use vector instead of this class.

Definition at line 28 of file MemBuffer.hh.

Constructor & Destructor Documentation

◆ MemBuffer() [1/3]

template<typename T , size_t ALIGNMENT = 0>
openmsx::MemBuffer< T, ALIGNMENT >::MemBuffer ( )
inline

Construct an empty MemBuffer, no memory is allocated.

Definition at line 33 of file MemBuffer.hh.

◆ MemBuffer() [2/3]

template<typename T , size_t ALIGNMENT = 0>
openmsx::MemBuffer< T, ALIGNMENT >::MemBuffer ( size_t  size)
inlineexplicit

Construct a (uninitialized) memory buffer of given size.

Definition at line 43 of file MemBuffer.hh.

◆ MemBuffer() [3/3]

template<typename T , size_t ALIGNMENT = 0>
openmsx::MemBuffer< T, ALIGNMENT >::MemBuffer ( MemBuffer< T, ALIGNMENT > &&  other)
inlinenoexcept

Move constructor.

Definition at line 52 of file MemBuffer.hh.

◆ ~MemBuffer()

template<typename T , size_t ALIGNMENT = 0>
openmsx::MemBuffer< T, ALIGNMENT >::~MemBuffer ( )
inline

Free the memory buffer.

Definition at line 73 of file MemBuffer.hh.

Member Function Documentation

◆ clear()

template<typename T , size_t ALIGNMENT = 0>
void openmsx::MemBuffer< T, ALIGNMENT >::clear ( )
inline

Free the allocated memory block and set the current size to 0.

Definition at line 125 of file MemBuffer.hh.

Referenced by openmsx::FileBase::munmap(), and openmsx::MemBuffer< const byte * >::resize().

◆ data() [1/2]

template<typename T , size_t ALIGNMENT = 0>
T* openmsx::MemBuffer< T, ALIGNMENT >::data ( )
inline

Definition at line 82 of file MemBuffer.hh.

◆ data() [2/2]

template<typename T , size_t ALIGNMENT = 0>
const T* openmsx::MemBuffer< T, ALIGNMENT >::data ( ) const
inline

Returns pointer to the start of the memory buffer.

This method can be called even when there's no buffer allocated.

Definition at line 81 of file MemBuffer.hh.

Referenced by openmsx::Rom::addPadding(), openmsx::OutputBuffer::allocate(), openmsx::DeltaBlockCopy::apply(), openmsx::SchedulerQueue< openmsx::SynchronizationPoint >::capacity(), openmsx::Ram::clear(), openmsx::DeltaBlockCopy::compress(), openmsx::ZMBVEncoder::compressFrame(), openmsx::OutputBuffer::deallocate(), openmsx::DeltaBlockCopy::DeltaBlockCopy(), openmsx::DeltaBlockDiff::DeltaBlockDiff(), openmsx::RomDatabase::getBufferStart(), openmsx::ResampleCoeffs::getCoeffs(), openmsx::DeltaBlockCopy::getData(), openmsx::RawFrame::getLineInfo(), openmsx::RawFrame::getLinePtrDirect(), openmsx::OutputBuffer::getPosition(), openmsx::ZlibInflate::inflate(), openmsx::SchedulerQueue< openmsx::SynchronizationPoint >::insert(), openmsx::OutputBuffer::insertAt(), openmsx::XMLLoader::load(), openmsx::SoundDevice::mixChannels(), openmsx::FileBase::mmap(), openmsx::Paper::Paper(), openmsx::OutputBuffer::release(), openmsx::RomDatabase::RomDatabase(), openmsx::SDLGLVisibleSurface::saveScreenshotGL(), openmsx::SDLVisibleSurface::saveScreenshotSDL(), openmsx::MLAAScaler< Pixel >::scaleImage(), openmsx::SDLOffScreenSurface::SDLOffScreenSurface(), SDLSurfacePtr::SDLSurfacePtr(), openmsx::Ram::serialize(), openmsx::OutputArchiveBase< Derived >::serialize_blob(), and openmsx::SchedulerQueue< openmsx::SynchronizationPoint >::spareFront().

◆ empty()

template<typename T , size_t ALIGNMENT = 0>
bool openmsx::MemBuffer< T, ALIGNMENT >::empty ( ) const
inline

No memory allocated?

Definition at line 103 of file MemBuffer.hh.

Referenced by openmsx::FileBase::mmap().

◆ operator=()

template<typename T , size_t ALIGNMENT = 0>
MemBuffer& openmsx::MemBuffer< T, ALIGNMENT >::operator= ( MemBuffer< T, ALIGNMENT > &&  other)
inlinenoexcept

Move assignment.

Definition at line 62 of file MemBuffer.hh.

◆ operator[]() [1/2]

template<typename T , size_t ALIGNMENT = 0>
T& openmsx::MemBuffer< T, ALIGNMENT >::operator[] ( size_t  i)
inline

Definition at line 93 of file MemBuffer.hh.

◆ operator[]() [2/2]

template<typename T , size_t ALIGNMENT = 0>
const T& openmsx::MemBuffer< T, ALIGNMENT >::operator[] ( size_t  i) const
inline

Access elements in the memory buffer.

Definition at line 86 of file MemBuffer.hh.

◆ resize()

template<typename T , size_t ALIGNMENT = 0>
void openmsx::MemBuffer< T, ALIGNMENT >::resize ( size_t  size)
inline

Grow or shrink the memory block.

In case of growing, the extra space is left uninitialized. It is possible (even likely) that the memory buffer is copied to a new location after this call, so data() will return a different pointer value.

Definition at line 111 of file MemBuffer.hh.

Referenced by openmsx::DeltaBlockCopy::compress(), openmsx::ZlibInflate::inflate(), openmsx::XMLLoader::load(), openmsx::RawFrame::RawFrame(), openmsx::OutputBuffer::release(), openmsx::RomDatabase::RomDatabase(), openmsx::SDLOffScreenSurface::SDLOffScreenSurface(), openmsx::SDLSoundDriver::SDLSoundDriver(), SDLSurfacePtr::SDLSurfacePtr(), and openmsx::WavData::WavData().

◆ swap()

template<typename T , size_t ALIGNMENT = 0>
void openmsx::MemBuffer< T, ALIGNMENT >::swap ( MemBuffer< T, ALIGNMENT > &  other)
inlinenoexcept

Swap the managed memory block of two MemBuffers.

Definition at line 136 of file MemBuffer.hh.

Referenced by openmsx::DeltaBlockCopy::compress().


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