MemoryBlock Class Reference

A class to hold a resizable block of raw data. More...

#include <juce_MemoryBlock.h>

Public Member Functions
	MemoryBlock () noexcept
	Create an uninitialised block with 0 size.
	MemoryBlock (size_t initialSize, bool initialiseToZero=false)
	Creates a memory block with a given initial size.
	MemoryBlock (const MemoryBlock &)
	Creates a copy of another memory block.
	MemoryBlock (const void *dataToInitialiseFrom, size_t sizeInBytes)
	Creates a memory block using a copy of a block of data.
	~MemoryBlock () noexcept
	Destructor.
MemoryBlock &	operator= (const MemoryBlock &)
	Copies another memory block onto this one.
	MemoryBlock (MemoryBlock &&) noexcept
	Move constructor.
MemoryBlock &	operator= (MemoryBlock &&) noexcept
	Move assignment operator.
bool	operator== (const MemoryBlock &other) const noexcept
	Compares two memory blocks.
bool	operator!= (const MemoryBlock &other) const noexcept
	Compares two memory blocks.
bool	matches (const void *data, size_t dataSize) const noexcept
	Returns true if the data in this MemoryBlock matches the raw bytes passed-in.
void *	getData () noexcept
	Returns a void pointer to the data.
const void *	getData () const noexcept
	Returns a void pointer to the data.
template<typename Type >
char &	operator[] (const Type offset) noexcept
	Returns a byte from the memory block.
template<typename Type >
const char &	operator[] (const Type offset) const noexcept
	Returns a byte from the memory block.
char *	begin () noexcept
	Returns an iterator for the data.
const char *	begin () const noexcept
	Returns an iterator for the data.
char *	end () noexcept
	Returns an end-iterator for the data.
const char *	end () const noexcept
	Returns an end-iterator for the data.
bool	isEmpty () const noexcept
	Returns true if the memory block has zero size.
size_t	getSize () const noexcept
	Returns the block's current allocated size, in bytes.
void	setSize (size_t newSize, bool initialiseNewSpaceToZero=false)
	Resizes the memory block.
void	ensureSize (size_t minimumSize, bool initialiseNewSpaceToZero=false)
	Increases the block's size only if it's smaller than a given size.
void	reset ()
	Frees all the blocks data, setting its size to 0.
void	fillWith (uint8 valueToUse) noexcept
	Fills the entire memory block with a repeated byte value.
void	append (const void *data, size_t numBytes)
	Adds another block of data to the end of this one.
void	replaceAll (const void *data, size_t numBytes)
	Resizes this block to the given size and fills its contents from the supplied buffer.
void	insert (const void *dataToInsert, size_t numBytesToInsert, size_t insertPosition)
	Inserts some data into the block.
void	removeSection (size_t startByte, size_t numBytesToRemove)
	Chops out a section of the block.
void	copyFrom (const void *srcData, int destinationOffset, size_t numBytes) noexcept
	Copies data into this MemoryBlock from a memory address.
void	copyTo (void *destData, int sourceOffset, size_t numBytes) const noexcept
	Copies data from this MemoryBlock to a memory address.
void	swapWith (MemoryBlock &other) noexcept
	Exchanges the contents of this and another memory block.
String	toString () const
	Attempts to parse the contents of the block as a zero-terminated UTF8 string.
void	loadFromHexString (StringRef sourceHexString)
	Parses a string of hexadecimal numbers and writes this data into the memory block.
void	setBitRange (size_t bitRangeStart, size_t numBits, int binaryNumberToApply) noexcept
	Sets a number of bits in the memory block, treating it as a long binary sequence.
int	getBitRange (size_t bitRangeStart, size_t numBitsToRead) const noexcept
	Reads a number of bits from the memory block, treating it as one long binary sequence.
String	toBase64Encoding () const
	Returns a string of characters in a JUCE-specific text encoding that represents the binary contents of this block.
bool	fromBase64Encoding (StringRef encodedString)
	Takes a string created by MemoryBlock::toBase64Encoding() and extracts the original data.

Detailed Description

A class to hold a resizable block of raw data.

Constructor & Destructor Documentation

MemoryBlock() [1/5]

MemoryBlock::MemoryBlock ( )

noexcept

Create an uninitialised block with 0 size.

MemoryBlock() [2/5]

MemoryBlock::MemoryBlock	(	size_t	initialSize,
		bool	initialiseToZero = false )

Creates a memory block with a given initial size.

Parameters

initialSize	the size of block to create
initialiseToZero	whether to clear the memory or just leave it uninitialised

MemoryBlock() [3/5]

MemoryBlock::MemoryBlock

(

const MemoryBlock &

)

Creates a copy of another memory block.

MemoryBlock() [4/5]

MemoryBlock::MemoryBlock	(	const void *	dataToInitialiseFrom,
		size_t	sizeInBytes )

Creates a memory block using a copy of a block of data.

Parameters

dataToInitialiseFrom	some data to copy into this block
sizeInBytes	how much space to use

~MemoryBlock()

MemoryBlock::~MemoryBlock ( )

noexcept

Destructor.

MemoryBlock() [5/5]

MemoryBlock::MemoryBlock ( MemoryBlock && )

noexcept

Move constructor.

Member Function Documentation

operator=() [1/2]

MemoryBlock & MemoryBlock::operator=

(

const MemoryBlock &

)

Copies another memory block onto this one.

This block will be resized and copied to exactly match the other one.

operator=() [2/2]

MemoryBlock & MemoryBlock::operator= ( MemoryBlock && )

noexcept

Move assignment operator.

operator==()

bool MemoryBlock::operator== ( const MemoryBlock & other ) const

noexcept

Compares two memory blocks.

Returns

true only if the two blocks are the same size and have identical contents.

operator!=()

bool MemoryBlock::operator!= ( const MemoryBlock & other ) const

noexcept

Compares two memory blocks.

Returns

true if the two blocks are different sizes or have different contents.

matches()

bool MemoryBlock::matches ( const void * data, size_t dataSize ) const

noexcept

Returns true if the data in this MemoryBlock matches the raw bytes passed-in.

getData() [1/2]

void * MemoryBlock::getData ( )

noexcept

Returns a void pointer to the data.

Note that the pointer returned will probably become invalid when the block is resized.

Referenced by StandalonePluginHolder::askUserToLoadState(), StandalonePluginHolder::askUserToSaveState(), and StandalonePluginHolder::reloadPluginState().

getData() [2/2]

const void * MemoryBlock::getData ( ) const

noexcept

Returns a void pointer to the data.

Note that the pointer returned will probably become invalid when the block is resized.

operator[]() [1/2]

template<typename Type >

char & MemoryBlock::operator[] ( const Type offset )

noexcept

Returns a byte from the memory block.

This returns a reference, so you can also use it to set a byte.

operator[]() [2/2]

template<typename Type >

const char & MemoryBlock::operator[] ( const Type offset ) const

noexcept

Returns a byte from the memory block.

begin() [1/2]

char * MemoryBlock::begin ( )

noexcept

Returns an iterator for the data.

begin() [2/2]

const char * MemoryBlock::begin ( ) const

noexcept

Returns an iterator for the data.

end() [1/2]

char * MemoryBlock::end ( )

noexcept

Returns an end-iterator for the data.

References begin().

end() [2/2]

const char * MemoryBlock::end ( ) const

noexcept

Returns an end-iterator for the data.

References begin().

isEmpty()

bool MemoryBlock::isEmpty ( ) const

noexcept

Returns true if the memory block has zero size.

getSize()

size_t MemoryBlock::getSize ( ) const

noexcept

Returns the block's current allocated size, in bytes.

Referenced by StandalonePluginHolder::askUserToLoadState(), StandalonePluginHolder::askUserToSaveState(), and StandalonePluginHolder::reloadPluginState().

setSize()

void MemoryBlock::setSize	(	size_t	newSize,
		bool	initialiseNewSpaceToZero = false )

Resizes the memory block.

Any data that is present in both the old and new sizes will be retained. When enlarging the block, the new space that is allocated at the end can either be cleared, or left uninitialised.

Parameters

newSize	the new desired size for the block
initialiseNewSpaceToZero	if the block gets enlarged, this determines whether to clear the new section or just leave it uninitialised

See also

ensureSize

ensureSize()

void MemoryBlock::ensureSize	(	size_t	minimumSize,
		bool	initialiseNewSpaceToZero = false )

Increases the block's size only if it's smaller than a given size.

Parameters

minimumSize	if the block is already bigger than this size, no action will be taken; otherwise it will be increased to this size
initialiseNewSpaceToZero	if the block gets enlarged, this determines whether to clear the new section or just leave it uninitialised

See also

setSize

reset()

void MemoryBlock::reset

(

)

Frees all the blocks data, setting its size to 0.

fillWith()

void MemoryBlock::fillWith ( uint8 valueToUse )

noexcept

Fills the entire memory block with a repeated byte value.

This is handy for clearing a block of memory to zero.

append()

void MemoryBlock::append	(	const void *	data,
		size_t	numBytes )

Adds another block of data to the end of this one.

The data pointer must not be null. This block's size will be increased accordingly.

replaceAll()

void MemoryBlock::replaceAll	(	const void *	data,
		size_t	numBytes )

Resizes this block to the given size and fills its contents from the supplied buffer.

The data pointer must not be null.

insert()

void MemoryBlock::insert	(	const void *	dataToInsert,
		size_t	numBytesToInsert,
		size_t	insertPosition )

Inserts some data into the block.

The dataToInsert pointer must not be null. This block's size will be increased accordingly. If the insert position lies outside the valid range of the block, it will be clipped to within the range before being used.

removeSection()

void MemoryBlock::removeSection	(	size_t	startByte,
		size_t	numBytesToRemove )

Chops out a section of the block.

This will remove a section of the memory block and close the gap around it, shifting any subsequent data downwards and reducing the size of the block.

If the range specified goes beyond the size of the block, it will be clipped.

copyFrom()

void MemoryBlock::copyFrom ( const void * srcData, int destinationOffset, size_t numBytes )

noexcept

Copies data into this MemoryBlock from a memory address.

Parameters

srcData	the memory location of the data to copy into this block
destinationOffset	the offset in this block at which the data being copied should begin
numBytes	how much to copy in (if this goes beyond the size of the memory block, it will be clipped so not to do anything nasty)

copyTo()

void MemoryBlock::copyTo ( void * destData, int sourceOffset, size_t numBytes ) const

noexcept

Copies data from this MemoryBlock to a memory address.

Parameters

destData	the memory location to write to
sourceOffset	the offset within this block from which the copied data will be read
numBytes	how much to copy (if this extends beyond the limits of the memory block, zeros will be used for that portion of the data)

swapWith()

void MemoryBlock::swapWith ( MemoryBlock & other )

noexcept

Exchanges the contents of this and another memory block.

No actual copying is required for this, so it's very fast.

toString()

String MemoryBlock::toString

(

)

const

Attempts to parse the contents of the block as a zero-terminated UTF8 string.

loadFromHexString()

void MemoryBlock::loadFromHexString

(

StringRef

sourceHexString

)

Parses a string of hexadecimal numbers and writes this data into the memory block.

The block will be resized to the number of valid bytes read from the string. Non-hex characters in the string will be ignored.

See also

String::toHexString()

setBitRange()

void MemoryBlock::setBitRange ( size_t bitRangeStart, size_t numBits, int binaryNumberToApply )

noexcept

Sets a number of bits in the memory block, treating it as a long binary sequence.

getBitRange()

int MemoryBlock::getBitRange ( size_t bitRangeStart, size_t numBitsToRead ) const

noexcept

Reads a number of bits from the memory block, treating it as one long binary sequence.

toBase64Encoding()

String MemoryBlock::toBase64Encoding

(

)

const

Returns a string of characters in a JUCE-specific text encoding that represents the binary contents of this block.

This uses a JUCE-specific (i.e. not standard!) 64-bit encoding system to convert binary data into a string of ASCII characters for purposes like storage in XML. Note that this proprietary format is mainly kept here for backwards-compatibility, and you may prefer to use the Base64::toBase64() method if you want to use the standard base-64 encoding.

See also

fromBase64Encoding, Base64::toBase64, Base64::convertToBase64

Referenced by StandalonePluginHolder::savePluginState().

fromBase64Encoding()

bool MemoryBlock::fromBase64Encoding

(

StringRef

encodedString

)

Takes a string created by MemoryBlock::toBase64Encoding() and extracts the original data.

The string passed in must have been created by to64BitEncoding(), and this block will be resized to recreate the original data block.

Note that these methods use a JUCE-specific (i.e. not standard!) 64-bit encoding system. You may prefer to use the Base64::convertFromBase64() method if you want to use the standard base-64 encoding.

See also

toBase64Encoding, Base64::convertFromBase64

Referenced by StandalonePluginHolder::reloadPluginState().

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

• juce_MemoryBlock.h