MemoryInputStream Class Reference

Allows a block of data to be accessed as a stream. More...

#include <juce_MemoryInputStream.h>

Inheritance diagram for MemoryInputStream:

Public Member Functions
	MemoryInputStream (const void *sourceData, size_t sourceDataSize, bool keepInternalCopyOfData)
	Creates a MemoryInputStream.
	MemoryInputStream (const MemoryBlock &data, bool keepInternalCopyOfData)
	Creates a MemoryInputStream.
	MemoryInputStream (MemoryBlock &&blockToTake)
	Creates a stream by moving from a MemoryBlock.
	~MemoryInputStream () override
	Destructor.
const void *	getData () const noexcept
	Returns a pointer to the source data block from which this stream is reading.
size_t	getDataSize () const noexcept
	Returns the number of bytes of source data in the block from which this stream is reading.
int64	getPosition () override
	Returns the offset of the next byte that will be read from the stream.
bool	setPosition (int64) override
	Tries to move the current read position of the stream.
int64	getTotalLength () override
	Returns the total number of bytes available for reading in this stream.
bool	isExhausted () override
	Returns true if the stream has no more data to read.
int	read (void *destBuffer, int maxBytesToRead) override
	Reads some data from the stream into a memory buffer.
void	skipNextBytes (int64 numBytesToSkip) override
	Reads and discards a number of bytes from the stream.
Public Member Functions inherited from InputStream
virtual	~InputStream ()=default
	Destructor.
int64	getNumBytesRemaining ()
	Returns the number of bytes available for reading, or a negative value if the remaining length is not known.
ssize_t	read (void *destBuffer, size_t maxBytesToRead)
virtual char	readByte ()
	Reads a byte from the stream.
virtual bool	readBool ()
	Reads a boolean from the stream.
virtual short	readShort ()
	Reads two bytes from the stream as a little-endian 16-bit value.
virtual short	readShortBigEndian ()
	Reads two bytes from the stream as a little-endian 16-bit value.
virtual int	readInt ()
	Reads four bytes from the stream as a little-endian 32-bit value.
virtual int	readIntBigEndian ()
	Reads four bytes from the stream as a big-endian 32-bit value.
virtual int64	readInt64 ()
	Reads eight bytes from the stream as a little-endian 64-bit value.
virtual int64	readInt64BigEndian ()
	Reads eight bytes from the stream as a big-endian 64-bit value.
virtual float	readFloat ()
	Reads four bytes as a 32-bit floating point value.
virtual float	readFloatBigEndian ()
	Reads four bytes as a 32-bit floating point value.
virtual double	readDouble ()
	Reads eight bytes as a 64-bit floating point value.
virtual double	readDoubleBigEndian ()
	Reads eight bytes as a 64-bit floating point value.
virtual int	readCompressedInt ()
	Reads an encoded 32-bit number from the stream using a space-saving compressed format.
virtual String	readNextLine ()
	Reads a UTF-8 string from the stream, up to the next linefeed or carriage return.
virtual String	readString ()
	Reads a zero-terminated UTF-8 string from the stream.
virtual String	readEntireStreamAsString ()
	Tries to read the whole stream and turn it into a string.
virtual size_t	readIntoMemoryBlock (MemoryBlock &destBlock, ssize_t maxNumBytesToRead=-1)
	Reads from the stream and appends the data to a MemoryBlock.

Additional Inherited Members
Protected Member Functions inherited from InputStream
	InputStream ()=default

Detailed Description

Allows a block of data to be accessed as a stream.

This can either be used to refer to a shared block of memory, or can make its own internal copy of the data when the MemoryInputStream is created.

Constructor & Destructor Documentation

MemoryInputStream() [1/3]

MemoryInputStream::MemoryInputStream	(	const void *	sourceData,
		size_t	sourceDataSize,
		bool	keepInternalCopyOfData )

Creates a MemoryInputStream.

Parameters

sourceData	the block of data to use as the stream's source
sourceDataSize	the number of bytes in the source data block
keepInternalCopyOfData	if false, the stream will just keep a pointer to the source data, so this data shouldn't be changed for the lifetime of the stream; if this parameter is true, the stream will make its own copy of the data and use that.

MemoryInputStream() [2/3]

MemoryInputStream::MemoryInputStream	(	const MemoryBlock &	data,
		bool	keepInternalCopyOfData )

Creates a MemoryInputStream.

Parameters

data	a block of data to use as the stream's source
keepInternalCopyOfData	if false, the stream will just keep a reference to the source data, so this data shouldn't be changed for the lifetime of the stream; if this parameter is true, the stream will make its own copy of the data and use that.

MemoryInputStream() [3/3]

MemoryInputStream::MemoryInputStream

(

MemoryBlock &&

blockToTake

)

Creates a stream by moving from a MemoryBlock.

~MemoryInputStream()

MemoryInputStream::~MemoryInputStream ( )

override

Destructor.

Member Function Documentation

getData()

const void * MemoryInputStream::getData ( ) const

noexcept

Returns a pointer to the source data block from which this stream is reading.

getDataSize()

size_t MemoryInputStream::getDataSize ( ) const

noexcept

Returns the number of bytes of source data in the block from which this stream is reading.

getPosition()

int64 MemoryInputStream::getPosition ( )

overridevirtual

Returns the offset of the next byte that will be read from the stream.

See also

setPosition

Implements InputStream.

setPosition()

bool MemoryInputStream::setPosition ( int64 newPosition )

overridevirtual

Tries to move the current read position of the stream.

The position is an absolute number of bytes from the stream's start.

Some streams might not be able to do this, in which case they should do nothing and return false. Others might be able to manage it by resetting themselves and skipping to the correct position, although this is obviously a bit slow.

Returns

true if the stream manages to reposition itself correctly

See also

getPosition

Implements InputStream.

getTotalLength()

int64 MemoryInputStream::getTotalLength ( )

overridevirtual

Returns the total number of bytes available for reading in this stream.

Note that this is the number of bytes available from the start of the stream, not from the current position.

If the size of the stream isn't actually known, this will return -1.

See also

getNumBytesRemaining

Implements InputStream.

isExhausted()

bool MemoryInputStream::isExhausted ( )

overridevirtual

Returns true if the stream has no more data to read.

Implements InputStream.

read()

int MemoryInputStream::read ( void * destBuffer, int maxBytesToRead )

overridevirtual

Reads some data from the stream into a memory buffer.

This is the only read method that subclasses actually need to implement, as the InputStream base class implements the other read methods in terms of this one (although it's often more efficient for subclasses to implement them directly).

Parameters

destBuffer	the destination buffer for the data. This must not be null.
maxBytesToRead	the maximum number of bytes to read - make sure the memory block passed in is big enough to contain this many bytes. This value must not be negative.

Returns

the actual number of bytes that were read, which may be less than maxBytesToRead if the stream is exhausted before it gets that far

Implements InputStream.

skipNextBytes()

void MemoryInputStream::skipNextBytes ( int64 numBytesToSkip )

overridevirtual

Reads and discards a number of bytes from the stream.

Some input streams might implement this more efficiently, but the base class will just keep reading data until the requisite number of bytes have been done. For large skips it may be quicker to call setPosition() with the required position.

Reimplemented from InputStream.

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

• juce_MemoryInputStream.h