SubregionStream Class Reference

Wraps another input stream, and reads from a specific part of it. More...

#include <juce_SubregionStream.h>

Inheritance diagram for SubregionStream:

Public Member Functions
	SubregionStream (InputStream *sourceStream, int64 startPositionInSourceStream, int64 lengthOfSourceStream, bool deleteSourceWhenDestroyed)
	Creates a SubregionStream from an input source.
	~SubregionStream () override
	Destructor.
int64	getTotalLength () override
	Returns the total number of bytes available for reading in this stream.
int64	getPosition () override
	Returns the offset of the next byte that will be read from the stream.
bool	setPosition (int64 newPosition) override
	Tries to move the current read position of the stream.
int	read (void *destBuffer, int maxBytesToRead) override
	Reads some data from the stream into a memory buffer.
bool	isExhausted () override
	Returns true if the stream has no more data to read.
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.
virtual void	skipNextBytes (int64 numBytesToSkip)
	Reads and discards a number of bytes from the stream.

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

Detailed Description

Wraps another input stream, and reads from a specific part of it.

This lets you take a subsection of a stream and present it as an entire stream in its own right.

Constructor & Destructor Documentation

SubregionStream()

SubregionStream::SubregionStream	(	InputStream *	sourceStream,
		int64	startPositionInSourceStream,
		int64	lengthOfSourceStream,
		bool	deleteSourceWhenDestroyed )

Creates a SubregionStream from an input source.

Parameters

sourceStream	the source stream to read from
startPositionInSourceStream	this is the position in the source stream that corresponds to position 0 in this stream
lengthOfSourceStream	this specifies the maximum number of bytes from the source stream that will be passed through by this stream. When the position of this stream exceeds lengthOfSourceStream, it will cause an end-of-stream. If the length passed in here is greater than the length of the source stream (as returned by getTotalLength()), then the smaller value will be used. Passing a negative value for this parameter means it will keep reading until the source's end-of-stream.
deleteSourceWhenDestroyed	whether the sourceStream that is passed in should be deleted by this object when it is itself deleted.

~SubregionStream()

SubregionStream::~SubregionStream ( )

override

Destructor.

This may also delete the source stream, if that option was chosen when the buffered stream was created.

Member Function Documentation

getTotalLength()

int64 SubregionStream::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.

getPosition()

int64 SubregionStream::getPosition ( )

overridevirtual

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

See also

setPosition

Implements InputStream.

setPosition()

bool SubregionStream::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.

read()

int SubregionStream::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.

isExhausted()

bool SubregionStream::isExhausted ( )

overridevirtual

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

Implements InputStream.

---

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

• juce_SubregionStream.h