juce::FileInputStream Class Reference

An input stream that reads from a local file. More...

#include <juce_FileInputStream.h>

Inheritance diagram for juce::FileInputStream:

Collaboration diagram for juce::FileInputStream:

Public Member Functions
	FileInputStream (const File &fileToRead)
	Creates a FileInputStream to read from the given file. More...
	~FileInputStream () override
	Destructor. More...
bool	failedToOpen () const noexcept
	Returns true if the stream couldn't be opened for some reason. More...
const File &	getFile () const noexcept
	Returns the file that this stream is reading from. More...
int64	getNumBytesRemaining ()
	Returns the number of bytes available for reading, or a negative value if the remaining length is not known. More...
int64	getPosition () override
	Returns the offset of the next byte that will be read from the stream. More...
const Result &	getStatus () const noexcept
	Returns the status of the file stream. More...
int64	getTotalLength () override
	Returns the total number of bytes available for reading in this stream. More...
bool	isExhausted () override
	Returns true if the stream has no more data to read. More...
bool	openedOk () const noexcept
	Returns true if the stream opened without problems. More...
int	read (void *, int) override
	Reads some data from the stream into a memory buffer. More...
ssize_t	read (void *destBuffer, size_t maxBytesToRead)
virtual bool	readBool ()
	Reads a boolean from the stream. More...
virtual char	readByte ()
	Reads a byte from the stream. More...
virtual int	readCompressedInt ()
	Reads an encoded 32-bit number from the stream using a space-saving compressed format. More...
virtual double	readDouble ()
	Reads eight bytes as a 64-bit floating point value. More...
virtual double	readDoubleBigEndian ()
	Reads eight bytes as a 64-bit floating point value. More...
virtual String	readEntireStreamAsString ()
	Tries to read the whole stream and turn it into a string. More...
virtual float	readFloat ()
	Reads four bytes as a 32-bit floating point value. More...
virtual float	readFloatBigEndian ()
	Reads four bytes as a 32-bit floating point value. More...
virtual int	readInt ()
	Reads four bytes from the stream as a little-endian 32-bit value. More...
virtual int64	readInt64 ()
	Reads eight bytes from the stream as a little-endian 64-bit value. More...
virtual int64	readInt64BigEndian ()
	Reads eight bytes from the stream as a big-endian 64-bit value. More...
virtual int	readIntBigEndian ()
	Reads four bytes from the stream as a big-endian 32-bit value. More...
virtual size_t	readIntoMemoryBlock (MemoryBlock &destBlock, ssize_t maxNumBytesToRead=-1)
	Reads from the stream and appends the data to a MemoryBlock. More...
virtual String	readNextLine ()
	Reads a UTF-8 string from the stream, up to the next linefeed or carriage return. More...
virtual short	readShort ()
	Reads two bytes from the stream as a little-endian 16-bit value. More...
virtual short	readShortBigEndian ()
	Reads two bytes from the stream as a little-endian 16-bit value. More...
virtual String	readString ()
	Reads a zero-terminated UTF-8 string from the stream. More...
bool	setPosition (int64) override
	Tries to move the current read position of the stream. More...
virtual void	skipNextBytes (int64 numBytesToSkip)
	Reads and discards a number of bytes from the stream. More...

Private Member Functions
void	openHandle ()
size_t	readInternal (void *, size_t)

Private Attributes
int64	currentPosition = 0
const File	file
void *	fileHandle = nullptr
Result	status { Result::ok() }

Detailed Description

An input stream that reads from a local file.

See also

InputStream, FileOutputStream, File::createInputStream

@tags{Core}

Constructor & Destructor Documentation

FileInputStream()

juce::FileInputStream::FileInputStream ( const File &  fileToRead )

explicit

Creates a FileInputStream to read from the given file.

After creating a FileInputStream, you should use openedOk() or failedToOpen() to make sure that it's OK before trying to read from it! If it failed, you can call getStatus() to get more error information.

~FileInputStream()

juce::FileInputStream::~FileInputStream ( )

override

Destructor.

References fileHandle, and juce::anonymous_namespace{juce_posix_SharedCode.h}::getFD().

Member Function Documentation

failedToOpen()

bool juce::FileInputStream::failedToOpen ( ) const

inlinenoexcept

Returns true if the stream couldn't be opened for some reason.

See also

getResult()

getFile()

const File& juce::FileInputStream::getFile ( ) const

inlinenoexcept

Returns the file that this stream is reading from.

getNumBytesRemaining()

int64 juce::InputStream::getNumBytesRemaining ( )

inherited

Returns the number of bytes available for reading, or a negative value if the remaining length is not known.

See also

getTotalLength

getPosition()

int64 juce::FileInputStream::getPosition ( )

overridevirtual

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

See also

setPosition

Implements juce::InputStream.

getStatus()

const Result& juce::FileInputStream::getStatus ( ) const

inlinenoexcept

Returns the status of the file stream.

The result will be ok if the file opened successfully. If an error occurs while opening or reading from the file, this will contain an error message.

getTotalLength()

int64 juce::FileInputStream::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 juce::InputStream.

isExhausted()

bool juce::FileInputStream::isExhausted ( )

overridevirtual

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

Implements juce::InputStream.

openedOk()

bool juce::FileInputStream::openedOk ( ) const

inlinenoexcept

Returns true if the stream opened without problems.

See also

getResult()

openHandle()

void juce::FileInputStream::openHandle ( )

private

References juce::gl::f, juce::anonymous_namespace{juce_posix_SharedCode.h}::fdToVoidPointer(), file, fileHandle, juce::File::getFullPathName(), juce::anonymous_namespace{juce_posix_SharedCode.h}::getResultForErrno(), status, and juce::String::toUTF8().

read() [1/2]

int juce::FileInputStream::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 juce::InputStream.

Referenced by readInternal().

read() [2/2]

ssize_t juce::InputStream::read ( void *  destBuffer, size_t  maxBytesToRead  )

inherited

readBool()

virtual bool juce::InputStream::readBool ( )

virtualinherited

Reads a boolean from the stream.

The bool is encoded as a single byte - non-zero for true, 0 for false. If the stream is exhausted, this will return false.

See also

OutputStream::writeBool

readByte()

virtual char juce::InputStream::readByte ( )

virtualinherited

Reads a byte from the stream.

If the stream is exhausted, this will return zero.

See also

OutputStream::writeByte

readCompressedInt()

virtual int juce::InputStream::readCompressedInt ( )

virtualinherited

Reads an encoded 32-bit number from the stream using a space-saving compressed format.

For small values, this is more space-efficient than using readInt() and OutputStream::writeInt() The format used is: number of significant bytes + up to 4 bytes in little-endian order.

See also

OutputStream::writeCompressedInt()

readDouble()

virtual double juce::InputStream::readDouble ( )

virtualinherited

Reads eight bytes as a 64-bit floating point value.

The raw 64-bit encoding of the double is read from the stream as a little-endian int64. If the stream is exhausted partway through reading the bytes, this will return zero.

See also

OutputStream::writeDouble, readFloat

readDoubleBigEndian()

virtual double juce::InputStream::readDoubleBigEndian ( )

virtualinherited

Reads eight bytes as a 64-bit floating point value.

The raw 64-bit encoding of the double is read from the stream as a big-endian int64. If the stream is exhausted partway through reading the bytes, this will return zero.

See also

OutputStream::writeDoubleBigEndian, readFloatBigEndian

readEntireStreamAsString()

virtual String juce::InputStream::readEntireStreamAsString ( )

virtualinherited

Tries to read the whole stream and turn it into a string.

This will read from the stream's current position until the end-of-stream. It can read from UTF-8 data, or UTF-16 if it detects suitable header-bytes.

readFloat()

virtual float juce::InputStream::readFloat ( )

virtualinherited

Reads four bytes as a 32-bit floating point value.

The raw 32-bit encoding of the float is read from the stream as a little-endian int. If the stream is exhausted partway through reading the bytes, this will return zero.

See also

OutputStream::writeFloat, readDouble

readFloatBigEndian()

virtual float juce::InputStream::readFloatBigEndian ( )

virtualinherited

Reads four bytes as a 32-bit floating point value.

The raw 32-bit encoding of the float is read from the stream as a big-endian int. If the stream is exhausted partway through reading the bytes, this will return zero.

See also

OutputStream::writeFloatBigEndian, readDoubleBigEndian

readInt()

virtual int juce::InputStream::readInt ( )

virtualinherited

Reads four bytes from the stream as a little-endian 32-bit value.

If the next four bytes are byte1 to byte4, this returns (byte1 | (byte2 << 8) | (byte3 << 16) | (byte4 << 24)).

If the stream is exhausted partway through reading the bytes, this will return zero.

See also

OutputStream::writeInt, readIntBigEndian

readInt64()

virtual int64 juce::InputStream::readInt64 ( )

virtualinherited

Reads eight bytes from the stream as a little-endian 64-bit value.

If the next eight bytes are byte1 to byte8, this returns (byte1 | (byte2 << 8) | (byte3 << 16) | (byte4 << 24) | (byte5 << 32) | (byte6 << 40) | (byte7 << 48) | (byte8 << 56)).

If the stream is exhausted partway through reading the bytes, this will return zero.

See also

OutputStream::writeInt64, readInt64BigEndian

readInt64BigEndian()

virtual int64 juce::InputStream::readInt64BigEndian ( )

virtualinherited

Reads eight bytes from the stream as a big-endian 64-bit value.

If the next eight bytes are byte1 to byte8, this returns (byte8 | (byte7 << 8) | (byte6 << 16) | (byte5 << 24) | (byte4 << 32) | (byte3 << 40) | (byte2 << 48) | (byte1 << 56)).

If the stream is exhausted partway through reading the bytes, this will return zero.

See also

OutputStream::writeInt64BigEndian, readInt64

readIntBigEndian()

virtual int juce::InputStream::readIntBigEndian ( )

virtualinherited

Reads four bytes from the stream as a big-endian 32-bit value.

If the next four bytes are byte1 to byte4, this returns (byte4 | (byte3 << 8) | (byte2 << 16) | (byte1 << 24)).

If the stream is exhausted partway through reading the bytes, this will return zero.

See also

OutputStream::writeIntBigEndian, readInt

readInternal()

size_t juce::FileInputStream::readInternal ( void *  buffer, size_t  numBytes  )

private

References juce::gl::buffer, fileHandle, juce::anonymous_namespace{juce_posix_SharedCode.h}::getFD(), juce::anonymous_namespace{juce_posix_SharedCode.h}::getResultForErrno(), read(), juce::gl::result, and status.

readIntoMemoryBlock()

virtual size_t juce::InputStream::readIntoMemoryBlock ( MemoryBlock &  destBlock, ssize_t  maxNumBytesToRead = -1  )

virtualinherited

Reads from the stream and appends the data to a MemoryBlock.

Parameters

destBlock	the block to append the data onto
maxNumBytesToRead	if this is a positive value, it sets a limit to the number of bytes that will be read - if it's negative, data will be read until the stream is exhausted.

Returns

the number of bytes that were added to the memory block

readNextLine()

virtual String juce::InputStream::readNextLine ( )

virtualinherited

Reads a UTF-8 string from the stream, up to the next linefeed or carriage return.

This will read up to the next "\n" or "\r\n" or end-of-stream.

After this call, the stream's position will be left pointing to the next character following the line-feed, but the linefeeds aren't included in the string that is returned.

readShort()

virtual short juce::InputStream::readShort ( )

virtualinherited

Reads two bytes from the stream as a little-endian 16-bit value.

If the next two bytes read are byte1 and byte2, this returns (byte1 | (byte2 << 8)). If the stream is exhausted partway through reading the bytes, this will return zero.

See also

OutputStream::writeShort, readShortBigEndian

readShortBigEndian()

virtual short juce::InputStream::readShortBigEndian ( )

virtualinherited

Reads two bytes from the stream as a little-endian 16-bit value.

If the next two bytes read are byte1 and byte2, this returns (byte2 | (byte1 << 8)). If the stream is exhausted partway through reading the bytes, this will return zero.

See also

OutputStream::writeShortBigEndian, readShort

readString()

virtual String juce::InputStream::readString ( )

virtualinherited

Reads a zero-terminated UTF-8 string from the stream.

This will read characters from the stream until it hits a null character or end-of-stream.

See also

OutputStream::writeString, readEntireStreamAsString

Reimplemented in juce::BufferedInputStream.

setPosition()

bool juce::FileInputStream::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 juce::InputStream.

skipNextBytes()

virtual void juce::InputStream::skipNextBytes ( int64  numBytesToSkip )

virtualinherited

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 in juce::MemoryInputStream.

Member Data Documentation

currentPosition

int64 juce::FileInputStream::currentPosition = 0

private

file

const File juce::FileInputStream::file

private

Referenced by openHandle().

fileHandle

void* juce::FileInputStream::fileHandle = nullptr

private

Referenced by openHandle(), readInternal(), and ~FileInputStream().

status

Result juce::FileInputStream::status { Result::ok() }

private

Referenced by openHandle(), and readInternal().

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

• juce_FileInputStream.h
• juce_posix_SharedCode.h