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juce::FileOutputStream Class Reference

An output stream that writes into a local file. More...

#include <juce_FileOutputStream.h>

Inheritance diagram for juce::FileOutputStream:
Collaboration diagram for juce::FileOutputStream:

Public Member Functions

 FileOutputStream (const File &fileToWriteTo, size_t bufferSizeToUse=16384)
 Creates a FileOutputStream. More...
 
 ~FileOutputStream () override
 Destructor. More...
 
bool failedToOpen () const noexcept
 Returns true if the stream couldn't be opened for some reason. More...
 
void flush () override
 If the stream is using a buffer, this will ensure it gets written out to the destination. More...
 
const FilegetFile () const
 Returns the file that this stream is writing to. More...
 
const StringgetNewLineString () const noexcept
 Returns the current new-line string that was set by setNewLineString(). More...
 
int64 getPosition () override
 Returns the stream's current position. More...
 
const ResultgetStatus () const noexcept
 Returns the status of the file stream. More...
 
bool openedOk () const noexcept
 Returns true if the stream opened without problems. More...
 
void setNewLineString (const String &newLineString)
 Sets the string to write to the stream when a new line is written. More...
 
bool setPosition (int64) override
 Tries to move the stream's output position. More...
 
Result truncate ()
 Attempts to truncate the file to the current write position. More...
 
bool write (const void *, size_t) override
 Writes a block of data to the stream. More...
 
virtual bool writeBool (bool boolValue)
 Writes a boolean to the stream as a single byte. More...
 
virtual bool writeByte (char byte)
 Writes a single byte to the stream. More...
 
virtual bool writeCompressedInt (int value)
 Writes a condensed binary encoding of a 32-bit integer. More...
 
virtual bool writeDouble (double value)
 Writes a 64-bit floating point value to the stream in a binary format. More...
 
virtual bool writeDoubleBigEndian (double value)
 Writes a 64-bit floating point value to the stream in a binary format. More...
 
virtual bool writeFloat (float value)
 Writes a 32-bit floating point value to the stream in a binary format. More...
 
virtual bool writeFloatBigEndian (float value)
 Writes a 32-bit floating point value to the stream in a binary format. More...
 
virtual int64 writeFromInputStream (InputStream &source, int64 maxNumBytesToWrite)
 Reads data from an input stream and writes it to this stream. More...
 
virtual bool writeInt (int value)
 Writes a 32-bit integer to the stream in a little-endian byte order. More...
 
virtual bool writeInt64 (int64 value)
 Writes a 64-bit integer to the stream in a little-endian byte order. More...
 
virtual bool writeInt64BigEndian (int64 value)
 Writes a 64-bit integer to the stream in a big-endian byte order. More...
 
virtual bool writeIntBigEndian (int value)
 Writes a 32-bit integer to the stream in a big-endian byte order. More...
 
bool writeRepeatedByte (uint8 byte, size_t numTimesToRepeat) override
 Writes a byte to the output stream a given number of times. More...
 
virtual bool writeShort (short value)
 Writes a 16-bit integer to the stream in a little-endian byte order. More...
 
virtual bool writeShortBigEndian (short value)
 Writes a 16-bit integer to the stream in a big-endian byte order. More...
 
virtual bool writeString (const String &text)
 Stores a string in the stream in a binary format. More...
 
virtual bool writeText (const String &text, bool asUTF16, bool writeUTF16ByteOrderMark, const char *lineEndings)
 Writes a string of text to the stream. More...
 

Private Member Functions

void closeHandle ()
 
bool flushBuffer ()
 
void flushInternal ()
 
void openHandle ()
 
int64 setPositionInternal (int64)
 
ssize_t writeInternal (const void *, size_t)
 

Private Attributes

HeapBlock< char > buffer
 
size_t bufferSize
 
size_t bytesInBuffer = 0
 
int64 currentPosition = 0
 
File file
 
void * fileHandle = nullptr
 
Result status { Result::ok() }
 

Detailed Description

An output stream that writes into a local file.

See also
OutputStream, FileInputStream, File::createOutputStream

{Core}

Constructor & Destructor Documentation

◆ FileOutputStream()

juce::FileOutputStream::FileOutputStream ( const File fileToWriteTo,
size_t  bufferSizeToUse = 16384 
)

Creates a FileOutputStream.

If the file doesn't exist, it will first be created. If the file can't be created or opened (for example, because the parent directory of the file does not exist), the failedToOpen() method will return true.

If the file already exists when opened, the stream's write-position will be set to the end of the file. To overwrite an existing file, you can truncate it like this:

if (stream.openedOk())
{
stream.setPosition (0);
stream.truncate();
...
}

Destroying a FileOutputStream object does not force the operating system to write the buffered data to disk immediately. If this is required you should call flush() before triggering the destructor.

See also
TemporaryFile

◆ ~FileOutputStream()

juce::FileOutputStream::~FileOutputStream ( )
override

Destructor.

Member Function Documentation

◆ closeHandle()

void juce::FileOutputStream::closeHandle ( )
private

◆ failedToOpen()

bool juce::FileOutputStream::failedToOpen ( ) const
inlinenoexcept

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

See also
getResult()

◆ flush()

void juce::FileOutputStream::flush ( )
overridevirtual

If the stream is using a buffer, this will ensure it gets written out to the destination.

Implements juce::OutputStream.

◆ flushBuffer()

bool juce::FileOutputStream::flushBuffer ( )
private

◆ flushInternal()

void juce::FileOutputStream::flushInternal ( )
private

Referenced by writeInternal().

◆ getFile()

const File& juce::FileOutputStream::getFile ( ) const
inline

Returns the file that this stream is writing to.

◆ getNewLineString()

const String& juce::OutputStream::getNewLineString ( ) const
inlinenoexceptinherited

Returns the current new-line string that was set by setNewLineString().

◆ getPosition()

int64 juce::FileOutputStream::getPosition ( )
overridevirtual

Returns the stream's current position.

See also
setPosition

Implements juce::OutputStream.

◆ getStatus()

const Result& juce::FileOutputStream::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 writing to the file, this will contain an error message.

◆ openedOk()

bool juce::FileOutputStream::openedOk ( ) const
inlinenoexcept

Returns true if the stream opened without problems.

See also
getResult()

◆ openHandle()

◆ setNewLineString()

void juce::OutputStream::setNewLineString ( const String newLineString)
inherited

Sets the string to write to the stream when a new line is written.

By default this will be set the value of NewLine::getDefault().

◆ setPosition()

bool juce::FileOutputStream::setPosition ( int64  newPosition)
overridevirtual

Tries to move the stream's output position.

Not all streams will be able to seek to a new position - this will return false if it fails to work.

See also
getPosition

Implements juce::OutputStream.

◆ setPositionInternal()

int64 juce::FileOutputStream::setPositionInternal ( int64  )
private

◆ truncate()

Result juce::FileOutputStream::truncate ( )

Attempts to truncate the file to the current write position.

To truncate a file to a specific size, first use setPosition() to seek to the appropriate location, and then call this method.

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

◆ write()

bool juce::FileOutputStream::write ( const void *  dataToWrite,
size_t  numberOfBytes 
)
overridevirtual

Writes a block of data to the stream.

When creating a subclass of OutputStream, this is the only write method that needs to be overloaded - the base class has methods for writing other types of data which use this to do the work.

Parameters
dataToWritethe target buffer to receive the data. This must not be null.
numberOfBytesthe number of bytes to write.
Returns
false if the write operation fails for some reason

Implements juce::OutputStream.

◆ writeBool()

virtual bool juce::OutputStream::writeBool ( bool  boolValue)
virtualinherited

Writes a boolean to the stream as a single byte.

This is encoded as a binary byte (not as text) with a value of 1 or 0.

Returns
false if the write operation fails for some reason
See also
InputStream::readBool

◆ writeByte()

virtual bool juce::OutputStream::writeByte ( char  byte)
virtualinherited

Writes a single byte to the stream.

Returns
false if the write operation fails for some reason
See also
InputStream::readByte

◆ writeCompressedInt()

virtual bool juce::OutputStream::writeCompressedInt ( int  value)
virtualinherited

Writes a condensed binary encoding of a 32-bit integer.

If you're storing a lot of integers which are unlikely to have very large values, this can save a lot of space, because values under 0xff will only take up 2 bytes, under 0xffff only 3 bytes, etc.

The format used is: number of significant bytes + up to 4 bytes in little-endian order.

Returns
false if the write operation fails for some reason
See also
InputStream::readCompressedInt

◆ writeDouble()

virtual bool juce::OutputStream::writeDouble ( double  value)
virtualinherited

Writes a 64-bit floating point value to the stream in a binary format.

The eight raw bytes of the double value are written out as a little-endian 64-bit int.

Returns
false if the write operation fails for some reason
See also
InputStream::readDouble

◆ writeDoubleBigEndian()

virtual bool juce::OutputStream::writeDoubleBigEndian ( double  value)
virtualinherited

Writes a 64-bit floating point value to the stream in a binary format.

The eight raw bytes of the double value are written out as a big-endian 64-bit int.

See also
InputStream::readDoubleBigEndian
Returns
false if the write operation fails for some reason

◆ writeFloat()

virtual bool juce::OutputStream::writeFloat ( float  value)
virtualinherited

Writes a 32-bit floating point value to the stream in a binary format.

The binary 32-bit encoding of the float is written as a little-endian int.

Returns
false if the write operation fails for some reason
See also
InputStream::readFloat

◆ writeFloatBigEndian()

virtual bool juce::OutputStream::writeFloatBigEndian ( float  value)
virtualinherited

Writes a 32-bit floating point value to the stream in a binary format.

The binary 32-bit encoding of the float is written as a big-endian int.

Returns
false if the write operation fails for some reason
See also
InputStream::readFloatBigEndian

◆ writeFromInputStream()

virtual int64 juce::OutputStream::writeFromInputStream ( InputStream source,
int64  maxNumBytesToWrite 
)
virtualinherited

Reads data from an input stream and writes it to this stream.

Parameters
sourcethe stream to read from
maxNumBytesToWritethe number of bytes to read from the stream (if this is less than zero, it will keep reading until the input is exhausted)
Returns
the number of bytes written

Reimplemented in juce::MemoryOutputStream.

◆ writeInt()

virtual bool juce::OutputStream::writeInt ( int  value)
virtualinherited

Writes a 32-bit integer to the stream in a little-endian byte order.

Returns
false if the write operation fails for some reason
See also
InputStream::readInt

◆ writeInt64()

virtual bool juce::OutputStream::writeInt64 ( int64  value)
virtualinherited

Writes a 64-bit integer to the stream in a little-endian byte order.

Returns
false if the write operation fails for some reason
See also
InputStream::readInt64

◆ writeInt64BigEndian()

virtual bool juce::OutputStream::writeInt64BigEndian ( int64  value)
virtualinherited

Writes a 64-bit integer to the stream in a big-endian byte order.

Returns
false if the write operation fails for some reason
See also
InputStream::readInt64BigEndian

◆ writeIntBigEndian()

virtual bool juce::OutputStream::writeIntBigEndian ( int  value)
virtualinherited

Writes a 32-bit integer to the stream in a big-endian byte order.

Returns
false if the write operation fails for some reason
See also
InputStream::readIntBigEndian

◆ writeInternal()

ssize_t juce::FileOutputStream::writeInternal ( const void *  data,
size_t  numBytes 
)
private

◆ writeRepeatedByte()

bool juce::FileOutputStream::writeRepeatedByte ( uint8  byte,
size_t  numTimesToRepeat 
)
overridevirtual

Writes a byte to the output stream a given number of times.

Returns
false if the write operation fails for some reason

Reimplemented from juce::OutputStream.

◆ writeShort()

virtual bool juce::OutputStream::writeShort ( short  value)
virtualinherited

Writes a 16-bit integer to the stream in a little-endian byte order.

This will write two bytes to the stream: (value & 0xff), then (value >> 8).

Returns
false if the write operation fails for some reason
See also
InputStream::readShort

◆ writeShortBigEndian()

virtual bool juce::OutputStream::writeShortBigEndian ( short  value)
virtualinherited

Writes a 16-bit integer to the stream in a big-endian byte order.

This will write two bytes to the stream: (value >> 8), then (value & 0xff).

Returns
false if the write operation fails for some reason
See also
InputStream::readShortBigEndian

◆ writeString()

virtual bool juce::OutputStream::writeString ( const String text)
virtualinherited

Stores a string in the stream in a binary format.

This isn't the method to use if you're trying to append text to the end of a text-file! It's intended for storing a string so that it can be retrieved later by InputStream::readString().

It writes the string to the stream as UTF8, including the null termination character.

For appending text to a file, instead use writeText, or operator<<

Returns
false if the write operation fails for some reason
See also
InputStream::readString, writeText, operator<<

◆ writeText()

virtual bool juce::OutputStream::writeText ( const String text,
bool  asUTF16,
bool  writeUTF16ByteOrderMark,
const char *  lineEndings 
)
virtualinherited

Writes a string of text to the stream.

It can either write the text as UTF-8 or UTF-16, and can also add the UTF-16 byte-order-mark bytes (0xff, 0xfe) to indicate the endianness (these should only be used at the start of a file).

If lineEndings is nullptr, then line endings in the text won't be modified. If you pass "\\n" or "\\r\\n" then this function will replace any existing line feeds.

Returns
false if the write operation fails for some reason

Member Data Documentation

◆ buffer

HeapBlock<char> juce::FileOutputStream::buffer
private

◆ bufferSize

size_t juce::FileOutputStream::bufferSize
private

◆ bytesInBuffer

size_t juce::FileOutputStream::bytesInBuffer = 0
private

◆ currentPosition

int64 juce::FileOutputStream::currentPosition = 0
private

◆ file

File juce::FileOutputStream::file
private

◆ fileHandle

void* juce::FileOutputStream::fileHandle = nullptr
private

◆ status

Result juce::FileOutputStream::status { Result::ok() }
private

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