IO_CACHE_ostream Class Reference

An output stream based on IO_CACHE class. More...

#include <basic_ostream.h>

Inheritance diagram for IO_CACHE_ostream:

Public Member Functions
	IO_CACHE_ostream ()
IO_CACHE_ostream &	operator= (const IO_CACHE_ostream &)=delete
	IO_CACHE_ostream (const IO_CACHE_ostream &)=delete
	~IO_CACHE_ostream () override
bool	open (PSI_file_key log_file_key, const char *file_name, myf flags)
	Open the output stream. More...
bool	close ()
	Closes the stream. More...
bool	write (const unsigned char *buffer, my_off_t length) override
	Write some bytes into the output stream. More...
bool	seek (my_off_t offset) override
	Put the write position to a given offset. More...
bool	truncate (my_off_t offset) override
	Truncate some data at the end of the output stream. More...
bool	flush () override
	Flush data to IO_CACHE's file if there is any data in IO_CACHE's buffer. More...
bool	sync () override
	Syncs the file to disk. More...
Public Member Functions inherited from Truncatable_ostream
	~Truncatable_ostream () override=default
Public Member Functions inherited from Basic_ostream
virtual	~Basic_ostream ()=default

Private Attributes
IO_CACHE	m_io_cache

Detailed Description

An output stream based on IO_CACHE class.

Constructor & Destructor Documentation

IO_CACHE_ostream() [1/2]

IO_CACHE_ostream::IO_CACHE_ostream ( )

default

IO_CACHE_ostream() [2/2]

IO_CACHE_ostream::IO_CACHE_ostream ( const IO_CACHE_ostream &  )

delete

~IO_CACHE_ostream()

IO_CACHE_ostream::~IO_CACHE_ostream ( )

override

Member Function Documentation

close()

bool IO_CACHE_ostream::close

(

)

Closes the stream.

It deinitializes IO_CACHE and close the file it opened.

Return values

false	Success
true	Error

flush()

bool IO_CACHE_ostream::flush ( )

overridevirtual

Flush data to IO_CACHE's file if there is any data in IO_CACHE's buffer.

Return values

false	Success
true	Error

Implements Truncatable_ostream.

open()

bool IO_CACHE_ostream::open	(	PSI_file_key	log_file_key,
		const char *	file_name,
		myf	flags
	)

Open the output stream.

It opens related file and initialize IO_CACHE.

Parameters

[in]	log_file_key	The PSI_file_key for this stream
[in]	file_name	The file will be opened
[in]	flags	The flags used by IO_CACHE.

Return values

false	Success
true	Error

operator=()

IO_CACHE_ostream & IO_CACHE_ostream::operator= ( const IO_CACHE_ostream &  )

delete

seek()

bool IO_CACHE_ostream::seek ( my_off_t  offset )

overridevirtual

Put the write position to a given offset.

The offset counts from the beginning of the file.

Parameters

[in]

offset

Where the write position will be

Return values

false	Success
true	Error

Implements Truncatable_ostream.

sync()

bool IO_CACHE_ostream::sync ( )

overridevirtual

Syncs the file to disk.

It doesn't check and flush any remaining data still left in IO_CACHE's buffer. So a call to flush() is necessary in order to persist all data including the data in buffer.

Return values

false	Success
true	Error

Implements Truncatable_ostream.

truncate()

bool IO_CACHE_ostream::truncate ( my_off_t  offset )

overridevirtual

Truncate some data at the end of the output stream.

Parameters

[in]

offset

Where the output stream will be truncated to.

Return values

false	Success
true	Error

Implements Truncatable_ostream.

write()

bool IO_CACHE_ostream::write ( const unsigned char *  buffer, my_off_t  length  )

overridevirtual

Write some bytes into the output stream.

When all data is written into the stream successfully, then it return false. Otherwise, true is returned. It will never returns false when partial data is written into the stream.

Parameters

[in]	buffer	Data to be written
[in]	length	Length of the data

Return values

false	Success.
true	Error.

Implements Basic_ostream.

Member Data Documentation

m_io_cache

IO_CACHE IO_CACHE_ostream::m_io_cache

private

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

• sql/basic_ostream.h
• sql/basic_ostream.cc