mem_outfile stores encoded j2k codestreams in memory More...

#include <ojph_file.h>

Inheritance diagram for ojph::mem_outfile:

Public Member Functions
	mem_outfile ()
	~mem_outfile () override
void	open (size_t initial_size=65536, bool clear_mem=false)
	Call this function to open a memory file.
size_t	write (const void *ptr, size_t size) override
	Call this function to write data to the memory file.
si64	tell () override
	Call this function to know the file size (i.e., number of bytes used to store the file).
int	seek (si64 offset, enum outfile_base::seek origin) override
	Call this function to change write pointer location; the function can expand file storage.
void	close () override
const ui8 *	get_data ()
	Call this function to access memory file data.
const ui8 *	get_data () const
	Call this function to access memory file data (for const objects).
void	write_to_file (const char *file_name) const
	Call this function to write the memory file data to a file.
size_t	get_used_size () const
	Call this function to get the used size of the memory file.
size_t	get_buf_size () const
	Call this function to get the total buffer size of the memory file including unused space (this is the allocated memory).
Public Member Functions inherited from ojph::outfile_base
virtual	~outfile_base ()
virtual void	flush ()

Private Member Functions
void	expand_storage (size_t new_size, bool clear_all)
	This function expands storage by x1.5 needed space.

Private Attributes
bool	is_open
bool	clear_mem
size_t	buf_size
size_t	used_size
ui8 *	buf
ui8 *	cur_ptr

Static Private Attributes
static const size_t	ALIGNED_ALLOC_MASK = 4096 - 1

Additional Inherited Members
Public Types inherited from ojph::outfile_base
enum	seek : int { OJPH_SEEK_SET = SEEK_SET , OJPH_SEEK_CUR = SEEK_CUR , OJPH_SEEK_END = SEEK_END }

Detailed Description

mem_outfile stores encoded j2k codestreams in memory

This code was first developed by Chris Hafey https://github.com/chafey I took the code and integrated with OpenJPH, with some modifications.

This class serves as a memory-based file storage. For example, generated j2k codestream is stored in memory instead of a conventional file. The memory buffer associated with this class grows with the addition of new data.

memory data can be accessed using get_data()

Definition at line 126 of file ojph_file.h.

Constructor & Destructor Documentation

◆ mem_outfile()

ojph::mem_outfile::mem_outfile ( )

A constructor

Definition at line 103 of file ojph_file.cpp.

References buf, buf_size, clear_mem, cur_ptr, is_open, and used_size.

◆ ~mem_outfile()

ojph::mem_outfile::~mem_outfile ( )

override

A destructor

Definition at line 111 of file ojph_file.cpp.

References buf, buf_size, clear_mem, cur_ptr, is_open, ojph::ojph_aligned_free(), and used_size.

Member Function Documentation

◆ close()

void ojph::mem_outfile::close ( )

overridevirtual

Call this function to close the file and deallocate memory

The object can be used again after calling close

Reimplemented from ojph::outfile_base.

Definition at line 135 of file ojph_file.cpp.

References buf, cur_ptr, and is_open.

◆ expand_storage()

void ojph::mem_outfile::expand_storage	(	size_t	new_size,
		bool	clear_all )

private

This function expands storage by x1.5 needed space.

It sets cur_ptr correctly, and clears the extended area of the buffer. It optionally clear the whole buffer

Parameters

new_size	New size of the buffer
clear_all	Set to true to clear whole buffer, not just expansion

Definition at line 200 of file ojph_file.cpp.

References ALIGNED_ALLOC_MASK, buf, buf_size, clear_mem, cur_ptr, ojph::ojph_aligned_free(), ojph::ojph_aligned_malloc(), OJPH_ERROR, tell(), and used_size.

Referenced by open(), seek(), and write().

◆ get_buf_size()

size_t ojph::mem_outfile::get_buf_size ( ) const

inline

Call this function to get the total buffer size of the memory file including unused space (this is the allocated memory).

Returns: the full size of the memory file in bytes.

Definition at line 219 of file ojph_file.h.

References buf_size.

◆ get_data() [1/2]

const ui8 * ojph::mem_outfile::get_data ( )

inline

Call this function to access memory file data.

It is not recommended to store the returned value because buffer storage address can change between write calls.

Returns: a constant pointer to the data.

Definition at line 187 of file ojph_file.h.

References buf.

◆ get_data() [2/2]

const ui8 * ojph::mem_outfile::get_data ( ) const

inline

Call this function to access memory file data (for const objects).

This is similar to the above function, except that it can be used with constant objects.

Returns: a constant pointer to the data.

Definition at line 198 of file ojph_file.h.

References buf.

◆ get_used_size()

size_t ojph::mem_outfile::get_used_size ( ) const

inline

Call this function to get the used size of the memory file.

Returns: the used size of the memory file in bytes.

Definition at line 211 of file ojph_file.h.

References used_size.

◆ open()

void ojph::mem_outfile::open	(	size_t	initial_size = 65536,
		bool	clear_mem = false )

Call this function to open a memory file.

This function creates a memory buffer to be used for storing the generated j2k codestream.

Parameters

initial_size	is the initial memory buffer size. The default value is 2^16.
clear_mem	if set to true, all allocated memory is reset to 0

Definition at line 121 of file ojph_file.cpp.

References buf, clear_mem, cur_ptr, expand_storage(), is_open, and used_size.

◆ seek()

int ojph::mem_outfile::seek	(	si64	offset,
		enum outfile_base::seek	origin )

overridevirtual

Call this function to change write pointer location; the function can expand file storage.

Returns: 0 on success, non-zero otherwise (not used).

The seek function expands the buffer whenever offset goes beyond the buffer end

Reimplemented from ojph::outfile_base.

Definition at line 143 of file ojph_file.cpp.

References buf, cur_ptr, expand_storage(), ojph::outfile_base::OJPH_SEEK_CUR, ojph::outfile_base::OJPH_SEEK_END, ojph::outfile_base::OJPH_SEEK_SET, tell(), and used_size.

◆ tell()

si64 ojph::mem_outfile::tell ( )

inlineoverridevirtual

Call this function to know the file size (i.e., number of bytes used to store the file).

Returns: the file size.

Reimplemented from ojph::outfile_base.

Definition at line 163 of file ojph_file.h.

References buf, and cur_ptr.

Referenced by expand_storage(), seek(), and write().

◆ write()

size_t ojph::mem_outfile::write	(	const void *	ptr,
		size_t	new_size )

overridevirtual

Call this function to write data to the memory file.

This function adds new data to the memory file. The memory buffer of the file grows as needed.

Parameters

ptr	is a pointer to new data.
size	the number of bytes in the new data.

Whenever the need arises, the buffer is expanded by a factor approx 1.5x

Implements ojph::outfile_base.

Definition at line 167 of file ojph_file.cpp.

References buf, buf_size, cur_ptr, expand_storage(), is_open, ojph_max, tell(), and used_size.

◆ write_to_file()

void ojph::mem_outfile::write_to_file ( const char * file_name ) const

Call this function to write the memory file data to a file.

Definition at line 187 of file ojph_file.cpp.

References buf, is_open, OJPH_ERROR, and used_size.

Member Data Documentation

◆ ALIGNED_ALLOC_MASK

const size_t ojph::mem_outfile::ALIGNED_ALLOC_MASK = 4096 - 1

staticprivate

Definition at line 242 of file ojph_file.h.

Referenced by expand_storage().

◆ buf

ui8* ojph::mem_outfile::buf

private

Definition at line 238 of file ojph_file.h.

Referenced by close(), expand_storage(), get_data(), get_data(), mem_outfile(), open(), seek(), tell(), write(), write_to_file(), and ~mem_outfile().

◆ buf_size

size_t ojph::mem_outfile::buf_size

private

Definition at line 236 of file ojph_file.h.

Referenced by expand_storage(), get_buf_size(), mem_outfile(), write(), and ~mem_outfile().

◆ clear_mem

bool ojph::mem_outfile::clear_mem

private

Definition at line 235 of file ojph_file.h.

Referenced by expand_storage(), mem_outfile(), open(), and ~mem_outfile().

◆ cur_ptr

ui8* ojph::mem_outfile::cur_ptr

private

Definition at line 239 of file ojph_file.h.

Referenced by close(), expand_storage(), mem_outfile(), open(), seek(), tell(), write(), and ~mem_outfile().

◆ is_open

bool ojph::mem_outfile::is_open

private

Definition at line 234 of file ojph_file.h.

Referenced by close(), mem_outfile(), open(), write(), write_to_file(), and ~mem_outfile().

◆ used_size

size_t ojph::mem_outfile::used_size

private

Definition at line 237 of file ojph_file.h.

Referenced by expand_storage(), get_used_size(), mem_outfile(), open(), seek(), write(), write_to_file(), and ~mem_outfile().

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

/build/openjph/src/OpenJPH-0.24.3/src/core/common/ojph_file.h
/build/openjph/src/OpenJPH-0.24.3/src/core/others/ojph_file.cpp

Public Member Functions

Private Member Functions

Private Attributes

Static Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ mem_outfile()

◆ ~mem_outfile()

Member Function Documentation

◆ close()

◆ expand_storage()

◆ get_buf_size()

◆ get_data() [1/2]

◆ get_data() [2/2]

◆ get_used_size()

◆ open()

◆ seek()

◆ tell()

◆ write()

◆ write_to_file()

Member Data Documentation

◆ ALIGNED_ALLOC_MASK

◆ buf

◆ buf_size

◆ clear_mem

◆ cur_ptr

◆ is_open

◆ used_size