xor_hd_code.c File Reference

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "xor_code.h"
#include "xor_hd_code_defs.h"

Go to the source code of this file.

Functions
static int	fragments_needed_one_data (xor_code_t *code_desc, int *missing_data, int *missing_parity, unsigned int *data_bm, unsigned int *parity_bm)
static int	fragments_needed_two_data (xor_code_t *code_desc, int *missing_data, int *missing_parity, unsigned int *data_bm, unsigned int *parity_bm)
static int	fragments_needed_three_data (xor_code_t *code_desc, int *missing_data, int *missing_parity, unsigned int *data_bm, unsigned int *parity_bm)
static int	fragments_needed_one_data_local (xor_code_t *code_desc, int fragment_to_reconstruct, int *fragments_to_exclude, unsigned int *data_bm, unsigned int *parity_bm)
int	xor_hd_fragments_needed (xor_code_t *code_desc, int *fragments_to_reconstruct, int *fragments_to_exclude, int *fragments_needed)
static void	decode_one_data (xor_code_t *code_desc, char **data, char **parity, int *missing_data, int *missing_parity, int blocksize)
static int	decode_two_data (xor_code_t *code_desc, char **data, char **parity, int *missing_data, int *missing_parity, int blocksize)
static int	decode_three_data (xor_code_t *code_desc, char **data, char **parity, int *missing_data, int *missing_parity, int blocksize)
int	xor_hd_decode (xor_code_t *code_desc, char **data, char **parity, int *missing_idxs, int blocksize, int decode_parity)
xor_code_t *	init_xor_hd_code (int k, int m, int hd)

Function Documentation

decode_one_data()

static void decode_one_data ( xor_code_t *  code_desc, char **  data, char **  parity, int *  missing_data, int *  missing_parity, int  blocksize  )

static

Definition at line 412 of file xor_hd_code.c.

References fast_memcpy(), index_of_connected_parity(), is_data_in_parity(), and xor_bufs_and_store().

Referenced by decode_two_data(), and xor_hd_decode().

decode_three_data()

static int decode_three_data ( xor_code_t *  code_desc, char **  data, char **  parity, int *  missing_data, int *  missing_parity, int  blocksize  )

static

Definition at line 462 of file xor_hd_code.c.

References decode_two_data(), fast_memcpy(), index_of_connected_parity(), is_data_in_parity(), num_missing_data_in_parity(), remove_from_missing_list(), and xor_bufs_and_store().

Referenced by xor_hd_decode().

decode_two_data()

static int decode_two_data ( xor_code_t *  code_desc, char **  data, char **  parity, int *  missing_data, int *  missing_parity, int  blocksize  )

static

Definition at line 429 of file xor_hd_code.c.

References decode_one_data(), fast_memcpy(), index_of_connected_parity(), is_data_in_parity(), and xor_bufs_and_store().

Referenced by decode_three_data(), and xor_hd_decode().

fragments_needed_one_data()

static int fragments_needed_one_data ( xor_code_t *  code_desc, int *  missing_data, int *  missing_parity, unsigned int *  data_bm, unsigned int *  parity_bm  )

static

Definition at line 34 of file xor_hd_code.c.

References index_of_connected_parity().

Referenced by fragments_needed_two_data(), and xor_hd_fragments_needed().

fragments_needed_one_data_local()

static int fragments_needed_one_data_local ( xor_code_t *  code_desc, int  fragment_to_reconstruct, int *  fragments_to_exclude, unsigned int *  data_bm, unsigned int *  parity_bm  )

static

Definition at line 176 of file xor_hd_code.c.

References get_missing_data(), get_missing_parity(), and index_of_connected_parity().

Referenced by xor_hd_fragments_needed().

fragments_needed_three_data()

static int fragments_needed_three_data ( xor_code_t *  code_desc, int *  missing_data, int *  missing_parity, unsigned int *  data_bm, unsigned int *  parity_bm  )

static

Definition at line 91 of file xor_hd_code.c.

References fragments_needed_two_data(), index_of_connected_parity(), is_data_in_parity(), num_missing_data_in_parity(), and remove_from_missing_list().

Referenced by xor_hd_fragments_needed().

fragments_needed_two_data()

static int fragments_needed_two_data ( xor_code_t *  code_desc, int *  missing_data, int *  missing_parity, unsigned int *  data_bm, unsigned int *  parity_bm  )

static

Definition at line 56 of file xor_hd_code.c.

References fragments_needed_one_data(), and index_of_connected_parity().

Referenced by fragments_needed_three_data(), and xor_hd_fragments_needed().

init_xor_hd_code()

xor_code_t* init_xor_hd_code	(	int	k,
		int	m,
		int	hd
	)

Definition at line 653 of file xor_hd_code.c.

References xor_code_encode(), xor_hd_decode(), and xor_hd_fragments_needed().

Referenced by flat_xor_hd_init().

xor_hd_decode()

int xor_hd_decode	(	xor_code_t *	code_desc,
		char **	data,
		char **	parity,
		int *	missing_idxs,
		int	blocksize,
		int	decode_parity
	)

Definition at line 559 of file xor_hd_code.c.

References decode_one_data(), decode_three_data(), decode_two_data(), get_failure_pattern(), get_missing_data(), get_missing_parity(), and selective_encode().

Referenced by init_xor_hd_code().

xor_hd_fragments_needed()

int xor_hd_fragments_needed	(	xor_code_t *	code_desc,
		int *	fragments_to_reconstruct,
		int *	fragments_to_exclude,
		int *	fragments_needed
	)

Re-visit this decision (KMG): This is non-optimal, but good enough in most cases. If there is a single data item to reconstruct, then try to find a connected parity with no items in fragments_to_exclude. If there is a single parity item to reconsturct or more than 1 data/parity element missing, then just work fragments_to_exclude into missing_idxs.

There is either more than one failed element, a failed parity element or we were unable to return the fragments needed for a simple reconstruction.

Add everything to missing_idxs (basically, give up on optimizing).

Definition at line 202 of file xor_hd_code.c.

References data_bit_lookup(), fragments_needed_one_data(), fragments_needed_one_data_local(), fragments_needed_three_data(), fragments_needed_two_data(), get_failure_pattern(), get_missing_data(), get_missing_parity(), and missing_elements_bm().

Referenced by init_xor_hd_code().