snapraid/parity.h
2012-10-09 23:02:46 +02:00

79 lines
2.3 KiB
C

/*
* Copyright (C) 2011 Andrea Mazzoleni
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __PARITY_H
#define __PARITY_H
/****************************************************************************/
/* parity */
struct snapraid_parity {
char path[PATH_MAX]; /**< Path of the file. */
int f; /**< Handle of the file. */
struct stat st; /**< Stat info of the opened file. */
data_off_t valid_size; /**< Size of the valid data. */
};
/**
* Computes the size of the parity data in number of blocks.
*/
block_off_t parity_size(struct snapraid_state* state);
/**
* Reports all the files outside the specified parity size.
*/
void parity_overflow(struct snapraid_state* state, data_off_t size);
/**
* Creates the parity file.
* \param out_size Return the size of the parity file.
*/
int parity_create(struct snapraid_parity* parity, const char* path, data_off_t* out_size);
/**
* Changes the parity size.
* \param out_size Return the size of the parity file. The out_size is set also on error to reflect a partial resize.
*/
int parity_chsize(struct snapraid_parity* parity, data_off_t size, data_off_t* out_size);
/**
* Opens an already existing parity file.
*/
int parity_open(struct snapraid_parity* parity, const char* path);
/**
* Flushes the parity file in the disk.
*/
int parity_sync(struct snapraid_parity* parity);
/**
* Closes the parity file.
*/
int parity_close(struct snapraid_parity* parity);
/**
* Read a block from the parity file.
*/
int parity_read(struct snapraid_parity* parity, block_off_t pos, unsigned char* block_buffer, unsigned block_size);
/**
* Writes a block in the parity file.
*/
int parity_write(struct snapraid_parity* parity, block_off_t pos, unsigned char* block_buffer, unsigned block_size);
#endif