snapraid/handle.h
2013-06-01 22:49:38 +02:00

84 lines
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 __HANDLE_H
#define __HANDLE_H
#include "state.h"
/****************************************************************************/
/* handle */
struct snapraid_handle {
char path[PATH_MAX]; /**< Path of the file. */
struct snapraid_disk* disk; /**< Disk of the file. */
struct snapraid_file* file; /**< File opened. When the file is closed, it's set to 0. */
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. */
int created; /**< If the file was created, otherwise it was already existing. */
int truncated; /**< If the file was truncated. */
};
/**
* Creates a file.
* The file is created if missing, and opened with write access.
* If the file has a different size than expected, it's enlarged or truncated to the correct size.
* If the file is created, the handle->created is set.
* If the file is truncated, the handle->truncated is set.
* The initial size of the file is stored in the file->st struct.
* If the file cannot be opened for write access, it's opened with read-only access.
* The read-only access works only if the file has already the correct size and doesn't need to be modified.
*/
int handle_create(struct snapraid_handle* handle, struct snapraid_file* file, int skip_sequential);
/**
* Opens a file.
* The file is opened for reading.
*/
int handle_open(struct snapraid_handle* handle, struct snapraid_file* file, FILE* out, int skip_sequential);
/**
* Closes a file.
*/
int handle_close(struct snapraid_handle* handle);
/**
* Read a block from a file.
* If the read block is shorter, it's padded with 0.
*/
int handle_read(struct snapraid_handle* handle, struct snapraid_block* block, unsigned char* block_buffer, unsigned block_size, FILE* out);
/**
* Writes a block to a file.
*/
int handle_write(struct snapraid_handle* handle, struct snapraid_block* block, unsigned char* block_buffer, unsigned block_size);
/**
* Changes the modification time of the file to the saved value.
*/
int handle_utime(struct snapraid_handle* handle);
/**
* Maps the unsorted list of disk to an ordered vector.
* \param diskmax The size of the vector.
* \return The allocated vector of pointers.
*/
struct snapraid_handle* handle_map(struct snapraid_state* state, unsigned* diskmax);
#endif