pcompress/rabin/global/dedupe_config.h

/*
 * This file is a part of Pcompress, a chunked parallel multi-
 * algorithm lossless compression and decompression program.
 *
 * Copyright (C) 2012-2013 Moinak Ghosh. All rights reserved.
 * Use is subject to license terms.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this program.
 * If not, see <http://www.gnu.org/licenses/>.
 *
 * moinakg@belenix.org, http://moinakg.wordpress.com/
 */

#ifndef	_C_ONFIG_H
#define	_C_ONFIG_H

#include <limits.h>
#include <utils.h>
#include <crypto_utils.h>

#ifdef	__cplusplus
extern "C" {
#endif

#define	DEFAULT_SIMILARITY_INTERVAL	5
#define	DEFAULT_CHUNK_CKSUM	CKSUM_SHA256
#define	DEFAULT_SIMILARITY_CKSUM	CKSUM_BLAKE256
#define	DEFAULT_COMPRESS		COMPRESS_LZ4
#define	CONTAINER_ITEMS		2048
#define	MIN_CK 1
#define	MAX_CK 5

// 8GB
#define	MIN_ARCHIVE_SZ (8589934592ULL)

typedef enum {
	MODE_SIMPLE = 0,
	MODE_SIMILARITY,
	MODE_ARCHIVE
} dedupe_mode_t;

typedef struct {
	char rootdir[PATH_MAX+1];
	uint32_t chunk_sz; // Numeric ID: 1 - 4k ... 5 - 64k
	int64_t archive_sz; // Total size of archive in bytes.
	int verify_chunks; // Whether to use memcmp() to compare chunks byte for byte.
	int algo; // Which compression algo for segments.
	compress_algo_t compress_level; // Default preset compression level per algo.
	cksum_t chunk_cksum_type; // Which digest to use for hash based chunk comparison.
	cksum_t similarity_cksum; // Which digest to use similarity based segment lookup.
	int chunk_cksum_sz; // Size of cksum in bytes.
	int similarity_cksum_sz; // Size of cksum in bytes.
	int pct_interval; // Similarity based match intervals in %age.
			// The items below are computed given the above
			// components.
	dedupe_mode_t dedupe_mode;

	uint32_t chunk_sz_bytes; // Average chunk size
	uint64_t segment_sz_bytes; // Segment size in bytes
	uint32_t segment_sz; // Number of chunks in one segment
	uint32_t container_sz; // Number of segments
	int directory_fanout; // Number of subdirectories in a directory
	int directory_levels; // Levels of nested directories
	int num_containers; // Number of containers in a directory
	int nthreads; // Number of threads processing data segments in parallel
	int seg_fd_w; 
	int *seg_fd_r; // One read-only fd per thread for mapping in portions of the
		       // segment metadata cache.
	void *dbdata;
} archive_config_t;

typedef struct _segment_entry {
	uint64_t chunk_offset;
	uint32_t chunk_length;
	uchar_t *chunk_cksum;
} segment_entry_t;

int read_config(char *configfile, archive_config_t *cfg);
int write_config(char *configfile, archive_config_t *cfg);
int set_config_s(archive_config_t *cfg, const char *algo, cksum_t ck, cksum_t ck_sim,
		uint32_t chunksize, size_t file_sz, uint64_t user_chunk_sz,
		int pct_interval);

#ifdef	__cplusplus
}
#endif

#endif