chunk-db.h

#ifndef __ZUNKFS_CHUNKDB_H__
#define __ZUNKFS_CHUNKDB_H__

#include <stdbool.h>
#include "list.h"

struct chunk_db;

struct chunk_db_type {
	const char *spec_prefix;
	unsigned info_size;
	struct list_head type_entry;
	/* return error string, freed by caller, NULL if successful */
	char *(*ctor)(const char *spec, struct chunk_db *chunk_db);
	/* return TRUE if successful, FALSE otherwise. */
	bool (*read_chunk)(unsigned char *chunk, const unsigned char *digest,
			void *db_info);
	bool (*write_chunk)(const unsigned char *chunk,
			const unsigned char *digest, void *db_info);
	/*
	 * Help string. Format is:
	 * <spec>   <description>.
	 * spec must be indented 3 spaces,
	 * and must not exceed 23 characters.
	 * A help line should not exceed 80 characters.
	 */
	const char *help;
};

/*
 * Chunk database.
 */
struct chunk_db {
	struct chunk_db_type *type;
	int mode;
	void *db_info;
	struct list_head db_entry;
};

#define CHUNKDB_RO 0 /* read-only */
#define CHUNKDB_RW 1 /* read-write */
#define CHUNKDB_WT 2 /* write thru */
#define CHUNKDB_NC 4 /* not-a-cache */

void register_chunkdb(struct chunk_db_type *type);
char *add_chunkdb(const char *spec);

void help_chunkdb(void);

#define REGISTER_CHUNKDB(type) \
static void __attribute__((constructor)) register_chunkdb_##type(void) \
{ \
	register_chunkdb(&type); \
}

#endif