ccan/ccan/tdb/tdb.h

#ifndef __TDB_H__
#define __TDB_H__

/* 
   Unix SMB/CIFS implementation.

   trivial database library

   Copyright (C) Andrew Tridgell 1999-2004
   
     ** NOTE! The following LGPL license applies to the tdb
     ** library. This does NOT imply that all of Samba is released
     ** under the LGPL
   
   This library 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 library 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 library; if not, see <http://www.gnu.org/licenses/>.
*/

#ifdef  __cplusplus
extern "C" {
#endif

#ifndef _SAMBA_BUILD_
/* For mode_t */
#include <sys/types.h>
/* For sig_atomic_t. */
#include <signal.h>
#endif

/* flags to tdb_store() */
#define TDB_REPLACE 1		/* Unused */
#define TDB_INSERT 2 		/* Don't overwrite an existing entry */
#define TDB_MODIFY 3		/* Don't create an existing entry    */

/* flags for tdb_open() */
#define TDB_DEFAULT 0 /* just a readability place holder */
#define TDB_CLEAR_IF_FIRST 1
#define TDB_INTERNAL 2 /* don't store on disk */
#define TDB_NOLOCK   4 /* don't do any locking */
#define TDB_NOMMAP   8 /* don't use mmap */
#define TDB_CONVERT 16 /* convert endian (internal use) */
#define TDB_BIGENDIAN 32 /* header is big-endian (internal use) */
#define TDB_NOSYNC   64 /* don't use synchronous transactions */
#define TDB_SEQNUM   128 /* maintain a sequence number */
#define TDB_VOLATILE   256 /* Activate the per-hashchain freelist, default 5 */
#define TDB_NO_NESTING 512 /* Dont allow transaction nesting */

#define TDB_ERRCODE(code, ret) ((tdb->ecode = (code)), ret)

/* error codes */
enum TDB_ERROR {TDB_SUCCESS=0, TDB_ERR_CORRUPT, TDB_ERR_IO, TDB_ERR_LOCK, 
		TDB_ERR_OOM, TDB_ERR_EXISTS, TDB_ERR_NOLOCK, TDB_ERR_LOCK_TIMEOUT,
		TDB_ERR_NOEXIST, TDB_ERR_EINVAL, TDB_ERR_RDONLY};

/* debugging uses one of the following levels */
enum tdb_debug_level {TDB_DEBUG_FATAL = 0, TDB_DEBUG_ERROR, 
		      TDB_DEBUG_WARNING, TDB_DEBUG_TRACE};

typedef struct TDB_DATA {
	unsigned char *dptr;
	size_t dsize;
} TDB_DATA;

#ifndef PRINTF_ATTRIBUTE
#if (__GNUC__ >= 3)
/** Use gcc attribute to check printf fns.  a1 is the 1-based index of
 * the parameter containing the format, and a2 the index of the first
 * argument. Note that some gcc 2.x versions don't handle this
 * properly **/
#define PRINTF_ATTRIBUTE(a1, a2) __attribute__ ((format (__printf__, a1, a2)))
#else
#define PRINTF_ATTRIBUTE(a1, a2)
#endif
#endif

/* this is the context structure that is returned from a db open */
typedef struct tdb_context TDB_CONTEXT;

typedef int (*tdb_traverse_func)(struct tdb_context *, TDB_DATA, TDB_DATA, void *);
typedef void (*tdb_log_func)(struct tdb_context *, enum tdb_debug_level, const char *, ...) PRINTF_ATTRIBUTE(3, 4);
typedef unsigned int (*tdb_hash_func)(TDB_DATA *key);

struct tdb_logging_context {
        tdb_log_func log_fn;
        void *log_private;
};

struct tdb_context *tdb_open(const char *name, int hash_size, int tdb_flags,
		      int open_flags, mode_t mode);
struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
			 int open_flags, mode_t mode,
			 const struct tdb_logging_context *log_ctx,
			 tdb_hash_func hash_fn);
void tdb_set_max_dead(struct tdb_context *tdb, int max_dead);

int tdb_reopen(struct tdb_context *tdb);
int tdb_reopen_all(int parent_longlived);
void tdb_set_logging_function(struct tdb_context *tdb, const struct tdb_logging_context *log_ctx);
enum TDB_ERROR tdb_error(struct tdb_context *tdb);
const char *tdb_errorstr(struct tdb_context *tdb);
TDB_DATA tdb_fetch(struct tdb_context *tdb, TDB_DATA key);
int tdb_parse_record(struct tdb_context *tdb, TDB_DATA key,
		     int (*parser)(TDB_DATA key, TDB_DATA data,
				   void *private_data),
		     void *private_data);
int tdb_delete(struct tdb_context *tdb, TDB_DATA key);
int tdb_store(struct tdb_context *tdb, TDB_DATA key, TDB_DATA dbuf, int flag);
int tdb_append(struct tdb_context *tdb, TDB_DATA key, TDB_DATA new_dbuf);
int tdb_close(struct tdb_context *tdb);
TDB_DATA tdb_firstkey(struct tdb_context *tdb);
TDB_DATA tdb_nextkey(struct tdb_context *tdb, TDB_DATA key);
int tdb_traverse(struct tdb_context *tdb, tdb_traverse_func fn, void *);
int tdb_traverse_read(struct tdb_context *tdb, tdb_traverse_func fn, void *);
int tdb_exists(struct tdb_context *tdb, TDB_DATA key);
int tdb_lockall(struct tdb_context *tdb);
int tdb_lockall_nonblock(struct tdb_context *tdb);
int tdb_unlockall(struct tdb_context *tdb);
int tdb_lockall_read(struct tdb_context *tdb);
int tdb_lockall_read_nonblock(struct tdb_context *tdb);
int tdb_unlockall_read(struct tdb_context *tdb);
int tdb_lockall_mark(struct tdb_context *tdb);
int tdb_lockall_unmark(struct tdb_context *tdb);
const char *tdb_name(struct tdb_context *tdb);
int tdb_fd(struct tdb_context *tdb);
tdb_log_func tdb_log_fn(struct tdb_context *tdb);
void *tdb_get_logging_private(struct tdb_context *tdb);
int tdb_transaction_start(struct tdb_context *tdb);
int tdb_transaction_commit(struct tdb_context *tdb);
int tdb_transaction_cancel(struct tdb_context *tdb);
int tdb_transaction_recover(struct tdb_context *tdb);
int tdb_get_seqnum(struct tdb_context *tdb);
int tdb_hash_size(struct tdb_context *tdb);
size_t tdb_map_size(struct tdb_context *tdb);
int tdb_get_flags(struct tdb_context *tdb);
void tdb_add_flags(struct tdb_context *tdb, unsigned flag);
void tdb_remove_flags(struct tdb_context *tdb, unsigned flag);
void tdb_enable_seqnum(struct tdb_context *tdb);
void tdb_increment_seqnum_nonblock(struct tdb_context *tdb);

/* Low level locking functions: use with care */
int tdb_chainlock(struct tdb_context *tdb, TDB_DATA key);
int tdb_chainlock_nonblock(struct tdb_context *tdb, TDB_DATA key);
int tdb_chainunlock(struct tdb_context *tdb, TDB_DATA key);
int tdb_chainlock_read(struct tdb_context *tdb, TDB_DATA key);
int tdb_chainunlock_read(struct tdb_context *tdb, TDB_DATA key);
int tdb_chainlock_mark(struct tdb_context *tdb, TDB_DATA key);
int tdb_chainlock_unmark(struct tdb_context *tdb, TDB_DATA key);

void tdb_setalarm_sigptr(struct tdb_context *tdb, volatile sig_atomic_t *sigptr);

/* Debug functions. Not used in production. */
void tdb_dump_all(struct tdb_context *tdb);
int tdb_printfreelist(struct tdb_context *tdb);
int tdb_validate_freelist(struct tdb_context *tdb, int *pnum_entries);
int tdb_wipe_all(struct tdb_context *tdb);
int tdb_freelist_size(struct tdb_context *tdb);

extern TDB_DATA tdb_null;

#ifdef  __cplusplus
}
#endif

#endif /* tdb.h */