gdk_logger.h

这个是内存数据库中的一个管理工具

#ifndef _LOGGER_H_
#define _LOGGER_H_

#define LOG_OK 0
#define LOG_ERR (-1)

#include <gdk.h>
#include <stream.h>

typedef struct logaction {
	int type;   /* type of change */
	int nr;
	int ht;     /* vid(-1),void etc */
	int tt;
	lng id;
	char *name; /* optional */
	BAT  *b;    /* temporary bat with changes */
} logaction;

/* during the recover process a number of transactions could be active */
typedef struct trans {
	int tid;  /* transaction id */
	int sz;	  /* sz of the changes array */
	int nr;	  /* nr of changes */

	logaction *changes; 

	struct trans *tr;
} trans;

typedef struct logger {
	int debug;
	int changes;
	int version;
	lng id;
	int tid;
	char *fn;
	char *dir;
	stream *log;
	/* Store log_bids (int) to circumvent trouble with reference counting */
	BAT *catalog;	/* int, str */
	BAT *seqs; 	/* int, lng */
	BAT *snapshots;	/* int, int the bid and tid of snapshot bat */
} logger;

#define BATSIZE 0

typedef int log_bid;



/* the sequence identifier for the sequence of log files */
#define LOG_SID	0
/* the sequence identifier for frontend objects */
#define OBJ_SID	1

gdk_export logger *logger_create(int debug, char *fn, char *logdir, char *dbname, int version);
gdk_export void logger_destroy(logger *lg);
gdk_export int logger_exit(logger *lg);
gdk_export int logger_restart(logger *lg);
gdk_export int logger_cleanup(logger *lg);
gdk_export int logger_changes(logger *lg);
gdk_export int logger_sequence(logger *lg, int seq, lng *id);

/* todo pass the transaction id */
gdk_export int log_bat(logger *lg, BAT *b, char *n);
gdk_export int log_bat_clear(logger *lg, char *n);
gdk_export int log_bat_persists(logger *lg, BAT *b, char *n);
gdk_export int log_bat_transient(logger *lg, char *n);
gdk_export int log_delta(logger *lg, BAT *b, char *n);

gdk_export int log_tstart(logger *lg);  /* TODO return transaction id */
gdk_export int log_tend(logger *lg);
gdk_export int log_abort(logger *lg);

gdk_export int log_sequence(logger *lg, int seq, lng id);

gdk_export log_bid logger_add_bat(logger *lg, BAT *b, char *name);
gdk_export void logger_del_bat(logger *lg, log_bid bid);
gdk_export log_bid logger_find_bat(logger *lg, char *name);

#endif /*_LOGGER_H_*/