enum
{
	LogMagic	= 0xDA7ACAFE,

	LogBlockSize	= 512,
};

typedef struct LogSuper LogSuper;
typedef union LogEntry LogEntry;
typedef struct Log Log;
typedef struct Transaction Transaction;

struct LogSuper
{
	u32int	magic;
	u32int	u1;
	u64int	start;
	u64int	end;
	u64int	u2[61];
};

enum
{
	LBEGIN	= 0xBEBEBEBE,
	LEND	= 0xEDEDEDED,
};

union LogEntry
{
	struct {
		u64int type;
		u64int tid;
		u64int off;
	} hdr;
	uchar block[LogBlockSize];
};

struct Log
{
	int	fd;

	vlong	blocks;

	LogSuper super;
};

Log* logopen(char *logfile);
void logclose(Log *l);
int logreadsuper(Log *l);
int logwritesuper(Log *l);

long logwrite(Log *l, vlong off, void *data, int ndata);
long logplay(Log *l);
/*
long writelog(Log *l, vlong off, void *data, int ndata);
long commitlog(Log *l);

Transaction *jstart(Log *l);
int jend(Log *l, Transaction *t);

long tblockwrite(Transaction *t);
*/