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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1996, 1997
* Sleepycat Software. All rights reserved.
*
* @(#)log.h 10.16 (Sleepycat) 11/9/97
*/
#ifndef _LOG_H_
#define _LOG_H_
struct __fname; typedef struct __fname FNAME;
struct __hdr; typedef struct __hdr HDR;
struct __log; typedef struct __log LOG;
struct __log_persist; typedef struct __log_persist LOGP;
#define MEGABYTE (1024 * 1024)
#define MAXLFNAME 99999 /* Maximum log file name. */
#define LFNAME "log.%05d" /* Log file name template. */
/* Default log name. */
#define DB_DEFAULT_LOG_FILE "__db_log.share"
#define DEFAULT_MAX (10 * 1048576) /* 10 Mb. */
/* Macros to lock/unlock the region and threads. */
#define LOCK_LOGTHREAD(dblp) \
if (F_ISSET(dblp, DB_AM_THREAD)) \
(void)__db_mutex_lock((dblp)->mutexp, -1)
#define UNLOCK_LOGTHREAD(dblp) \
if (F_ISSET(dblp, DB_AM_THREAD)) \
(void)__db_mutex_unlock((dblp)->mutexp, -1);
#define LOCK_LOGREGION(dblp) \
(void)__db_mutex_lock(&((RLAYOUT *)(dblp)->lp)->lock, (dblp)->fd)
#define UNLOCK_LOGREGION(dblp) \
(void)__db_mutex_unlock(&((RLAYOUT *)(dblp)->lp)->lock, (dblp)->fd)
/*
* The per-process table that maps log file-id's to DB structures.
*/
typedef struct __db_entry {
DB *dbp; /* Associated DB structure. */
int refcount; /* Reference counted. */
int deleted; /* File was not found during open. */
} DB_ENTRY;
/*
* DB_LOG
* Per-process log structure.
*/
struct __db_log {
/* These fields need to be protected for multi-threaded support. */
db_mutex_t *mutexp; /* Mutex for thread protection. */
DB_ENTRY *dbentry; /* Recovery file-id mapping. */
#define DB_GROW_SIZE 64
u_int32_t dbentry_cnt; /* Entries. Grows by DB_GROW_SIZE. */
/*
* These fields are always accessed while the region lock is held, so they do
* not have to be protected by the thread lock as well OR, they are only used
* when threads are not being used, i.e. most cursor operations are disallowed
* on threaded logs.
*/
u_int32_t lfname; /* Log file "name". */
int lfd; /* Log file descriptor. */
DB_LSN c_lsn; /* Cursor: current LSN. */
DBT c_dbt; /* Cursor: return DBT structure. */
int c_fd; /* Cursor: file descriptor. */
u_int32_t c_off; /* Cursor: previous record offset. */
u_int32_t c_len; /* Cursor: current record length. */
/* These fields are not protected. */
LOG *lp; /* Address of the shared LOG. */
DB_ENV *dbenv; /* Reference to error information. */
void *maddr; /* Address of mmap'd region. */
void *addr; /* Address of shalloc() region. */
int fd; /* Region file descriptor. */
char *dir; /* Directory argument. */
u_int32_t flags; /* Support the DB_AM_XXX flags. */
};
/*
* HDR --
* Log record header.
*/
struct __hdr {
u_int32_t prev; /* Previous offset. */
u_int32_t cksum; /* Current checksum. */
u_int32_t len; /* Current length. */
};
struct __log_persist {
u_int32_t magic; /* DB_LOGMAGIC */
u_int32_t version; /* DB_LOGVERSION */
u_int32_t lg_max; /* Maximum file size. */
int mode; /* Log file mode. */
};
/*
* LOG --
* Shared log region. One of these is allocated in shared memory,
* and describes the log.
*/
struct __log {
RLAYOUT rlayout; /* General region information. */
LOGP persist; /* Persistent information. */
SH_TAILQ_HEAD(__fq) fq; /* List of file names. */
/*
* The lsn LSN is the file offset that we're about to write and which
* we will return to the user.
*/
DB_LSN lsn; /* LSN at current file offset. */
/*
* The s_lsn LSN is the last LSN that we know is on disk, not just
* written, by synced.
*/
DB_LSN s_lsn; /* LSN of the last sync. */
u_int32_t len; /* Length of the last record. */
u_int32_t w_off; /* Current write offset in the file. */
DB_LSN c_lsn; /* LSN of the last checkpoint. */
time_t chkpt; /* Time of the last checkpoint. */
DB_LOG_STAT stat; /* Log statistics. */
/*
* The f_lsn LSN is the LSN (returned to the user) that "owns" the
* first byte of the buffer. If the record associated with the LSN
* spans buffers, it may not reflect the physical file location of
* the first byte of the buffer.
*/
DB_LSN f_lsn; /* LSN of first byte in the buffer. */
size_t b_off; /* Current offset in the buffer. */
u_int8_t buf[4 * 1024]; /* Log buffer. */
};
/*
* FNAME --
* File name and id.
*/
struct __fname {
SH_TAILQ_ENTRY q; /* File name queue. */
u_int16_t ref; /* Reference count. */
u_int32_t id; /* Logging file id. */
DBTYPE s_type; /* Saved DB type. */
u_int32_t fileid_off; /* Unique file id offset. */
size_t name_off; /* Name offset. */
};
#include "log_auto.h"
#include "log_ext.h"
#endif /* _LOG_H_ */
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