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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1996-2001
* Sleepycat Software. All rights reserved.
*
* Id: log.h,v 11.25 2001/04/25 19:06:39 margo Exp
*/
#ifndef _LOG_H_
#define _LOG_H_
struct __db_log; typedef struct __db_log DB_LOG;
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 LFPREFIX "log." /* Log file name prefix. */
#define LFNAME "log.%010d" /* Log file name template. */
#define LFNAME_V1 "log.%05d" /* Log file name template, rev 1. */
#define LG_MAX_DEFAULT (10 * MEGABYTE) /* 10 MB. */
#define LG_BSIZE_DEFAULT (32 * 1024) /* 32 KB. */
#define LG_BASE_REGION_SIZE (60 * 1024) /* 60 KB. */
/*
* The per-process table that maps log file-id's to DB structures.
*/
typedef struct __db_entry {
TAILQ_HEAD(dblist, __db) dblist; /* Associated DB structures. */
u_int32_t refcount; /* Reference counted. */
u_int32_t count; /* Number of ops on a deleted db. */
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.
*
* !!!
* As this structure is allocated in per-process memory, the mutex may need
* to be stored elsewhere on architectures unable to support mutexes in heap
* memory, e.g., HP/UX 9.
*/
MUTEX *mutexp; /* Mutex for thread protection. */
DB_ENTRY *dbentry; /* Recovery file-id mapping. */
#define DB_GROW_SIZE 64
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". */
DB_FH lfh; /* Log file handle. */
DB_LSN c_lsn; /* Cursor: current LSN. */
DBT c_dbt; /* Cursor: return DBT structure. */
DB_FH c_fh; /* Cursor: file handle. */
FILE *c_fp; /* Cursor: file pointer. */
u_int32_t c_off; /* Cursor: previous record offset. */
u_int32_t c_len; /* Cursor: current record length. */
u_int32_t r_file; /* Cursor: current read file */
u_int32_t r_off; /* Cursor: offset of read buffer. */
u_int32_t r_size; /* Cursor: size of data in read buf. */
u_int8_t *bufp; /* Region buffer. */
u_int8_t *readbufp; /* Read buffer. */
/* These fields are not protected. */
DB_ENV *dbenv; /* Reference to error information. */
REGINFO reginfo; /* Region information. */
#define DBLOG_RECOVER 0x01 /* We are in recovery. */
#define DBLOG_FORCE_OPEN 0x02 /* Force the db open even
* if it appears to be deleted.
*/
u_int32_t 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 {
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, but 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 chkpt_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. */
roff_t buffer_off; /* Log buffer offset. */
u_int32_t buffer_size; /* Log buffer size. */
#ifdef MUTEX_SYSTEM_RESOURCES
#define LG_MAINT_SIZE (sizeof(roff_t) * DB_MAX_HANDLES)
roff_t maint_off; /* offset of region maintenance info */
#endif
};
/*
* FNAME --
* File name and id.
*/
struct __fname {
SH_TAILQ_ENTRY q; /* File name queue. */
u_int16_t ref; /* Reference count. */
u_int16_t locked; /* Table is locked. */
int32_t id; /* Logging file id. */
DBTYPE s_type; /* Saved DB type. */
roff_t name_off; /* Name offset. */
db_pgno_t meta_pgno; /* Page number of the meta page. */
u_int8_t ufid[DB_FILE_ID_LEN]; /* Unique file id. */
};
/* File open/close register log record opcodes. */
#define LOG_CHECKPOINT 1 /* Checkpoint: file name/id dump. */
#define LOG_CLOSE 2 /* File close. */
#define LOG_OPEN 3 /* File open. */
#define LOG_RCLOSE 4 /* File close after recovery. */
#define CHECK_LSN(redo, cmp, lsn, prev) \
DB_ASSERT(!DB_REDO(redo) || (cmp) >= 0); \
if (DB_REDO(redo) && (cmp) < 0) { \
__db_err(dbenv, \
"Log sequence error: page LSN %lu:%lu; previous LSN %lu %lu", \
(u_long)(lsn)->file, (u_long)(lsn)->offset, \
(u_long)(prev)->file, (u_long)(prev)->offset); \
goto out; \
}
/*
* Status codes indicating the validity of a log file examined by
* __log_valid().
*/
typedef enum {
DB_LV_INCOMPLETE,
DB_LV_NONEXISTENT,
DB_LV_NORMAL,
DB_LV_OLD_READABLE,
DB_LV_OLD_UNREADABLE
} logfile_validity;
#include "log_auto.h"
#include "log_ext.h"
#endif /* _LOG_H_ */
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