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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1996-2002
* Sleepycat Software. All rights reserved.
*
* $Id: log.h,v 11.60 2002/08/06 06:37:08 bostic Exp $
*/
#ifndef _LOG_H_
#define _LOG_H_
struct __db_log; typedef struct __db_log DB_LOG;
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 {
DB *dbp; /* Open dbp for this file id. */
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.
*/
DB_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. */
u_int8_t *bufp; /* Region 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 len; /* Current length. */
u_int8_t chksum[DB_MAC_KEY]; /* Current checksum. */
u_int8_t iv[DB_IV_BYTES]; /* IV */
u_int32_t orig_size; /* Original size of log record */
/* !!! - 'size' is not written to log, must be last in hdr */
size_t size; /* Size of header to use */
};
/*
* We use HDR internally, and then when we write out, we write out
* prev, len, and then a 4-byte checksum if normal operation or
* a crypto-checksum and IV and original size if running in crypto
* mode. We must store the original size in case we pad. Set the
* size when we set up the header. We compute a DB_MAC_KEY size
* checksum regardless, but we can safely just use the first 4 bytes.
*/
#define HDR_NORMAL_SZ 12
#define HDR_CRYPTO_SZ 12 + DB_MAC_KEY + DB_IV_BYTES
struct __log_persist {
u_int32_t magic; /* DB_LOGMAGIC */
u_int32_t version; /* DB_LOGVERSION */
u_int32_t log_size; /* Log file size. */
u_int32_t mode; /* Log file mode. */
};
/*
* LOG --
* Shared log region. One of these is allocated in shared memory,
* and describes the log.
*/
struct __log {
/*
* Due to alignment constraints on some architectures (e.g. HP-UX),
* DB_MUTEXes must be the first element of shalloced structures,
* and as a corollary there can be only one per structure. Thus,
* flush_mutex_off points to a mutex in a separately-allocated chunk.
*/
DB_MUTEX fq_mutex; /* Mutex guarding file name list. */
LOGP persist; /* Persistent information. */
SH_TAILQ_HEAD(__fq1) fq; /* List of file names. */
int32_t fid_max; /* Max fid allocated. */
roff_t free_fid_stack; /* Stack of free file ids. */
int free_fids; /* Height of free fid stack. */
int free_fids_alloced; /* Number of free fid slots alloc'ed. */
/*
* 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 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_int32_t w_off; /* Current write offset in the file. */
u_int32_t len; /* Length of the last record. */
/*
* The s_lsn LSN is the last LSN that we know is on disk, not just
* written, but synced. This field is protected by the flush mutex
* rather than by the region mutex.
*/
int in_flush; /* Log flush in progress. */
roff_t flush_mutex_off; /* Mutex guarding flushing. */
DB_LSN s_lsn; /* LSN of the last sync. */
DB_LOG_STAT stat; /* Log statistics. */
/*
* The waiting_lsn is used by the replication system. It is the
* first LSN that we are holding without putting in the log, because
* we received one or more log records out of order. Associated with
* the waiting_lsn is the number of log records that we still have to
* receive before we decide that we should request it again.
*/
DB_LSN waiting_lsn; /* First log record after a gap. */
DB_LSN verify_lsn; /* LSN we are waiting to verify. */
u_int32_t wait_recs; /* Records to wait before requesting. */
u_int32_t rcvd_recs; /* Records received while waiting. */
/*
* The ready_lsn is also used by the replication system. It is the
* next LSN we expect to receive. It's normally equal to "lsn",
* except at the beginning of a log file, at which point it's set
* to the LSN of the first record of the new file (after the
* header), rather than to 0.
*/
DB_LSN ready_lsn;
/*
* During initialization, the log system walks forward through the
* last log file to find its end. If it runs into a checkpoint
* while it's doing so, it caches it here so that the transaction
* system doesn't need to walk through the file again on its
* initialization.
*/
DB_LSN cached_ckp_lsn;
roff_t buffer_off; /* Log buffer offset in the region. */
u_int32_t buffer_size; /* Log buffer size. */
u_int32_t log_size; /* Log file's size. */
u_int32_t log_nsize; /* Next log file's size. */
u_int32_t ncommit; /* Number of txns waiting to commit. */
DB_LSN t_lsn; /* LSN of first commit */
SH_TAILQ_HEAD(__commit) commits;/* list of txns waiting to commit. */
SH_TAILQ_HEAD(__free) free_commits;/* free list of commit structs. */
#ifdef HAVE_MUTEX_SYSTEM_RESOURCES
#define LG_MAINT_SIZE (sizeof(roff_t) * DB_MAX_HANDLES)
roff_t maint_off; /* offset of region maintenance info */
#endif
};
/*
* __db_commit structure --
* One of these is allocated for each transaction waiting
* to commit.
*/
struct __db_commit {
DB_MUTEX mutex; /* Mutex for txn to wait on. */
DB_LSN lsn; /* LSN of commit record. */
SH_TAILQ_ENTRY links; /* Either on free or waiting list. */
#define DB_COMMIT_FLUSH 0x0001 /* Flush the log when you wake up. */
u_int32_t flags;
};
/*
* FNAME --
* File name and id.
*/
struct __fname {
SH_TAILQ_ENTRY q; /* File name queue. */
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. */
u_int32_t create_txnid; /*
* Txn ID of the DB create, stored so
* we can log it at register time.
*/
};
/* 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 || IS_NOT_LOGGED_LSN(*lsn)); \
if (DB_REDO(redo) && (cmp) < 0 && !IS_NOT_LOGGED_LSN(*(lsn))) { \
__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 "dbinc_auto/dbreg_auto.h"
#include "dbinc_auto/dbreg_ext.h"
#include "dbinc_auto/log_ext.h"
#endif /* !_LOG_H_ */
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