log.h
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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_ */