/*- * See the file LICENSE for redistribution information. * * Copyright (c) 1996-2003 * Sleepycat Software. All rights reserved. * * $Id: log.h,v 1.2 2004/03/30 01:21:28 jtownsen Exp $ */ #ifndef _LOG_H_ #define _LOG_H_ /******************************************************* * DBREG: * The DB file register code keeps track of open files. It's stored * in the log subsystem's shared region, and so appears in the log.h * header file, but is logically separate. *******************************************************/ /* * 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; /* * 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. */ int is_durable; /* Is this file durable or not. */ }; /* File open/close register log record opcodes. */ #define DBREG_CHKPNT 1 /* Checkpoint: file name/id dump. */ #define DBREG_CLOSE 2 /* File close. */ #define DBREG_OPEN 3 /* File open. */ #define DBREG_RCLOSE 4 /* File close after recovery. */ /******************************************************* * LOG: * The log subsystem information. *******************************************************/ 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. */ /* * 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. */ u_int32_t lfname; /* Log file "name". */ DB_FH *lfhp; /* 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. */ /* * !!! - NOTE that the next 6 fields, waiting_lsn, verify_lsn, * max_wait_lsn, wait_recs, rcvd_recs, and ready_lsn are NOT * protected by the log region lock. They are protected by * db_rep->db_mutexp. If you need access to both, you must * acquire the db_mutexp before acquiring the log region lock. * * 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. * * The max_wait_lsn is used to control retransmission in the face * of dropped messages. If we are requesting all records from the * current gap (i.e., chunk of the log that we are missing), then * the max_wait_lsn contains the first LSN that we are known to have * in the __db.rep.db. If we requested only a single record, then * the max_wait_lsn has the LSN of that record we requested. */ DB_LSN waiting_lsn; /* First log record after a gap. */ DB_LSN verify_lsn; /* LSN we are waiting to verify. */ DB_LSN max_wait_lsn; /* Maximum LSN requested. */ 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; }; #define CHECK_LSN(redo, cmp, lsn, prev) \ 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); \ ret = EINVAL; \ 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_ */