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Diffstat (limited to 'db2/include/log.h')
| -rw-r--r-- | db2/include/log.h | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/db2/include/log.h b/db2/include/log.h new file mode 100644 index 0000000000..970dfd153a --- /dev/null +++ b/db2/include/log.h @@ -0,0 +1,157 @@ +/*- + * See the file LICENSE for redistribution information. + * + * Copyright (c) 1996, 1997 + * Sleepycat Software. All rights reserved. + * + * @(#)log.h 10.8 (Sleepycat) 8/18/97 + */ + +#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 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 return per-process address, offsets. */ +#define ADDR(base, offset) ((void *)((u_int8_t *)((base)->addr) + offset)) +#define OFFSET(base, p) ((u_int8_t *)(p) - (u_int8_t *)(base)->addr) + +/* Macros to lock/unlock the region and threads. */ +#define LOCK_LOGTHREAD(dblp) \ + if (F_ISSET(dblp, DB_AM_THREAD)) \ + (void)__db_mutex_lock(&(dblp)->mutex, -1, \ + (dblp)->dbenv == NULL ? NULL : (dblp)->dbenv->db_yield) +#define UNLOCK_LOGTHREAD(dblp) \ + if (F_ISSET(dblp, DB_AM_THREAD)) \ + (void)__db_mutex_unlock(&(dblp)->mutex, -1); +#define LOCK_LOGREGION(dblp) \ + (void)__db_mutex_lock(&((RLAYOUT *)(dblp)->lp)->lock, \ + (dblp)->fd, (dblp)->dbenv == NULL ? NULL : (dblp)->dbenv->db_yield) +#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 mutex; /* 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. */ + + 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. */ + + DB_LSN lsn; /* LSN at current file offset. */ + DB_LSN c_lsn; /* LSN of the last checkpoint. */ + DB_LSN s_lsn; /* LSN of the last sync. */ + DB_LSN span_lsn; /* LSN spanning buffer write. */ + + u_int32_t len; /* Length of the last record. */ + + size_t b_off; /* Current offset in the buffer. */ + u_int32_t w_off; /* Current write offset in the file. */ + + time_t chkpt; /* Time of the last checkpoint. */ + u_int32_t written; /* Bytes written since checkpoint. */ + + 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_ */ |