usr/src/cmd/sendmail/db/include/log.h

   1 /*-
   2  * See the file LICENSE for redistribution information.
   3  *
   4  * Copyright (c) 1996, 1997, 1998
   5  *      Sleepycat Software.  All rights reserved.
   6  *
   7  *      @(#)log.h       10.30 (Sleepycat) 10/11/98
   8  */
   9
  10 #ifndef _LOG_H_
  11 #define _LOG_H_
  12
  13 struct __fname;         typedef struct __fname FNAME;
  14 struct __hdr;           typedef struct __hdr HDR;
  15 struct __log;           typedef struct __log LOG;
  16 struct __log_persist;   typedef struct __log_persist LOGP;
  17
  18 #ifndef MAXLFNAME
  19 #define LFPREFIX        "log."          /* Log file name prefix. */
  20 #define LFNAME          "log.%010d"     /* Log file name template. */
  21 #define LFNAME_V1       "log.%05d"      /* Log file name template, rev 1. */
  22 #define MAXLFNAME       2000000000      /* Maximum log file name. */
  23 #endif
  24                                         /* Default log name. */
  25 #define DB_DEFAULT_LOG_FILE     "__db_log.share"
  26
  27 #define DEFAULT_MAX     (10 * MEGABYTE) /* 10 Mb. */
  28
  29 /* Macros to lock/unlock the region and threads. */
  30 #define LOCK_LOGTHREAD(dblp)                                            \
  31         if (F_ISSET(dblp, DB_AM_THREAD))                                \
  32                 (void)__db_mutex_lock((dblp)->mutexp, -1)
  33 #define UNLOCK_LOGTHREAD(dblp)                                          \
  34         if (F_ISSET(dblp, DB_AM_THREAD))                                \
  35                 (void)__db_mutex_unlock((dblp)->mutexp, -1);
  36 #define LOCK_LOGREGION(dblp)                                            \
  37         (void)__db_mutex_lock(&((RLAYOUT *)(dblp)->lp)->lock,           \
  38             (dblp)->reginfo.fd)
  39 #define UNLOCK_LOGREGION(dblp)                                          \
  40         (void)__db_mutex_unlock(&((RLAYOUT *)(dblp)->lp)->lock,         \
  41             (dblp)->reginfo.fd)
  42
  43 /* Check for region catastrophic shutdown. */
  44 #define LOG_PANIC_CHECK(dblp) {                                         \
  45         if ((dblp)->lp->rlayout.panic)                                  \
  46                 return (DB_RUNRECOVERY);                                \
  47 }
  48
  49 /*
  50  * The per-process table that maps log file-id's to DB structures.
  51  */
  52 typedef struct __db_entry {
  53         DB       *dbp;                  /* Associated DB structure. */
  54         char     *name;                 /* File name. */
  55         u_int32_t refcount;             /* Reference counted. */
  56         int       deleted;              /* File was not found during open. */
  57 } DB_ENTRY;
  58
  59 /*
  60  * DB_LOG
  61  *      Per-process log structure.
  62  */
  63 struct __db_log {
  64 /* These fields need to be protected for multi-threaded support. */
  65         db_mutex_t      *mutexp;        /* Mutex for thread protection. */
  66
  67         DB_ENTRY *dbentry;              /* Recovery file-id mapping. */
  68 #define DB_GROW_SIZE    64
  69         u_int32_t dbentry_cnt;          /* Entries.  Grows by DB_GROW_SIZE. */
  70
  71 /*
  72  * These fields are always accessed while the region lock is held, so they do
  73  * not have to be protected by the thread lock as well OR, they are only used
  74  * when threads are not being used, i.e. most cursor operations are disallowed
  75  * on threaded logs.
  76  */
  77         u_int32_t lfname;               /* Log file "name". */
  78         int       lfd;                  /* Log file descriptor. */
  79
  80         DB_LSN    c_lsn;                /* Cursor: current LSN. */
  81         DBT       c_dbt;                /* Cursor: return DBT structure. */
  82         int       c_fd;                 /* Cursor: file descriptor. */
  83         u_int32_t c_off;                /* Cursor: previous record offset. */
  84         u_int32_t c_len;                /* Cursor: current record length. */
  85
  86 /* These fields are not protected. */
  87         LOG      *lp;                   /* Address of the shared LOG. */
  88
  89         DB_ENV   *dbenv;                /* Reference to error information. */
  90         REGINFO   reginfo;              /* Region information. */
  91
  92         void     *addr;                 /* Address of shalloc() region. */
  93
  94         char     *dir;                  /* Directory argument. */
  95
  96 /*
  97  * These fields are used by XA; since XA forbids threaded execution, these
  98  * do not have to be protected.
  99  */
 100         void    *xa_info;               /* Committed transaction list that
 101                                          * has to be carried between calls
 102                                          * to xa_recover. */
 103         DB_LSN  xa_lsn;                 /* Position of an XA recovery scan. */
 104         DB_LSN  xa_first;               /* LSN to which we need to roll back
 105                                            for this XA recovery scan. */
 106
 107         /*
 108          * !!!
 109          * Currently used to hold:
 110          *      DB_AM_THREAD    (a DB flag)
 111          *      DBC_RECOVER     (a DBC flag)
 112          * If they are ever the same bits, we're in serious trouble.
 113          */
 114 #if DB_AM_THREAD == DBC_RECOVER
 115         DB_AM_THREAD, DBC_RECOVER, FLAG MISMATCH
 116 #endif
 117         u_int32_t flags;
 118 };
 119
 120 /*
 121  * HDR --
 122  *      Log record header.
 123  */
 124 struct __hdr {
 125         u_int32_t prev;                 /* Previous offset. */
 126         u_int32_t cksum;                /* Current checksum. */
 127         u_int32_t len;                  /* Current length. */
 128 };
 129
 130 struct __log_persist {
 131         u_int32_t magic;                /* DB_LOGMAGIC */
 132         u_int32_t version;              /* DB_LOGVERSION */
 133
 134         u_int32_t lg_max;               /* Maximum file size. */
 135         int       mode;                 /* Log file mode. */
 136 };
 137
 138 /*
 139  * LOG --
 140  *      Shared log region.  One of these is allocated in shared memory,
 141  *      and describes the log.
 142  */
 143 struct __log {
 144         RLAYOUT   rlayout;              /* General region information. */
 145
 146         LOGP      persist;              /* Persistent information. */
 147
 148         SH_TAILQ_HEAD(__fq) fq;         /* List of file names. */
 149
 150         /*
 151          * The lsn LSN is the file offset that we're about to write and which
 152          * we will return to the user.
 153          */
 154         DB_LSN    lsn;                  /* LSN at current file offset. */
 155
 156         /*
 157          * The s_lsn LSN is the last LSN that we know is on disk, not just
 158          * written, but synced.
 159          */
 160         DB_LSN    s_lsn;                /* LSN of the last sync. */
 161
 162         u_int32_t len;                  /* Length of the last record. */
 163
 164         u_int32_t w_off;                /* Current write offset in the file. */
 165
 166         DB_LSN    chkpt_lsn;            /* LSN of the last checkpoint. */
 167         time_t    chkpt;                /* Time of the last checkpoint. */
 168
 169         DB_LOG_STAT stat;               /* Log statistics. */
 170
 171         /*
 172          * The f_lsn LSN is the LSN (returned to the user) that "owns" the
 173          * first byte of the buffer.  If the record associated with the LSN
 174          * spans buffers, it may not reflect the physical file location of
 175          * the first byte of the buffer.
 176          */
 177         DB_LSN    f_lsn;                /* LSN of first byte in the buffer. */
 178         size_t    b_off;                /* Current offset in the buffer. */
 179         u_int8_t buf[4 * 1024];         /* Log buffer. */
 180 };
 181
 182 /*
 183  * FNAME --
 184  *      File name and id.
 185  */
 186 struct __fname {
 187         SH_TAILQ_ENTRY q;               /* File name queue. */
 188
 189         u_int16_t ref;                  /* Reference count. */
 190
 191         u_int32_t id;                   /* Logging file id. */
 192         DBTYPE    s_type;               /* Saved DB type. */
 193
 194         size_t    name_off;             /* Name offset. */
 195         u_int8_t  ufid[DB_FILE_ID_LEN]; /* Unique file id. */
 196 };
 197
 198 /* File open/close register log record opcodes. */
 199 #define LOG_CHECKPOINT  1               /* Checkpoint: file name/id dump. */
 200 #define LOG_CLOSE       2               /* File close. */
 201 #define LOG_OPEN        3               /* File open. */
 202
 203 #include "log_auto.h"
 204 #include "log_ext.h"
 205 #endif /* _LOG_H_ */