00001 /*- 00002 * See the file LICENSE for redistribution information. 00003 * 00004 * Copyright (c) 1996, 1997, 1998, 1999, 2000 00005 * Sleepycat Software. All rights reserved. 00006 * 00007 * $Id: log_8h-source.html,v 1.1 2008年06月08日 10:20:10 sebdiaz Exp $ 00008 */ 00009 00010 #ifndef _LOG_H_ 00011 #define _LOG_H_ 00012 00013 struct __db_log; typedef struct __db_log DB_LOG; 00014 struct __fname; typedef struct __fname FNAME; 00015 struct __hdr; typedef struct __hdr HDR; 00016 struct __log; typedef struct __log LOG; 00017 struct __log_persist; typedef struct __log_persist LOGP; 00018 00019 #ifndef MAXLFNAME 00020 #define LFPREFIX "log." /* Log file name prefix. */ 00021 #define LFNAME "log.%010d" /* Log file name template. */ 00022 #define LFNAME_V1 "log.%05d" /* Log file name template, rev 1. */ 00023 #define MAXLFNAME 2000000000 /* Maximum log file name. */ 00024 #endif 00025 00026 #define LG_MAX_DEFAULT (10 * MEGABYTE) /* 10 MB. */ 00027 #define LG_BSIZE_DEFAULT (32 * 1024) /* 32 KB. */ 00028 #define LG_BASE_REGION_SIZE (60 * 1024) /* 60 KB. */ 00029 00030 /* 00031 * The log region isn't fixed size because we store the registered 00032 * file names there. 00033 */ 00034 #define LOG_REGION_SIZE (30 * 1024) 00035 00036 /* 00037 * The per-process table that maps log file-id's to DB structures. 00038 */ 00039 typedef struct __db_entry { 00040 TAILQ_HEAD(dblist, __db) dblist; /* Associated DB structures. */ 00041 u_int32_t refcount; /* Reference counted. */ 00042 u_int32_t count; /* Number of ops on a deleted db. */ 00043 int deleted; /* File was not found during open. */ 00044 } DB_ENTRY; 00045 00046 /* 00047 * DB_LOG 00048 * Per-process log structure. 00049 */ 00050 struct __db_log { 00051 /* 00052 * These fields need to be protected for multi-threaded support. 00053 * 00054 * !!! 00055 * As this structure is allocated in per-process memory, the mutex may need 00056 * to be stored elsewhere on architectures unable to support mutexes in heap 00057 * memory, e.g., HP/UX 9. 00058 */ 00059 MUTEX *mutexp; /* Mutex for thread protection. */ 00060 00061 DB_ENTRY *dbentry; /* Recovery file-id mapping. */ 00062 #define DB_GROW_SIZE 64 00063 int32_t dbentry_cnt; /* Entries. Grows by DB_GROW_SIZE. */ 00064 00065 /* 00066 * These fields are always accessed while the region lock is held, so they do 00067 * not have to be protected by the thread lock as well, OR, they are only used 00068 * when threads are not being used, i.e. most cursor operations are disallowed 00069 * on threaded logs. 00070 */ 00071 u_int32_t lfname; /* Log file "name". */ 00072 DB_FH lfh; /* Log file handle. */ 00073 00074 DB_LSN c_lsn; /* Cursor: current LSN. */ 00075 DBT c_dbt; /* Cursor: return DBT structure. */ 00076 DB_FH c_fh; /* Cursor: file handle. */ 00077 FILE *c_fp; /* Cursor: file pointer. */ 00078 u_int32_t c_off; /* Cursor: previous record offset. */ 00079 u_int32_t c_len; /* Cursor: current record length. */ 00080 u_int32_t r_file; /* Cursor: current read file */ 00081 u_int32_t r_off; /* Cursor: offset of read buffer. */ 00082 u_int32_t r_size; /* Cursor: size of data in read buf. */ 00083 00084 u_int8_t *bufp; /* Region buffer. */ 00085 u_int8_t *readbufp; /* Read buffer. */ 00086 00087 /* These fields are not protected. */ 00088 DB_ENV *dbenv; /* Reference to error information. */ 00089 REGINFO reginfo; /* Region information. */ 00090 00091 /* 00092 * These fields are used by XA; since XA forbids threaded execution, these 00093 * do not have to be protected. 00094 */ 00095 void *xa_info; /* Committed transaction list that 00096 * has to be carried between calls 00097 * to xa_recover. */ 00098 DB_LSN xa_lsn; /* Position of an XA recovery scan. */ 00099 DB_LSN xa_first; /* LSN to which we need to roll back 00100 for this XA recovery scan. */ 00101 00102 #define DBLOG_RECOVER 0x01 /* We are in recovery. */ 00103 #define DBLOG_FORCE_OPEN 0x02 /* Force the db open even 00104 * if it appears to be deleted. 00105 */ 00106 u_int32_t flags; 00107 }; 00108 00109 /* 00110 * HDR -- 00111 * Log record header. 00112 */ 00113 struct __hdr { 00114 u_int32_t prev; /* Previous offset. */ 00115 u_int32_t cksum; /* Current checksum. */ 00116 u_int32_t len; /* Current length. */ 00117 }; 00118 00119 struct __log_persist { 00120 u_int32_t magic; /* DB_LOGMAGIC */ 00121 u_int32_t version; /* DB_LOGVERSION */ 00122 00123 u_int32_t lg_max; /* Maximum file size. */ 00124 int mode; /* Log file mode. */ 00125 }; 00126 00127 /* 00128 * LOG -- 00129 * Shared log region. One of these is allocated in shared memory, 00130 * and describes the log. 00131 */ 00132 struct __log { 00133 LOGP persist; /* Persistent information. */ 00134 00135 SH_TAILQ_HEAD(__fq) fq; /* List of file names. */ 00136 00137 /* 00138 * The lsn LSN is the file offset that we're about to write and which 00139 * we will return to the user. 00140 */ 00141 DB_LSN lsn; /* LSN at current file offset. */ 00142 00143 /* 00144 * The s_lsn LSN is the last LSN that we know is on disk, not just 00145 * written, but synced. 00146 */ 00147 DB_LSN s_lsn; /* LSN of the last sync. */ 00148 00149 u_int32_t len; /* Length of the last record. */ 00150 00151 u_int32_t w_off; /* Current write offset in the file. */ 00152 00153 DB_LSN chkpt_lsn; /* LSN of the last checkpoint. */ 00154 time_t chkpt; /* Time of the last checkpoint. */ 00155 00156 DB_LOG_STAT stat; /* Log statistics. */ 00157 00158 /* 00159 * The f_lsn LSN is the LSN (returned to the user) that "owns" the 00160 * first byte of the buffer. If the record associated with the LSN 00161 * spans buffers, it may not reflect the physical file location of 00162 * the first byte of the buffer. 00163 */ 00164 DB_LSN f_lsn; /* LSN of first byte in the buffer. */ 00165 size_t b_off; /* Current offset in the buffer. */ 00166 00167 roff_t buffer_off; /* Log buffer offset. */ 00168 u_int32_t buffer_size; /* Log buffer size. */ 00169 }; 00170 00171 /* 00172 * FNAME -- 00173 * File name and id. 00174 */ 00175 struct __fname { 00176 SH_TAILQ_ENTRY q; /* File name queue. */ 00177 00178 u_int16_t ref; /* Reference count. */ 00179 u_int16_t locked; /* Table is locked. */ 00180 00181 int32_t id; /* Logging file id. */ 00182 DBTYPE s_type; /* Saved DB type. */ 00183 00184 roff_t name_off; /* Name offset. */ 00185 db_pgno_t meta_pgno; /* Page number of the meta page. */ 00186 u_int8_t ufid[DB_FILE_ID_LEN]; /* Unique file id. */ 00187 }; 00188 00189 /* File open/close register log record opcodes. */ 00190 #define LOG_CHECKPOINT 1 /* Checkpoint: file name/id dump. */ 00191 #define LOG_CLOSE 2 /* File close. */ 00192 #define LOG_OPEN 3 /* File open. */ 00193 00194 #define CHECK_LSN(redo, cmp, lsn, prev) \ 00195 DB_ASSERT(!DB_REDO(redo) || cmp >=0); \ 00196 if (DB_REDO(redo) && cmp < 0) { \ 00197 CDB___db_err(dbenv, "Log sequence error: page LSN %lu %lu" \ 00198 "previous LSN %lu %lu", lsn.file, lsn.offset, \ 00199 prev.file, prev.offset); \ 00200 goto out; \ 00201 } 00202 00203 #include "log_auto.h" 00204 #include "log_ext.h" 00205 #endif /* _LOG_H_ */