diff options
Diffstat (limited to 'db2/log/log_findckp.c')
| -rw-r--r-- | db2/log/log_findckp.c | 141 |
1 files changed, 0 insertions, 141 deletions
diff --git a/db2/log/log_findckp.c b/db2/log/log_findckp.c deleted file mode 100644 index ab13c8380e..0000000000 --- a/db2/log/log_findckp.c +++ /dev/null @@ -1,141 +0,0 @@ -/*- - * See the file LICENSE for redistribution information. - * - * Copyright (c) 1996, 1997, 1998 - * Sleepycat Software. All rights reserved. - */ - -#include "config.h" - -#ifndef lint -static const char sccsid[] = "@(#)log_findckp.c 10.17 (Sleepycat) 9/17/98"; -#endif /* not lint */ - -#ifndef NO_SYSTEM_INCLUDES -#include <sys/types.h> - -#include <errno.h> -#include <string.h> -#endif - -#include "db_int.h" -#include "shqueue.h" -#include "log.h" -#include "txn.h" -#include "common_ext.h" - -/* - * __log_findckp -- - * - * Looks for the most recent checkpoint that occurs before the most recent - * checkpoint LSN, subject to the constraint that there must be at least two - * checkpoints. The reason you need two checkpoints is that you might have - * crashed during the most recent one and may not have a copy of all the - * open files. This is the point from which recovery can start and the - * point up to which archival/truncation can take place. Checkpoints in - * the log look like: - * - * ------------------------------------------------------------------- - * | ckp A, ckplsn 100 | .... record .... | ckp B, ckplsn 600 | ... - * ------------------------------------------------------------------- - * LSN 500 LSN 1000 - * - * If we read what log returns from using the DB_CKP parameter to logput, - * we'll get the record at LSN 1000. The checkpoint LSN there is 600. - * Now we have to scan backwards looking for a checkpoint before LSN 600. - * We find one at 500. This means that we can truncate the log before - * 500 or run recovery beginning at 500. - * - * Returns 0 if we find a suitable checkpoint or we retrieved the - * first record in the log from which to start. - * Returns DB_NOTFOUND if there are no log records. - * Returns errno on error. - * - * PUBLIC: int __log_findckp __P((DB_LOG *, DB_LSN *)); - */ -int -__log_findckp(lp, lsnp) - DB_LOG *lp; - DB_LSN *lsnp; -{ - DBT data; - DB_LSN ckp_lsn, final_ckp, last_ckp, next_lsn; - __txn_ckp_args *ckp_args; - int ret, verbose; - - verbose = lp->dbenv != NULL && lp->dbenv->db_verbose != 0; - - /* - * Need to find the appropriate point from which to begin - * recovery. - */ - memset(&data, 0, sizeof(data)); - if (F_ISSET(lp, DB_AM_THREAD)) - F_SET(&data, DB_DBT_MALLOC); - ZERO_LSN(ckp_lsn); - if ((ret = log_get(lp, &last_ckp, &data, DB_CHECKPOINT)) != 0) { - if (ret == ENOENT) - goto get_first; - else - return (ret); - } - - final_ckp = last_ckp; - next_lsn = last_ckp; - do { - if (F_ISSET(lp, DB_AM_THREAD)) - __os_free(data.data, data.size); - - if ((ret = log_get(lp, &next_lsn, &data, DB_SET)) != 0) - return (ret); - if ((ret = __txn_ckp_read(data.data, &ckp_args)) != 0) { - if (F_ISSET(lp, DB_AM_THREAD)) - __os_free(data.data, data.size); - return (ret); - } - if (IS_ZERO_LSN(ckp_lsn)) - ckp_lsn = ckp_args->ckp_lsn; - if (verbose) { - __db_err(lp->dbenv, "Checkpoint at: [%lu][%lu]", - (u_long)last_ckp.file, (u_long)last_ckp.offset); - __db_err(lp->dbenv, "Checkpoint LSN: [%lu][%lu]", - (u_long)ckp_args->ckp_lsn.file, - (u_long)ckp_args->ckp_lsn.offset); - __db_err(lp->dbenv, "Previous checkpoint: [%lu][%lu]", - (u_long)ckp_args->last_ckp.file, - (u_long)ckp_args->last_ckp.offset); - } - last_ckp = next_lsn; - next_lsn = ckp_args->last_ckp; - __os_free(ckp_args, sizeof(*ckp_args)); - - /* - * Keep looping until either you 1) run out of checkpoints, - * 2) you've found a checkpoint before the most recent - * checkpoint's LSN and you have at least 2 checkpoints. - */ - } while (!IS_ZERO_LSN(next_lsn) && - (log_compare(&last_ckp, &ckp_lsn) > 0 || - log_compare(&final_ckp, &last_ckp) == 0)); - - if (F_ISSET(lp, DB_AM_THREAD)) - __os_free(data.data, data.size); - - /* - * At this point, either, next_lsn is ZERO or ckp_lsn is the - * checkpoint lsn and last_ckp is the LSN of the last checkpoint - * before ckp_lsn. If the compare in the loop is still true, then - * next_lsn must be 0 and we need to roll forward from the - * beginning of the log. - */ - if (log_compare(&last_ckp, &ckp_lsn) > 0 || - log_compare(&final_ckp, &last_ckp) == 0) { -get_first: if ((ret = log_get(lp, &last_ckp, &data, DB_FIRST)) != 0) - return (ret); - if (F_ISSET(lp, DB_AM_THREAD)) - __os_free(data.data, data.size); - } - *lsnp = last_ckp; - - return (IS_ZERO_LSN(last_ckp) ? DB_NOTFOUND : 0); -} |