diff options
Diffstat (limited to 'debian/htdig/htdig-3.2.0b6/db/env_recover.c')
| -rw-r--r-- | debian/htdig/htdig-3.2.0b6/db/env_recover.c | 339 |
1 files changed, 339 insertions, 0 deletions
diff --git a/debian/htdig/htdig-3.2.0b6/db/env_recover.c b/debian/htdig/htdig-3.2.0b6/db/env_recover.c new file mode 100644 index 00000000..f695baa9 --- /dev/null +++ b/debian/htdig/htdig-3.2.0b6/db/env_recover.c @@ -0,0 +1,339 @@ +/*- + * See the file LICENSE for redistribution information. + * + * Copyright (c) 1996, 1997, 1998, 1999 + * Sleepycat Software. All rights reserved. + */ + +#include "db_config.h" + +#ifndef lint +static const char copyright[] = +"@(#) Copyright (c) 1996, 1997, 1998, 1999\n\ + Sleepycat Software Inc. All rights reserved.\n"; +static const char sccsid[] = "@(#)env_recover.c 11.6 (Sleepycat) 10/1/99"; +#endif + +#ifndef NO_SYSTEM_INCLUDES +#include <sys/types.h> + +#if TIME_WITH_SYS_TIME +#include <sys/time.h> +#include <time.h> +#else +#if HAVE_SYS_TIME_H +#include <sys/time.h> +#else +#include <time.h> +#endif +#endif + +#include <string.h> +#endif + +#include "db_int.h" +#include "db_page.h" +#include "db_dispatch.h" +#include "db_am.h" +#include "log.h" +#include "txn.h" + +static float CDB___lsn_diff __P((DB_LSN *, DB_LSN *, DB_LSN *, u_int32_t, int)); + +/* + * CDB___db_apprec -- + * Perform recovery. + * + * PUBLIC: int CDB___db_apprec __P((DB_ENV *, u_int32_t)); + */ +int +CDB___db_apprec(dbenv, flags) + DB_ENV *dbenv; + u_int32_t flags; +{ + DBT data; + DB_LSN ckp_lsn, first_lsn, last_lsn, lsn, open_lsn; + DB_TXNREGION *region; + __txn_ckp_args *ckp_args; + time_t now; + float nfiles; + int is_thread, progress, ret; + void *txninfo; + + COMPQUIET(nfiles, (float)0); + + /* Initialize the transaction list. */ + if ((ret = CDB___db_txnlist_init(&txninfo)) != 0) + return (ret); + + /* + * Save the state of the thread flag -- we don't need it on at the + * moment because we're single-threaded until recovery is complete. + */ + is_thread = F_ISSET(dbenv, DB_ENV_THREAD) ? 1 : 0; + F_CLR(dbenv, DB_ENV_THREAD); + + /* + * Recovery is done in three passes: + * Pass #0: + * We need to find the position from which we will open files + * We need to open files beginning with the last to next + * checkpoint because we might have crashed after writing the + * last checkpoint record, but before having written out all + * the open file information. + * Pass #1: + * Read forward through the log from the second to last checkpoint + * opening and closing files so that at the end of the log we have + * the "current" set of files open. + * Pass #2: + * Read backward through the log undoing any uncompleted TXNs. + * If doing catastrophic recovery, we read to the beginning of + * the log, otherwise, to the most recent checkpoint that occurs + * before the most recent checkpoint LSN, which is returned by + * CDB___log_findckp(). During this pass, checkpoint file information + * is ignored, and file openings and closings are undone. + * Pass #3: + * Read forward through the log from the LSN found in pass #2, + * redoing any committed TXNs. During this pass, checkpoint + * file information is ignored, and file openings and closings + * are redone. + */ + + /* + * Pass #0 + * Find the second to last checkpoint in the log. This is the point + * from which we want to begin pass #1 (the TXN_OPENFILES pass). + */ + memset(&data, 0, sizeof(data)); + ckp_args = NULL; + + if ((ret = CDB_log_get(dbenv, &ckp_lsn, &data, DB_CHECKPOINT)) != 0) { + /* + * If we don't find a checkpoint, start from the beginning. + * If that fails, we're done. Note, we do not require that + * there be log records if we're performing recovery. + */ +first: if ((ret = CDB_log_get(dbenv, &ckp_lsn, &data, DB_FIRST)) != 0) { + if (ret == DB_NOTFOUND) + ret = 0; + else + CDB___db_err(dbenv, "First log record not found"); + goto out; + } + open_lsn = ckp_lsn; + } else if ((ret = CDB___txn_ckp_read(data.data, &ckp_args)) != 0) { + CDB___db_err(dbenv, "Invalid checkpoint record at [%ld][%ld]\n", + (u_long)ckp_lsn.file, (u_long)ckp_lsn.offset); + goto out; + } else if (IS_ZERO_LSN(ckp_args->last_ckp) || + (ret = CDB_log_get(dbenv, &ckp_args->last_ckp, &data, DB_SET)) != 0) + goto first; + else + open_lsn = ckp_args->last_ckp; + + /* + * Find out the last lsn, so that we can estimate how far along we + * are in recovery. This will help us determine how much log there + * is between the first LSN that we're going to be working with and + * the last one. We assume that each of the three phases takes the + * same amount of time (a false assumption) and then use the %-age + * of the amount of log traversed to figure out how much of the + * pass we've accomplished. + */ + if (dbenv->db_feedback != NULL) { + if ((ret = CDB_log_get(dbenv, &last_lsn, &data, DB_LAST)) != 0) + goto out; + if (last_lsn.file == ckp_lsn.file) + nfiles = (float)(last_lsn.offset - ckp_lsn.offset) / + dbenv->lg_max; + else + nfiles = (float)(last_lsn.file - ckp_lsn.file) + + (float)(dbenv->lg_max - ckp_lsn.offset + + last_lsn.offset) / dbenv->lg_max; + } + + /* + * Pass #1 + * Now, ckp_lsn is either the lsn of the second to last checkpoint + * or the lsn of the first record in the log. Open_lsn is the second + * to last checkpoint or the beinning of the log; begin the + * TXN_OPENFILES pass from that lsn, and proceed to the end of the log. + */ + lsn = open_lsn; + for (;;) { + if (dbenv->tx_recover != NULL) + ret = dbenv->tx_recover(dbenv, + &data, &lsn, TXN_OPENFILES, txninfo); + else + ret = CDB___db_dispatch(dbenv, + &data, &lsn, TXN_OPENFILES, txninfo); + if (ret != 0 && ret != DB_TXN_CKP) + goto msgerr; + if ((ret = CDB_log_get(dbenv, &lsn, &data, DB_NEXT)) != 0) { + if (ret == DB_NOTFOUND) + break; + goto out; + } + if (dbenv->db_feedback != NULL) { + progress = (int)(33 * CDB___lsn_diff(&ckp_lsn, + &last_lsn, &lsn, dbenv->lg_max, 1) / nfiles); + dbenv->db_feedback(dbenv, DB_RECOVER, progress); + } + } + + /* + * Pass #2. + * + * Before we can begin pass #2, backward roll phase, we determine how + * far back in the log to recover. If we are doing catastrophic + * recovery, then we go as far back as we have files. If we are + * doing normal recovery, we go as back to the most recent checkpoint + * that occurs before the most recent checkpoint LSN. + */ + if (LF_ISSET(DB_RECOVER_FATAL)) { + ZERO_LSN(first_lsn); + } else + if ((ret = CDB___log_findckp(dbenv, &first_lsn)) == DB_NOTFOUND) { + /* + * We don't require that log files exist if recovery + * was specified. + */ + ret = 0; + goto out; + } + + if (FLD_ISSET(dbenv->verbose, DB_VERB_RECOVERY)) + CDB___db_err(dbenv, "Recovery starting from [%lu][%lu]", + (u_long)first_lsn.file, (u_long)first_lsn.offset); + + for (ret = CDB_log_get(dbenv, &lsn, &data, DB_LAST); + ret == 0 && CDB_log_compare(&lsn, &first_lsn) > 0; + ret = CDB_log_get(dbenv, &lsn, &data, DB_PREV)) { + if (dbenv->tx_recover != NULL) + ret = dbenv->tx_recover(dbenv, + &data, &lsn, TXN_BACKWARD_ROLL, txninfo); + else + ret = CDB___db_dispatch(dbenv, + &data, &lsn, TXN_BACKWARD_ROLL, txninfo); + if (ret != 0) { + if (ret != DB_TXN_CKP) + goto msgerr; + else + ret = 0; + } + if (dbenv->db_feedback != NULL) { + progress = 34 + (int)(33 * CDB___lsn_diff(&ckp_lsn, + &last_lsn, &lsn, dbenv->lg_max, 0) / nfiles); + dbenv->db_feedback(dbenv, DB_RECOVER, progress); + } + } + if (ret != 0 && ret != DB_NOTFOUND) + goto out; + + /* + * Pass #3. + */ + for (ret = CDB_log_get(dbenv, &lsn, &data, DB_NEXT); + ret == 0; ret = CDB_log_get(dbenv, &lsn, &data, DB_NEXT)) { + if (dbenv->tx_recover != NULL) + ret = dbenv->tx_recover(dbenv, + &data, &lsn, TXN_FORWARD_ROLL, txninfo); + else + ret = CDB___db_dispatch(dbenv, + &data, &lsn, TXN_FORWARD_ROLL, txninfo); + if (ret != 0) { + if (ret != DB_TXN_CKP) + goto msgerr; + else + ret = 0; + } + if (dbenv->db_feedback != NULL) { + progress = 67 + (int)(33 * CDB___lsn_diff(&ckp_lsn, + &last_lsn, &lsn, dbenv->lg_max, 1) / nfiles); + dbenv->db_feedback(dbenv, DB_RECOVER, progress); + } + } + if (ret != DB_NOTFOUND) + goto out; + + /* Now close all the db files that are open. */ + CDB___log_close_files(dbenv); + + /* + * Now set the last checkpoint lsn and the current time, + * take a checkpoint, and reset the txnid. + */ + (void)time(&now); + region = ((DB_TXNMGR *)dbenv->tx_handle)->reginfo.primary; + region->last_ckp = ckp_lsn; + region->time_ckp = (u_int32_t)now; + if ((ret = CDB_txn_checkpoint(dbenv, 0, 0)) != 0) + goto out; + region->last_txnid = TXN_MINIMUM; + + if (FLD_ISSET(dbenv->verbose, DB_VERB_RECOVERY)) { + CDB___db_err(dbenv, "Recovery complete at %.24s", ctime(&now)); + CDB___db_err(dbenv, "%s %lx %s [%lu][%lu]", + "Maximum transaction ID", + ((DB_TXNHEAD *)txninfo)->maxid, + "Recovery checkpoint", + (u_long)region->last_ckp.file, + (u_long)region->last_ckp.offset); + } + + if (0) { +msgerr: CDB___db_err(dbenv, "Recovery function for LSN %lu %lu failed", + (u_long)lsn.file, (u_long)lsn.offset); + } + +out: if (is_thread) + F_SET(dbenv, DB_ENV_THREAD); + CDB___db_txnlist_end(dbenv, txninfo); + if (ckp_args != NULL) + CDB___os_free(ckp_args, sizeof(*ckp_args)); + + return (ret); +} + +/* + * Figure out how many logfiles we have processed. If we are moving + * forward (is_forward != 0), then we're computing current - low. If + * we are moving backward, we are compouting high - current. max is + * the number of bytes per logfile. + */ +static float +CDB___lsn_diff(low, high, current, max, is_forward) + DB_LSN *low, *high, *current; + u_int32_t max; + int is_forward; +{ + float nf; + + /* + * There are three cases in each direction. If you are in the + * same file, then all you need worry about is the difference in + * offsets. If you are in different files, then either your offsets + * put you either more or less than the integral difference in the + * number of files -- we need to handle both of these. + */ + if (is_forward) { + if (current->file == low->file) + nf = (float)(current->offset - low->offset) / max; + else if (current->offset < low->offset) + nf = (float)(current->file - low->file - 1) + + (float)(max - low->offset + current->offset) / max; + else + nf = (float)(current->file - low->file) + + (float)(current->offset - low->offset) / max; + } else { + if (current->file == high->file) + nf = (float)(high->offset - current->offset) / max; + else if (current->offset > high->offset) + nf = (float)(high->file - current->file - 1) + + (float)(max - current->offset + high->offset) / max; + else + nf = (float)(high->file - current->file) + + (float)(high->offset - current->offset) / max; + } + return (nf); +} |