Edit File: ex_apprec.c
/*- * See the file LICENSE for redistribution information. * * Copyright (c) 1996,2008 Oracle. All rights reserved. * * $Id: ex_apprec.c,v 12.9 2008/04/16 13:27:33 margo Exp $ */ #include <sys/types.h> #include <sys/stat.h> #include <errno.h> #include <stddef.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include "db_config.h" #include "db.h" #include "db_int.h" #include "dbinc/db_swap.h" #include "ex_apprec.h" int apprec_dispatch __P((DB_ENV *, DBT *, DB_LSN *, db_recops)); int open_env __P((const char *, FILE *, const char *, DB_ENV **)); int verify_absence __P((DB_ENV *, const char *)); int verify_presence __P((DB_ENV *, const char *)); int main(argc, argv) int argc; char *argv[]; { extern char *optarg; DB_ENV *dbenv; DB_LSN lsn; DB_TXN *txn; DBT dirnamedbt; int ret; const char *home; char ch, dirname[256]; const char *progname = "ex_apprec"; /* Program name. */ /* Default home. */ home = "TESTDIR"; while ((ch = getopt(argc, argv, "h:")) != EOF) switch (ch) { case 'h': home = optarg; break; default: fprintf(stderr, "usage: %s [-h home]", progname); exit(EXIT_FAILURE); } printf("Set up environment.\n"); if ((ret = open_env(home, stderr, progname, &dbenv)) != 0) return (EXIT_FAILURE); printf("Create a directory in a transaction.\n"); /* * This application's convention is to log the full directory name, * including trailing nul. */ memset(&dirnamedbt, 0, sizeof(dirnamedbt)); sprintf(dirname, "%s/MYDIRECTORY", home); dirnamedbt.data = dirname; dirnamedbt.size = strlen(dirname) + 1; if ((ret = dbenv->txn_begin(dbenv, NULL, &txn, 0)) != 0) { dbenv->err(dbenv, ret, "txn_begin"); return (EXIT_FAILURE); } /* * Remember, always log actions before you execute them! * Since this log record is describing a file system operation and * we have no control over when file system operations go to disk, * we need to flush the log record immediately to ensure that the * log record is on disk before the operation it describes. The * flush would not be necessary were we doing an operation into the * BDB mpool and using LSNs that mpool knew about. */ memset(&lsn, 0, sizeof(lsn)); if ((ret = ex_apprec_mkdir_log(dbenv, txn, &lsn, DB_FLUSH, &dirnamedbt)) != 0) { dbenv->err(dbenv, ret, "mkdir_log"); return (EXIT_FAILURE); } if (mkdir(dirname, 0755) != 0) { dbenv->err(dbenv, errno, "mkdir"); return (EXIT_FAILURE); } printf("Verify the directory's presence: "); verify_presence(dbenv, dirname); printf("check.\n"); /* Now abort the transaction and verify that the directory goes away. */ printf("Abort the transaction.\n"); if ((ret = txn->abort(txn)) != 0) { dbenv->err(dbenv, ret, "txn_abort"); return (EXIT_FAILURE); } printf("Verify the directory's absence: "); verify_absence(dbenv, dirname); printf("check.\n"); /* Now do the same thing over again, only with a commit this time. */ printf("Create a directory in a transaction.\n"); memset(&dirnamedbt, 0, sizeof(dirnamedbt)); sprintf(dirname, "%s/MYDIRECTORY", home); dirnamedbt.data = dirname; dirnamedbt.size = strlen(dirname) + 1; if ((ret = dbenv->txn_begin(dbenv, NULL, &txn, 0)) != 0) { dbenv->err(dbenv, ret, "txn_begin"); return (EXIT_FAILURE); } memset(&lsn, 0, sizeof(lsn)); if ((ret = ex_apprec_mkdir_log(dbenv, txn, &lsn, 0, &dirnamedbt)) != 0) { dbenv->err(dbenv, ret, "mkdir_log"); return (EXIT_FAILURE); } if (mkdir(dirname, 0755) != 0) { dbenv->err(dbenv, errno, "mkdir"); return (EXIT_FAILURE); } printf("Verify the directory's presence: "); verify_presence(dbenv, dirname); printf("check.\n"); /* Now abort the transaction and verify that the directory goes away. */ printf("Commit the transaction.\n"); if ((ret = txn->commit(txn, 0)) != 0) { dbenv->err(dbenv, ret, "txn_commit"); return (EXIT_FAILURE); } printf("Verify the directory's presence: "); verify_presence(dbenv, dirname); printf("check.\n"); printf("Now remove the directory, then run recovery.\n"); if ((ret = dbenv->close(dbenv, 0)) != 0) { fprintf(stderr, "DB_ENV->close: %s\n", db_strerror(ret)); return (EXIT_FAILURE); } if (rmdir(dirname) != 0) { fprintf(stderr, "%s: rmdir failed with error %s", progname, strerror(errno)); } verify_absence(dbenv, dirname); /* Opening with DB_RECOVER runs recovery. */ if ((ret = open_env(home, stderr, progname, &dbenv)) != 0) return (EXIT_FAILURE); printf("Verify the directory's presence: "); verify_presence(dbenv, dirname); printf("check.\n"); /* Close the handle. */ if ((ret = dbenv->close(dbenv, 0)) != 0) { fprintf(stderr, "DB_ENV->close: %s\n", db_strerror(ret)); return (EXIT_FAILURE); } return (EXIT_SUCCESS); } int open_env(home, errfp, progname, dbenvp) const char *home, *progname; FILE *errfp; DB_ENV **dbenvp; { DB_ENV *dbenv; int ret; /* * Create an environment object and initialize it for error * reporting. */ if ((ret = db_env_create(&dbenv, 0)) != 0) { fprintf(errfp, "%s: %s\n", progname, db_strerror(ret)); return (ret); } dbenv->set_errfile(dbenv, errfp); dbenv->set_errpfx(dbenv, progname); /* Set up our custom recovery dispatch function. */ if ((ret = dbenv->set_app_dispatch(dbenv, apprec_dispatch)) != 0) { dbenv->err(dbenv, ret, "set_app_dispatch"); return (ret); } /* * Open the environment with full transactional support, running * recovery. */ if ((ret = dbenv->open(dbenv, home, DB_CREATE | DB_RECOVER | DB_INIT_LOCK | DB_INIT_LOG | DB_INIT_MPOOL | DB_INIT_TXN, 0)) != 0) { dbenv->err(dbenv, ret, "environment open: %s", home); dbenv->close(dbenv, 0); return (ret); } *dbenvp = dbenv; return (0); } /* * Sample application dispatch function to handle user-specified log record * types. */ int apprec_dispatch(dbenv, dbt, lsn, op) DB_ENV *dbenv; DBT *dbt; DB_LSN *lsn; db_recops op; { u_int32_t rectype; /* Pull the record type out of the log record. */ LOGCOPY_32(dbenv->env, &rectype, dbt->data); switch (rectype) { case DB_ex_apprec_mkdir: return (ex_apprec_mkdir_recover(dbenv, dbt, lsn, op)); default: /* * We've hit an unexpected, allegedly user-defined record * type. */ dbenv->errx(dbenv, "Unexpected log record type encountered"); return (EINVAL); } } int verify_absence(dbenv, dirname) DB_ENV *dbenv; const char *dirname; { if (access(dirname, F_OK) == 0) { dbenv->errx(dbenv, "Error--directory present!"); exit(EXIT_FAILURE); } return (0); } int verify_presence(dbenv, dirname) DB_ENV *dbenv; const char *dirname; { if (access(dirname, F_OK) != 0) { dbenv->errx(dbenv, "Error--directory not present!"); exit(EXIT_FAILURE); } return (0); }
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