db.c

这是linux下运行的mysql软件包,可用于linux 下安装 php + mysql + apach 的网络配置

			(void)__dbreg_revoke_id(dbp, 0);
		else
			(void)__dbreg_close_id(dbp, txn);

		/* Discard the log FNAME. */
		(void)__dbreg_teardown(dbp);
	}

	/* Clear out fields that normally get set during open. */
	memset(dbp->fileid, 0, sizeof(dbp->fileid));
	dbp->adj_fileid = 0;
	dbp->meta_pgno = 0;
	dbp->cur_lid = DB_LOCK_INVALIDID;
	dbp->associate_lid = DB_LOCK_INVALIDID;
	dbp->cl_id = 0;

	/*
	 * If we are being refreshed with a txn specified, then we need
	 * to make sure that we clear out the lock handle field, because
	 * releasing all the locks for this transaction will release this
	 * lock and we don't want close to stumble upon this handle and
	 * try to close it.
	 */
	if (txn != NULL)
		LOCK_INIT(dbp->handle_lock);

	F_CLR(dbp, DB_AM_DBM_ERROR);
	F_CLR(dbp, DB_AM_DISCARD);
	F_CLR(dbp, DB_AM_INMEM);
	F_CLR(dbp, DB_AM_RECOVER);
	F_CLR(dbp, DB_AM_OPEN_CALLED);
	F_CLR(dbp, DB_AM_RDONLY);
	F_CLR(dbp, DB_AM_SWAP);

	return (ret);
}

/*
 * __db_log_page
 *	Log a meta-data or root page during a subdatabase create operation.
 *
 * PUBLIC: int __db_log_page __P((DB *, DB_TXN *, DB_LSN *, db_pgno_t, PAGE *));
 */
int
__db_log_page(dbp, txn, lsn, pgno, page)
	DB *dbp;
	DB_TXN *txn;
	DB_LSN *lsn;
	db_pgno_t pgno;
	PAGE *page;
{
	DBT page_dbt;
	DB_LSN new_lsn;
	int ret;

	if (!LOGGING_ON(dbp->dbenv) || txn == NULL)
		return (0);

	memset(&page_dbt, 0, sizeof(page_dbt));
	page_dbt.size = dbp->pgsize;
	page_dbt.data = page;

	ret = __crdel_metasub_log(dbp, txn, &new_lsn, 0, pgno, &page_dbt, lsn);

	if (ret == 0)
		page->lsn = new_lsn;
	return (ret);
}

/*
 * __db_backup_name
 *	Create the backup file name for a given file.
 *
 * PUBLIC: int __db_backup_name __P((DB_ENV *,
 * PUBLIC:     const char *, DB_TXN *, char **));
 */
#undef	BACKUP_PREFIX
#define	BACKUP_PREFIX	"__db."

#undef	MAX_LSN_TO_TEXT
#define	MAX_LSN_TO_TEXT	17

int
__db_backup_name(dbenv, name, txn, backup)
	DB_ENV *dbenv;
	const char *name;
	DB_TXN *txn;
	char **backup;
{
	DB_LSN lsn;
	size_t len;
	int plen, ret;
	char *p, *retp;

	/*
	 * Create the name.  Backup file names are in one of two forms:
	 *
	 *	In a transactional env: __db.LSN(8).LSN(8)
	 * and
	 *	in a non-transactional env: __db.FILENAME.
	 *
	 * If the transaction doesn't have a current LSN, we write
	 * a dummy log record to force it, so that we ensure that
	 * all tmp names are unique.
	 *
	 * In addition, the name passed may contain an env-relative path.
	 * In that case, put the __db. in the right place (in the last
	 * component of the pathname).
	 */
	if (txn != NULL) {
		if (IS_ZERO_LSN(txn->last_lsn)) {
			/*
			 * Write dummy log record.   The two choices for
			 * dummy log records are __db_noop_log and
			 * __db_debug_log; unfortunately __db_noop_log requires
			 * a valid dbp, and we aren't guaranteed to be able
			 * to pass one in here.
			 */
			if ((ret = __db_debug_log(dbenv, txn, &lsn, 0,
			    NULL, 0, NULL, NULL, 0)) != 0)
				return (ret);
		} else
			lsn = txn->last_lsn;
	}

	/*
	 * Part of the name may be a full path, so we need to make sure that
	 * we allocate enough space for it, even in the case where we don't
	 * use the entire filename for the backup name.
	 */
	len = strlen(name) + strlen(BACKUP_PREFIX) + MAX_LSN_TO_TEXT;
	    
	if ((ret = __os_malloc(dbenv, len, &retp)) != 0)
		return (ret);

	/*
	 * There are four cases here:
	 *	1. simple path w/out transaction
	 *	2. simple path + transaction
	 *	3. multi-component path w/out transaction
	 *	4. multi-component path + transaction
	 */
	if ((p = __db_rpath(name)) == NULL) {
		if (txn == NULL)	/* case 1 */
			snprintf(retp, len, "%s%s.", BACKUP_PREFIX, name);
		else			/* case 2 */
			snprintf(retp, len,
			    "%s%x.%x", BACKUP_PREFIX, lsn.file, lsn.offset);
	} else {
		plen = (int)(p - name) + 1;
		p++;
		if (txn == NULL)	/* case 3 */
			snprintf(retp, len,
			    "%.*s%s%s.", plen, name, BACKUP_PREFIX, p);
		else 			/* case 4 */
			snprintf(retp, len,
			    "%.*s%x.%x.", plen, name, lsn.file, lsn.offset);
	}

	*backup = retp;
	return (0);
}

/*
 * __dblist_get --
 *	Get the first element of dbenv->dblist with
 *	dbp->adj_fileid matching adjid.
 *
 * PUBLIC: DB *__dblist_get __P((DB_ENV *, u_int32_t));
 */
DB *
__dblist_get(dbenv, adjid)
	DB_ENV *dbenv;
	u_int32_t adjid;
{
	DB *dbp;

	for (dbp = LIST_FIRST(&dbenv->dblist);
	    dbp != NULL && dbp->adj_fileid != adjid;
	    dbp = LIST_NEXT(dbp, dblistlinks))
		;

	return (dbp);
}

/*
 * __db_disassociate --
 *	Destroy the association between a given secondary and its primary.
 */
static int
__db_disassociate(sdbp)
	DB *sdbp;
{
	DBC *dbc;
	int ret, t_ret;

	ret = 0;

	sdbp->s_callback = NULL;
	sdbp->s_primary = NULL;
	sdbp->get = sdbp->stored_get;
	sdbp->close = sdbp->stored_close;

	/*
	 * Complain, but proceed, if we have any active cursors.  (We're in
	 * the middle of a close, so there's really no turning back.)
	 */
	if (sdbp->s_refcnt != 1 ||
	    TAILQ_FIRST(&sdbp->active_queue) != NULL ||
	    TAILQ_FIRST(&sdbp->join_queue) != NULL) {
		__db_err(sdbp->dbenv,
    "Closing a primary DB while a secondary DB has active cursors is unsafe");
		ret = EINVAL;
	}
	sdbp->s_refcnt = 0;

	while ((dbc = TAILQ_FIRST(&sdbp->free_queue)) != NULL)
		if ((t_ret = __db_c_destroy(dbc)) != 0 && ret == 0)
			ret = t_ret;

	F_CLR(sdbp, DB_AM_SECONDARY);
	return (ret);
}

#if CONFIG_TEST
/*
 * __db_testcopy
 *	Create a copy of all backup files and our "main" DB.
 *
 * PUBLIC: #if CONFIG_TEST
 * PUBLIC: int __db_testcopy __P((DB_ENV *, DB *, const char *));
 * PUBLIC: #endif
 */
int
__db_testcopy(dbenv, dbp, name)
	DB_ENV *dbenv;
	DB *dbp;
	const char *name;
{
	DB_MPOOLFILE *mpf;

	DB_ASSERT(dbp != NULL || name != NULL);

	if (name == NULL) {
		mpf = dbp->mpf;
		name = R_ADDR(mpf->dbmp->reginfo, mpf->mfp->path_off);
	}

	if (dbp != NULL && dbp->type == DB_QUEUE)
		return (__qam_testdocopy(dbp, name));
	else
		return (__db_testdocopy(dbenv, name));
}

static int
__qam_testdocopy(dbp, name)
	DB *dbp;
	const char *name;
{
	QUEUE_FILELIST *filelist, *fp;
	char buf[256], *dir;
	int ret;

	filelist = NULL;
	if ((ret = __db_testdocopy(dbp->dbenv, name)) != 0)
		return (ret);
	if (dbp->mpf != NULL &&
	    (ret = __qam_gen_filelist(dbp, &filelist)) != 0)
		return (ret);

	if (filelist == NULL)
		return (0);
	dir = ((QUEUE *)dbp->q_internal)->dir;
	for (fp = filelist; fp->mpf != NULL; fp++) {
		snprintf(buf, sizeof(buf),
		    QUEUE_EXTENT, dir, PATH_SEPARATOR[0], name, fp->id);
		if ((ret = __db_testdocopy(dbp->dbenv, buf)) != 0)
			return (ret);
	}

	__os_free(dbp->dbenv, filelist);
	return (0);
}

/*
 * __db_testdocopy
 *	Create a copy of all backup files and our "main" DB.
 *
 */
static int
__db_testdocopy(dbenv, name)
	DB_ENV *dbenv;
	const char *name;
{
	size_t len;
	int dircnt, i, ret;
	char **namesp, *backup, *copy, *dir, *p, *real_name;
	real_name = NULL;
	/* Get the real backing file name. */
	if ((ret = __db_appname(dbenv,
	    DB_APP_DATA, name, 0, NULL, &real_name)) != 0)
		return (ret);

	copy = backup = NULL;
	namesp = NULL;

	/*
	 * Maximum size of file, including adding a ".afterop".
	 */
	len = strlen(real_name) + strlen(BACKUP_PREFIX) + MAX_LSN_TO_TEXT + 9;

	if ((ret = __os_malloc(dbenv, len, &copy)) != 0)
		goto out;

	if ((ret = __os_malloc(dbenv, len, &backup)) != 0)
		goto out;

	/*
	 * First copy the file itself.
	 */
	snprintf(copy, len, "%s.afterop", real_name);
	__db_makecopy(real_name, copy);

	if ((ret = __os_strdup(dbenv, real_name, &dir)) != 0)
		goto out;
	__os_free(dbenv, real_name);
	real_name = NULL;
	/*
	 * Create the name.  Backup file names are of the form:
	 *
	 *	__db.name.0x[lsn-file].0x[lsn-offset]
	 *
	 * which guarantees uniqueness.  We want to look for the
	 * backup name, followed by a '.0x' (so that if they have
	 * files named, say, 'a' and 'abc' we won't match 'abc' when
	 * looking for 'a'.
	 */
	snprintf(backup, len, "%s%s.0x", BACKUP_PREFIX, name);

	/*
	 * We need the directory path to do the __os_dirlist.
	 */
	p = __db_rpath(dir);
	if (p != NULL)
		*p = '\0';
	ret = __os_dirlist(dbenv, dir, &namesp, &dircnt);
#if DIAGNOSTIC
	/*
	 * XXX
	 * To get the memory guard code to work because it uses strlen and we
	 * just moved the end of the string somewhere sooner.  This causes the
	 * guard code to fail because it looks at one byte past the end of the
	 * string.
	 */
	*p = '/';
#endif
	__os_free(dbenv, dir);
	if (ret != 0)
		goto out;
	for (i = 0; i < dircnt; i++) {
		/*
		 * Need to check if it is a backup file for this.
		 * No idea what namesp[i] may be or how long, so
		 * must use strncmp and not memcmp.  We don't want
		 * to use strcmp either because we are only matching
		 * the first part of the real file's name.  We don't
		 * know its LSN's.
		 */
		if (strncmp(namesp[i], backup, strlen(backup)) == 0) {
			if ((ret = __db_appname(dbenv, DB_APP_DATA,
			    namesp[i], 0, NULL, &real_name)) != 0)
				goto out;

			/*
			 * This should not happen.  Check that old
			 * .afterop files aren't around.
			 * If so, just move on.
			 */
			if (strstr(real_name, ".afterop") != NULL) {
				__os_free(dbenv, real_name);
				real_name = NULL;
				continue;
			}
			snprintf(copy, len, "%s.afterop", real_name);
			__db_makecopy(real_name, copy);
			__os_free(dbenv, real_name);
			real_name = NULL;
		}
	}
out:
	if (backup != NULL)
		__os_free(dbenv, backup);
	if (copy != NULL)
		__os_free(dbenv, copy);
	if (namesp != NULL)
		__os_dirfree(dbenv, namesp, dircnt);
	if (real_name != NULL)
		__os_free(dbenv, real_name);
	return (ret);
}

static void
__db_makecopy(src, dest)
	const char *src, *dest;
{
	DB_FH rfh, wfh;
	size_t rcnt, wcnt;
	char *buf;

	memset(&rfh, 0, sizeof(rfh));
	memset(&wfh, 0, sizeof(wfh));

	if (__os_malloc(NULL, 1024, &buf) != 0)
		return;

	if (__os_open(NULL,
	    src, DB_OSO_RDONLY, __db_omode("rw----"), &rfh) != 0)
		goto err;
	if (__os_open(NULL, dest,
	    DB_OSO_CREATE | DB_OSO_TRUNC, __db_omode("rw----"), &wfh) != 0)
		goto err;

	for (;;)
		if (__os_read(NULL, &rfh, buf, 1024, &rcnt) < 0 || rcnt == 0 ||
		    __os_write(NULL, &wfh, buf, rcnt, &wcnt) < 0)
			break;

err:	__os_free(NULL, buf);
	if (F_ISSET(&rfh, DB_FH_VALID))
		__os_closehandle(NULL, &rfh);
	if (F_ISSET(&wfh, DB_FH_VALID))
		__os_closehandle(NULL, &wfh);
}
#endif