Re: (ITS#7672) LMDB: mdb_dbi_flags fails with newly created DataBase

[hyc@symas.com]

sog@msg.com.mx wrote:
> Full_Name: Salvador Ortiz
> Version: 24
> OS: Linux
> URL:
> Submission from: (NULL) (187.162.45.111)
>
>
> Using mdb_dbi_flags with newly created database fails or lies.

mdb_dbi_flags() has been changed to take a txn instead of an env pointer. 
Fixed in mdb.master.

> In the case of MAIN _DBI, if I set some flags in mdb_dbi_open, the flags isn't
> propagated to the environment, I think the fix is simple:
>
> --- a/libraries/liblmdb/mdb.c
> +++ b/libraries/liblmdb/mdb.c
> @@ -7881,6 +7881,7 @@ int mdb_dbi_open(MDB_txn *txn, const char *name, unsigned
> int flags, MDB_dbi *db
>                          /* make sure flag changes get committed */
>                          if ((txn->mt_dbs[MAIN_DBI].md_flags | f2) !=
> txn->mt_dbs[MAIN_DBI].md_flags) {
>                                  txn->mt_dbs[MAIN_DBI].md_flags |= f2;
> +                               txn->mt_env->me_dbflags[MAIN_DBI] =
> txn->mt_dbs[MAIN_DBI].md_flags;
>                                  txn->mt_flags |= MDB_TXN_DIRTY;
>                          }
>                  }
>
> But in the case of a newly created named database, env->me_numdbs isn't adjusted
> until the transaction is committed, so mdb_env_flags fails.
>
> The more that I think about it, seems that the proper way to get the flags of an
> opened db is with a new API, something like:
>
> int mbd_get_flags(MDB_txn *, MDB_dbi dbi, unsigned int *flags)
> {
> 	if (txn == NULL || arg == NULL || dbi >= txn->mt_numdbs)
> 		return EINVAL;
>
> 	*flags = txn->mt_dbflags[dbi];
>          return MDB_SUCCESS;
> }
>
>
> Comments?
>
>


-- 
   -- Howard Chu
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