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| author | Howard Chu <hyc@openldap.org> | 2016-04-09 20:42:45 +0100 |
|---|---|---|
| committer | Howard Chu <hyc@openldap.org> | 2016-04-09 20:42:45 +0100 |
| commit | c8dbd772f751471fd2824bbb27ac9b8b392af465 (patch) | |
| tree | a476becce056d188ae9a0b92ef37e0da913c98c9 | |
| parent | 8fff90db7ed1e650395f39f9e8b22673aa74aa2b (diff) | |
| download | lmdb-c8dbd772f751471fd2824bbb27ac9b8b392af465.tar.gz lmdb-c8dbd772f751471fd2824bbb27ac9b8b392af465.tar.bz2 lmdb-c8dbd772f751471fd2824bbb27ac9b8b392af465.zip | |
mdb_drop optimization
If we know there are no sub-DBs and no overflow pages, skip leaf scan.
| -rw-r--r-- | libraries/liblmdb/mdb.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c index acab07b..2d8e458 100644 --- a/libraries/liblmdb/mdb.c +++ b/libraries/liblmdb/mdb.c @@ -10501,8 +10501,11 @@ mdb_drop0(MDB_cursor *mc, int subs) /* DUPSORT sub-DBs have no ovpages/DBs. Omit scanning leaves. * This also avoids any P_LEAF2 pages, which have no nodes. + * Also if the DB doesn't have sub-DBs and has no overflow + * pages, omit scanning leaves. */ - if (mc->mc_flags & C_SUB) + if ((mc->mc_flags & C_SUB) || + (!subs && !mc->mc_db->md_overflow_pages)) mdb_cursor_pop(mc); mdb_cursor_copy(mc, &mx); @@ -10529,6 +10532,9 @@ mdb_drop0(MDB_cursor *mc, int subs) pg, omp->mp_pages); if (rc) goto done; + mc->mc_db->md_overflow_pages -= omp->mp_pages; + if (!mc->mc_db->md_overflow_pages && !subs) + break; } else if (subs && (ni->mn_flags & F_SUBDATA)) { mdb_xcursor_init1(mc, ni); rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0); @@ -10536,6 +10542,8 @@ mdb_drop0(MDB_cursor *mc, int subs) goto done; } } + if (!subs && !mc->mc_db->md_overflow_pages) + goto pop; } else { if ((rc = mdb_midl_need(&txn->mt_free_pgs, n)) != 0) goto done; @@ -10557,6 +10565,7 @@ mdb_drop0(MDB_cursor *mc, int subs) /* no more siblings, go back to beginning * of previous level. */ +pop: mdb_cursor_pop(mc); mc->mc_ki[0] = 0; for (i=1; i<mc->mc_snum; i++) { |