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authorHoward Chu <hyc@symas.com>2016-04-09 20:44:05 +0100
committerHoward Chu <hyc@symas.com>2016-04-09 20:44:05 +0100
commit66b1e13aa750777a80815c0c9dd7f535b7434c19 (patch)
treee3ad3201c4de1d372e776f525d9ba7966334fd62
parentMigration (diff)
downloadmonero-66b1e13aa750777a80815c0c9dd7f535b7434c19.tar.xz
mdb_drop optimization
If we know there are no sub-DBs and no overflow pages, skip leaf scan.
-rw-r--r--external/db_drivers/liblmdb/mdb.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/external/db_drivers/liblmdb/mdb.c b/external/db_drivers/liblmdb/mdb.c
index acab07b82..2d8e458f7 100644
--- a/external/db_drivers/liblmdb/mdb.c
+++ b/external/db_drivers/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++) {