Leave extra space when creating a fake page

Minimizes the number of memcpy's if additional dups are stored.

diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index 21fa97792cca9062f460cd29c3777032b3517401..be009ced553e74128693c5279117e9c61e5df67f 100644 (file)
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -4321,6 +4321,7 @@ more:
                                if (mc->mc_db->md_flags & MDB_DUPFIXED) {
                                        fp->mp_flags |= P_LEAF2;
                                        fp->mp_pad = data->mv_size;
+                                       fp->mp_upper += 2 * data->mv_size;      /* leave space for 2 more */
                                } else {
                                        fp->mp_upper += 2 * sizeof(indx_t) + 2 * NODESIZE +
                                                (dkey.mv_size & 1) + (data->mv_size & 1);
@@ -4341,6 +4342,7 @@ more:
 
                                fp = NODEDATA(leaf);
                                if (flags == MDB_CURRENT) {
+reuse:
                                        fp->mp_flags |= P_DIRTY;
                                        COPY_PGNO(fp->mp_pgno, mc->mc_pg[mc->mc_top]->mp_pgno);
                                        mc->mc_xcursor->mx_cursor.mc_pg[0] = fp;
@@ -4349,6 +4351,9 @@ more:
                                }
                                if (mc->mc_db->md_flags & MDB_DUPFIXED) {
                                        offset = fp->mp_pad;
+                                       if (SIZELEFT(fp) >= offset)
+                                               goto reuse;
+                                       offset *= 4;    /* space for 4 more */
                                } else {
                                        offset = NODESIZE + sizeof(indx_t) + data->mv_size;
                                }