Ignore key, broken by 5bda3565a9
and some older code. Document and clarify MDB_CURRENT usage.
Also affects non-MDB_CURRENT put() with empty data and a key
which matches by the mdb_set_compare function but not by memcmp.
db_mid2l_insert(): Move assert to mdb.c.
mdb_cursor_set(): Previous assert cannot fail now.
mdb_cursor_put(): Check mc/key and return EINVAL.
mdb_cursor_dbi(): No error return, so just segfault if cursor==NULL.
mdb_cursor_put(): Use free sub-page space added by a
previous put(existing DUPSORT item), if any.
Tweak NUMKEYS code to avoid a new signedness warning.
Use a sub-DB for DUPSORT item #1/#2 per key if needed: Not a sub-
page too big for a node, nor an overflow page (which not all DUPSORT
code checks for). Move "insert" code, to avoid non-loop goto upwards.
(This is the commit which needs the change to xdata.mv_size in
commit 9d6e4a9163 "page sizes".)
Handle keys stored by a liblmdb with a bigger MDB_MAXKEYSIZE.
mdb_get/mdb_del(absent key bigger than our MDB_MAXKEYSIZE)
now return MDB_NOTFOUND instead of MDB_BAD_VALSIZE.
Change me_nodemax to not count the mp_ptrs[] entry. That's mostly
how it was used. Compare node sizes ">" me_nodemax instead of ">=".
The ">=" was a workaround for confusing sizes with and without the
mp_ptrs[] entry, but broke for nodes with size (old me_nodemax-1).
Explicitly make me_nodemax even. An odd value could break the
comparisons. It was even anyway because MDB_MINKEYS == 2.
Use DB page size = min(32k, OS pagesize). Previous limit was 8k
(MDB_MINKEYS*MDB_PAGESIZE).
Handle DB pagesize < OS pagesize. That's an I/O pessimization,
but transactions remain atomic: Only writing the MDB_meta must
be atomic, and it fits in one OS page.
Don't truncate desired subpage size: Asssign it to a size_t
(mv_size), not an uint16_t (mp_upper).
Hallvard Furuseth