Commit c97f4ed1 authored by Howard Chu's avatar Howard Chu
Browse files

ITS#8557 fix mdb_cursor_last

Optimize mdb_page_search_root(PS_LAST) when cursor is already near
last position, ignoring C_EOF flag for now.
parent 307a2e02
......@@ -5459,8 +5459,17 @@ mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int flags)
if (flags & (MDB_PS_FIRST|MDB_PS_LAST)) {
i = 0;
if (flags & MDB_PS_LAST)
if (flags & MDB_PS_LAST) {
i = NUMKEYS(mp) - 1;
/* if already init'd, see if we're already in right place */
if (mc->mc_flags & C_INITIALIZED) {
if (mc->mc_ki[mc->mc_top] == i) {
mc->mc_top = mc->mc_snum++;
mp = mc->mc_pg[mc->mc_top];
goto ready;
}
}
}
} else {
int exact;
node = mdb_node_search(mc, key, &exact);
......@@ -5486,6 +5495,7 @@ mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int flags)
if ((rc = mdb_cursor_push(mc, mp)))
return rc;
ready:
if (flags & MDB_PS_MODIFY) {
if ((rc = mdb_page_touch(mc)) != 0)
return rc;
......@@ -6224,16 +6234,13 @@ mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data)
if (mc->mc_xcursor)
mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
if (!(mc->mc_flags & C_EOF)) {
if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
rc = mdb_page_search(mc, NULL, MDB_PS_LAST);
if (rc != MDB_SUCCESS)
return rc;
}
mdb_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));
if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
rc = mdb_page_search(mc, NULL, MDB_PS_LAST);
if (rc != MDB_SUCCESS)
return rc;
}
mdb_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));
mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]) - 1;
mc->mc_flags |= C_INITIALIZED|C_EOF;
leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment