maple_tree: Add append operation

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 6b893447e2a7ebf9fe5de54123779591649427b5..a67bc3ea1e96e81a89fd4236f81c0d540b2ab06e 100644 (file)
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -3216,6 +3216,45 @@ static inline int mas_spanning_store(struct ma_state *mas, void *entry)
        return mas_spanning_rebalance(mas, &mast, height + 1);
 }
 
+static inline bool mas_append(struct ma_state *mas, void *entry,
+                             unsigned long min, unsigned char end,
+                             void *content, enum maple_type mt)
+{
+       void **slots = ma_slots(mas_mn(mas), mt);
+       unsigned long *pivots = ma_pivots(mas_mn(mas), mt);
+       unsigned char new_end;
+       unsigned char max_slots = mt_slots[mt];
+
+       /* slot store would happen if the last entry wasn't being split, so add
+        * one.
+        */
+       new_end = end + 1;
+       //printk("store %lu - %lu| %lu %lu\n", mas->index, mas->last, min, mas->max);
+       if (min < mas->index)
+               new_end++;
+
+       if (new_end >= max_slots)
+               return false;
+
+       //printk("move last to %u\n", new_end);
+       if (new_end < max_slots - 1)
+               pivots[new_end] = pivots[end];
+       slots[new_end--] = content;
+
+       //printk("store to %u\n", new_end);
+       if (new_end < max_slots - 1)
+               pivots[new_end] = mas->last;
+       slots[new_end--] = entry;
+
+       if (min < mas->index) {
+               //printk("fix min in %u\n", new_end);
+               pivots[new_end] = mas->index - 1;
+               mas->offset++;
+       }
+
+       mas_update_gap(mas);
+       return true;
+}
 static inline bool mas_node_store(struct ma_state *mas, void *entry,
                                  unsigned long min, unsigned long max,
                                  unsigned char end, void *content,
@@ -3339,8 +3378,13 @@ static inline bool mas_slot_store(struct ma_state *mas, void *entry,
        if (offset + 1 >= mt_slots[mt]) // out of room.
                return false;
 
-       if (max > mas->last) // going to split a single entry.
+       if (max > mas->last){ // going to split a single entry.
+               if ((offset == end) &&
+                   mas_append(mas, entry, min, end, content, mt))
+                   return true;
+
                goto try_node_store;
+       }
 
        lmax = mas_logical_pivot(mas, pivots, offset + 1, mt);
        if (lmax < mas->last) // going to overwrite too many slots.