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B+TREE: _remove returns a boolean indicating if the item

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removed was present or not
This commit is contained in:
Patrick Pelissier committed 2018-04-04 22:35:47 +02:00
1 parent 4925297a35
commit c91864c2a7
1 file changed
+12 -9
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m-bptree.h
+12 -9
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@@ -69,17 +69,18 @@
#endif
#define BPTREEI_CONTRACT(N, key_oplist, b) do { \
assert (N >= 3); \
assert (N >= 3); /* TBC: 2 instead ? */ \
BPTREEI_NODE_CONTRACT(N, key_oplist, (b)->root, (b)->root); \
assert ((b)->root->next == NULL); \
} while (0)
/* Max depth of the B+tree
*/
/* Max depth of any B+tree */
#define BPTREEI_MAX_STACK ((int)(CHAR_BIT*sizeof (size_t)))
#define BPTREEI_DEF2(name, N, key_t, key_oplist, value_t, value_oplist, isMap, tree_t, node_t, pit_t) \
\
typedef key_t M_C(name, _type_t); \
\
/* Node of a B+TREE */ \
typedef struct M_C(name, _node_s) { \
int num; /* Abs=Number of keys. Sign <0 is leaf */ \
@@ -479,13 +480,14 @@
assert(false); \
} \
\
static inline void M_C(name, _remove)(tree_t b, key_t const key) \
static inline bool M_C(name, _remove)(tree_t b, key_t const key) \
{ \
pit_t pit; \
node_t leaf = M_C(name, _search_leaf)(pit, b, key); \
int k = M_C(name, _search_and_remove_leaf)(leaf, key); \
/* If not found, or number of keys greater than N>2 or root */ \
if (M_LIKELY (M_C(name, _get_num)(leaf) >= N/2) || k < 0 || pit->num == 0) return; \
if (k < 0) return false; \
if (M_LIKELY (M_C(name, _get_num)(leaf) >= N/2) || pit->num == 0) return true; \
/* Leaf is too small. Needs rebalancing */ \
assert (M_C(name, _get_num)(leaf) == N/2-1); \
bool pass1 = true; \
@@ -499,11 +501,11 @@
/* if we can still one key to keep our node balanced */ \
if (k > 0 && M_C(name, _get_num)(parent->kind.node[k-1]) > N/2) { \
M_C(name, _left_shift)(parent, k-1); \
return; \
return true; \
} else if (k < M_C(name, _get_num)(parent) \
&& M_C(name, _get_num)(parent->kind.node[k+1]) > N/2) { \
M_C(name, _right_shift)(parent, k); \
return; \
return true; \
} \
/* Merge both nodes, removing 'k' from parent */ \
if (k == M_C(name, _get_num)(parent)) \
@@ -512,7 +514,7 @@
/* Merge 'k' & 'k+1' & remove 'k' from parent */ \
M_C(name, _merge_node)(parent, k, pass1); \
/* Check if we need to backport */ \
if (M_C(name, _get_num)(parent) >= N/2) return; \
if (M_C(name, _get_num)(parent) >= N/2) return true; \
if (pit->num == 0) { \
/* We reach the root */ \
if (M_C(name, _get_num)(parent) == 0) { \
@@ -520,12 +522,13 @@
b->root = parent->kind.node[0]; \
M_GET_DEL key_oplist (parent); \
} \
return; \
return true; \
} \
/* Next iteration */ \
leaf = parent; \
pass1 = false; \
} \
} \
\
#endif