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Add basic iterator for B+tree

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I can't match the exact interface of a dictionary of the key and the value are in separate place in the structure
(so I can't return a pair of (key,value)). Instead I return a pair of pointer (key_ptr, value_ptr).
I don't see any other way which doesn't evolve copy of the key/value.
For the RBtree interface, no such problem occurs.
This commit is contained in:
Patrick Pelissier committed 2018-04-05 22:44:36 +02:00
1 parent 75217d4914
commit 91db494898
1 file changed
+106 -4
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m-bptree.h
+106 -4
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@@ -31,13 +31,15 @@
USAGE: BPTREE_DEF2(name, N, key_t, key_oplist, value_t, value_oplist) */ USAGE: BPTREE_DEF2(name, N, key_t, key_oplist, value_t, value_oplist) */
#define BPTREE_DEF2(name, N, key_t, key_oplist, value_t, value_oplist) \ #define BPTREE_DEF2(name, N, key_t, key_oplist, value_t, value_oplist) \
BPTREEI_DEF2(name, N, key_t, key_oplist, value_t, value_oplist, 1, \ BPTREEI_DEF2(name, N, key_t, key_oplist, value_t, value_oplist, 1, \
M_C(name, _t), M_C(name, _node_t), M_C(name, _pit_t)) M_C(name, _t), M_C(name, _node_t), M_C(name, _pit_t), \
M_C(name, _it_t))
/* Define a B+tree of a given type, of size N. /* Define a B+tree of a given type, of size N.
USAGE: BPTREE_DEF(name, N, type, [, oplist_of_the_type]) */ USAGE: BPTREE_DEF(name, N, type, [, oplist_of_the_type]) */
#define BPTREE_DEF(name, N, type, oplist) \ #define BPTREE_DEF(name, N, type, oplist) \
BPTREEI_DEF2(name, N, type, oplist, type, oplist, 0, \ BPTREEI_DEF2(name, N, type, oplist, type, oplist, 0, \
M_C(name, _t), M_C(name, _node_t), M_C(name, _pit_t)) M_C(name, _t), M_C(name, _node_t), M_C(name, _pit_t), \
M_C(name, _it_t))
//TODO: oplist //TODO: oplist
@@ -78,9 +80,13 @@
/* Max depth of any B+tree */ /* Max depth of any B+tree */
#define BPTREEI_MAX_STACK ((int)(CHAR_BIT*sizeof (size_t))) #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) \ #define BPTREEI_DEF2(name, N, key_t, key_oplist, value_t, value_oplist, isMap, tree_t, node_t, pit_t, it_t) \
\ \
typedef key_t M_C(name, _type_t); \ M_IF(isMap)( \
typedef struct M_C(name, _pair_s) { \
key_t *key_ptr; \
value_t *value_ptr; } M_C(name, _type_t), \
typedef key_t M_C(name, _type_t)); \
\ \
/* Node of a B+TREE */ \ /* Node of a B+TREE */ \
typedef struct M_C(name, _node_s) { \ typedef struct M_C(name, _node_s) { \
@@ -105,6 +111,13 @@
node_t parent[BPTREEI_MAX_STACK]; \ node_t parent[BPTREEI_MAX_STACK]; \
} pit_t[1]; \ } pit_t[1]; \
\ \
/* Iterator */ \
typedef struct M_C(name, _it_s) { \
M_IF(isMap)(struct M_C(name, _pair_s) pair;,) \
node_t node; \
int idx; \
} it_t[1]; \
\
/* Can be optimized later to alloc for leaf or for node */ \ /* Can be optimized later to alloc for leaf or for node */ \
static inline node_t M_C(name, _new_node)(void) \ static inline node_t M_C(name, _new_node)(void) \
{ \ { \
@@ -241,6 +254,11 @@
return NULL; \ return NULL; \
} \ } \
\ \
static inline const value_t *M_C(name, _cget)(tree_t b, key_t const key) \
{ \
return M_CONST_CAST(value_t, M_C(name, _get)(b, key)); \
} \
\
static inline int M_C(name, _search_and_insert_leaf)(node_t n, key_t const key M_IF(isMap)( M_DEFERRED_COMMA value_t const value,) ) \ static inline int M_C(name, _search_and_insert_leaf)(node_t n, key_t const key M_IF(isMap)( M_DEFERRED_COMMA value_t const value,) ) \
{ \ { \
assert (M_C(name, _is_leaf)(n)); \ assert (M_C(name, _is_leaf)(n)); \
@@ -497,6 +515,7 @@
\ \
static inline bool 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) \
{ \ { \
BPTREEI_CONTRACT(N, key_oplist, b); \
pit_t pit; \ pit_t pit; \
node_t leaf = M_C(name, _search_leaf)(pit, b, key); \ node_t leaf = M_C(name, _search_leaf)(pit, b, key); \
int k = M_C(name, _search_and_remove_leaf)(leaf, key); \ int k = M_C(name, _search_and_remove_leaf)(leaf, key); \
@@ -557,5 +576,88 @@
} \ } \
return M_C(name, _remove)(b, key); \ return M_C(name, _remove)(b, key); \
} \ } \
\
static inline void \
M_C(name, _it)(it_t it, const tree_t b) \
{ \
BPTREEI_CONTRACT(N, key_oplist, b); \
assert (it != NULL); \
node_t n = b->root; \
/* Scan down the nodes */ \
while (!M_C(name, _is_leaf)(n)) { \
n = n->kind.node[0]; \
} \
it->node = n; \
it->idx = 0; \
} \
\
static inline void \
M_C(name, _it_end)(it_t it, const tree_t b) \
{ \
BPTREEI_CONTRACT(N, key_oplist, b); \
assert (it != NULL); \
node_t n = b->root; \
/* Scan down the nodes */ \
while (!M_C(name, _is_leaf)(n)) { \
n = n->kind.node[n->num]; \
} \
it->node = n; \
it->idx = n->num; \
} \
\
static inline void \
M_C(name, _it_set)(it_t itd, const it_t its) \
{ \
assert (itd != NULL && its != NULL); \
itd->node = its->node; \
itd->idx = its->idx; \
} \
\
static inline bool \
M_C(name, _end_p)(it_t it) \
{ \
assert (it != NULL && it->node != NULL); \
assert (M_C(name, _is_leaf)(it->node)); \
return it->node->next ==NULL && it->idx >= -it->node->num; \
} \
\
static inline bool \
M_C(name, _it_equal_p)(const it_t it1, const it_t it2) \
{ \
return it1->node == it2->node && it1->idx == it2->idx; \
} \
\
static inline void \
M_C(name, _next)(it_t it) \
{ \
assert (it != NULL && it->node != NULL); \
it->idx ++; \
if (it->idx >= -it->node->num && it->node->next != NULL) { \
it->node = it->node->next; \
it->idx = 0; \
} \
} \
\
static inline M_C(name, _type_t) * \
M_C(name, _ref)(it_t it) \
{ \
assert (it != NULL && it->node != NULL); \
assert (it->idx <= -it->node->num); \
M_IF(isMap)( \
it->pair.key_ptr = &it->node->key[it->idx]; \
it->pair.value_ptr = &it->node->kind.value[it->idx]; \
return &it->pair \
, \
return &it->node->key[it->idx] \
); \
} \
\
static inline const M_C(name, _type_t) * \
M_C(name, _cref)(it_t it) \
{ \
return M_CONST_CAST(M_C(name, _type_t), M_C(name, _ref)(it)); \
} \
#endif #endif