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#define GB_NO_WINDOWS_H
#define GB_IMPLEMENTATION
#include "gb/gb.h"
#include "string.cpp"
// Hasing
gb_inline u64 hashing_proc(void const *data, isize len) {
return gb_murmur64(data, len);
}
gb_inline u64 hash_string(String s) {
return hashing_proc(s.text, s.len);
}
gb_inline u64 hash_pointer(void *ptr) {
uintptr u = cast(uintptr)ptr;
u64 p = cast(u64)u;
return p;
}
#define gb_for_array(index_, array_) for (isize index_ = 0; index_ < gb_array_count(array_); index_++)
// Doubly Linked Lists
#define DLIST_SET(curr_element, next_element) do { \
(curr_element)->next = (next_element); \
(curr_element)->next->prev = (curr_element); \
(curr_element) = (curr_element)->next; \
} while (0)
#define DLIST_APPEND(root_element, curr_element, next_element) do { \
if ((root_element) == NULL) \
(root_element) = (curr_element) = (next_element); \
else \
DLIST_SET(curr_element, next_element); \
} while (0)
////////////////////////////////////////////////////////////////
//
// Generic Data Structures
//
////////////////////////////////////////////////////////////////
typedef struct MapFindResult {
isize hash_index;
isize entry_prev;
isize entry_index;
} MapFindResult;
template <typename T>
struct MapEntry {
u64 key;
isize next;
T value;
};
template <typename T>
struct Map {
gbArray(isize) hashes;
gbArray(MapEntry<T>) entries;
};
template <typename T> void map_init (Map<T> *h, gbAllocator a);
template <typename T> void map_destroy(Map<T> *h);
template <typename T> T * map_get (Map<T> *h, u64 key);
template <typename T> void map_set (Map<T> *h, u64 key, T value);
template <typename T> void map_remove (Map<T> *h, u64 key);
template <typename T> void map_clear (Map<T> *h);
template <typename T> void map_grow (Map<T> *h);
template <typename T> void map_rehash (Map<T> *h, isize new_count);
template <typename T>
gb_inline void map_init(Map<T> *h, gbAllocator a) {
gb_array_init(h->hashes, a);
gb_array_init(h->entries, a);
}
template <typename T>
gb_inline void map_destroy(Map<T> *h) {
if (h->entries) gb_array_free(h->entries);
if (h->hashes) gb_array_free(h->hashes);
}
template <typename T>
gb_internal isize map__add_entry(Map<T> *h, u64 key) {
MapEntry<T> e = {0};
e.key = key;
e.next = -1;
gb_array_append(h->entries, e);
return gb_array_count(h->entries)-1;
}
template <typename T>
gb_internal MapFindResult map__find(Map<T> *h, u64 key) {
MapFindResult fr = {-1, -1, -1};
if (gb_array_count(h->hashes) > 0) {
fr.hash_index = key % gb_array_count(h->hashes);
fr.entry_index = h->hashes[fr.hash_index];
while (fr.entry_index >= 0) {
if (h->entries[fr.entry_index].key == key)
return fr;
fr.entry_prev = fr.entry_index;
fr.entry_index = h->entries[fr.entry_index].next;
}
}
return fr;
}
template <typename T>
gb_internal b32 map__full(Map<T> *h) {
return 0.75f * gb_array_count(h->hashes) <= gb_array_count(h->entries);
}
template <typename T>
gb_inline void map_grow(Map<T> *h) {
isize new_count = GB_ARRAY_GROW_FORMULA(gb_array_count(h->entries));
map_rehash(h, new_count);
}
template <typename T>
void map_rehash(Map<T> *h, isize new_count) {
isize i, j;
Map<T> nh = {0};
map_init(&nh, gb_array_allocator(h->hashes));
gb_array_resize(nh.hashes, new_count);
gb_array_reserve(nh.entries, gb_array_count(h->entries));
for (i = 0; i < new_count; i++)
nh.hashes[i] = -1;
for (i = 0; i < gb_array_count(h->entries); i++) {
MapEntry<T> *e = &h->entries[i];
MapFindResult fr;
if (gb_array_count(nh.hashes) == 0)
map_grow(&nh);
fr = map__find(&nh, e->key);
j = map__add_entry(&nh, e->key);
if (fr.entry_prev < 0)
nh.hashes[fr.hash_index] = j;
else
nh.entries[fr.entry_prev].next = j;
nh.entries[j].next = fr.entry_index;
nh.entries[j].value = e->value;
if (map__full(&nh))
map_grow(&nh);
}
map_destroy(h);
*h = nh;
}
template <typename T>
gb_inline T *map_get(Map<T> *h, u64 key) {
isize index = map__find(h, key).entry_index;
if (index >= 0)
return &h->entries[index].value;
return NULL;
}
template <typename T>
void map_set(Map<T> *h, u64 key, T value) {
isize index;
MapFindResult fr;
if (gb_array_count(h->hashes) == 0)
map_grow(h);
fr = map__find(h, key);
if (fr.entry_index >= 0) {
index = fr.entry_index;
} else {
index = map__add_entry(h, key);
if (fr.entry_prev >= 0) {
h->entries[fr.entry_prev].next = index;
} else {
h->hashes[fr.hash_index] = index;
}
}
h->entries[index].value = value;
if (map__full(h))
map_grow(h);
}
template <typename T>
void map_remove(Map<T> *h, u64 key) {
MapFindResult fr = map__find(h, key);
if (fr.entry_index >= 0) {
if (fr.entry_prev < 0) {
h->hashes[fr.hash_index] = h->entries[fr.entry_index].next;
} else {
h->entries[fr.entry_prev].next = h->entries[fr.entry_index].next;
}
if (fr.entry_index == gb_array_count(h->entries)-1) {
gb_array_pop(h->entries);
return;
}
h->entries[fr.entry_index] = h->entries[gb_array_count(h->entries)-1];
MapFindResult last = map__find(h, h->entries[fr.entry_index].key);
if (last.entry_prev >= 0) {
h->entries[last.entry_prev].next = fr.entry_index;
} else {
h->hashes[last.hash_index] = fr.entry_index;
}
}
}
template <typename T>
gb_inline void map_clear(Map<T> *h) {
gb_array_clear(h->hashes);
gb_array_clear(h->entries);
}
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