Files
Odin/src/map.c
2017-06-05 18:01:41 +01:00

365 lines
9.1 KiB
C

/*
Example of usage:
#define MAP_TYPE String
#define MAP_PROC map_string_
#define MAP_NAME MapString
#include "map.c"
*/
// A `Map` is an unordered hash table which can allow for a key to point to multiple values
// with the use of the `multi_*` procedures.
// TODO(bill): I should probably allow the `multi_*` stuff to be #ifdefed out
#ifndef MAP_UTIL_STUFF
#define MAP_UTIL_STUFF
// NOTE(bill): This util stuff is the same for every `Map`
typedef struct MapFindResult {
isize hash_index;
isize entry_prev;
isize entry_index;
} MapFindResult;
typedef enum HashKeyKind {
HashKey_Default,
HashKey_String,
HashKey_Pointer,
} HashKeyKind;
typedef struct HashKey {
HashKeyKind kind;
u64 key;
union {
String string; // if String, s.len > 0
void * ptr;
};
} HashKey;
gb_inline HashKey hashing_proc(void const *data, isize len) {
HashKey h = {HashKey_Default};
h.kind = HashKey_Default;
// h.key = gb_murmur64(data, len);
h.key = gb_fnv64a(data, len);
// h.key = MurmurHash3_128(data, len, 0x3803cb8e);
return h;
}
gb_inline HashKey hash_string(String s) {
HashKey h = hashing_proc(s.text, s.len);
h.kind = HashKey_String;
h.string = s;
return h;
}
gb_inline HashKey hash_pointer(void *ptr) {
HashKey h = {HashKey_Default};
// h.key = u128_from_u64(cast(u64)cast(uintptr)ptr);
h.key = cast(u64)cast(uintptr)ptr;
h.ptr = ptr;
h.kind = HashKey_Default;
return h;
}
bool hash_key_equal(HashKey a, HashKey b) {
if (a.key == b.key) {
// NOTE(bill): If two string's hashes collide, compare the strings themselves
if (a.kind == HashKey_String) {
if (b.kind == HashKey_String) {
return str_eq(a.string, b.string);
}
return false;
}
return true;
}
return false;
}
#endif
#define _J2_IND(a, b) a##b
#define _J2(a, b) _J2_IND(a, b)
/*
MAP_TYPE - Entry type
MAP_PROC - Function prefix (e.g. entity_map_)
MAP_NAME - Name of Map (e.g. EntityMap)
*/
#define MAP_ENTRY _J2(MAP_NAME,Entry)
typedef struct MAP_ENTRY {
HashKey key;
isize next;
MAP_TYPE value;
} MAP_ENTRY;
typedef struct MAP_NAME {
Array(isize) hashes;
Array(MAP_ENTRY) entries;
} MAP_NAME;
void _J2(MAP_PROC,init) (MAP_NAME *h, gbAllocator a);
void _J2(MAP_PROC,init_with_reserve)(MAP_NAME *h, gbAllocator a, isize capacity);
void _J2(MAP_PROC,destroy) (MAP_NAME *h);
MAP_TYPE *_J2(MAP_PROC,get) (MAP_NAME *h, HashKey key);
void _J2(MAP_PROC,set) (MAP_NAME *h, HashKey key, MAP_TYPE value);
void _J2(MAP_PROC,remove) (MAP_NAME *h, HashKey key);
void _J2(MAP_PROC,clear) (MAP_NAME *h);
void _J2(MAP_PROC,grow) (MAP_NAME *h);
void _J2(MAP_PROC,rehash) (MAP_NAME *h, isize new_count);
// Mutlivalued map procedure
MAP_ENTRY *_J2(MAP_PROC,multi_find_first)(MAP_NAME *h, HashKey key);
MAP_ENTRY *_J2(MAP_PROC,multi_find_next) (MAP_NAME *h, MAP_ENTRY *e);
isize _J2(MAP_PROC,multi_count) (MAP_NAME *h, HashKey key);
void _J2(MAP_PROC,multi_get_all) (MAP_NAME *h, HashKey key, MAP_TYPE *items);
void _J2(MAP_PROC,multi_insert) (MAP_NAME *h, HashKey key, MAP_TYPE value);
void _J2(MAP_PROC,multi_remove) (MAP_NAME *h, HashKey key, MAP_ENTRY *e);
void _J2(MAP_PROC,multi_remove_all)(MAP_NAME *h, HashKey key);
gb_inline void _J2(MAP_PROC,init)(MAP_NAME *h, gbAllocator a) {
array_init(&h->hashes, a);
array_init(&h->entries, a);
}
gb_inline void _J2(MAP_PROC,init_with_reserve)(MAP_NAME *h, gbAllocator a, isize capacity) {
array_init_reserve(&h->hashes, a, capacity);
array_init_reserve(&h->entries, a, capacity);
}
gb_inline void _J2(MAP_PROC,destroy)(MAP_NAME *h) {
array_free(&h->entries);
array_free(&h->hashes);
}
gb_internal isize _J2(MAP_PROC,_add_entry)(MAP_NAME *h, HashKey key) {
MAP_ENTRY e = {0};
e.key = key;
e.next = -1;
array_add(&h->entries, e);
return h->entries.count-1;
}
gb_internal MapFindResult _J2(MAP_PROC,_find)(MAP_NAME *h, HashKey key) {
MapFindResult fr = {-1, -1, -1};
if (h->hashes.count > 0) {
fr.hash_index = key.key % h->hashes.count;
fr.entry_index = h->hashes.e[fr.hash_index];
while (fr.entry_index >= 0) {
if (hash_key_equal(h->entries.e[fr.entry_index].key, key)) {
return fr;
}
fr.entry_prev = fr.entry_index;
fr.entry_index = h->entries.e[fr.entry_index].next;
}
}
return fr;
}
gb_internal MapFindResult _J2(MAP_PROC,_find_from_entry)(MAP_NAME *h, MAP_ENTRY *e) {
MapFindResult fr = {-1, -1, -1};
if (h->hashes.count > 0) {
fr.hash_index = e->key.key % h->hashes.count;
fr.entry_index = h->hashes.e[fr.hash_index];
while (fr.entry_index >= 0) {
if (&h->entries.e[fr.entry_index] == e) {
return fr;
}
fr.entry_prev = fr.entry_index;
fr.entry_index = h->entries.e[fr.entry_index].next;
}
}
return fr;
}
gb_internal b32 _J2(MAP_PROC,_full)(MAP_NAME *h) {
return 0.75f * h->hashes.count <= h->entries.count;
}
gb_inline void _J2(MAP_PROC,grow)(MAP_NAME *h) {
isize new_count = ARRAY_GROW_FORMULA(h->entries.count);
_J2(MAP_PROC,rehash)(h, new_count);
}
void _J2(MAP_PROC,rehash)(MAP_NAME *h, isize new_count) {
isize i, j;
MAP_NAME nh = {0};
_J2(MAP_PROC,init)(&nh, h->hashes.allocator);
array_resize(&nh.hashes, new_count);
array_reserve(&nh.entries, h->entries.count);
for (i = 0; i < new_count; i++) {
nh.hashes.e[i] = -1;
}
for (i = 0; i < h->entries.count; i++) {
MAP_ENTRY *e = &h->entries.e[i];
MapFindResult fr;
if (nh.hashes.count == 0) {
_J2(MAP_PROC,grow)(&nh);
}
fr = _J2(MAP_PROC,_find)(&nh, e->key);
j = _J2(MAP_PROC,_add_entry)(&nh, e->key);
if (fr.entry_prev < 0) {
nh.hashes.e[fr.hash_index] = j;
} else {
nh.entries.e[fr.entry_prev].next = j;
}
nh.entries.e[j].next = fr.entry_index;
nh.entries.e[j].value = e->value;
if (_J2(MAP_PROC,_full)(&nh)) {
_J2(MAP_PROC,grow)(&nh);
}
}
_J2(MAP_PROC,destroy)(h);
*h = nh;
}
gb_inline MAP_TYPE *_J2(MAP_PROC,get)(MAP_NAME *h, HashKey key) {
isize index = _J2(MAP_PROC,_find)(h, key).entry_index;
if (index >= 0) {
return &h->entries.e[index].value;
}
return NULL;
}
void _J2(MAP_PROC,set)(MAP_NAME *h, HashKey key, MAP_TYPE value) {
isize index;
MapFindResult fr;
if (h->hashes.count == 0)
_J2(MAP_PROC,grow)(h);
fr = _J2(MAP_PROC,_find)(h, key);
if (fr.entry_index >= 0) {
index = fr.entry_index;
} else {
index = _J2(MAP_PROC,_add_entry)(h, key);
if (fr.entry_prev >= 0) {
h->entries.e[fr.entry_prev].next = index;
} else {
h->hashes.e[fr.hash_index] = index;
}
}
h->entries.e[index].value = value;
if (_J2(MAP_PROC,_full)(h)) {
_J2(MAP_PROC,grow)(h);
}
}
void _J2(MAP_PROC,_erase)(MAP_NAME *h, MapFindResult fr) {
MapFindResult last;
if (fr.entry_prev < 0) {
h->hashes.e[fr.hash_index] = h->entries.e[fr.entry_index].next;
} else {
h->entries.e[fr.entry_prev].next = h->entries.e[fr.entry_index].next;
}
if (fr.entry_index == h->entries.count-1) {
array_pop(&h->entries);
return;
}
h->entries.e[fr.entry_index] = h->entries.e[h->entries.count-1];
last = _J2(MAP_PROC,_find)(h, h->entries.e[fr.entry_index].key);
if (last.entry_prev >= 0) {
h->entries.e[last.entry_prev].next = fr.entry_index;
} else {
h->hashes.e[last.hash_index] = fr.entry_index;
}
}
void _J2(MAP_PROC,remove)(MAP_NAME *h, HashKey key) {
MapFindResult fr = _J2(MAP_PROC,_find)(h, key);
if (fr.entry_index >= 0) {
_J2(MAP_PROC,_erase)(h, fr);
}
}
gb_inline void _J2(MAP_PROC,clear)(MAP_NAME *h) {
array_clear(&h->hashes);
array_clear(&h->entries);
}
#if 1
MAP_ENTRY *_J2(MAP_PROC,multi_find_first)(MAP_NAME *h, HashKey key) {
isize i = _J2(MAP_PROC,_find)(h, key).entry_index;
if (i < 0) {
return NULL;
}
return &h->entries.e[i];
}
MAP_ENTRY *_J2(MAP_PROC,multi_find_next)(MAP_NAME *h, MAP_ENTRY *e) {
isize i = e->next;
while (i >= 0) {
if (hash_key_equal(h->entries.e[i].key, e->key)) {
return &h->entries.e[i];
}
i = h->entries.e[i].next;
}
return NULL;
}
isize _J2(MAP_PROC,multi_count)(MAP_NAME *h, HashKey key) {
isize count = 0;
MAP_ENTRY *e = _J2(MAP_PROC,multi_find_first)(h, key);
while (e != NULL) {
count++;
e = _J2(MAP_PROC,multi_find_next)(h, e);
}
return count;
}
void _J2(MAP_PROC,multi_get_all)(MAP_NAME *h, HashKey key, MAP_TYPE *items) {
isize i = 0;
MAP_ENTRY *e = _J2(MAP_PROC,multi_find_first)(h, key);
while (e != NULL) {
items[i++] = e->value;
e = _J2(MAP_PROC,multi_find_next)(h, e);
}
}
void _J2(MAP_PROC,multi_insert)(MAP_NAME *h, HashKey key, MAP_TYPE value) {
MapFindResult fr;
isize i;
if (h->hashes.count == 0) {
_J2(MAP_PROC,grow)(h);
}
// Make
fr = _J2(MAP_PROC,_find)(h, key);
i = _J2(MAP_PROC,_add_entry)(h, key);
if (fr.entry_prev < 0) {
h->hashes.e[fr.hash_index] = i;
} else {
h->entries.e[fr.entry_prev].next = i;
}
h->entries.e[i].next = fr.entry_index;
h->entries.e[i].value = value;
// Grow if needed
if (_J2(MAP_PROC,_full)(h)) {
_J2(MAP_PROC,grow)(h);
}
}
void _J2(MAP_PROC,multi_remove)(MAP_NAME *h, HashKey key, MAP_ENTRY *e) {
MapFindResult fr = _J2(MAP_PROC,_find_from_entry)(h, e);
if (fr.entry_index >= 0) {
_J2(MAP_PROC,_erase)(h, fr);
}
}
void _J2(MAP_PROC,multi_remove_all)(MAP_NAME *h, HashKey key) {
while (_J2(MAP_PROC,get)(h, key) != NULL) {
_J2(MAP_PROC,remove)(h, key);
}
}
#endif
#undef _J2
#undef MAP_TYPE
#undef MAP_PROC
#undef MAP_NAME
#undef MAP_ENTRY