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#include "map.h"
#include "crash.h"
#include <stdlib.h>
#define DEFAULT_CAPACITY 16
void map_init(
map_t* map,
hash_func_t hash_func,
eq_func_t eq_func,
double load_limit
) {
map_init_capacity(
map, hash_func, eq_func, load_limit, DEFAULT_CAPACITY);
}
void map_init_capacity(
map_t* map,
hash_func_t hash_func,
eq_func_t eq_func,
double load_limit,
size_t capacity
) {
map->hash_func = hash_func;
map->eq_func = eq_func;
map->load_limit = load_limit;
map->size = 0;
map->__num_buckets = capacity / load_limit + 1;
map->__buckets = calloc(map->__num_buckets, sizeof(struct __map_entry*));
if (map->__buckets == NULL)
crash(
"Out of memory allocating %ld hash buckets\n", map->__num_buckets);
}
void map_destroy(map_t* map) {
for (size_t i = 0; i < map->__num_buckets; i++) {
struct __map_entry* node = map->__buckets[i];
while (node != NULL) {
struct __map_entry* next = node->next;
free(node);
node = next;
}
}
free(map->__buckets);
}
static struct __map_entry** fetch_map_slot(const map_t* map, const void* key) {
struct __map_entry** bucket =
&map->__buckets[map->hash_func(key) % map->__num_buckets];
struct __map_entry* cur = *bucket;
if (cur == NULL || map->eq_func(key, cur->key)) return bucket;
while (cur->next != NULL && !map->eq_func(key, cur->next->key)) {
cur = cur->next;
}
return &cur->next;
}
bool map_contains(const map_t* map, const void *key) {
return *fetch_map_slot(map, key) != NULL;
}
void* map_get(const map_t* map, const void* key) {
return map_get_or_default(map, key, NULL);
}
void* map_get_or_default(const map_t* map, const void* key, void* default_val) {
struct __map_entry* entry = *fetch_map_slot(map, key);
return entry == NULL ? default_val : entry->value;
}
static void rehash_map(map_t* map) {
size_t old_num_buckets = map->__num_buckets;
struct __map_entry** old_buckets = map->__buckets;
map->__num_buckets <<= 1;
map->__buckets = calloc(map->__num_buckets, sizeof(struct __map_entry*));
for (size_t i = 0; i < old_num_buckets; i++) {
struct __map_entry* entry = old_buckets[i];
while (entry != NULL) {
struct __map_entry* next = entry->next;
entry->next = NULL;
struct __map_entry** slot = fetch_map_slot(map, entry->key);
*slot = entry;
entry = next;
}
}
free(old_buckets);
}
static void map_insert_allocating(
map_t* map,
struct __map_entry** slot,
void* key,
void* val
) {
if ((double) ++map->size / map->__num_buckets > map->load_limit) {
rehash_map(map);
slot = fetch_map_slot(map, key);
}
struct __map_entry* entry = calloc(1, sizeof(struct __map_entry));
if (entry == NULL)
crash("Out of memory allocating hash entry\n");
entry->key = key;
entry->value = val;
entry->next = NULL;
*slot = entry;
}
void* map_compute_if_absent(map_t* map, void* key, void* default_val) {
struct __map_entry** slot = fetch_map_slot(map, key);
struct __map_entry* entry = *slot;
if (entry != NULL) return entry->value;
map_insert_allocating(map, slot, key, default_val);
return default_val;
}
void map_put(map_t* map, void* key, void* val) {
struct __map_entry** slot = fetch_map_slot(map, key);
struct __map_entry* entry = *slot;
if (entry != NULL) {
entry->value = val;
return;
}
map_insert_allocating(map, slot, key, val);
}
void* map_remove(map_t* map, const void* key) {
struct __map_entry** slot = fetch_map_slot(map, key);
struct __map_entry* entry = *slot;
if (entry == NULL) return NULL;
map->size--;
*slot = entry->next;
void* rv = entry->value;
free(entry);
return rv;
}
void map_foreach_readonly(
map_t* map,
map_foreach_func_t foreach_func,
void* data
) {
for (size_t i = 0; i < map->__num_buckets; i++) {
struct __map_entry* entry = map->__buckets[i];
while (entry != NULL) {
foreach_func(entry->key, entry->value, data);
entry = entry->next;
}
}
}
void map_foreach_readwrite(
map_t* map,
map_foreach_func_t foreach_func,
void* data
) {
void** keys = malloc(map->size * sizeof(void*));
void** vals = malloc(map->size * sizeof(void*));
size_t idx = 0;
for (size_t i = 0; i < map->__num_buckets; i++) {
struct __map_entry* entry = map->__buckets[i];
while (entry != NULL) {
keys[idx] = entry->key;
vals[idx++] = entry->value;
entry = entry->next;
}
}
for (size_t i = 0; i < idx; i++) {
foreach_func(keys[i], vals[i], data);
}
free(keys);
free(vals);
}
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