#include
#include “refcount.h”
#include “map.h”
#define MAP_SIZE 997
struct map_entry {
int key;
void* value; // … reference counted
};
struct map_entry map[MAP_SIZE];
int hash (int key) {
return key % MAP_SIZE;
}
///////////////////
/// Public Interface (see map.h)
void map_put (int key, void* value) {
int h = hash (key);
for (int i=0; i < MAP_SIZE; i++) {
struct map_entry* e = map + ((h+i) % MAP_SIZE);
if (e->key == key) {
// update existing entry
rc_free_ref (e->value); // … release map’s reference on old value
rc_keep_ref (value); // … map holds reference to new value
e->value = value;
break;
} else if (e->key == 0) {
// add new entry
rc_keep_ref (value); // .. map holds reference to new value
e->key = key;
e->value = value;
break;
}
}
}
void* map_get (int key) {
int h = hash (key);
for (int i=0; i < MAP_SIZE; i++) {
struct map_entry* e = map + ((h+i) % MAP_SIZE);
if (e->key == key) {
rc_keep_ref (e->value); // … caller will also hold reference to value
return e->value;
} else if (e->key == 0)
return NULL;
}
return NULL;
}
void map_delete_all() {
for (int i=0; i < MAP_SIZE; i++)
if (map[i].key) {
rc_free_ref (map[i].value); // ... release map's reference to value
map[i].key = 0;
map[i].value = NULL;
}
}