static bool
gu_map_entry_is_free(GuMap* map, GuMapData* data, size_t idx)
{
if (idx == data->zero_idx) {
return false;
} else if (map->kind == GU_MAP_ADDR) {
const void* key = ((const void**)data->keys)[idx];
return key == NULL;
} else if (map->kind == GU_MAP_WORD) {
GuWord key = ((GuWord*)data->keys)[idx];
return key == 0;
}
gu_assert(map->kind == GU_MAP_GENERIC);
const void* key = &data->keys[idx * map->key_size];
return gu_map_buf_is_zero(key, map->key_size);
}
static bool
gu_map_lookup(GuMap* map, const void* key, size_t* idx_out)
{
size_t n = map->data.n_entries;
switch (map->kind) {
case GU_MAP_GENERIC: {
GuHasher* hasher = map->hasher;
GuEquality* eq = (GuEquality*) hasher;
GuHash hash = hasher->hash(hasher, key);
size_t idx = hash % n;
size_t offset = (hash % (n - 2)) + 1;
size_t key_size = map->key_size;
while (true) {
void* entry_key = &map->data.keys[idx * key_size];
if (gu_map_buf_is_zero(entry_key, key_size) &&
map->data.zero_idx != idx) {
*idx_out = idx;
return false;
} else if (eq->is_equal(eq, key, entry_key)) {
*idx_out = idx;
return true;
}
idx = (idx + offset) % n;
}
gu_impossible();
break;
}
case GU_MAP_ADDR: {
GuHash hash = (GuHash) key;
size_t idx = hash % n;
size_t offset = (hash % (n - 2)) + 1;
while (true) {
const void* entry_key =
((const void**)map->data.keys)[idx];
if (entry_key == NULL && map->data.zero_idx != idx) {
*idx_out = idx;
return false;
} else if (entry_key == key) {
*idx_out = idx;
return true;
}
idx = (idx + offset) % n;
}
gu_impossible();
break;
}
case GU_MAP_WORD: {
GuWord w = *(const GuWord*)key;
GuHash hash = (GuHash) w;
size_t idx = hash % n;
size_t offset = (hash % (n - 2)) + 1;
while (true) {
GuWord entry_key = ((GuWord*)map->data.keys)[idx];
if (entry_key == 0 && map->data.zero_idx != idx) {
*idx_out = idx;
return false;
} else if (entry_key == w) {
*idx_out = idx;
return true;
}
idx = (idx + offset) % n;
}
gu_impossible();
break;
}
case GU_MAP_STRING: {
GuHasher* hasher = map->hasher;
GuEquality* eq = (GuEquality*) hasher;
GuHash hash = hasher->hash(hasher, key);
size_t idx = hash % n;
size_t offset = (hash % (n - 2)) + 1;
while (true) {
GuString entry_key =
((GuString*)map->data.keys)[idx];
if (entry_key == NULL && map->data.zero_idx != idx) {
*idx_out = idx;
return false;
} else if (eq->is_equal(eq, key, entry_key)) {
*idx_out = idx;
return true;
}
idx = (idx + offset) % n;
}
gu_impossible();
break;
}
default:
gu_impossible();
}
gu_impossible();
return false;
}
