jtc-utils
Version:
Utilities for Japanese Traditional Companies
112 lines (111 loc) • 3.59 kB
JavaScript
export class PackedMap {
map;
init;
constructor(init) {
if (init instanceof Map) {
this.map = init;
}
else {
this.map = new Map();
this.init = init;
}
}
initialize() {
if (!this.init) {
return;
}
const map = new Map();
this.init({
set(key, value) {
const key1 = key >>> 5;
const key2 = key & 0b11111;
let array = map.get(key1);
if (!array) {
array = new Array();
map.set(key1, array);
}
if (!array[key2]) {
array[key2] = value;
}
},
});
for (const [key, value] of map.entries()) {
let flags = 0;
let max = 1;
const filtered = value.filter((item, index) => {
if (item != null) {
flags |= 1 << (31 - index);
if ((item & 0xffff0000) !== 0) {
max = Math.max(max, 4);
}
else if ((item & 0xffffff00) !== 0) {
max = Math.max(max, 2);
}
return true;
}
return false;
});
if (max === 1) {
const array = new Uint8Array(filtered.length + 4);
array[0] = (flags >>> 24) & 0xff;
array[1] = (flags >>> 16) & 0xff;
array[2] = (flags >>> 8) & 0xff;
array[3] = flags & 0xff;
array.set(filtered, 4);
this.map.set(key, array);
}
else if (max === 2) {
const array = new Uint16Array(filtered.length + 2);
array[0] = (flags >>> 16) & 0xffff;
array[1] = flags & 0xffff;
array.set(filtered, 2);
this.map.set(key, array);
}
else {
const array = new Uint32Array(filtered.length + 1);
array[0] = flags;
array.set(filtered, 1);
this.map.set(key, array);
}
}
this.init = undefined;
}
get(key) {
this.initialize();
const key1 = key >>> 5;
const key2 = key & 0b11111;
const array = this.map?.get(key1);
if (array) {
if (array.BYTES_PER_ELEMENT === 1) {
const shifted = ((array[0] << 24) | (array[1] << 16) | (array[2] << 8) | array[3]) >>>
(31 - key2);
if ((shifted & 0x1) !== 0) {
return array[bitcount(shifted) - 1 + 4];
}
}
else if (array.BYTES_PER_ELEMENT === 2) {
const shifted = ((array[0] << 16) | array[1]) >>> (31 - key2);
if ((shifted & 0x1) !== 0) {
return array[bitcount(shifted) - 1 + 2];
}
}
else {
const shifted = array[0] >>> (31 - key2);
if ((shifted & 0x1) !== 0) {
return array[bitcount(shifted) - 1 + 1];
}
}
}
}
get size() {
return this.map?.size ?? 0;
}
}
function bitcount(n) {
n = n - ((n >>> 1) & 0x55555555);
n = (n & 0x33333333) + ((n >>> 2) & 0x33333333);
n = (n + (n >>> 4)) & 0x0f0f0f0f;
n = n + (n >>> 8);
n = n + (n >>> 16);
return n & 0x3f;
}