@remotion/gif
Version:
Embed GIFs in a Remotion video
283 lines (271 loc) • 8.65 kB
JavaScript
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.QuickLRU = void 0;
class QuickLRU {
/**
The maximum number of milliseconds an item should remain in the cache.
@default Infinity
By default, `maxAge` will be `Infinity`, which means that items will never expire.
Lazy expiration upon the next write or read call.
Individual expiration of an item can be specified by the `set(key, value, maxAge)` method.
*/
maxAge;
/**
The maximum number of items before evicting the least recently used items.
*/
maxSize;
/**
Called right before an item is evicted from the cache.
Useful for side effects or for items like object URLs that need explicit cleanup (`revokeObjectURL`).
*/
onEviction;
_size;
cache;
oldCache;
/**
Simple ["Least Recently Used" (LRU) cache](https://en.m.wikipedia.org/wiki/Cache_replacement_policies#Least_Recently_Used_.28LRU.29).
The instance is an [`Iterable`](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Iteration_protocols) of `[key, value]` pairs so you can use it directly in a [`for…of`](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Statements/for...of) loop.
@example
```
import { QuickLRU } from 'quick-lru-ts';
const lru = new QuickLRU({maxSize: 1000});
lru.set('🦄', '🌈');
lru.has('🦄');
//=> true
lru.get('🦄');
//=> '🌈'
```
*/
constructor(options) {
if (!(options.maxSize && options.maxSize > 0)) {
throw new TypeError('`maxSize` must be a number greater than 0');
}
if (typeof options.maxAge === 'number' && options.maxAge === 0) {
throw new TypeError('`maxAge` must be a number greater than 0');
}
this.maxSize = options.maxSize;
this.maxAge = options.maxAge || Number.POSITIVE_INFINITY;
this.onEviction = options.onEviction;
this.cache = new Map();
this.oldCache = new Map();
this._size = 0;
}
_emitEvictions(cache) {
if (typeof this.onEviction !== 'function') {
return;
}
for (const [key, item] of cache) {
this.onEviction(key, item.value);
}
}
_deleteIfExpired(key, item) {
if (item === undefined)
return true;
if (typeof item.expiry === 'number' && item.expiry <= Date.now()) {
if (typeof this.onEviction === 'function') {
this.onEviction(key, item.value);
}
return this.delete(key);
}
return false;
}
_getOrDeleteIfExpired(key, item) {
const deleted = this._deleteIfExpired(key, item);
if (deleted === false) {
return item.value;
}
}
_getItemValue(key, item) {
if (item === undefined)
return undefined;
return item.expiry ? this._getOrDeleteIfExpired(key, item) : item.value;
}
_peek(key, cache) {
const item = cache.get(key);
return this._getItemValue(key, item);
}
_set(key, value) {
this.cache.set(key, value);
this._size++;
if (this._size >= this.maxSize) {
this._size = 0;
this._emitEvictions(this.oldCache);
this.oldCache = this.cache;
this.cache = new Map();
}
}
_moveToRecent(key, item) {
this.oldCache.delete(key);
this._set(key, item);
}
*_entriesAscending() {
for (const item of this.oldCache) {
const [key, value] = item;
if (!this.cache.has(key)) {
const deleted = this._deleteIfExpired(key, value);
if (deleted === false) {
yield item;
}
}
}
for (const item of this.cache) {
const [key, value] = item;
const deleted = this._deleteIfExpired(key, value);
if (deleted === false) {
yield item;
}
}
}
/**
Get an item.
@returns The stored item or `undefined`.
*/
get(key) {
if (this.cache.has(key)) {
const item = this.cache.get(key);
return this._getItemValue(key, item);
}
if (this.oldCache.has(key)) {
const item = this.oldCache.get(key);
if (this._deleteIfExpired(key, item) === false) {
this._moveToRecent(key, item);
return item.value;
}
}
}
set(key, value, { maxAge = this.maxAge } = {}) {
const expiry = typeof maxAge === 'number' && maxAge !== Number.POSITIVE_INFINITY
? Date.now() + maxAge
: undefined;
if (this.cache.has(key)) {
this.cache.set(key, {
value,
expiry,
});
}
else {
this._set(key, { value, expiry });
}
}
has(key) {
if (this.cache.has(key)) {
return !this._deleteIfExpired(key, this.cache.get(key));
}
if (this.oldCache.has(key)) {
return !this._deleteIfExpired(key, this.oldCache.get(key));
}
return false;
}
peek(key) {
if (this.cache.has(key)) {
return this._peek(key, this.cache);
}
if (this.oldCache.has(key)) {
return this._peek(key, this.oldCache);
}
}
delete(key) {
const deleted = this.cache.delete(key);
if (deleted) {
this._size--;
}
return this.oldCache.delete(key) || deleted;
}
clear() {
this.cache.clear();
this.oldCache.clear();
this._size = 0;
}
resize(maxSize) {
if (!(maxSize && maxSize > 0)) {
throw new TypeError('`maxSize` must be a number greater than 0');
}
const items = [...this._entriesAscending()];
const removeCount = items.length - maxSize;
if (removeCount < 0) {
this.cache = new Map(items);
this.oldCache = new Map();
this._size = items.length;
}
else {
if (removeCount > 0) {
this._emitEvictions(items.slice(0, removeCount));
}
this.oldCache = new Map(items.slice(removeCount));
this.cache = new Map();
this._size = 0;
}
this.maxSize = maxSize;
}
*keys() {
for (const [key] of this) {
yield key;
}
}
*values() {
for (const [, value] of this) {
yield value;
}
}
*[Symbol.iterator]() {
for (const item of this.cache) {
const [key, value] = item;
const deleted = this._deleteIfExpired(key, value);
if (deleted === false) {
yield [key, value.value];
}
}
for (const item of this.oldCache) {
const [key, value] = item;
if (!this.cache.has(key)) {
const deleted = this._deleteIfExpired(key, value);
if (deleted === false) {
yield [key, value.value];
}
}
}
}
/**
Iterable for all entries, starting with the newest (descending in recency).
*/
*entriesDescending() {
let items = [...this.cache];
for (let i = items.length - 1; i >= 0; --i) {
const item = items[i];
const [key, value] = item;
const deleted = this._deleteIfExpired(key, value);
if (deleted === false) {
yield [key, value.value];
}
}
items = [...this.oldCache];
for (let i = items.length - 1; i >= 0; --i) {
const item = items[i];
const [key, value] = item;
if (!this.cache.has(key)) {
const deleted = this._deleteIfExpired(key, value);
if (deleted === false) {
yield [key, value.value];
}
}
}
}
*entriesAscending() {
for (const [key, value] of this._entriesAscending()) {
yield [key, value.value];
}
}
get size() {
if (!this._size) {
return this.oldCache.size;
}
let oldCacheSize = 0;
for (const key of this.oldCache.keys()) {
if (!this.cache.has(key)) {
oldCacheSize++;
}
}
return Math.min(this._size + oldCacheSize, this.maxSize);
}
}
exports.QuickLRU = QuickLRU;