muse/src/services/cache.ts

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import {injectable} from 'inversify';
import {Cache} from '../models/index.js';
import debug from '../utils/debug.js';
type Seconds = number;
type Options = {
expiresIn: Seconds;
key?: string;
};
const futureTimeToDate = (time: Seconds) => new Date(new Date().getTime() + (time * 1000));
@injectable()
export default class CacheProvider {
async wrap<T extends [...any[], Options], F>(func: (...options: any) => Promise<F>, ...options: T): Promise<F> {
if (options.length === 0) {
throw new Error('Missing cache options');
}
const functionArgs = options.slice(0, options.length - 1);
const {
key = JSON.stringify(functionArgs),
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expiresIn,
} = options[options.length - 1] as Options;
if (key.length < 4) {
throw new Error(`Cache key ${key} is too short.`);
}
const cachedResult = await Cache.findByPk(key);
if (cachedResult) {
if (new Date() < cachedResult.expiresAt) {
debug(`Cache hit: ${key}`);
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return JSON.parse(cachedResult.value) as F;
}
await cachedResult.destroy();
}
debug(`Cache miss: ${key}`);
const result = await func(...options as any[]);
// Save result
await Cache.upsert({
key,
value: JSON.stringify(result),
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expiresAt: futureTimeToDate(expiresIn),
});
return result;
}
}