// Copyright (c) 2018, Compiler Explorer Authors
// All rights reserved.
//
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// modification, are permitted provided that the following conditions are met:
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//     * Redistributions of source code must retain the above copyright notice,
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// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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import {Buffer} from 'buffer';

import {LRUCache} from 'lru-cache';

import type {GetResult} from '../../types/cache.interfaces.js';

import {BaseCache} from './base.js';

export class InMemoryCache extends BaseCache {
    readonly cacheMb: number;
    private readonly cache: LRUCache<string, Buffer>;

    constructor(cacheName: string, cacheMb: number) {
        super(cacheName, `InMemoryCache(${cacheMb}Mb)`, 'memory');
        this.cacheMb = cacheMb;
        this.cache = new LRUCache({
            maxSize: cacheMb * 1024 * 1024,
            sizeCalculation: n => n.length,
        });
    }

    override statString(): string {
        return `${super.statString()}, LRU has ${this.cache.size} item(s) totalling ${this.cache.calculatedSize} bytes`;
    }

    override async getInternal(key: string): Promise<GetResult> {
        const cached = this.cache.get(key);
        return {hit: !!cached, data: cached};
    }

    override async putInternal(key: string, value: Buffer): Promise<void> {
        this.cache.set(key, value);
    }
}
