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// Copyright (c) 2018, Compiler Explorer Authors
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
import { BaseCache } from './base';
// A write-through multiple cache.
// Writes get pushed to all caches, but reads are serviced from the first cache that returns
// a hit.
export class MultiCache extends BaseCache {
constructor(cacheName, ...upstream) {
super(cacheName, 'Multi', 'multi');
this.countersEnabled = false;
this.upstream = upstream;
}
statString() {
return `${super.statString()}. ${this.upstream.map(c => `${c.name}: ${c.statString()}`).join('. ')}`;
}
async getInternal(key) {
for (const cache of this.upstream) {
const result = await cache.get(key);
// TODO: could propagate hits to lower-level caches. But that's a lot of work and it's not
// clear to me it is better than just serving from the lowest-level cache.
if (result.hit) return result;
}
return {hit: false};
}
putInternal(object, value, creator) {
return Promise.all(this.upstream.map(cache => {
return cache.put(object, value, creator);
}));
}
}