test/cache-tests.js

// Copyright (c) 2018, Compiler Explorer Authors
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import AWS from 'aws-sdk-mock';
import temp from 'temp';

import { createCacheFromConfig } from '../lib/cache/from-config';
import { InMemoryCache } from '../lib/cache/in-memory';
import { MultiCache } from '../lib/cache/multi';
import { NullCache } from '../lib/cache/null';
import { OnDiskCache } from '../lib/cache/on-disk';
import { S3Cache } from '../lib/cache/s3';

import { fs, path } from './utils';

function newTempDir() {
    temp.track(true);
    return temp.mkdirSync({prefix: 'compiler-explorer-cache-tests', dir: process.env.tmpDir});
}

function basicTests(factory) {
    it('should start empty', () => {
        const cache = factory();
        cache.stats().should.eql({hits: 0, puts: 0, gets: 0});
        return cache.get('not a key', 'subsystem').should.eventually.contain({hit: false})
            .then((x) => {
                cache.stats().should.eql({hits: 0, puts: 0, gets: 1});
                return x;
            });
    });

    it('should store and retrieve strings', () => {
        const cache = factory();
        return cache.put('a key', 'a value', 'bob')
            .then(() => {
                cache.stats().should.eql({hits: 0, puts: 1, gets: 0});
                return cache.get('a key').should.eventually.eql({
                    hit: true,
                    data: Buffer.from('a value'),
                });
            }).then(x => {
                cache.stats().should.eql({hits: 1, puts: 1, gets: 1});
                return x;
            });
    });

    it('should store and retrieve binary buffers', () => {
        const cache = factory();
        const buffer = Buffer.alloc(2 * 1024);
        buffer.fill('@');
        return cache.put('a key', buffer, 'bob')
            .then(() => {
                cache.stats().should.eql({hits: 0, puts: 1, gets: 0});
                return cache.get('a key').should.eventually.eql({
                    hit: true,
                    data: buffer,
                });
            }).then(x => {
                cache.stats().should.eql({hits: 1, puts: 1, gets: 1});
                return x;
            });
    });
}

describe('In-memory caches', () => {
    basicTests(() => new InMemoryCache('test', 10));
    it('should give extra stats', () => {
        const cache = new InMemoryCache('test', 1);
        cache.statString().should.equal(
            '0 puts; 0 gets, 0 hits, 0 misses (0.00%), LRU has 0 item(s) totalling 0 bytes');
    });

    it('should evict old objects', () => {
        const cache = new InMemoryCache('test', 1);
        return cache.put('a key', 'a value', 'bob')
            .then(() => {
                const promises = [];
                const oneK = ''.padEnd(1024);
                for (let i = 0; i < 1024; i++) {
                    promises.push(cache.put(`key${i}`, oneK));
                }
                return Promise.all(promises);
            })
            .then(() => {
                return cache.get('a key').should.eventually.contain({hit: false});
            });
    });
});

describe('Multi caches', () => {
    basicTests(() => new MultiCache(
        'test',
        new InMemoryCache('test', 10),
        new InMemoryCache('test', 20),
        new InMemoryCache('test', 30)));

    it('should write through', () => {
        const subCache1 = new InMemoryCache('test', 1);
        const subCache2 = new InMemoryCache('test', 1);
        const cache = new MultiCache('test', subCache1, subCache2);
        return cache.put('a key', 'a value', 'bob')
            .then(() => {
                return Promise.all([
                    cache.get('a key').should.eventually.eql({hit: true, data: Buffer.from('a value')}),
                    subCache1.get('a key').should.eventually.eql({hit: true, data: Buffer.from('a value')}),
                    subCache2.get('a key').should.eventually.eql({hit: true, data: Buffer.from('a value')}),
                ]);
            });
    });

    it('services from the first cache hit', async () => {
        const subCache1 = new InMemoryCache('test', 1);
        const subCache2 = new InMemoryCache('test', 1);
        // Set up caches with deliberately skew values for the same key.
        subCache1.put('a key', 'cache1');
        subCache2.put('a key', 'cache2');
        const cache = new MultiCache('test', subCache1, subCache2);
        await cache.get('a key').should.eventually.eql({hit: true, data: Buffer.from('cache1')});

        subCache1.hits.should.equal(1);
        subCache1.gets.should.equal(1);
        subCache2.hits.should.equal(0);
        subCache2.gets.should.equal(0);

        await subCache1.get('a key').should.eventually.eql({hit: true, data: Buffer.from('cache1')});
        await subCache2.get('a key').should.eventually.eql({hit: true, data: Buffer.from('cache2')});
    });
});

describe('On disk caches', () => {
    basicTests(() => new OnDiskCache('test', newTempDir(), 10));
    it('should evict old objects', () => {
        const tempDir = newTempDir();
        const cache = new OnDiskCache('test', tempDir, 1);
        return cache.put('a key', 'a value', 'bob')
            .then(() => {
                const promises = [];
                const oneHundredK = ''.padEnd(1024 * 100);
                for (let i = 0; i < 12; i++) {
                    promises.push(cache.put(`key${i}`, oneHundredK));
                }
                return Promise.all(promises);
            })
            .then(() => {
                return cache.get('a key').should.eventually.contain({hit: false});
            });
    });

    it('should handle existing data', () => {
        const tempDir = newTempDir();
        fs.writeFileSync(path.join(tempDir, 'abcdef'), 'this is abcdef');
        fs.mkdirSync(path.join(tempDir, 'path'));
        fs.writeFileSync(path.join(tempDir, 'path', 'test'), 'this is path/test');
        const cache = new OnDiskCache('test', tempDir, 1);
        return Promise.all([
            cache.get('abcdef').should.eventually.eql({hit: true, data: Buffer.from('this is abcdef')}),
            cache.get(path.join('path', 'test')).should.eventually.eql({
                hit: true,
                data: Buffer.from('this is path/test'),
            })]);
    });

    // MRG ideally handle the case of pre-populated stuff overflowing the size
    // and test sorting by mtime, but that might be too tricky.
});

const S3FS = {};

function setup() {
    beforeEach(() => {
        AWS.mock('S3', 'getObject', (params, callback) => {
            params.Bucket.should.equal('test.bucket');
            const result = S3FS[params.Key];
            if (!result) {
                const error = new Error('Not found');
                error.code = 'NoSuchKey';
                callback(error);
            } else {
                callback(null, {Body: result});
            }
        });
        AWS.mock('S3', 'putObject', (params, callback) => {
            params.Bucket.should.equal('test.bucket');
            S3FS[params.Key] = params.Body;
            callback(null, {});
        });

    });
    afterEach(() => {
        AWS.restore();
    });
}

describe('S3 tests', () => {
    setup();
    basicTests(() => new S3Cache('test', 'test.bucket', 'cache', 'uk-north-1'));
    // BE VERY CAREFUL - the below can be used with sufficient permissions to test on prod (With mocks off)...
    // basicTests(() => new S3Cache(''test', storage.godbolt.org', 'cache', 'us-east-1'));
});

describe('Config tests', () => {
    setup();
    it('should create null cache on empty config', () => {
        const cache = createCacheFromConfig('name', '');
        cache.constructor.should.eql(NullCache);
        cache.cacheName.should.eql('name');
    });
    it('should throw on bad types', () => {
        (() => createCacheFromConfig('test', 'InMemory')).should.throw();
        (() => createCacheFromConfig('test', 'NotAType()')).should.throw();
    });
    it('should create in memory caches', () => {
        const cache = createCacheFromConfig('test', 'InMemory(123)');
        cache.constructor.should.eql(InMemoryCache);
        cache.cacheMb.should.equal(123);
        (() => createCacheFromConfig('test', 'InMemory()')).should.throw();
        (() => createCacheFromConfig('test', 'InMemory(argh)')).should.throw();
        (() => createCacheFromConfig('test', 'InMemory(123,yibble)')).should.throw();
    });
    it('should create on disk caches', () => {
        const tempDir = newTempDir();
        const cache = createCacheFromConfig('test', `OnDisk(${tempDir},456)`);
        cache.constructor.should.eql(OnDiskCache);
        cache.path.should.equal(tempDir);
        cache.cacheMb.should.equal(456);
        (() => createCacheFromConfig('test', 'OnDisk()')).should.throw();
        (() => createCacheFromConfig('test', 'OnDisk(argh,yibble)')).should.throw();
        (() => createCacheFromConfig('test', 'OnDisk(/tmp/moo,456,blah)')).should.throw();
    });
    it('should create S3 caches', () => {
        const cache = createCacheFromConfig('test', `S3(test.bucket,cache,uk-north-1)`);
        cache.constructor.should.eql(S3Cache);
        cache.bucket.should.equal('test.bucket');
        cache.path.should.equal('cache');
        cache.region.should.equal('uk-north-1');
        (() => createCacheFromConfig('test', 'S3()')).should.throw();
        (() => createCacheFromConfig('test', 'S3(argh,yibble)')).should.throw();
        (() => createCacheFromConfig('test', 'S3(/tmp/moo,456,blah,nork)')).should.throw();
    });
    it('should create multi caches', () => {
        const tempDir = newTempDir();
        const cache = createCacheFromConfig('multi', `InMemory(123);OnDisk(${tempDir},456);S3(test.bucket,cache,uk-north-1)`);
        cache.constructor.should.eql(MultiCache);
        cache.upstream.length.should.equal(3);
        cache.upstream[0].constructor.should.eql(InMemoryCache);
        cache.upstream[1].constructor.should.eql(OnDiskCache);
        cache.upstream[2].constructor.should.eql(S3Cache);
        cache.upstream[0].cacheName.should.eql('multi');
        cache.upstream[1].cacheName.should.eql('multi');
        cache.upstream[2].cacheName.should.eql('multi');
    });
});