Benchmark: Delete or not delete

Tests:

Use delete
const content = '0'.repeat(53000); // ~53kb var cache = {}; let i = 100; // will give us ~5Mb while (i--) { const name = `item-${i}`; cache[name] = content; } // we will delete all 100 items function invalidateItem() { return true; } const invalidatedCache = (cache) => { const updatedCache = {}; Object.assign(updatedCache, cache); Object.keys(cache).filter(invalidateItem).forEach((name) => delete updatedCache[name]); return updatedCache; }; invalidatedCache(cache);
Use undefined
const content = '0'.repeat(53000); // ~53kb var cache = {}; let i = 100; // will give us ~5Mb while (i--) { const name = `item-${i}`; cache[name] = content; } // we will delete all 100 items function invalidateItem() { return true; } const invalidatedCache = (cache) => { const updatedCache = {}; Object.assign(updatedCache, cache); Object.keys(cache).filter(invalidateItem).forEach((name) => { updatedCache[name] = undefined; }); return updatedCache; }; invalidatedCache(cache);
Use filter and reduce
const content = '0'.repeat(53000); // ~53kb var cache = {}; let i = 100; // will give us ~5Mb while (i--) { const name = `item-${i}`; cache[name] = content; } // we will delete all 100 items function invalidateItem() { return true; } const invalidatedCache = (cache) => { const updatedCache = Object.keys(cache).filter(invalidateItem).reduce((cacheClone, key) => { cacheClone[key] = cache[key]; return cacheClone; }, Object.create(null)); return updatedCache; }; invalidatedCache(cache);

Rendered benchmark preparation results:

Previous results

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Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/95.0.4638.69 Safari/537.36

Browser/OS: Chrome 95 on Windows

Delete or not delete (version: 0)