# Cache values in memory

> Store values with CACHE.set() and an expiration, read them with CACHE.get() and clear them with remove() or reset().

Framework: total5
Product: Total.js 5 (total5@0.0.19)
Language: en
Content-SHA256: f39f6142602f34545a96180b8c66d6dffc02dcddad842094041e48d80b4315ea
Snapshot: c0700e321579725c5cf4f5ace1ad7d2866d1b4f93c24a63c0b41b6b7998e976c
Sources: total5-installed@total5@0.0.19
Review: not-recorded

`CACHE` is an in-memory key-value store with expiration. `CACHE.set(key, value, expire)` stores a value (the expiration is a text such as `'10 seconds'` or `'5 minutes'`, default `'5 minutes'`). `CACHE.get(key, default)` returns the value, or the default once it has expired. `CACHE.remove(key)` deletes one key and `CACHE.reset(search)` deletes every key that contains the text.

Use it for results that are expensive to compute and may be a little stale. The cache lives in the process: it is cleared on restart and is not shared between processes.

```js controllers/cache.js
exports.install = function() {
	ROUTE('GET /slow/', slow);
	ROUTE('DELETE /slow/', clear);
};

var computed = 0;

function slow($) {

	var cached = CACHE.get('slow-result');

	if (cached) {
		$.json({ value: cached, cached: true, computed: computed });
		return;
	}

	computed++;
	var value = 'result-' + computed;
	CACHE.set('slow-result', value, '1 second');
	$.json({ value: value, cached: false, computed: computed });
}

function clear($) {
	CACHE.remove('slow-result');
	$.json({ ok: true });
}
```