dpd redis cache

on get.js

if(!ctx.server.redisClient) {
    var redis = require('redis');
    ctx.server.redisClient = redis.createClient(global.process.env.REDIS_URL);
}

if (!internal || !query.key) return;
//console.log('cache getting', query.key);

$addCallback();
ctx.server.redisClient.get(query.key, function(err, value) {
    if (err || !value) {
      ctx.res.statusCode = 404;
      $finishCallback();
      return;
    }
    //console.log('got redis cache item for', query.key, value.length);
    setResult(JSON.parse(value));
    $finishCallback();
});

on post.js

if(!ctx.server.redisClient) {
    var redis = require('redis');
    ctx.server.redisClient = redis.createClient(global.process.env.REDIS_URL);
}

if (!internal || !body.key) return;
console.log('cache setting', body.key);

$addCallback();
ctx.server.redisClient.set(body.key, JSON.stringify(body.data), function(err) {
    if (err) {
        console.error(err);
    }
    ctx.server.redisClient.expire(body.key, 60); // expire key in 60 seconds

    setResult(body.data);
    $finishCallback();
});

Create a dpd-event with the above code, name it 'cache'.

Use it like:

dpd.cache.get({key: 'some cache key'}).catch(err => { 
  // oops, not cached, cache it now... 
  var data = computeExpensiveValue();
  return dpd.cache.post({key: 'some cache key', data: data })
}).then(expensiveValue => { 
  // do something with the cached value, which will now be cached as well

})