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aggregate

Aggregate function calls accross a tick

Aggregate.js

ATTENTION: Still basically untested.

Making aggregating multiple similar asynchronous requests easy.

During a tick calls to specially wrapped functions are aggregated. The aggregated function is then executed exactly once. The results are demultiplexed to the individual callers.

A typical usage scenario might be fetching data about single users:

var getUsers = function(ids, callbackWithUserMap) {
  // some database call resulting in
  // callbackWithUserMap(null, {id1: user1, id2: user2});
}

// in multiple concurrent requests
getUsers([1,2,3], callback);
getUsers([2,3,4], callback);
getUsers([2,3], callback);

With the help of this libary, the actual get method only gets called once with [1,2,3,4] while the results are properly dispatched to the separate callers.

var aggregate = require('aggregate');

var getUsers = aggregate(getUsers);

And you get a convenience function for single users for free:

var getUser = getUsers.forSingleId();

getUser(3, function(err,user) {
});

TODO

More concrete example with benchmark.

Gotchas

  • Only use aggregated functions if you do not need transactional guarantees or similar.

  • Logging could be removed to get rid of overhead and unecessary depedencies.

  • CoffeeScript required.