volos-quota-memory

In-memory provider for Quota enforcement in the Volos system.

Usage no npm install needed!

<script type="module">
  import volosQuotaMemory from 'https://cdn.skypack.dev/volos-quota-memory';
</script>

README

volos-quota-memory

This is a memory-backed implementation of quota support for Volos.

Once initialized, the interface to the module is exactly what is in the "volos-quota-common" module. See that module for detailed docs.

Initialization

To initialize a quota, you call "create" on the exported module and pass a single "options" object. It can contain the following parameters:

  • timeUnit: How often the quota resets -- may be minute, hour, day, week, or month
  • interval: Works with the timeUnit to determine how often the quota resets. For instance, every 5 days or 2 weeks.
  • startTime: A time at which the quota calculations should begin. For instance, if there is no start time then a quota set to reset in "one day" will reset 24 hours after the first message is received, but if the start time is set to the top of the hour on some day, then the quota will always reset at the top of the hour. Start time is not allowed for "month" timeUnit as it always uses Gregorian month boundaries.
  • allow: The maximum number of requests to allow. This may be overridden on each "apply" call if desired.

Once the quota has been initialized, the module that is returned has the programming interface defined by the "volos-quota-common" module.

Example

var quotaModule = require('volos-quota-memory');
var quota = quotaModule.create({
  timeUnit: 'day',
  interval: 1,
  allow: 10
  });

quota.apply({ identifier: 'Foo', weight: 1 }, function(err, result) {
  if (err) {
    throw err;
  } else {
    console.log('Quota status: %s', result.isAllowed);
  }
});