statto-backend

An abstract statto-backend which provides common tests.

Synopsis

Imagine that you'd like to implement a backend using a database called 'FreshDB'.

var util = require('util')
var stattoBackend = require('statto-backend')

function StattoBackendFreshDB() {
    // ... implementation details ...
}

util.inherits(StattoBackendFreshDB, stattoBackend.StattoBackendAbstract)

Who is this package for?

This package should be used by developers writing a new backend for statto. For implementation examples, please see the following packages:

• statto-backend-memory - for testing purposes
• statto-backend-fs - for a simple implementation example
• statto-backend-leveldb - a fast local backend
• statto-backend-mongodb - using MongoDB (coming soon)
• statto-backend-postgres - using Postgres (coming soon)

All of these packages also pass the test suite contained in this package. Again see these other projects for further details.

Implementing a Backend

Many functions within a backend are implemented (naively) by the stattoBackend.StattoBackendAbstract class. This means two things:

1. You only have to implement a few functions to get a fully working backend
2. You can rely on the abstract class to implement the rest of the interface properly

However:

1. You may want to implement more methods so that you can make efficiency gains that the database affords you

Methods

To get a fully working interface using the stattoBackend.StattoBackendAbstract class, you just need to implement:

• .addRaw(raw, callback) - should store the raw stats into the datastore
  • raw - the raw stats emitted by the statto server
  • callback - the callback to which any error is passed, no other data
• .getRaws(date, callback) - should retrieve all raw stats stored for this timestamp
  • date - a date or ts for which records should be retrieved (where ts ~~ 2015-04-04T00:53:15.000Z)
  • callback - a fn(err, rawArray) which is called back with an array of stats for this timestamp
• .setStats(stats, callback) - should store the processed stats into the datastore
  • stats - the processed stats created from all the raw stats for the same timestamp
  • callback - the callback to which any error is passed, no other data
• .getStats(date, callback) - should retrieve the processed stats stored for this timestamp
  • date - a date or ts for which records should be retrieved (where ts ~~ 2015-04-04T00:53:15.000Z)
  • callback - a fn(err, stats) which is called back with the stats for this timestamp

Methods implemented by stattoBackend.StattoBackendAbstract:

• .getStats(date, callback) - should retrieve the merged stats for this timestamp
  • date - a date or ts for which the stats record should be retrieved (where ts ~~ 2015-04-04T00:53:15.000Z)
  • callback - a fn(err, stats) which is called back with the stats for this timestamp

Author

Written by Andrew Chilton - Twitter.

Written for Tynio.

License

The MIT License (MIT). Copyright 2015 Tynio Ltd.

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