Overview

A Redis adapter for the node-orm2 ORM.

Redis + Node ~= Peanut Butter + Chocolate :blue_heart:

Usage

Incorporating this Redis adapter into your project is pretty straight forward, provided you're already using node-orm2 today.

If you're not already using node-orm2, please check their Github page for details of how to get started.

After that, you can start working with Redis by requiring this package and calling orm.addAdapter:

var redium = require('redium');

//more code here
orm.addAdapter('redis', redium.adapter);
orm.connect(connectionString, function(err, db){
  //stuff
});

Additionally, it's recommended that you use the supplied plugin, as doing so will enable advanced persistance options:

orm.connect(connectionString, function(err, db){
  //error check
  db.use(redium.plugin);
});

After the plugin is configured (above), you can specify how individual model properties are indexed. Indexing options include:

• ignore - These properties will be persisted, but cannot be queried on directly.
• discrete - Discrete properties are those who have a limited set of values. By default Boolean properties are discrete.
• series - Series is the default for all non-Boolean values, and represents data that is continous in nature. Dates are an excellent conceptual representative of Series.

Each index type has it's unique pros and cons, so it's highly recommended that each application consider their own data set and customize appropriately. To customize the index options, add an indexes section to your model options:

db.define("orders", {
  shipping_address: String,
  total: Number,
  order_date: Date,
  warehouse_code: Number,
  tracking_number: String
}, {
  indexes: {
    warehouse_code: redium.index.discrete,
    tracking_number: redium.index.ignore
  }
});

In the above example, the tracking_number property is not indexed, while the warehouse_code is indexed as a discrete property.

How it works

Under the hood, this Redis adapter makes several assumptions about how your keyspace should be managed. Each persisted model is stored as a Hash, and ancillary sets and sorted sets are created to faciliate searches.

Doing both allows for models to quickly be reconstituted and easily queried, at the cost of slightly more storage space per record.

Keyspace Map

Ideally you should not have to worry about the Redis keys generated and maintained by this adapter. However, in the interest of documenting those keys, should you ever need them:

Primay model keys:

• {model}:id:{uuid} - A Hash containing all the properties and values of a specific instance of a model.

Index keys

• {model}:{prop} - a sorted set whose members are primary model keys.
• {model}:{prop}:sets - if a property is discrete, the set will exist to document all the discrete sets for this property.
• {model}:{prop}-{value} - for discrete sets, this set will exist for a given value containing primary model keys.

Considerations

• Each model has to have an id, it has to be called id, and it'll be assign as a GUID (unless already assigned).
• When querying with a String property, only equalities are supported.
  • This is due to how strings are indexed.
• not-equals (orm.ne) is not supported.
  • No, it will not be supported. Ever.
• Limit & Offset are "supported", but don't make a lot of sense for Redis, YMMV.
  • Because of this, lt, gt, lte, and gte are discouraged for querying against continuous series (e.g. dates) - see the next bullet for more info.
• Each sub-filter has a hard limit of the number of keys it'll match. Any sub-filter exiting this limit will abort the entire filter, and return an error.
  • This is done to prevent queries from running amok. Hard limit is currently 10,000 records.
  • Seriously, this (and the previous bullet on offset & limit) aren't issues - this is Redis, not SQL, find a more natural way to paginate your data!

License

Copyright (c) 2014, Jason Whitehorn All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

• Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
• Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.