redis-rating

A Redis module that helps you calculate the real rating from positive/negative rating feedbacks.

The blog post how not to sort by average rating described the algorithm we use.

Install

Build from source:

$ git clone https://github.com/poga/redis-rating.git
$ cd redis-rating
$ cargo build --release
$ cp target/release/libredis_rating.dylib /path/to/modules/

Run Redis pointing to the newly built module:

redis-server --loadmodule /path/to/modules/libredis_rating.so

Alternatively add the following to a redis.conf file:

loadmodule /path/to/modules/libredis_rating.so

Usage

RT.RATEPOS

RT.RATEPOS <key> [<count>]

Add count positive rating to key. count is default to 1.

Response

The command will respond with an array of integers. The first integer is the total number of positive votes. The second integer is the total number of votes.

RT.RATENEG

RT.RATEPOS <key> [<count>]

Add count negative rating to key. count is default to 1.

Response

The command will respond with an array of integers. The first integer is the total number of positive votes. The second integer is the total number of votes.

RT.GET

RT.RATEPOS <key>

Estimate the Real rating of the given key. Rating = Lower bound of Wilson score confidence interval for a Bernoulli parameter

Response

Returns a double, which is the estimated rating of the key.

License

This module is based on brandur's redis-cell.

The following files is copied from brandur's project with minor modification. Therefore preserve the original license

The MIT License, Copyright (c) 2016 Brandur and contributors
* `src/redis/*`
* `src/error.rs`
* `src/marcos.rs`
* `build.rs`

Everything else is licensed under The MIT License (Chieh Po).