reds

reds

reds (red-s) is a light-weight Redis search for node.js. This module was originally developed to provide search capabilities for Kue a priority job queue, however it is very much a light general purpose search library that could be integrated into a blog, a documentation server, etc.

Installation

  $ npm install reds

Example

reds acts against arbitrary numeric or string based ids, so you could utilize this library with essentially anything you wish. The following example just uses an array for our "database", containing some strings, which we add to reds by calling reds.add() padding the body of text and an id of some kind, in this case the index.

var strs = [];
strs.push('Tobi wants four dollars');
strs.push('Tobi only wants $4');
strs.push('Loki is really fat');
strs.push('Loki, Jane, and Tobi are ferrets');
strs.push('Manny is a cat');
strs.push('Luna is a cat');
strs.push('Mustachio is a cat');

strs.forEach(function(str, i){ reds.add(str, i); });

To perform a query against reds simply invoke reds.search() with a string, and pass a callback, which receives an array of ids when present, or an empty array otherwise.

reds.search(query = 'Tobi dollars', function(err, ids){
  if (err) throw err;
  console.log('Search results for "%s":', query);
  ids.forEach(function(id){
    console.log('  - %s', strs[id]);
  });
  process.exit();
});

By default reds performs a union of the search words, the previous example would yield the following output:

Search results for "Tobi dollars":
  - Tobi wants four dollars
  - Tobi only wants $4
  - Loki, Jane, and Tobi are ferrets

We can tweak reds to intersect by passing either "intersect" or "and" to reds.search() after the callback, indicating that all the constants computed must be present for the id to match.

reds.search(query = 'tobi dollars', function(err, ids){
  if (err) throw err;
  console.log('Search results for "%s":', query);
  ids.forEach(function(id){
    console.log('  - %s', strs[id]);
  });
  process.exit();
}, 'and');

The intersection would yield the following since only one string contains both "Tobi" and "dollars".

Search results for "tobi dollars":
  - Tobi wants four dollars

About

Currently reds strips stop words and applies the metaphone algorithm to the remaining words before mapping the constants in Redis sets. For example the following text:

Tobi is a ferret and he only wants four dollars

Converts to the following constant map:

{
  Tobi: 'TB',
  ferret: 'FRT',
  wants: 'WNTS',
  four: 'FR',
  dollars: 'TLRS'
}

This also means that phonetically similar words will match, for example "stefen", "stephen", "steven" and "stefan" all resolve to the constant "STFN". Reds takes this further and applies the porter stemming algorithm to "stem" words, for example "counts", and "counting" become "count".

Consider we have the following bodies of text:

Tobi really wants four dollars
For some reason tobi is always wanting four dollars

The following search query will then match both of these bodies, and "wanting", and "wants" both reduce to "want".

tobi wants four dollars

License

(The MIT License)

Copyright (c) 2011 TJ Holowaychuk <[e-mail]>

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.