level-trie

The TRIE data structure and search algorithm, on top of leveldb.

Usage

Store some words in a trie, then query them:

var level = require('level');
var Trie = require('level-trie');
var db = level(__dirname + '/db');
 
var trie = new Trie(db);
 
trie.add('bar');
trie.add('baz');
trie.add('foo');
 
trie.createSearchStream('fabulous')
  .on('data', console.log);
  // => foo
  // => bar
  // => baz

API

Trie(db)

Create a new Trie that stores its data in db.

If you don't want to use a whole database for the trie, pass in a database's section using level-sublevel.

Trie#add(string[, fn])

Add string to the trie. This causes a batch operation with as many puts as characters in string + 1.

Trie#remove(string[, fn])

Remove string from the trie.

Trie#createSearchStream(string, options)

Create a readable Stream that emits all the strings stored in the trie, ordered by size of the common prefix. Abort reading with stream#end or use the limit option.

Possible options are:

• limit: Emit max. x entries.
• follow: Keep the stream open and emit new data that comes in. When used in conjunction with limit the last emitted historical entry will define the border of what a new entry that's emitted needs to fit in, e.g. it mustn't be further away from the search string.

Installation

With npm do:

$ npm install level-trie

License

Copyright (c) 2013 Julian Gruber <julian@juliangruber.com>

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.