fast-feed

fast-feed

Node.JS module for parsing newsfeeds (RSS 2 and Atom). It should be one of the fastest feed parsers. Uses RapidXML.

Usage

Without callback (throws exception):

var fastFeed = require('fast-feed');
fastFeed.parse(xml_string);

With callback:

var fastFeed = require('fast-feed');
fastFeed.parse(xml_string, function(err, feed) {
    if (err) throw err;
    console.log(feed);
});

Do not parse content/description:

var fastFeed = require('fast-feed');
fastFeed.parse(xml_string, { content: false });

Or:

var fastFeed = require('fast-feed');
fastFeed.parse(xml_string, { content: false }, function(err, feed) {
    if (err) throw err;
    console.log(feed);
});

Extracted feed attributes

For Atom feeds:

{
    type: "atom",
    title: String,
    id: String,
    link: String,
    author: String,
    author_uri: String,
    author_email: String,
    extensions: [Extension],
    items: [{
        id: String,
        title: String,
        date: Date,
        author: String,
        author_uri: String,
        author_email: String,
        summary: String,
        content: String,
        links: [{
            rel: String,
            href: String,
            type: String,
            hreflang: String,
            title: String,
            length: String,
            text: String
        }],
        link: String,
        extensions: [Extension]
    }]
}

Any attribute besides type might be missing. summary and content are missing when the content: false option is used.

For RSS 2 feeds:

{
    type: "rss",
    title: String,
    description: String,
    link: String,
    author: String,
    extensions: [Extension],
    items: [{
        id: String,
        link: String,
        date: Date,
        title: String,
        author: String,
        description: String,
        content: String,
        extensions: [Extension]
    }]
}

Any attribute besides type might be missing. description is missing from items when the content: false option is used.

The content property of an RSS 2 item is extracted when the item contains a <content:encoded> element. The information about the content module can be found on MDN.

Feed extensions

Feed extensions are supported on the syntax level. Particulary, any element on the feed/channel/item using a namespace and having no nested elements is considered an extension. Extensions contain the following data:

{
    name: String, // name of the element, such as dc:title
    value: String, // string contents of the element
    attributes: { String: String } // element attributes
}

Parsing feed extensions is not enabled by default. Use the extensions: true option for the parse function to enable them. The extensions/attributes property will be missing instead of being empty when the feed/item has no extension. This has been done to reduce the gc stress.

A single element can have multiple extensions with the same name. Extension names are not normalized into lowercase.

Supported Node/io.js versions

This package uses Nan and has been tested (install+running tests) on:

• io.js 1.5.1
• node 0.10.24
• node 0.12.0

Running tests

Install dependencies:

npm install

Build the addon:

node-gyp configure build

Run tests (requires mocha globally installed):

make test

Testing leaks

Leak testing uses assumption that RSS (not the feed but memory) set grows slowly. If it grows fast then the extension (or something else) leaks.

Good

RSS grows slowly:

$ make test-leak
node --gc_global tests-leak/cdata.js
{ rss: 12419072, heapTotal: 6163968, heapUsed: 2259008 }
{ rss: 12955648, heapTotal: 6163968, heapUsed: 2392424 }
{ rss: 12955648, heapTotal: 6163968, heapUsed: 2257952 }
{ rss: 12955648, heapTotal: 6163968, heapUsed: 2118152 }
{ rss: 14901248, heapTotal: 8261120, heapUsed: 1976096 }
{ rss: 14901248, heapTotal: 8261120, heapUsed: 3899040 }
{ rss: 14901248, heapTotal: 8261120, heapUsed: 3755944 }
{ rss: 14901248, heapTotal: 8261120, heapUsed: 3614592 }
{ rss: 14901248, heapTotal: 8261120, heapUsed: 3473584 }
{ rss: 14901248, heapTotal: 8261120, heapUsed: 3331376 }
{ rss: 14901248, heapTotal: 8261120, heapUsed: 3188704 }
{ rss: 14901248, heapTotal: 8261120, heapUsed: 3048720 }
{ rss: 14901248, heapTotal: 8261120, heapUsed: 2905936 }
{ rss: 14901248, heapTotal: 8261120, heapUsed: 2764424 }
{ rss: 14901248, heapTotal: 8261120, heapUsed: 2623784 }
{ rss: 14901248, heapTotal: 8261120, heapUsed: 2481888 }
{ rss: 14901248, heapTotal: 8261120, heapUsed: 2340056 }

Bad

RSS grows rapidly:

$ make test-leak
node --gc_global tests-leak/cdata.js
{ rss: 79446016, heapTotal: 6163968, heapUsed: 2259008 }
{ rss: 146755584, heapTotal: 6163968, heapUsed: 2392424 }
{ rss: 213798912, heapTotal: 6163968, heapUsed: 2257952 }
{ rss: 281112576, heapTotal: 6163968, heapUsed: 2118152 }
{ rss: 349970432, heapTotal: 8261120, heapUsed: 1976096 }
{ rss: 417284096, heapTotal: 8261120, heapUsed: 3899040 }
{ rss: 484597760, heapTotal: 8261120, heapUsed: 3755944 }
{ rss: 551641088, heapTotal: 8261120, heapUsed: 3614592 }
{ rss: 618954752, heapTotal: 8261120, heapUsed: 3473584 }
{ rss: 685998080, heapTotal: 8261120, heapUsed: 3331376 }
{ rss: 753311744, heapTotal: 8261120, heapUsed: 3188704 }
{ rss: 820625408, heapTotal: 8261120, heapUsed: 3048720 }
{ rss: 887668736, heapTotal: 8261120, heapUsed: 2905936 }
{ rss: 954982400, heapTotal: 8261120, heapUsed: 2764424 }
{ rss: 1022025728, heapTotal: 8261120, heapUsed: 2623784 }
{ rss: 1089339392, heapTotal: 8261120, heapUsed: 2481888 }

License

The binding code is covered with the MIT license. RapidXML is dual-licensed (MIT and Boost Software License, see LICENSE.rapidxml).