EASYSAX - pure javascript sax-style parser for xml

Simple and fast SAX XML parser.

• Incremental processing: EasySAX supports incremental data processing. This allows parsing files several gigabytes in size with minimal RAM consumption, passing data to the parser as it is read.
• Namespaces: Supports namespace normalization.
• Fast: High-performance streaming engine.

The parser was written for the RSS reader http://zzreader.com (not working) Remains the fastest SAX XML parser for JS by 2026

Install

$ npm install easysax

Benchmark

sh: node benchmark/stream.js

file: mock elems text
------------------------------------------------------------------------------------------
only load - total: 91.13 time: 0.35 500 MB
easysax ns=on uq=on attr=on - total: 2238.40 time: 2151.18 500 MB 6254753 6254754
easysax ns=off uq=on attr=on - total: 1840.96 time: 1755.02 500 MB 6254753 6254754
easysax ns=off uq=off attr=on - total: 1711.58 time: 1625.02 500 MB 6254753 6254754
easysax ns=off uq=off attr=off - total: 1383.35 time: 1296.81 500 MB 6254753 6254754
ltx - total: 2563.93 time: 2477.30 500 MB 6254753 6254753

sh: node benchmark/stream.js -file AS_HOUSES_PARAMS.XML

file: ./AS_HOUSES_PARAMS.XML elems text
------------------------------------------------------------------------------------------
only load - total: 3777.53 time: 5.34 4.74 GB
easysax ns=on uq=on attr=on - total: 44596.10 time: 40821.88 4.74 GB 27997407 1
easysax ns=off uq=on attr=on - total: 39105.67 time: 35382.78 4.74 GB 27997407 1
easysax ns=off uq=off attr=on - total: 36759.76 time: 32966.74 4.74 GB 27997407 1
easysax ns=off uq=off attr=off - total: 20291.19 time: 16555.40 4.74 GB 27997407 1
ltx - total: 57810.57 time: 54235.45 4.74 GB 27997407 1

https://github.com/vflash/sax-benchmark

sh: node bench-01.js

count - 100000
size - 25
easysax ns=on entityDecode=on getAttr=on : 100.050ms
easysax ns=off entityDecode=on getAttr=on : 82.520ms
easysax ns=off entityDecode=off getAttr=on : 69.133ms
easysax ns=off entityDecode=off getAttr=off: 29.226ms
saxjs : 346.182ms
libxml: 852.098ms
expat : 705.867ms
expat buffer: 712.212ms
ltx: 137.998ms

sh: node bench-02.js

count - 1000
size - 22750
easysax ns=on entityDecode=on getAttr=on : 151.511ms
easysax ns=off entityDecode=on getAttr=on : 114.646ms
easysax ns=off entityDecode=off getAttr=on : 88.604ms
easysax ns=off entityDecode=off getAttr=off: 80.773ms
saxjs : 1484.910ms
libxml: 1058.808ms
expat : 1028.151ms
expat buffer: 853.925ms
ltx: 359.173ms

sh: node bench-03.js

count - 1000
size - 121786
easysax ns=on entityDecode=on getAttr=on : 1769.676ms
easysax ns=off entityDecode=on getAttr=on : 1475.585ms
easysax ns=off entityDecode=off getAttr=on : 1214.665ms
easysax ns=off entityDecode=off getAttr=off: 405.799ms
saxjs : 10765.309ms
libxml: 5387.832ms
expat : 6734.018ms
expat buffer: 5865.209ms
ltx: 2953.910ms

Example of use

varparser=newEasySax();// if namespace is requiredparser.ns('rss',{'http://www.w3.org/2005/Atom': 'atom','http://www.w3.org/1999/xhtml': 'xhtml','http://search.yahoo.com/mrss/': 'media','http://purl.org/rss/1.0/': 'rss','http://purl.org/dc/elements/1.1/': 'dc','http://www.w3.org/1999/02/22-rdf-syntax-ns#' : 'rdf','http://purl.org/rss/1.0/modules/content/': 'content','http://www.yandex.ru': 'yandex','http://news.yandex.ru': 'yandex','http://backend.userland.com/rss2': 'rss'});parser.on('error',function(msg){// console.log('error - ' + msg);});parser.on('startNode',function(elementName,getAttr,isTagEnd,getStringNode){// elementName -- (string) element name. If namespaces are enabled, it automatically sets the prefix// getAttr() -- (function) parse attributes and return an object// isTagEnd -- (boolean) flag that the element is empty "<elem/>"// getStringNode() -- (function) returns the unparsed string of the element. example: <item title="text" id="x345">});parser.on('endNode',function(elementName,isTagStart,getStringNode){// isTagStart -- (boolean) flag that the element is empty "<elem/>"});parser.on('textNode',function(text){// text -- (String) line of text});parser.on('cdata',function(text){// text -- (String) CDATA element text string});parser.on('comment',function(text){// text - (String) comment text});//parser.on('question', function() {}); // <? ... ?>//parser.on('attention', function() {}); // <!XXXXX zzzz="eeee">parser.write(stringChunk);parser.write(stringChunk);
...
parser.end(stringChunk);