Fast XML Parser vs @nodable/flexible-xml-parser

Compact Output

This is equivalent to running fast-xml-parser with preserveOrder mode false. Parser produces compact JS output. In this case fast-xml-parser goes through 2 layers of processing. But Flexible XML Parser gives the opportunity to write direct output builder for any format.

	ptest	ptest_with_prolog	sample
fast-xml-parser	19721.54801	20030.72751	19731.82809
@nodable/flexible-xml-parser	33500.48755	32858.31683	33274.53886
Total	1.69867434	1.640395578	1.686338372

All the values in the table shows requests per second

Sequential Output

This is equivalent to running fast-xml-parser with preserveOrder mode true. Parser produces JS array.

	ptest	ptest_with_prolog	sample
fast-xml-parser (preserveOrder)	24482.78044	21866.79117	7986.529038
@nodable/flexible-xml-parser	30151.67155	26204.83804	11267.0917
Total	1.23154605	1.19838516	1.410762003

All the values in the table shows requests per second

higher is better

Sequential Output with IO

This test includes reading file, parsing, writing the output to file.Fast XML parser doesn't support streams directly so it reads synchronously. Flexible XML Parser using stream reader and stream writer (output builder).

	1.5 KB	13 MB	98 MB
fast-xml-parser (preserveOrder)	2534.349036	0.77777445	0.096257164
@nodable/flexible-xml-parser (using streams)	4176.031814	0.475603819	0.016075023
Total	1.647772961	0.61149324	0.167000801

All the values in the table shows requests per second

Though, the performance of Flexible XML Parser is degrading with increasing file size but there is a clear advantage in memory.

File Size: 1.5 KB

All the values in the table are in MBs.

	heap used	heap total	RSS
before FXP	5.11	9.78	53.39
after FXP	5.41	10.28	54.39
before Flexible	5.4	10.53	54.39
after Flexible	5.66	11.03	54.64

File Size: 13 MB

All the values in the table are in MBs.

	heap used	heap total	RSS
before FXP	5.11	9.78	54.02
after FXP	127.45	164.28	230.75
before Flexible	5.49	38.28	208.07
after Flexible	18.18	52.49	223.09

File Size: 101 MB

All the values in the table are in MBs.

	heap used	heap total	RSS
before FXP	5.11	10.03	53.57
after FXP	920.21	968.91	1019.68
before Flexible	5.48	38.53	848.61
after Flexible	102.31	144.2	948.99