[x3d-public] Efficient XML Interchange (EXI) for JSON - W3C working draft

Mon Feb 1 23:00:52 PST 2016

The following W3C Working Draft document has been published by the EXI working group.

	Efficient XML Interchange (EXI) for JSON
	http://www.w3.org/TR/exi-for-json

Daniel Peintner has designed an interesting adaptation of EXI: creation of a special datatype-based XML schema that allows expressing any JSON structure in XML form, then subsequently taking advantage of EXI compression capabilities for compactness and performance.

Feedback on this working draft is welcome.  EXI for JSON provides more options for X3D JSON scene authors and users.

This emerging capability also bodes well for this year's planned application of EXI to .x3d XML encoding, in concert with Fraunhofer's Shape Resource Container (SRC), and together with XML Encryption and XML Signature/Authentication.  This provides a rich set of options for authors.  We expect achieve a more capable, more compact and highly performant Efficient Binary Encoding for X3D.

This new addition of EXI for JSON means that we'll also have have multiple ways to compare compression of X3D scenes and, through testing, will be able to confirm that we have indeed developed a new encoding worthy of broad adoption.

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Efficient XML Interchange (EXI) for JSON
W3C First Public Working Draft 28 January 2016

This version:
     http://www.w3.org/TR/2016/WD-exi-for-json-20160128
Latest version:
     http://www.w3.org/TR/exi-for-json
Editors:
     Daniel Peintner, Siemens AG
     Don Brutzman, Web3D Consortium

Abstract.  The Efficient XML Interchange (EXI) format is a compact representation that simultaneously optimizes performance and the utilization of computational resources. The EXI format was designed to support XML representation. With a relatively small set of transformations it may also be used for JSON, a popular format for exchange of structured data on the Web.
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Additional background.  Past work at NPS has shown that EXI consistently meets or beats JSON-based compression schemes for a wide range of test cases.  Even greater EXI benefits are likely when performance considerations (such as speed of decompression) are compared.  These test outcomes are similar to results shown when comparing EXI to .gzip or .zip compression.

Thesis reference:

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EVALUATION OF EFFICIENT XML INTERCHANGE (EXI) FOR LARGE DATASETS AND AS AN ALTERNATIVE TO BINARY JSON ENCODINGS

Bruce Hill, Lieutenant, United States Navy

Thesis, Master of Science in Network Operations and Technology, March 2015

Advisor: Don Brutzman, Department of Information Sciences.  Co-Advisor: Don McGregor, MOVES Institute.

Abstract.  Current and emerging Navy information concepts, including network-centric warfare and Navy Tactical Cloud, presume high network throughput and interoperability. The Extensible Markup Language (XML) addresses the latter requirement, but its verbosity is problematic for afloat networks. JavaScript Object Notation (JSON) is an alternative to XML common in web applications and some non-relational databases. Compact, binary encodings exist for both formats. Efficient XML Interchange (EXI) is a standardized, binary encoding of XML. Binary JSON (BSON) and Compact Binary Object Representation (CBOR) are JSON-compatible encodings. This work evaluates EXI compaction against both encodings, and extends evaluations of EXI for datasets up to 4 gigabytes. Generally, a configuration of EXI exists that produces a more compact encoding than BSON or CBOR. Tests show EXI compacts structured, non-multimedia data in Microsoft Office files better than the default format. The Navy needs 
 to imme
diately consider EXI for use in web, sensor, and office document applications to improve throughput over constrained networks. To maximize EXI benefits, future work needs to evaluate EXI’s parameters, as well as tune XML schema documents, on a case-by-case basis prior to EXI deployment. A suite of test examples and an evaluation framework also need to be developed to support this process.

Received Outstanding Thesis Award from NPS Information Sciences Department.

Keywords: Extensible Markup Language (XML), Efficient XML Interchange (EXI), JavaScript Object Notation (JSON), Compact Binary Object Representation (CBOR), Binary JSON (BSON), data serialization, data interoperability.

Links: catalog, slideset (.pdf), thesis.
https://calhoun.nps.edu/handle/10945/45196
https://wiki.nps.edu/download/attachments/547356759/HillEXIbriefingBigThingsSmall2015March29.pptx
https://wiki.nps.edu/download/attachments/547356759/HillEXIbriefingBigThingsSmall2015March29.pdf
https://wiki.nps.edu/download/attachments/547356759/15Mar_Hill_Bruce.pdf
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Acknowledgement: such work would not be possible without the steady liaison efforts between the World Wide Web Consortium (W3C) and the Web3D Consortium.  No single company or institution anywhere can produce anything near the same results that such open partnerships can achieve.  Membership has value.

	Web3D Liaisons and Partnerships
	http://www.web3d.org/about/liaisons

Have fun with EXI, JSON and X3D!

all the best, Don
-- 
Don Brutzman  Naval Postgraduate School, Code USW/Br       brutzman at nps.edu
Watkins 270,  MOVES Institute, Monterey CA 93943-5000 USA   +1.831.656.2149
X3D graphics, virtual worlds, navy robotics http://faculty.nps.edu/brutzman