What’s a Quick Infoset?

[ad_1]

Fast Infoset (FI) is a specification that describes a means of providing data in an extensible markup language (XML) document in a binary-encoded format. The encoded XML output is referred to as a fast information set document and is considerably smaller than its full XML representation. While similar in concept to other document compression techniques, the encoding scheme used not only compresses an XML document, but also improves XML data processing.

The FI specification was jointly developed by the International Telecoms Union (ITU-T) and the International Organization for Standardization (ISO) to build on the World Wide Web Consortium’s (W3C) XML Information Set recommendation. A W3C infoset is a means of defining data that can be contained in an XML document, but need not be. According to the W3C recommendation, an infoset must meet the appropriate syntax requirements for what is known as well-formed XML, and must also adhere to the appropriate element and attribute names identified in an XML namespace. The original XML document, however, does not need to be valid before being encoded into a quick infoset document. This means that the infoset need not be contained in an XML document and can be generated by other means.

The encoding method used in fast infoset documents is known as Abstract Syntax Notation One (ASN.1). Using the ASN.1 coding language as the basis for the Fast Infoset protocol allows the document to retain all the self-describing aspects of an XML document, as well as some additional functionality. Strings used regularly in the document are indexed and replaced by a number. This includes XML names and their attributes. Any binary data, such as images or videos, can also be included directly within the encoding without having to go through an additional encoding scheme.

As a serialization technique, Fast Infoset differs somewhat from other methods. One example is the XML Efficient Interchange Technique (EXI), which is the binary XML format recommended by the W3C. While an EXI document can provide a more compact representation of the XML infoset, it requires that the XML schema, the full description of the original XML document, be known at both ends of the transmission so that encoding and decoding of the document can take place. A FI encoding can also use advanced features that also use XML schema for additional compression.

The fast infoset coding technique is used in many telecommunications areas. It is most commonly found on the Internet, to conserve bandwidth during transfer, improve server performance for XML data delivery, and relieve stress on client applications on the receiving end. This is particularly useful on mobile Internet platforms, where devices can have significantly reduced processing power and transmission throughput.

[ad_2]