This is the public web page for the Efficient Extensible Interchange (EXI) Working Group of the Efficient XML Interchange (EXI) Format (Second Edition). Feb 11, The Efficient XML Interchange Working Group has published a W3C Recommendation of Efficient XML Interchange (EXI) Format (Second. , Efficient XML Interchange (EXI) Format (Second Edition) Recommendation. , Proposed Edited Recommendation. .
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SE qname RightHandSide that were previously added to the grammar upon the first occurrence of the element that has the qualified name qname are evaluated as follows when they are iterchange. No known applications currently use this media type. The format described in this document is the specification so recommended.
Efficient Extensible Interchange Working Group
Events that belong to the same block are transformed into lower entropy groups of similar values called channelswhich are individually interchage suited for standard compression algorithms. Datatypes that are directly derived from another by union and their subtypes are always represented as String regardless of the availability of enumerated values.
Efficiemt, the i th part of an event code is encoded as an n -bit unsigned integer 7. The string table is organized into partitions so that the indices assigned to compact identifiers can stay relatively small.
XEP-0322: Efficient XML Interchange (EXI) Format
Specifically, the value of each Attribute AT event is placed in the channel identified by the qname of the Attribute and the value of each Character CH event is placed in the channel identified by the qname of its parent Start Element SE event.
Let target-type be the value of the xsi: Computed based on text content item of DT to which each unparsed entity information set item maps. The following table lists inetrchange entries that are initially populated in uri partitions, where partition name URI denotes that they are entries in the uri partition.
A sign value of zero 0 is used to represent positive integers and a sign value of one 1 is used to represent negative integers. Applications can use a set of fidelity options to specify the XML features they require. This includes all string table partitions containing local-names and all string table partitions containing value content items. EXI is a very compact representation effidient the Extensible Markup Language XML Information Set that is intended effcient simultaneously optimize performance and the utilization of computational resources.
Therefore, the server and client can create their own Schema IDs, according to some algorithm. In addition, the length of each event code in the event code tree is assigned statically without analyzing the data.
An event code tree is similar to a Huffman tree [Huffman Interchagne in that shorter paths are generally used for symbols that are considered more likely. Such omissions hinder interoperability in uncontrolled environments.
If the exponent value is – 2 14the mantissa value 1 represents INF, the mantissa value -1 represents -INF and any other mantissa value represents NaN. The content of each event in an EXI body is represented according to its type see Table Each production in a grammar has an event code that distinguishes its event from that of other productions that share the same left-hand-side non-terminal symbol.
The channels in a block are further organized into compressed streams. If the setup fails a second time, i. EXI Options EXI Option Description Default Value alignment Alignment of event codes and content items bit-packed compression Onterchange if EXI compression is to be edi for better compactness false strict Strict interpretation of schema is used to achieve better compactness false fragment Indicates if the body is to be encoded as an EXI fragment instead of an EXI document false preserve A set of options that controls whether comments, processing instructions, etc.
Efficient XML Interchange (EXI) Primer
Unsigned Integer nonNegativeInteger or integer with either minInclusive facet specified with a value equal to or greater than 0, or minExclusive facet specified with a value equal to or greater than The following sections describe the grammars used to inform the EXI encoding. All productions of the form LeftHandSide: The Second Edition incorporates a number of corrections that were published as errata against the Intercbange Edition, as well as other changes that help make the specification more readable and ibterchange.
Exactly same message should be sent from the server to the client to close the opposite way efficinet the stream example omitted. EXI is useful for. To reduce compression overhead, smaller channels are combined before compressing them, while larger channels are compressed independently.
Efficient XML Interchange (EXI) Format
Since this feficient sure each EXI body starts at an even byte boundary, it permits the recipient to decompress the body into an XML stanza.
All productions in the built-in element grammar of the form LeftHandSide: For example, the SOAP 1. Self-contained elements may be read independently from the rest of the EXI body, allowing them to be indexed for random access.
Those applications that ever find Datatype Representation Map useful should make sure that they exchange such documents only among the parties that are pre-known or discovered to be able to process the user-defined datatype representations that are in use. The development of the Efficient XML Interchange EXI format was guided by five design principlesnamely, the format had to be general, minimal, efficient, flexible, and interoperable.
When the indicator has the value of 1, the prefix of the NS is used as the effective prefix of the element’s interchamge. Fidelity options Fidelity interdhange Effect Preserve.