ronaldtse
commented
3 years ago For every registry, there is an XML file describing its contents, which is where we will get the dates and details of this registry.
e.g. for sip-parameters:
$ wget https://www.iana.org/assignments/sip-parameters/sip-parameters.xmlThe only metadata to obtain is this:
<?xml version='1.0' encoding='UTF-8'?>
<?xml-stylesheet type="text/xsl" href="sip-parameters.xsl"?>
<?xml-model href="sip-parameters.rng" schematypens="http://relaxng.org/ns/structure/1.0" ?>
<registry xmlns="http://www.iana.org/assignments" id="sip-parameters">
<title>Session Initiation Protocol (SIP) Parameters</title>
<created>2002-01</created>
<updated>2021-01-20</updated>The rest are "sub-registry" information. There are 80 "sub-registries" in this particular registry:
$ grep '<registry' sip-parameters.xml | wc -l
81e.g.
<registry id="sip-parameters-2">
<title>Header Fields</title>
<expert>Adam Roach</expert>
<xref type="rfc" data="rfc3261"/>
<xref type="rfc" data="rfc3427"/>
<xref type="rfc" data="rfc5727"/>
<note>The table below lists the header fields currently defined for the
Session Initiation Protocol (SIP) <xref type="rfc" data="rfc3261"/>. Some headers have
single-letter compact forms (Section 7.3 of RFC 3261). Header field
names are case-insensitive.
Standard header fields and messages MUST NOT begin with the leading
characters "P-". Existing "P-" header field registrations are
considered grandfathered, but new registrations of Informational
header fields should not begin with the leading characters "P-"
(unless the "P-" would preserve compatibility with an pre-existing
unregistered usage of the header field, at the discretion of the
Designated Expert). Short forms of header fields MUST only be
assigned to standards track header fields. At the discretion of the
Designated Expert, a header registration may require a Standards
Action.
</note>
rjsparks
There is a limited number of IANA registries -- they rarely change.
According to the mechanism used by today's IANA fetching script: https://trac.ietf.org/trac/xml2rfc/browser/website/public/rfc/bibxml-iana/nph-index.pl
Every registry corresponds to a single BibXML entry: https://xml2rfc.tools.ietf.org/public/rfc/bibxml-iana/reference.IANA.sip-parameters.xml
=>
Given that there are only 581 registries, performing 581 requests per-day isn't so bad. Instead of needing a 24-hour expiring cache, it would be more effective to scan the 581 pages daily and generate a static BibXML dataset.
These are the 581 registries today: