Hanlding Collection Resources

UNIS’s approach to rely on hyperlinks for resources can slow some operations; specifically inserting new big Topology, Domain, or Network.

In this document we refere to Topology, Domain and Network as network resources collection.

To mitigate the long round trip times for inserting each resource type, UNIS allows inserting the entire network resources collection with self hyperlinks. Self hyperlinks use JSONPath or JSONPointer. When UNIS receive’s a POST request to insert new Topology, Domain, or Network, it checks each network resource included (e.g. nodes, ports, links, etc…) and generate new ids and selfRefs if needed.

Self Hyperlinks

JSONPath

JSONPath is an XPath equivlent for the JSON documents [JSONPATH]. The following table gives an overview of the JSONPath syntax.

JSONPath	Description
$	the root object.
@	the current object.
. or []	child operator.
..	recursive descent.
*	wildcard for all names regadlress their names.
[]	subscript operator.
?()	applies a fileter expression.

JSONPointer

JSONPointer identifes a specific value in JSON document [JSONPOINTER].

Examples

Example JSON Document

The following is a simple Topology example:

{
    "$schema": "http://unis.crest.iu.edu/schema/20120709/topology#",
    "id": "1",
    "nodes": [
        {
            "$schema": "http://unis.crest.iu.edu/schema/20120709/node#",
            "name": "node1",
            "urn": "urn:ogf:network:domain=example.com:node=node1",
            "description": "This is a sample node",
            "ports": [
                {
                    "href": "$..[?(@.[name=port1])]",
                    "rel": "full"
                },
                {
                    "href": "$..[?(@.[name=port2])]",
                    "rel": "full"
                }
            ]
        },
        {
            "$schema": "http://unis.crest.iu.edu/schema/20120709/node#",
            "name": "node2",
            "urn": "urn:ogf:network:domain=example.com:node=node2",
            "description": "This is a sample node2",
            "ports": [
                {
                    "href": "$..[?(@.[name=port3])]",
                    "rel": "full"
                }
            ]
        }
    ],
    "ports": [
        {
            "$schema": "http://unis.crest.iu.edu/schema/20120709/port#",
            "name": "port1",
            "urn": "urn:ogf:network:domain=example.com:port=port1",
            "capacity": 1000
        },
        {
            "$schema": "http://unis.crest.iu.edu/schema/20120709/port#",
            "name": "port2",
            "urn": "urn:ogf:network:domain=example.com:port=port2",
            "capacity": 10000000
        },
        {
            "$schema": "http://unis.crest.iu.edu/schema/20120709/port#",
            "name": "port3",
            "urn": "urn:ogf:network:domain=example.com:port=port3",
            "capacity": 10000000000
        }
    ]
}

JSONPath Examples

The following table shows some JSONPath queries and their results:

JSONPath	Reuslt
$.*	return the entire document.
$.nodes	return all nodes in the document
$.ports[0]	return the first port.
$.ports[?(@.name==”port2”)]	return the port which has attribue name=port2.
$..[?(@.name==”port2”)]	return any object which has attribue name=port2.

JSONPointer Examples

JSONPointer	Reuslt
#/	return the entire document.
#/nodes	return all nodes in the document
#/ports/0	return the first port.

Footnotes

[JSONPATH]

http://goessner.net/articles/JsonPath/

[JSONPOINTER]

http://tools.ietf.org/html/draft-pbryan-zyp-json-pointer-02