#SNMP Pro: DateAndTime Syntax Support

Well, I blogged about syntax validation in a previous post, which should be one of the coolest features for SharpSnmpPro.Mib assembly. But there is an interesting story about that untold.

The Beginning of DateAndTime Support

In fact a very long time ago OctetString class has a special implementation of ToString. It was not written by me, but Malcolm. Malcolm tried to use it to convert an OctetString instance to DateAndTime value. However, that was not a good way as you never know if that instance should be interpreted in that format.

Anyway, that was the start. Later I moved that logic to a separate method called ToDateString, but it was not improved in the future releases.

Five Years After

Now five years passed, and we have syntax validation ready. Is it a good time now to support DateAndTime completely? Yes, of course.

Assume we have such an entity defined in MIB document,

testEntity5 OBJECT-TYPE
  SYNTAX DateAndTime
  MAX-ACCESS read-only
  STATUS current
  DESCRIPTION
    "A textual description of the entity. This value should
    include the full name and version identification of
    the system's hardware type, software operating-system,
    and networking software."
  ::= { test 5 }

We expect it can be properly understood by #SNMP Pro, so the following test case is prepared,

Yes, that passes now with SharpSnmpPro.Mib and we know DateAndTime support is finally finished.

IDecoder Interface

Behind the scene, the raw data we passed in is handled by a new class called DataAndTimeDecoder, which is built into to SharpSnmpPro.Mib. Its source code is as below,

At runtime, a class called DecoderRegistry will hold all the decoders (which implements IDecoder). Whenever #SNMP Pro thinks it is a must to use a decoder, it goes to the registry and picks up the one that matches the syntax.

It is very easy to write your own decoder and replace the one built-in. You can simply use DecoderRegistry.Register your decoder. Make sure you set the correct key, which is the name of the syntax, such as SNMPv2-TC::DateAndTime.