Falaise  3.3.0
SuperNEMO Software Toolkit
Manage tags in Falaise

Table of Contents

Introduction to tags

A tag is the unique identifier of an official configuration of the SuperNEMO experiment. Such a configuration may concern a specific geometry model, the version of a software component, a model of the experiment in the context of the Monte Carlo simulation, an assembly of data processing modules for the reconstruction pipeline, a special hardware setup for data collection runs... A tag can also be used to identify some specific set of resources provided by/stored in a unique resource file.

Tag are thus associated to some logical entities. The tag does not provide the address, if any, of the tagged entity it is associated to. However, a tag may be associated to some concrete resource (i.e. a file). The real location of such a resource must be provided by a resolver tool, when this makes sense. Such a location can be the path of a resource file in the Falaise installation directory. It can be an URL to be accessed through a network, using a specific protocol.

A tag is implemented through the URN concept (see https://fr.wikipedia.org/wiki/Uniform_Resource_Name). An URN is a simple character string which uses the urn scheme.

Example: the "urn:snemo:demonstrator:setup:1.0" tag is associated to a specific model of the SuperNEMO demonstrator experiment, including its geometry model and possibly the configuration of the electronics, the database, the control and monitoring system. The "urn:snemo:demonstrator:setup:1.0" tag is thus unique. Once the model of the experiment, built as the assembly of several core components, is represented in the Falaise library and/or companion tools, its unique tag is officially published. The relationship between a specific setup and its tag is bijective. This is a strict rule that must be applied during the full lifecycle of the experiment.

Tag categories

As mentioned above, a tag is associated to a logical entity, i.e. something that makes sense to remember, store, associate to some other entities.

A tag must be associated to a category. A category is represented by a simple character string which identify a concept or topic. Falaise supports several tag categories:

Tag registration

When a tag is publised as the offical and unique identifier of some entity used within Falaise, it must be registered in a special database. A dedicated URN database service is provided by the Falaise library to manage the registration of all tags used in the library.

Practically, tags are described in files stored in the resources/urn/db/ source directory. A new URN entry must be added in one of the existing files from this directory in order to update the list of published tags. Eventually, additional files can be added to address some new categories of tags. These files are named URN DB files. They use the datatools::multi_properties format.

As a minimum, a tag record provides the URN of the tag, its category and a short description of the entity identified by the tag. It can also contains other informations such as the dependees of the entity, addressed by topic (see below).

The resources/urn/db/snemo_setup_db.conf files defines the full list of tag registration URN DB files to be loaded when the Falaise library starts.

Tag dependencies


Tag to file resolver

The fltags application

Print usage :

$ fltags --help