View Source RDF.Canonicalization (RDF.ex v2.0.0)

An implementation of the standard RDF Dataset Canonicalization Algorithm.

See https://www.w3.org/TR/rdf-canon/.

Options

All functions in this module support the following options:

:hash_algorithm: Allows to set the hash algorithm to be used. Any of the :crypto.hash_algorithm() values of Erlang's :crypto module are allowed. Defaults to the runtime configured :canon_hash_algorithm of the :rdf application or :sha256 if not configured otherwise.
```
config :rdf,
  canon_hash_algorithm: :sha512
```
:hndq_call_limit: This algorithm has to go through complex cycles that may in extreme situations result in an unreasonably long canonicalization process. Although this never occurs in practice, attackers may use some "poison graphs" to create such situations (see the security consideration section in the specification). This implementation sets a maximum call limit for the Hash N-Degree Quads algorithm which can be configured with this value. Note, that actual limit is the product of the multiplication of the given value with the number blank nodes in the input graph. Defaults to the runtime configured :hndq_call_limit of the :rdf application or 50 if not configured otherwise.
```
config :rdf,
  hndq_call_limit: 10
```

Summary

Functions

canonicalize(input, opts \\ [])

Canonicalizes the blank nodes of a graph or dataset according to the RDF Dataset Canonicalization spec.

isomorphic?(a, b, opts \\ [])

Checks whether two graphs or datasets are equal, regardless of the concrete names of the blank nodes they contain.

Functions

canonicalize(input, opts \\ [])

@spec canonicalize(
  RDF.Graph.t() | RDF.Dataset.t(),
  keyword()
) :: {RDF.Dataset.t(), RDF.Canonicalization.State.t()}

Canonicalizes the blank nodes of a graph or dataset according to the RDF Dataset Canonicalization spec.

This function always returns a RDF.Dataset and wraps it in a tuple with the resulting internal state from which the blank node mapping can be retrieved. If you want to get just a RDF.Dataset back, use RDF.Dataset.canonicalize/2. If you want to canonicalize just a RDF.Graph and get a RDF.Graph back, use RDF.Graph.canonicalize/2.

See module documentation on the available options.

isomorphic?(a, b, opts \\ [])

@spec isomorphic?(
  RDF.Graph.t() | RDF.Dataset.t(),
  RDF.Graph.t() | RDF.Dataset.t(),
  keyword()
) ::
  boolean()

Checks whether two graphs or datasets are equal, regardless of the concrete names of the blank nodes they contain.

See module documentation on the available options.

Examples

iex> RDF.Graph.new([{~B<foo>, EX.p(), ~B<bar>}, {~B<bar>, EX.p(), 42}])
...> |> RDF.Canonicalization.isomorphic?(
...>      RDF.Graph.new([{~B<b1>, EX.p(), ~B<b2>}, {~B<b2>, EX.p(), 42}]))
true

iex> RDF.Graph.new([{~B<foo>, EX.p(), ~B<bar>}, {~B<bar>, EX.p(), 42}])
...> |> RDF.Canonicalization.isomorphic?(
...>      RDF.Graph.new([{~B<b1>, EX.p(), ~B<b2>}, {~B<b3>, EX.p(), 42}]))
false