Module: RDF::Repository::Implementation

Defined in:
lib/rdf/repository.rb

Overview

A default Repository implementation supporting atomic writes and serializable transactions.

See Also:

Defined Under Namespace

Classes: SerializedTransaction

Constant Summary collapse

DEFAULT_GRAPH = 
false

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.extend_object(obj) ⇒ Object 



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# File 'lib/rdf/repository.rb', line 250

def self.extend_object(obj)
  obj.instance_variable_set(:@data, obj.options.delete(:data) || 
                                    Hamster::Hash.new)
  obj.instance_variable_set(:@tx_class, 
                            obj.options.delete(:transaction_class) || 
                            SerializedTransaction)
  super
end

Instance Method Details

#apply_changeset(changeset) ⇒ Object

See Also:



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# File 'lib/rdf/repository.rb', line 341

def apply_changeset(changeset)
  data = @data
  changeset.deletes.each do |del|
    if del.constant?
      data = delete_from(data, del)
    else
      # we need this condition to handle wildcard statements
      query_pattern(del) { |stmt| data = delete_from(data, stmt) }
    end
  end
  changeset.inserts.each { |ins| data = insert_to(data, ins) }
  @data = data
end

#count ⇒ Object

See Also:



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# File 'lib/rdf/repository.rb', line 277

def count
  count = 0
  @data.each do |_, ss|
    ss.each do |_, ps|
      ps.each { |_, os| count += os.size }
    end
  end
  count
end

#each_graph(&block) ⇒ Object

See Also:



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# File 'lib/rdf/repository.rb', line 304

def each_graph(&block)
  if block_given?
    @data.each_key do |gn|
      yield RDF::Graph.new(graph_name: (gn == DEFAULT_GRAPH ? nil : gn), data: self)
    end
  end
  enum_graph
end

#each_statement(&block) ⇒ Object Also known as: each

See Also:



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# File 'lib/rdf/repository.rb', line 323

def each_statement(&block)
  if block_given?
    @data.each do |g, ss|
      ss.each do |s, ps|
        ps.each do |p, os|
          os.each do |o, object_options|
            yield RDF::Statement.new(s, p, o, object_options.merge(graph_name: g.equal?(DEFAULT_GRAPH) ? nil : g))
          end
        end
      end
    end
  end
  enum_statement
end

#graph_names(options = nil, &block) ⇒ Object

See Also:



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# File 'lib/rdf/repository.rb', line 297

def graph_names(options = nil, &block)        
  @data.keys.reject { |g| g == DEFAULT_GRAPH }.to_a
end

#has_graph?(graph) ⇒ Boolean

Returns:

  • (Boolean)

See Also:



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# File 'lib/rdf/repository.rb', line 290

def has_graph?(graph)
  @data.has_key?(graph)
end

#has_statement?(statement) ⇒ Boolean

Returns:

  • (Boolean)

See Also:



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# File 'lib/rdf/repository.rb', line 316

def has_statement?(statement)
  has_statement_in?(@data, statement)
end

#isolation_level ⇒ Object

See Also:



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# File 'lib/rdf/repository.rb', line 357

def isolation_level
  :serializable
end

#snapshot ⇒ Dataset

A readable & queryable snapshot of the repository for isolated reads.

Returns:

  • (Dataset) —

    an immutable Dataset containing a current snapshot of the Repository contents.

See Also:



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# File 'lib/rdf/repository.rb', line 368

def snapshot
  self.class.new(data: @data).freeze
end

#supports?(feature) ⇒ Boolean

Returns:

  • (Boolean)

See Also:



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# File 'lib/rdf/repository.rb', line 262

def supports?(feature)
  case feature.to_sym
  when :graph_name       then @options[:with_graph_name]
  when :inference        then false  # forward-chaining inference
  when :validity         then @options.fetch(:with_validity, true)
  when :literal_equality then true
  when :atomic_write     then true
  when :snapshots        then true
  else false
  end
end