Module: DataMapper::Is::Checksumed::ClassMethods

Defined in:
lib/dm-is-checksumed/is/checksumed.rb

Instance Method Summary collapse

Instance Method Details

#all(query = Undefined) ⇒ DataMapper::Collection

Substitutes any checksumed properties with the checksums of their values.

Parameters:

  • query (DataMapper::Undefined, DataMapper::Query, Hash) (defaults to: Undefined) —

    The query.

Returns:

  • (DataMapper::Collection) —

    The matching resources.



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# File 'lib/dm-is-checksumed/is/checksumed.rb', line 76

def all(query=Undefined)
  super(checksum_query(query))
end

#calculate_checksum(data) ⇒ String

Calculates the SHA256 checksum of the given data.

Parameters:

  • data (#to_s) —

    The data to checksum.

Returns:

  • (String) —

    The SHA256 hex-digest of the data.



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# File 'lib/dm-is-checksumed/is/checksumed.rb', line 48

def calculate_checksum(data)
  Digest::SHA256.hexdigest(data.to_s)
end

#checksum(name, options = {}) ⇒ Object (protected)

Defines a checksum property for another property.

Parameters:

  • name (Symbol) —

    The name of the property to checksum.

  • options (Hash) (defaults to: {}) —

    Additional options.

Options Hash (options):

  • :unique (Boolean) — default: true —

    Specifies whether the checksums are to be unique, or if duplicates are allowed.



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# File 'lib/dm-is-checksumed/is/checksumed.rb', line 121

def checksum(name,options={})
  # build the checksum property options
  property_options = {
    :length => 64,
    :required => true,
    :default => lambda { |resource,property|
      calculate_checksum(resource.attribute_get(name))
    }
  }

  if options.fetch(:unique,true)
    property_options[:unique] = true
  else
    property_options[:index] = true
  end

  property :"#{name}_checksum", String, property_options
  checksumed_properties << name
end

#checksum_query(query) ⇒ Hash, DataMapper::Undefined

Filters a query, replacing the checksumed properties, with their accompanying checksums.

Parameters:

  • query (Hash, DataMapper::Undefined) —

    The query to filter.

Returns:

  • (Hash, DataMapper::Undefined) —

    The filtered query.



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# File 'lib/dm-is-checksumed/is/checksumed.rb', line 90

def checksum_query(query)
  return query unless query.kind_of?(Hash)

  new_query = {}

  query.each do |name,value|
    if (name.respond_to?(:to_sym) && checksumed_properties.include?(name.to_sym))
      new_query[:"#{name}_checksum"] = calculate_checksum(value)
    else
      new_query[name] = value
    end
  end

  return new_query
end

#checksumed?(name) ⇒ Boolean

Determines if a checksum property was defined for another property.

Parameters:

  • name (Symbol, String) —

    The name of the property.

Returns:

  • (Boolean) —

    Specifies whether the property has an checksum property.



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# File 'lib/dm-is-checksumed/is/checksumed.rb', line 35

def checksumed?(name)
  checksumed_properties.include?(name.to_sym)
end

#checksumed_properties ⇒ Set<Symbol>

The properties which have accompanying checksums.

Returns:

  • (Set<Symbol>) —

    The property names.



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# File 'lib/dm-is-checksumed/is/checksumed.rb', line 21

def checksumed_properties
  @checksumed_properties ||= Set[]
end

#first(query = Undefined) ⇒ DataMapper::Resource?

Substitutes any checksumed properties with the checksums of their values.

Parameters:

  • query (DataMapper::Undefined, DataMapper::Query, Hash) (defaults to: Undefined) —

    The query.

Returns:

  • (DataMapper::Resource, nil) —

    The matching resource.



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# File 'lib/dm-is-checksumed/is/checksumed.rb', line 62

def first(query=Undefined)
  super(checksum_query(query))
end