Class: Datadog::AppSec::Utils::HTTP::MediaRange

Inherits:
Object
  • Object
show all
Defined in:
lib/datadog/appsec/utils/http/media_range.rb

Overview

Implementation of media range for content negotiation

Defined Under Namespace

Classes: ParseError

Constant Summary collapse

WILDCARD = 
'*'
WILDCARD_RE = 
::Regexp.escape(WILDCARD)
TOKEN_RE =

See: www.rfc-editor.org/rfc/rfc7230#section-3.2.6

/[-#$%&'*+.^_`|~A-Za-z0-9]+/.freeze
PARAMETER_RE =

See: www.rfc-editor.org/rfc/rfc7231#section-3.1.1.1

%r{ # rubocop:disable Style/RegexpLiteral
  (?:
    (?<parameter_name>#{TOKEN_RE})
    =
    (?:
      (?<parameter_value>#{TOKEN_RE})
      |
      "(?<parameter_value>[^"]+)"
    )
  )
}ix.freeze
ACCEPT_EXT_RE =

See: www.rfc-editor.org/rfc/rfc7231#section-5.3.2

%r{ # rubocop:disable Style/RegexpLiteral
  (?:
    (?<ext_name>#{TOKEN_RE})
    =
    (?:
      (?<ext_value>#{TOKEN_RE})
      |
      "(?<ext_value>[^"]+)"
    )
  )
}ix.freeze
QVALUE_RE =

See: www.rfc-editor.org/rfc/rfc7231#section-5.3.1

%r{ # rubocop:disable Style/RegexpLiteral
  0(?:\.\d{1,3})?
  |
  1(?:\.0{1,3})?
}ix.freeze
MEDIA_RANGE_RE =

See: www.rfc-editor.org/rfc/rfc7231#section-5.3.2

%r{
  \A
  (?:
    (?<type>#{WILDCARD_RE})/(?<subtype>#{WILDCARD_RE})
    |
    (?<type>#{TOKEN_RE})/(?<subtype>#{WILDCARD_RE})
    |
    (?<type>#{TOKEN_RE})/(?<subtype>#{TOKEN_RE})
  )
  (?<parameters>
    (?:
      \s*;\s*
      (?!q=)
      #{PARAMETER_RE}
    )*
  )
  (?<accept_params>
    (?<weight>
      \s*;\s*
      (?:q=
        (?<quality>
          #{QVALUE_RE}
        )
      )
    )
    (?<accept_exts>
      (?<accept_ext>
        (?:
          \s*;\s*
          (?!q=)
          #{ACCEPT_EXT_RE}
        )*
      )
    )
  )?
  \Z
}ix.freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(media_range) ⇒ MediaRange

rubocop:disable Metrics/PerceivedComplexity, Metrics/CyclomaticComplexity

Raises:



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# File 'lib/datadog/appsec/utils/http/media_range.rb', line 94

def initialize(media_range) # rubocop:disable Metrics/PerceivedComplexity, Metrics/CyclomaticComplexity
  media_range_match = MEDIA_RANGE_RE.match(media_range)

  raise ParseError, media_range.inspect if media_range_match.nil?

  @type = (media_range_match['type'] || WILDCARD).downcase
  @subtype = (media_range_match['subtype'] || WILDCARD).downcase
  @quality = (media_range_match['quality'] || 1.0).to_f
  @parameters = {}
  @accept_ext = {}

  parameters = media_range_match['parameters']

  return if parameters.nil?

  parameters.split(';').map(&:strip).each do |parameter|
    parameter_match = PARAMETER_RE.match(parameter)

    next if parameter_match.nil?

    parameter_name = parameter_match['parameter_name']
    parameter_value = parameter_match['parameter_value']

    next if parameter_name.nil? || parameter_value.nil?

    @parameters[parameter_name.downcase] = parameter_value.downcase
  end

  accept_exts = media_range_match['accept_exts']

  return if accept_exts.nil?

  accept_exts.split(';').map(&:strip).each do |ext|
    ext_match = ACCEPT_EXT_RE.match(ext)

    next if ext_match.nil?

    ext_name = ext_match['ext_name']
    ext_value = ext_match['ext_value']

    next if ext_name.nil? || ext_value.nil?

    @accept_ext[ext_name.downcase] = ext_value.downcase
  end
end

Instance Attribute Details

#accept_ext ⇒ Object (readonly)

Returns the value of attribute accept_ext.



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# File 'lib/datadog/appsec/utils/http/media_range.rb', line 92

def accept_ext
  @accept_ext
end

#parameters ⇒ Object (readonly)

Returns the value of attribute parameters.



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# File 'lib/datadog/appsec/utils/http/media_range.rb', line 92

def parameters
  @parameters
end

#quality ⇒ Object (readonly)

Returns the value of attribute quality.



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# File 'lib/datadog/appsec/utils/http/media_range.rb', line 92

def quality
  @quality
end

#subtype ⇒ Object (readonly)

Returns the value of attribute subtype.



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# File 'lib/datadog/appsec/utils/http/media_range.rb', line 92

def subtype
  @subtype
end

#type ⇒ Object (readonly)

Returns the value of attribute type.



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# File 'lib/datadog/appsec/utils/http/media_range.rb', line 92

def type
  @type
end

Instance Method Details

#<=>(other) ⇒ Object

Compare two MediaRange for ordering



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# File 'lib/datadog/appsec/utils/http/media_range.rb', line 141

def <=>(other)
  unless (q = quality <=> other.quality) == 0 || q.nil?
    return q
  end

  if (s = specificity <=> other.specificity) != 0
    return s
  end

  unless wildcard?(:type)
    if wildcard?(:subtype) && !other.wildcard?(:subtype)
      return -1
    elsif !wildcard?(:subtype) && other.wildcard?(:subtype)
      return 1
    end
  end

  if wildcard?(:type) && !other.wildcard?(:type)
    return -1
  elsif !wildcard?(:type) && other.wildcard?(:type)
    return 1
  end

  0
end

#===(other) ⇒ Object

Compare with a MediaType for match

returns true if the MediaType is accepted by this MediaRange



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# File 'lib/datadog/appsec/utils/http/media_range.rb', line 170

def ===(other)
  return self === MediaType.new(other) if other.is_a?(::String)

  type == other.type && subtype == other.subtype && other.parameters.all? { |k, v| parameters[k] == v } ||
    type == other.type && wildcard?(:subtype) ||
    wildcard?(:type) && wildcard?(:subtype)
end

#specificity ⇒ Object 



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# File 'lib/datadog/appsec/utils/http/media_range.rb', line 178

def specificity
  @parameters.count
end

#to_s ⇒ Object 



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# File 'lib/datadog/appsec/utils/http/media_range.rb', line 188

def to_s
  s = +"#{@type}/#{@subtype}"

  s << ';' << @parameters.map { |k, v| "#{k}=#{v}" }.join(';') if @parameters.count > 0
  s << ";q=#{@quality}" if @quality < 1.0
  s << ';' << @accept_ext.map { |k, v| "#{k}=#{v}" }.join(';') if @accept_ext.count > 0

  s
end

#wildcard?(field = nil) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/datadog/appsec/utils/http/media_range.rb', line 182

def wildcard?(field = nil)
  return wildcard?(:type) || wildcard?(:subtype) if field.nil?

  instance_variable_get(:"@#{field}") == WILDCARD
end