hometown/app/helpers/jsonld_helper.rb
Akihiko Odaki 40e5d2303b Validate HTTP response length while receiving (#6891)
to_s method of HTTP::Response keeps blocking while it receives the whole
content, no matter how it is big. This means it may waste time to receive
unacceptably large files. It may also consume memory and disk in the
process. This solves the inefficency by checking response length while
receiving.
2018-03-26 14:02:10 +02:00

90 lines
2.3 KiB
Ruby

# frozen_string_literal: true
module JsonLdHelper
def equals_or_includes?(haystack, needle)
haystack.is_a?(Array) ? haystack.include?(needle) : haystack == needle
end
def first_of_value(value)
value.is_a?(Array) ? value.first : value
end
# The url attribute can be a string, an array of strings, or an array of objects.
# The objects could include a mimeType. Not-included mimeType means it's text/html.
def url_to_href(value, preferred_type = nil)
single_value = if value.is_a?(Array) && !value.first.is_a?(String)
value.find { |link| preferred_type.nil? || ((link['mimeType'].presence || 'text/html') == preferred_type) }
elsif value.is_a?(Array)
value.first
else
value
end
if single_value.nil? || single_value.is_a?(String)
single_value
else
single_value['href']
end
end
def as_array(value)
value.is_a?(Array) ? value : [value]
end
def value_or_id(value)
value.is_a?(String) || value.nil? ? value : value['id']
end
def supported_context?(json)
!json.nil? && equals_or_includes?(json['@context'], ActivityPub::TagManager::CONTEXT)
end
def unsupported_uri_scheme?(uri)
!uri.start_with?('http://', 'https://')
end
def canonicalize(json)
graph = RDF::Graph.new << JSON::LD::API.toRdf(json)
graph.dump(:normalize)
end
def fetch_resource(uri, id)
unless id
json = fetch_resource_without_id_validation(uri)
return unless json
uri = json['id']
end
json = fetch_resource_without_id_validation(uri)
json.present? && json['id'] == uri ? json : nil
end
def fetch_resource_without_id_validation(uri)
build_request(uri).perform do |response|
response.code == 200 ? body_to_json(response.body_with_limit) : nil
end
end
def body_to_json(body)
body.is_a?(String) ? Oj.load(body, mode: :strict) : body
rescue Oj::ParseError
nil
end
def merge_context(context, new_context)
if context.is_a?(Array)
context << new_context
else
[context, new_context]
end
end
private
def build_request(uri)
request = Request.new(:get, uri)
request.add_headers('Accept' => 'application/activity+json, application/ld+json')
request
end
end