Resource Sign Service

README.md

❯ rspec resource_sign_service_spec.rb
----| Hash test |----
{:a=>{:b=>"b", :c=>"c"}, :d=>"d"}  vs  {:d=>"d", :a=>{:c=>"c", :b=>"b"}}
+dIsjfhtier7LrkhmcNC9g==  vs  +dIsjfhtier7LrkhmcNC9g==
________________________________________________________________________________________
.----| Array test |----
[{:a=>{:b=>"b", :c=>"c"}, :d=>"d"}, {:d=>"d", :a=>{:c=>"c", :b=>"b"}}]  vs  [{:d=>"d", :a=>{:c=>"c", :b=>"b"}}, {:a=>{:b=>"b", :c=>"c"}, :d=>"d"}]
nGY1apVXDjKbeEtURBYe3A==  vs  nGY1apVXDjKbeEtURBYe3A==
________________________________________________________________________________________
.----| Json Text test |----
{"a":{"b":"b","c":"c"},"d":"d"}  vs  {"d":"d","a":{"c":"c","b":"b"}}
+dIsjfhtier7LrkhmcNC9g==  vs  +dIsjfhtier7LrkhmcNC9g==
________________________________________________________________________________________
.----| File binary test |----
/Users/wangha/Downloads/WechatIMG20.jpeg  vs  /Users/wangha/Downloads/WechatIMG20 copy.jpeg
x+yOEBqy4qnkkSbMqDm5Ug==  vs  x+yOEBqy4qnkkSbMqDm5Ug==
________________________________________________________________________________________
.

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4 examples, 0 failures

resource_sign_service.rb

# frozen_string_literal: true

require 'openssl' unless defined?(OpenSSL::Digest)
require 'multi_json' unless defined?(MultiJson)

class ResourceSignService
  def signature(content)
    case content.class.name
    when 'Hash'
      arr = []
      content.each { |k, v| arr << "#{signature k}:#{signature v}" }

      signature(arr)
    when 'Array'
      str = ''
      content.sort.each { |v| str += signature(v) }

      signature(str)
    when 'String'
      content = MultiJson.load(content) if %r{^(\{|\[)(.*)(\]|\})$}.match?(content)

      content.is_a?(String) ? signature_str(content) : signature(content)
    else
      case true
      when content.respond_to?(:read)
        signature_io(content)
      when content.respond_to?(:to_h)
        signature(content.to_h)
      when content.respond_to?(:as_json)
        signature(content.as_json)
      when content.respond_to?(:to_s)
        signature(content.to_s)
      else
        content.class.to_s
      end
    end
  end

  private

  CHUNK_SIZE = 1 * 1024 * 1024 # one MB

  def signature_str(str)
    OpenSSL::Digest::MD5.base64digest(str)
  end

  def signature_io(io, digest: nil, chunk_size: CHUNK_SIZE)
    digest ||= OpenSSL::Digest::MD5.new

    loop do
      chunk = io.read(chunk_size)
      break unless chunk

      digest.update(chunk)
    end
    io.rewind

    digest.base64digest
  end
end

resource_sign_service_spec.rb

# frozen_string_literal: true

require 'rspec/core' unless defined?(RSpec)
require './resource_sign_service' unless defined?(ResourceSignService)

RSpec.describe ResourceSignService do
  let(:obj_a) { { a: { b: 'b', c: 'c' }, d: 'd' } }
  let(:obj_b) { { d: 'd', a: { c: 'c', b: 'b' } } }
  let(:arr_a) { [obj_a, obj_b] }
  let(:arr_b) { [obj_b, obj_a] }
  let(:json_a) { MultiJson.dump(obj_a) }
  let(:json_b) { MultiJson.dump(obj_b) }
  let(:file_path_a) { '/Users/wangha/Downloads/WechatIMG20.jpeg' }
  let(:file_path_b) { '/Users/wangha/Downloads/WechatIMG20 copy.jpeg' }

  describe 'match object with signature' do
    it 'Hash' do
      puts '----| Hash test |----'
      puts "#{obj_a}  vs  #{obj_b}"
      sign_a = subject.signature(obj_a)
      sign_b = subject.signature(obj_b)
      puts "#{sign_a}  vs  #{sign_b}"
      puts '_' * 88

      expect(sign_a).to eq(sign_b)
    end

    it 'Array' do
      puts '----| Array test |----'
      puts "#{arr_a}  vs  #{arr_b}"
      sign_a = subject.signature(arr_a)
      sign_b = subject.signature(arr_b)
      puts "#{sign_a}  vs  #{sign_b}"
      puts '_' * 88

      expect(sign_a).to eq(sign_b)
    end

    it 'Json' do
      puts '----| Json Text test |----'
      puts "#{json_a}  vs  #{json_b}"
      sign_a = subject.signature(json_a)
      sign_b = subject.signature(json_b)
      puts "#{sign_a}  vs  #{sign_b}"
      puts '_' * 88

      expect(sign_a).to eq(sign_b)
    end

    xit 'File' do
      puts '----| File binary test |----'
      file_a = File.open(file_path_a, 'rb')
      file_b = File.open(file_path_b, 'rb')

      puts "#{file_path_a}  vs  #{file_path_b}"
      sign_a = subject.signature(file_a)
      sign_b = subject.signature(file_b)
      puts "#{sign_a}  vs  #{sign_b}"
      puts '_' * 88

      expect(sign_a).to eq(sign_b)
    end
  end
end