Parse x-total header get the count of records

lib/gitlab.rb

@@ -4,7 +4,8 @@
 require 'gitlab/objectified_hash'
 require 'gitlab/configuration'
 require 'gitlab/error'
-require 'gitlab/page_links'
+require 'gitlab/headers/page_links'
+require 'gitlab/headers/total'
 require 'gitlab/paginated_response'
 require 'gitlab/file_response'
 require 'gitlab/request'

lib/gitlab/headers/page_links.rb

@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Headers
+    # Parses link header.
+    #
+    # @private
+    class PageLinks
+      HEADER_LINK = 'Link'
+      DELIM_LINKS = ','
+      LINK_REGEX = /<([^>]+)>; rel="([^"]+)"/.freeze
+      METAS = %w[last next first prev].freeze
+
+      attr_accessor(*METAS)
+
+      def initialize(headers)
+        link_header = headers[HEADER_LINK]
+
+        extract_links(link_header) if link_header && link_header =~ /(next|first|last|prev)/
+      end
+
+      private
+
+      def extract_links(header)
+        header.split(DELIM_LINKS).each do |link|
+          LINK_REGEX.match(link.strip) do |match|
+            url = match[1]
+            meta = match[2]
+            next if !url || !meta || METAS.index(meta).nil?
+
+            send("#{meta}=", url)
+          end
+        end
+      end
+    end
+  end
+end

lib/gitlab/headers/total.rb

@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Headers
+    # Parses total header.
+    #
+    # @private
+    class Total
+      HEADER_TOTAL = 'x-total'
+      TOTAL_REGEX = /^\d+$/.freeze
+
+      attr_accessor :total
+
+      def initialize(headers)
+        header_total = headers[HEADER_TOTAL]
+
+        extract_total(header_total) if header_total
+      end
+
+      private
+
+      def extract_total(header_total)
+        TOTAL_REGEX.match(header_total.strip) do |match|
+          @total = match[0]
+        end
+      end
+    end
+  end
+end

lib/gitlab/paginated_response.rb

@@ -30,7 +30,8 @@ def respond_to_missing?(method_name, include_private = false)
     end
 
     def parse_headers!(headers)
-      @links = PageLinks.new headers
+      @links = Headers::PageLinks.new headers
+      @total = Headers::Total.new headers
     end
 
     def each_page
@@ -58,6 +59,10 @@ def paginate_with_limit(limit, &block)
       lazy_paginate.take(limit).each(&block)
     end
 
+    def total
+      @total.total
+    end
+
     def last_page?
       !(@links.nil? || @links.last.nil?)
     end

spec/gitlab/page_links_spec.rb → spec/gitlab/headers/page_links_spec.rb

@@ -2,7 +2,7 @@
 
 require 'spec_helper'
 
-RSpec.describe Gitlab::PageLinks do
+RSpec.describe Gitlab::Headers::PageLinks do
   before do
     @page_links = described_class.new('Link' => '<http://example.com/api/v3/projects?page=1&per_page=5>; rel="first", <http://example.com/api/v3/projects?page=20&per_page=5>; rel="last", <http://example.com/api/v3/projects?page=7&per_page=5>; rel="prev", <http://example.com/api/v3/projects?page=9&per_page=5>; rel="next"')
   end

spec/gitlab/headers/total_spec.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::Headers::Total do
+  before do
+    @total = described_class.new('x-total' => ' 8 ')
+  end
+
+  describe '.extract_total' do
+    it 'extracts total header appropriately' do
+      expect(@total.total).to eql('8')
+    end
+  end
+end

spec/gitlab/paginated_response_spec.rb

@@ -8,7 +8,7 @@
     @paginated_response = described_class.new array
   end
 
-  it 'responds to *_page and has_*_page methods' do
+  it 'responds to total, *_page and has_*_page methods' do
     expect(@paginated_response).to respond_to :first_page
     expect(@paginated_response).to respond_to :last_page
     expect(@paginated_response).to respond_to :next_page
@@ -17,11 +17,12 @@
     expect(@paginated_response).to respond_to :has_last_page?
     expect(@paginated_response).to respond_to :has_next_page?
     expect(@paginated_response).to respond_to :has_prev_page?
+    expect(@paginated_response).to respond_to :total
   end
 
   describe '.parse_headers!' do
     it 'parses headers' do
-      @paginated_response.parse_headers!('Link' => '<http://example.com/api/v3/projects?page=1&per_page=5>; rel="first", <http://example.com/api/v3/projects?page=20&per_page=5>; rel="last"')
+      @paginated_response.parse_headers!('Link' => '<http://example.com/api/v3/projects?page=1&per_page=5>; rel="first", <http://example.com/api/v3/projects?page=20&per_page=5>; rel="last"', 'x-total' => '8')
       client = @paginated_response.client = double('client')
       first_page_response = double('first_page_response')
       last_page_response = double('last_page_response')
@@ -36,6 +37,7 @@
       expect(@paginated_response.last_page).to be last_page_response
       expect(@paginated_response.next_page).to be_nil
       expect(@paginated_response.prev_page).to be_nil
+      expect(@paginated_response.total).to eq('8')
     end
 
     context 'when the Link header endpoint does not match the configured endpoint' do