Can parse root .gitattributes file for a ref

config/initializers/rugged_use_gitlab_git_attributes.rb

@@ -7,7 +7,7 @@
 # repository-wide language statistics:
 # <https://github.com/github/linguist/blob/v4.7.0/lib/linguist/lazy_blob.rb#L33-L36>
 #
-# The options passed by Linguist are those assumed by Gitlab::Git::Attributes
+# The options passed by Linguist are those assumed by Gitlab::Git::InfoAttributes
 # anyway, and there is no great efficiency gain from just fetching the listed
 # attributes with our implementation, so we ignore the additional arguments.
 #
@@ -19,7 +19,7 @@ module Rugged
       end
 
       def attributes
-        @attributes ||= Gitlab::Git::Attributes.new(path)
+        @attributes ||= Gitlab::Git::InfoAttributes.new(path)
       end
     end
 

lib/gitlab/git/attributes_at_ref_parser.rb

@@ -0,0 +1,14 @@
+module Gitlab
+  module Git
+    # Parses root .gitattributes file at a given ref
+    class AttributesAtRefParser
+      delegate :attributes, to: :@parser
+
+      def initialize(repository, ref)
+        blob = repository.blob_at(ref, '.gitattributes')
+
+        @parser = AttributesParser.new(blob&.data)
+      end
+    end
+  end
+end

lib/gitlab/git/attributes_parser.rb

@@ -1,42 +1,26 @@
-# Gitaly note: JV: not sure what to make of this class. Why does it use
-# the full disk path of the repository to look up attributes This is
-# problematic in Gitaly, because Gitaly hides the full disk path to the
-# repository from gitlab-ce.
-
 module Gitlab
   module Git
     # Class for parsing Git attribute files and extracting the attributes for
     # file patterns.
-    #
-    # Unlike Rugged this parser only needs a single IO call (a call to `open`),
-    # vastly reducing the time spent in extracting attributes.
-    #
-    # This class _only_ supports parsing the attributes file located at
-    # `$GIT_DIR/info/attributes` as GitLab doesn't use any other files
-    # (`.gitattributes` is copied to this particular path).
-    #
-    # Basic usage:
-    #
-    #     attributes = Gitlab::Git::Attributes.new(some_repo.path)
-    #
-    #     attributes.attributes('README.md') # => { "eol" => "lf }
-    class Attributes
-      # path - The path to the Git repository.
-      def initialize(path)
-        @path = File.expand_path(path)
-        @patterns = nil
+    class AttributesParser
+      def initialize(attributes_data)
+        @data = attributes_data || ""
+
+        if @data.is_a?(File)
+          @patterns = parse_file
+        end
       end
 
       # Returns all the Git attributes for the given path.
       #
-      # path - A path to a file for which to get the attributes.
+      # file_path - A path to a file for which to get the attributes.
       #
       # Returns a Hash.
-      def attributes(path)
-        full_path = File.join(@path, path)
+      def attributes(file_path)
+        absolute_path = File.join('/', file_path)
 
         patterns.each do |pattern, attrs|
-          return attrs if File.fnmatch?(pattern, full_path)
+          return attrs if File.fnmatch?(pattern, absolute_path)
         end
 
         {}
@@ -98,16 +82,10 @@ module Gitlab
 
       # Iterates over every line in the attributes file.
       def each_line
-        full_path = File.join(@path, 'info/attributes')
+        @data.each_line do |line|
+          break unless line.valid_encoding?
 
-        return unless File.exist?(full_path)
-
-        File.open(full_path, 'r') do |handle|
-          handle.each_line do |line|
-            break unless line.valid_encoding?
-
-            yield line.strip
-          end
+          yield line.strip
         end
       end
 
@@ -125,7 +103,8 @@ module Gitlab
 
           parsed = attrs ? parse_attributes(attrs) : {}
 
-          pairs << [File.join(@path, pattern), parsed]
+          absolute_pattern = File.join('/', pattern)
+          pairs << [absolute_pattern, parsed]
         end
 
         # Newer entries take precedence over older entries.

lib/gitlab/git/info_attributes.rb

@@ -0,0 +1,49 @@
+# Gitaly note: JV: not sure what to make of this class. Why does it use
+# the full disk path of the repository to look up attributes This is
+# problematic in Gitaly, because Gitaly hides the full disk path to the
+# repository from gitlab-ce.
+
+module Gitlab
+  module Git
+    # Parses gitattributes at `$GIT_DIR/info/attributes`
+    #
+    # Unlike Rugged this parser only needs a single IO call (a call to `open`),
+    # vastly reducing the time spent in extracting attributes.
+    #
+    # This class _only_ supports parsing the attributes file located at
+    # `$GIT_DIR/info/attributes` as GitLab doesn't use any other files
+    # (`.gitattributes` is copied to this particular path).
+    #
+    # Basic usage:
+    #
+    #     attributes = Gitlab::Git::InfoAttributes.new(some_repo.path)
+    #
+    #     attributes.attributes('README.md') # => { "eol" => "lf }
+    class InfoAttributes
+      delegate :attributes, :patterns, to: :parser
+
+      # path - The path to the Git repository.
+      def initialize(path)
+        @repo_path = File.expand_path(path)
+      end
+
+      def parser
+        @parser ||= begin
+          if File.exist?(attributes_path)
+            File.open(attributes_path, 'r') do |file_handle|
+              AttributesParser.new(file_handle)
+            end
+          else
+            AttributesParser.new("")
+          end
+        end
+      end
+
+      private
+
+      def attributes_path
+        @attributes_path ||= File.join(@repo_path, 'info/attributes')
+      end
+    end
+  end
+end

lib/gitlab/git/repository.rb

@@ -102,7 +102,7 @@ module Gitlab
         )
         @path = File.join(storage_path, @relative_path)
         @name = @relative_path.split("/").last
-        @attributes = Gitlab::Git::Attributes.new(path)
+        @attributes = Gitlab::Git::InfoAttributes.new(path)
       end
 
       def ==(other)
@@ -1011,6 +1011,18 @@ module Gitlab
         attributes(path)[name]
       end
 
+      # Check .gitattributes for a given ref
+      #
+      # This only checks the root .gitattributes file,
+      # it does not traverse subfolders to find additional .gitattributes files
+      #
+      # This method is around 30 times slower than `attributes`,
+      # which uses `$GIT_DIR/info/attributes`
+      def attributes_at(ref, file_path)
+        parser = AttributesAtRefParser.new(self, ref)
+        parser.attributes(file_path)
+      end
+
       def languages(ref = nil)
         Gitlab::GitalyClient.migrate(:commit_languages) do |is_enabled|
           if is_enabled

spec/lib/gitlab/git/attributes_at_ref_parser_spec.rb

@@ -0,0 +1,28 @@
+require 'spec_helper'
+
+describe Gitlab::Git::AttributesAtRefParser, seed_helper: true do
+  let(:project) { create(:project, :repository) }
+  let(:repository) { project.repository }
+
+  subject { described_class.new(repository, 'lfs') }
+
+  it 'loads .gitattributes blob' do
+    repository.raw # Initialize repository in advance since this also checks attributes
+
+    expected_filter = 'filter=lfs diff=lfs merge=lfs'
+    receive_blob = receive(:new).with(a_string_including(expected_filter))
+    expect(Gitlab::Git::AttributesParser).to receive_blob.and_call_original
+
+    subject
+  end
+
+  it 'handles missing blobs' do
+    expect { described_class.new(repository, 'non-existant-branch') }.not_to raise_error
+  end
+
+  describe '#attributes' do
+    it 'returns the attributes as a Hash' do
+      expect(subject.attributes('test.lfs')['filter']).to eq('lfs')
+    end
+  end
+end

spec/lib/gitlab/git/attributes_parser_spec.rb

@@ -1,11 +1,10 @@
 require 'spec_helper'
 
-describe Gitlab::Git::Attributes, seed_helper: true do
-  let(:path) do
-    File.join(SEED_STORAGE_PATH, 'with-git-attributes.git')
-  end
+describe Gitlab::Git::AttributesParser, seed_helper: true do
+  let(:attributes_path) { File.join(SEED_STORAGE_PATH, 'with-git-attributes.git', 'info', 'attributes') }
+  let(:data) { File.read(attributes_path) }
 
-  subject { described_class.new(path) }
+  subject { described_class.new(data) }
 
   describe '#attributes' do
     context 'using a path with attributes' do
@@ -66,6 +65,26 @@ describe Gitlab::Git::Attributes, seed_helper: true do
         expect(subject.attributes('test.foo')).to eq({})
       end
     end
+
+    context 'when attributes data is a file handle' do
+      subject do
+        File.open(attributes_path, 'r') do |file_handle|
+          described_class.new(file_handle)
+        end
+      end
+
+      it 'returns the attributes as a Hash' do
+        expect(subject.attributes('test.txt')).to eq({ 'text' => true })
+      end
+    end
+
+    context 'when attributes data is nil' do
+      let(:data) { nil }
+
+      it 'returns an empty Hash' do
+        expect(subject.attributes('test.foo')).to eq({})
+      end
+    end
   end
 
   describe '#patterns' do
@@ -74,14 +93,14 @@ describe Gitlab::Git::Attributes, seed_helper: true do
     end
 
     it 'parses an entry that uses a tab to separate the pattern and attributes' do
-      expect(subject.patterns[File.join(path, '*.md')])
+      expect(subject.patterns[File.join('/', '*.md')])
         .to eq({ 'gitlab-language' => 'markdown' })
     end
 
     it 'stores patterns in reverse order' do
       first = subject.patterns.to_a[0]
 
-      expect(first[0]).to eq(File.join(path, 'bla/bla.txt'))
+      expect(first[0]).to eq(File.join('/', 'bla/bla.txt'))
     end
 
     # It's a bit hard to test for something _not_ being processed. As such we'll
@@ -89,14 +108,6 @@ describe Gitlab::Git::Attributes, seed_helper: true do
     it 'ignores any comments and empty lines' do
       expect(subject.patterns.length).to eq(10)
     end
-
-    it 'does not parse anything when the attributes file does not exist' do
-      expect(File).to receive(:exist?)
-        .with(File.join(path, 'info/attributes'))
-        .and_return(false)
-
-      expect(subject.patterns).to eq({})
-    end
   end
 
   describe '#parse_attributes' do
@@ -132,17 +143,9 @@ describe Gitlab::Git::Attributes, seed_helper: true do
       expect { |b| subject.each_line(&b) }.to yield_successive_args(*args)
     end
 
-    it 'does not yield when the attributes file does not exist' do
-      expect(File).to receive(:exist?)
-        .with(File.join(path, 'info/attributes'))
-        .and_return(false)
-
-      expect { |b| subject.each_line(&b) }.not_to yield_control
-    end
-
     it 'does not yield when the attributes file has an unsupported encoding' do
-      path = File.join(SEED_STORAGE_PATH, 'with-invalid-git-attributes.git')
-      attrs = described_class.new(path)
+      path = File.join(SEED_STORAGE_PATH, 'with-invalid-git-attributes.git', 'info', 'attributes')
+      attrs = described_class.new(File.read(path))
 
       expect { |b| attrs.each_line(&b) }.not_to yield_control
     end

spec/lib/gitlab/git/info_attributes_spec.rb

@@ -0,0 +1,43 @@
+require 'spec_helper'
+
+describe Gitlab::Git::InfoAttributes, seed_helper: true do
+  let(:path) do
+    File.join(SEED_STORAGE_PATH, 'with-git-attributes.git')
+  end
+
+  subject { described_class.new(path) }
+
+  describe '#attributes' do
+    context 'using a path with attributes' do
+      it 'returns the attributes as a Hash' do
+        expect(subject.attributes('test.txt')).to eq({ 'text' => true })
+      end
+
+      it 'returns an empty Hash for a defined path without attributes' do
+        expect(subject.attributes('bla/bla.txt')).to eq({})
+      end
+    end
+  end
+
+  describe '#parser' do
+    it 'parses a file with entries' do
+      expect(subject.patterns).to be_an_instance_of(Hash)
+      expect(subject.patterns["/*.txt"]).to eq({ 'text' => true })
+    end
+
+    it 'does not parse anything when the attributes file does not exist' do
+      expect(File).to receive(:exist?)
+        .with(File.join(path, 'info/attributes'))
+        .and_return(false)
+
+      expect(subject.patterns).to eq({})
+    end
+
+    it 'does not parse attributes files with unsupported encoding' do
+      path = File.join(SEED_STORAGE_PATH, 'with-invalid-git-attributes.git')
+      subject = described_class.new(path)
+
+      expect(subject.patterns).to eq({})
+    end
+  end
+end

spec/support/test_env.rb

@@ -20,7 +20,7 @@ module TestEnv
     'improve/awesome'                    => '5937ac0',
     'merged-target'                      => '21751bf',
     'markdown'                           => '0ed8c6c',
-    'lfs'                                => 'be93687',
+    'lfs'                                => '55bc176',
     'master'                             => 'b83d6e3',
     'merge-test'                         => '5937ac0',
     "'test'"                             => 'e56497b',