Consistently create, update, and delete files, taking CRLF settings into account

1 files changed, 124 insertions, 0 deletions

diff --git a/lib/gitlab/git/index.rb b/lib/gitlab/git/index.rb
new file mode 100644
index 00000000000..3d0000879f8
--- /dev/null
+++ b/lib/gitlab/git/index.rb
@@ -0,0 +1,124 @@
+module Gitlab
+  module Git
+    class Index
+      DEFAULT_MODE = 0o100644
+
+      attr_reader :repository, :raw_index
+
+      def initialize(repository)
+        @repository = repository
+        @raw_index = repository.rugged.index
+      end
+
+      def read_tree(tree)
+        raw_index.read_tree(tree)
+      end
+
+      def write_tree
+        raw_index.write_tree(repository.rugged)
+      end
+
+      def get(*args)
+        raw_index.get(*args)
+      end
+
+      def create(options)
+        normalize_options!(options)
+
+        file_entry = raw_index.get(options[:file_path])
+        if file_entry
+          raise Gitlab::Git::Repository::InvalidBlobName.new("Filename already exists")
+        end
+
+        add_blob(options)
+      end
+
+      def create_dir(options)
+        normalize_options!(options)
+
+        file_entry = raw_index.get(options[:file_path])
+        if file_entry
+          raise Gitlab::Git::Repository::InvalidBlobName.new("Directory already exists as a file")
+        end
+
+        options = options.dup
+        options[:file_path] += '/.gitkeep'
+        options[:content] = ''
+
+        add_blob(options)
+      end
+
+      def update(options)
+        normalize_options!(options)
+
+        file_entry = raw_index.get(options[:file_path])
+        unless file_entry
+          raise Gitlab::Git::Repository::InvalidBlobName.new("File doesn't exist")
+        end
+
+        add_blob(options, mode: file_entry[:mode])
+      end
+
+      def move(options)
+        normalize_options!(options)
+
+        file_entry = raw_index.get(options[:previous_path])
+        unless file_entry
+          raise Gitlab::Git::Repository::InvalidBlobName.new("File doesn't exist")
+        end
+
+        raw_index.remove(options[:previous_path])
+
+        add_blob(options, mode: file_entry[:mode])
+      end
+
+      def delete(options)
+        normalize_options!(options)
+
+        file_entry = raw_index.get(options[:file_path])
+        unless file_entry
+          raise Gitlab::Git::Repository::InvalidBlobName.new("File doesn't exist")
+        end
+
+        raw_index.remove(options[:file_path])
+      end
+
+      private
+
+      def normalize_options!(options)
+        options[:file_path] = normalize_path(options[:file_path]) if options[:file_path]
+        options[:previous_path] = normalize_path(options[:previous_path]) if options[:previous_path]
+      end
+
+      def normalize_path(path)
+        pathname = Gitlab::Git::PathHelper.normalize_path(path)
+
+        if pathname.each_filename.include?('..')
+          raise Gitlab::Git::Repository::InvalidBlobName.new('Invalid path')
+        end
+
+        pathname.to_s
+      end
+
+      def add_blob(options, mode: nil)
+        content = options[:content]
+        return unless content
+
+        content = Base64.decode64(content) if options[:encoding] == 'base64'
+
+        detect = CharlockHolmes::EncodingDetector.new.detect(content)
+        unless detect && detect[:type] == :binary
+          # When writing to the repo directly as we are doing here,
+          # the `core.autocrlf` config isn't taken into account.
+          content.gsub!("\r\n", "\n") if repository.autocrlf
+        end
+
+        oid = repository.rugged.write(content, :blob)
+
+        raw_index.add(path: options[:file_path], oid: oid, mode: mode || DEFAULT_MODE)
+      rescue Rugged::IndexError => e
+        raise Gitlab::Git::Repository::InvalidBlobName.new(e.message)
+      end
+    end
+  end
+end