Move checksum calculation to Gitlab::Git::Repository

lib/gitlab/git/checksum.rb

-module Gitlab
-  module Git
-    class Checksum
-      include Gitlab::Git::Popen
-
-      EMPTY_REPOSITORY_CHECKSUM = '0000000000000000000000000000000000000000'.freeze
-
-      Failure = Class.new(StandardError)
-
-      attr_reader :path, :relative_path, :storage, :storage_path, :gl_repository
-
-      def initialize(storage, relative_path, gl_repository)
-        @storage       = storage
-        @storage_path  = Gitlab.config.repositories.storages[storage].legacy_disk_path
-        @relative_path = "#{relative_path}.git"
-        @path          = File.join(storage_path, @relative_path)
-        @gl_repository = gl_repository
-      end
-
-      def calculate
-        unless repository_exists?
-          failure!(Gitlab::Git::Repository::NoRepository, 'No repository for such path')
-        end
-
-        raw_repository.gitaly_migrate(:calculate_checksum) do |is_enabled|
-          if is_enabled
-            calculate_checksum_gitaly
-          else
-            calculate_checksum_by_shelling_out
-          end
-        end
-      end
-
-      private
-
-      def repository_exists?
-        raw_repository.exists?
-      end
-
-      def calculate_checksum_gitaly
-        gitaly_repository_client.calculate_checksum
-      end
-
-      def calculate_checksum_by_shelling_out
-        args = %W(--git-dir=#{path} show-ref --heads --tags)
-        output, status = run_git(args)
-
-        if status&.zero?
-          refs = output.split("\n")
-
-          result = refs.inject(nil) do |checksum, ref|
-            value = Digest::SHA1.hexdigest(ref).hex
-
-            if checksum.nil?
-              value
-            else
-              checksum ^ value
-            end
-          end
-
-          result.to_s(16)
-        else
-          # Empty repositories return with a non-zero status and an empty output.
-          if output&.empty?
-            EMPTY_REPOSITORY_CHECKSUM
-          else
-            failure!(Gitlab::Git::Checksum::Failure, output)
-          end
-        end
-      end
-
-      def failure!(klass, message)
-        Gitlab::GitLogger.error("'git show-ref --heads --tags' in #{path}: #{message}")
-
-        raise klass.new("Could not calculate the checksum for #{path}: #{message}")
-      end
-
-      def circuit_breaker
-        @circuit_breaker ||= Gitlab::Git::Storage::CircuitBreaker.for_storage(storage)
-      end
-
-      def raw_repository
-        @raw_repository ||= Gitlab::Git::Repository.new(storage, relative_path, gl_repository)
-      end
-
-      def gitaly_repository_client
-        raw_repository.gitaly_repository_client
-      end
-
-      def run_git(args)
-        circuit_breaker.perform do
-          popen([Gitlab.config.git.bin_path, *args], path)
-        end
-      end
-    end
-  end
-end

lib/gitlab/git/repository.rb

@@ -23,6 +23,7 @@ module Gitlab
       SQUASH_WORKTREE_PREFIX = 'squash'.freeze
       GITALY_INTERNAL_URL = 'ssh://gitaly/internal.git'.freeze
       GITLAB_PROJECTS_TIMEOUT = Gitlab.config.gitlab_shell.git_timeout
+      EMPTY_REPOSITORY_CHECKSUM = '0000000000000000000000000000000000000000'.freeze
       NoRepository = Class.new(StandardError)
       InvalidBlobName = Class.new(StandardError)
@@ -31,6 +32,7 @@ module Gitlab
       DeleteBranchError = Class.new(StandardError)
       CreateTreeError = Class.new(StandardError)
       TagExistsError = Class.new(StandardError)
+      ChecksumError = Class.new(StandardError)
       class << self
         # Unlike `new`, `create` takes the repository path
@@ -1502,6 +1504,16 @@ module Gitlab
         FileUtils.rm_rf(worktree_git_path) if worktree_git_path && File.exist?(worktree_git_path)
       end
+      def checksum
+        gitaly_migrate(:calculate_checksum) do |is_enabled|
+          if is_enabled
+            gitaly_repository_client.calculate_checksum
+          else
+            calculate_checksum_by_shelling_out
+          end
+        end
+      end
+
       private
       def local_write_ref(ref_path, ref, old_ref: nil, shell: true)
@@ -2420,6 +2432,34 @@ module Gitlab
       def sha_from_ref(ref)
         rev_parse_target(ref).oid
       end
+
+      def calculate_checksum_by_shelling_out
+        raise NoRepository unless exists?
+
+        args = %W(--git-dir=#{path} show-ref --heads --tags)
+        output, status = run_git(args)
+
+        if status.nil? || !status.zero?
+          # Empty repositories return with a non-zero status and an empty output.
+          return EMPTY_REPOSITORY_CHECKSUM if output&.empty?
+
+          raise ChecksumError, output
+        end
+
+        refs = output.split("\n")
+
+        result = refs.inject(nil) do |checksum, ref|
+          value = Digest::SHA1.hexdigest(ref).hex
+
+          if checksum.nil?
+            value
+          else
+            checksum ^ value
+          end
+        end
+
+        result.to_s(16)
+      end
     end
   end
 end

spec/lib/gitlab/git/checksum_spec.rb

-require 'spec_helper'
-
-describe Gitlab::Git::Checksum, seed_helper: true do
-  let(:storage) { 'default' }
-  let(:gl_repository) { 'project-123' }
-
-  shared_examples 'calculating checksum' do
-    it 'raises Gitlab::Git::Repository::NoRepository when there is no repo' do
-      checksum = described_class.new(storage, 'nonexistent-repo', gl_repository)
-
-      expect { checksum.calculate }.to raise_error Gitlab::Git::Repository::NoRepository
-    end
-
-    it 'pretends that checksum is 000000... when the repo is empty' do
-      FileUtils.rm_rf(File.join(SEED_STORAGE_PATH, 'empty-repo.git'))
-
-      system(git_env, *%W(#{Gitlab.config.git.bin_path} init --bare empty-repo.git),
-             chdir: SEED_STORAGE_PATH,
-             out:   '/dev/null',
-             err:   '/dev/null')
-
-      checksum = described_class.new(storage, 'empty-repo', gl_repository)
-
-      expect(checksum.calculate).to eq '0000000000000000000000000000000000000000'
-    end
-
-    it 'calculates the checksum when there is a repo' do
-      checksum = described_class.new(storage, 'gitlab-git-test', gl_repository)
-
-      expect(checksum.calculate).to eq '54f21be4c32c02f6788d72207fa03ad3bce725e4'
-    end
-  end
-
-  context 'when calculate_checksum Gitaly feature is enabled' do
-    it_behaves_like 'calculating checksum'
-  end
-
-  context 'when calculate_checksum Gitaly feature is disabled', :disable_gitaly do
-    it_behaves_like 'calculating checksum'
-
-    it "raises a Gitlab::Git::Repository::Failure error if the `popen` call to git returns a non-zero exit code" do
-      checksum = described_class.new(storage, 'gitlab-git-test', gl_repository)
-
-      allow(checksum).to receive(:popen).and_return(['output', nil])
-
-      expect { checksum.calculate }.to raise_error Gitlab::Git::Checksum::Failure
-    end
-  end
-end

spec/lib/gitlab/git/repository_spec.rb

@@ -2184,6 +2184,55 @@ describe Gitlab::Git::Repository, seed_helper: true do
     end
   end
+  describe '#checksum' do
+    shared_examples 'calculating checksum' do
+      it 'calculates the checksum for non-empty repo' do
+        expect(repository.checksum).to eq '54f21be4c32c02f6788d72207fa03ad3bce725e4'
+      end
+
+      it 'returns 0000000000000000000000000000000000000000 for an empty repo' do
+        FileUtils.rm_rf(File.join(storage_path, 'empty-repo.git'))
+
+        system(git_env, *%W(#{Gitlab.config.git.bin_path} init --bare empty-repo.git),
+               chdir: storage_path,
+               out:   '/dev/null',
+               err:   '/dev/null')
+
+        empty_repo = described_class.new('default', 'empty-repo.git', '')
+
+        expect(empty_repo.checksum).to eq '0000000000000000000000000000000000000000'
+      end
+
+      it 'raises a no repository exception when there is no repo' do
+        broken_repo = described_class.new('default', 'a/path.git', '')
+
+        expect { broken_repo.checksum }.to raise_error(Gitlab::Git::Repository::NoRepository)
+      end
+    end
+
+    context 'when calculate_checksum Gitaly feature is enabled' do
+      it_behaves_like 'calculating checksum'
+    end
+
+    context 'when calculate_checksum Gitaly feature is disabled', :disable_gitaly do
+      it_behaves_like 'calculating checksum'
+
+      describe 'when storage is broken', :broken_storage  do
+        it 'raises a storage exception when storage is not available' do
+          broken_repo = described_class.new('broken', 'a/path.git', '')
+
+          expect { broken_repo.rugged }.to raise_error(Gitlab::Git::Storage::Inaccessible)
+        end
+      end
+
+      it "raises a Gitlab::Git::Repository::Failure error if the `popen` call to git returns a non-zero exit code" do
+        allow(repository).to receive(:popen).and_return(['output', nil])
+
+        expect { repository.checksum }.to raise_error Gitlab::Git::Repository::ChecksumError
+      end
+    end
+  end
+
   context 'gitlab_projects commands' do
     let(:gitlab_projects) { repository.gitlab_projects }
     let(:timeout) { Gitlab.config.gitlab_shell.git_timeout }