Rewrite Diff::CommitDiff in Ruby

4 files changed, 127 insertions, 1 deletions

diff --git a/internal/service/diff/commit.go b/internal/service/diff/commit.go
index 7b5ff8d71..eb8d4a648 100644
--- a/internal/service/diff/commit.go
+++ b/internal/service/diff/commit.go
@@ -9,6 +9,7 @@ import (
 	pb "gitlab.com/gitlab-org/gitaly-proto/go"
 	"gitlab.com/gitlab-org/gitaly/internal/diff"
 	"gitlab.com/gitlab-org/gitaly/internal/git"
+	"gitlab.com/gitlab-org/gitaly/internal/rubyserver"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 )
@@ -19,6 +20,35 @@ type requestWithLeftRightCommitIds interface {
 }
 
 func (s *server) CommitDiff(in *pb.CommitDiffRequest, stream pb.DiffService_CommitDiffServer) error {
+	ctx := stream.Context()
+
+	client, err := s.DiffServiceClient(ctx)
+	if err != nil {
+		return err
+	}
+
+	clientCtx, err := rubyserver.SetHeaders(ctx, in.GetRepository())
+	if err != nil {
+		return err
+	}
+
+	rubyStream, err := client.CommitDiff(clientCtx, in)
+	if err != nil {
+		return err
+	}
+
+	return rubyserver.Proxy(func() error {
+		resp, err := rubyStream.Recv()
+		if err != nil {
+			md := rubyStream.Trailer()
+			stream.SetTrailer(md)
+			return err
+		}
+		return stream.Send(resp)
+	})
+}
+
+/*
 	grpc_logrus.Extract(stream.Context()).WithFields(log.Fields{
 		"LeftCommitId":           in.LeftCommitId,
 		"RightCommitId":          in.RightCommitId,
@@ -111,7 +141,7 @@ func (s *server) CommitDiff(in *pb.CommitDiffRequest, stream pb.DiffService_Comm
 		return nil
 	})
 }
-
+*/
 func (s *server) CommitDelta(in *pb.CommitDeltaRequest, stream pb.DiffService_CommitDeltaServer) error {
 	grpc_logrus.Extract(stream.Context()).WithFields(log.Fields{
 		"LeftCommitId":  in.LeftCommitId,
diff --git a/ruby/lib/gitaly_server/diff_service.rb b/ruby/lib/gitaly_server/diff_service.rb
index 340146ea8..17e9029c9 100644
--- a/ruby/lib/gitaly_server/diff_service.rb
+++ b/ruby/lib/gitaly_server/diff_service.rb
@@ -15,5 +15,73 @@ module GitalyServer
         end
       end
     end
+
+    def commit_diff(request, call)
+      bridge_exceptions do
+        repo = Gitlab::Git::Repository.from_gitaly(request.repository, call)
+
+        options = {
+          :ignore_whitespace_change => request.ignore_whitespace_change,
+          :limits => request.enforce_limits,
+          :expanded => !(request.enforce_limits || request.collapse_diffs),
+          :max_lines => request.max_lines,
+          :max_files => request.max_files,
+          :max_bytes => request.max_bytes,
+          :safe_max_lines => request.safe_max_lines,
+          :safe_max_files => request.safe_max_files,
+          :safe_max_bytes => request.safe_max_bytes,
+        }
+
+        Enumerator.new do |y|
+          repo.diff(request.left_commit_id, request.right_commit_id, options, *request.paths.to_a).each do |diff|
+            response = Gitaly::CommitDiffResponse.new(
+              :from_path => diff.old_path.b,
+              :to_path => diff.new_path.b,
+              :from_id => diff.old_id,
+              :to_id => diff.new_id,
+              :old_mode => diff.a_mode.to_i(base=8),
+              :new_mode => diff.b_mode.to_i(base=8),
+              :binary => diff.has_binary_notice?,
+              :overflow_marker => diff.too_large?,
+              :collapsed => diff.collapsed?
+            )
+            io = StringIO.new(diff.diff)
+
+            chunk = io.read(Gitlab.config.git.write_buffer_size)
+            chunk = strip_diff_headers(chunk)
+            response.raw_patch_data = chunk.b
+            y.yield response
+            while chunk = io.read(Gitlab.config.git.write_buffer_size)
+              response.raw_patch_data = chunk.b
+              y.yield response
+            end
+            response.raw_patch_data = ""
+            response.end_of_patch = true
+            y.yield response
+          end
+        end
+      end
+    end
+
+    private
+
+    # Stolen from Gitlab::Git::Diff since that is private
+
+    # Strip out the information at the beginning of the patch's text to match
+    # Grit's output
+    def strip_diff_headers(diff_text)
+      # Delete everything up to the first line that starts with '---' or
+      # 'Binary'
+      diff_text.sub!(/\A.*?^(@@ )/m, '\1')
+
+      if diff_text.start_with?('@@ ')
+        diff_text
+      else
+        # If the diff_text did not contain a line starting with '---' or
+        # 'Binary', return the empty string. No idea why; we are just
+        # preserving behavior from before the refactor.
+        ''
+      end
+    end
   end
 end
diff --git a/ruby/lib/gitlab/git.rb b/ruby/lib/gitlab/git.rb
index 80516553a..8b4028c8f 100644
--- a/ruby/lib/gitlab/git.rb
+++ b/ruby/lib/gitlab/git.rb
@@ -44,6 +44,7 @@ end
 
 require_relative 'git/gitaly_remote_repository.rb'
 require_relative 'git/repository.rb'
+require_relative 'git/diff.rb'
 require_relative 'git/gitlab_projects.rb'
 
 class String
diff --git a/ruby/lib/gitlab/git/diff.rb b/ruby/lib/gitlab/git/diff.rb
new file mode 100644
index 000000000..0f5711534
--- /dev/null
+++ b/ruby/lib/gitlab/git/diff.rb
@@ -0,0 +1,27 @@
+module Gitlab
+  module Git
+    # These are monkey patches on top of the vendored version of Diff.
+		class Diff
+      attr_reader :old_id, :new_id
+
+			def init_from_rugged(rugged)
+        if rugged.is_a?(Rugged::Patch)
+          init_from_rugged_patch(rugged)
+          d = rugged.delta
+        else
+          d = rugged
+        end
+
+        @new_path = encode!(d.new_file[:path])
+        @old_path = encode!(d.old_file[:path])
+        @a_mode = d.old_file[:mode].to_s(8)
+        @b_mode = d.new_file[:mode].to_s(8)
+        @new_file = d.added?
+        @renamed_file = d.renamed?
+        @deleted_file = d.deleted?
+				@old_id = d.old_file[:oid] || BLANK_SHA
+				@new_id = d.new_file[:oid] || BLANK_SHA
+      end
+		end
+	end
+end