1 files changed, 63 insertions, 2 deletions
diff --git a/internal/service/commit/stats.go b/internal/service/commit/stats.go
index c4284b1c5..adc9d3bbd 100644
--- a/internal/service/commit/stats.go
+++ b/internal/service/commit/stats.go
@@ -1,12 +1,73 @@
 package commit
 
 import (
+	"bufio"
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+
 	"golang.org/x/net/context"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
 
 	pb "gitlab.com/gitlab-org/gitaly-proto/go"
+	"gitlab.com/gitlab-org/gitaly/internal/helper"
+)
+
+var (
+	commitRegex = regexp.MustCompile("([a-f0-9]{40})")
 )
 
-func (s server) CommitStats(ctx context.Context, in *pb.CommitStatsRequest) (*pb.CommitStatsResponse, error) {
+func (server) CommitStats(ctx context.Context, in *pb.CommitStatsRequest) (*pb.CommitStatsResponse, error) {
+	repoPath, err := helper.GetRepoPath(in.GetRepository())
+	if err != nil {
+		return nil, err
+	}
+
+	if len(in.GetRevision()) == 0 {
+		return nil, grpc.Errorf(codes.InvalidArgument, "no revision given")
+	}
+
+	// NOTE: append `^{commit}` so we only fetch the commit...
+	revision := fmt.Sprintf("%s^{commit}", in.GetRevision())
+	cmd, err := helper.GitCommandReader("--git-dir", repoPath, "show", "--format='%H'", "--numstat", revision)
+	if err != nil {
+		return nil, grpc.Errorf(codes.Internal, err.Error())
+	}
+
+	resp := &pb.CommitStatsResponse{}
+	scanner := bufio.NewScanner(cmd)
+	for scanner.Scan() {
+		line := scanner.Text()
+
+		// Don't try to match OID if it's already set
+		if len(resp.Oid) == 0 {
+			// Use Regex since we wanna be _really_ sure that this is a commit SHA
+			if matches := commitRegex.FindStringSubmatch(line); len(matches) >= 2 {
+				resp.Oid = matches[1]
+			}
+			// if OID isn't set, or just been set, continue
+			continue
+		}
+		if stats := strings.SplitN(line, "\t", 3); len(stats) == 3 {
+			var a, d int64
+			a, err = strconv.ParseInt(stats[0], 10, 32)
+			if err != nil {
+				return nil, grpc.Errorf(codes.Internal, err.Error())
+			}
+			d, err = strconv.ParseInt(stats[1], 10, 32)
+			if err != nil {
+				return nil, grpc.Errorf(codes.Internal, err.Error())
+			}
+			resp.Additions += int32(a)
+			resp.Deletions += int32(d)
+		}
+	}
+
+	if err = cmd.Wait(); err != nil {
+		return nil, grpc.Errorf(codes.Internal, err.Error())
+	}
 
-	return nil, nil
+	return resp, nil
 }