Fix performance regression on startup in repos with many tags (#4777)

- **PR Description**

In #4663 we added information in the tags panel about the selected tag
(whether it's annotated etc). Unfortunately this introduced a
performance regression in repositories with many tags, so revert this
and implement the feature in a slightly different way to avoid the
performance hit.

Fixes #4770.

Author: stefanhaller

pkg/commands/git_commands/tag.go

@@ -1,6 +1,8 @@
 package git_commands
 
 import (
+	"strings"
+
 	"github.com/jesseduffield/gocui"
 	"github.com/jesseduffield/lazygit/pkg/commands/oscommands"
 )
@@ -74,3 +76,13 @@ func (self *TagCommands) ShowAnnotationInfo(tagName string) (string, error) {
 
 	return self.cmd.New(cmdArgs).RunWithOutput()
 }
+
+func (self *TagCommands) IsTagAnnotated(tagName string) (bool, error) {
+	cmdArgs := NewGitCmd("cat-file").
+		Arg("-t").
+		Arg("refs/tags/" + tagName).
+		ToArgv()
+
+	output, err := self.cmd.New(cmdArgs).RunWithOutput()
+	return strings.TrimSpace(output) == "tag", err
+}

pkg/commands/git_commands/tag_loader.go

@@ -1,7 +1,7 @@
 package git_commands
 
 import (
-	"strings"
+	"regexp"
 
 	"github.com/jesseduffield/lazygit/pkg/commands/models"
 	"github.com/jesseduffield/lazygit/pkg/commands/oscommands"
@@ -26,34 +26,30 @@ func NewTagLoader(
 }
 
 func (self *TagLoader) GetTags() ([]*models.Tag, error) {
-	// get tags, sorted by creation date (descending)
+	// get remote branches, sorted  by creation date (descending)
 	// see: https://git-scm.com/docs/git-tag#Documentation/git-tag.txt---sortltkeygt
-	cmdArgs := NewGitCmd("for-each-ref").
-		Arg("--sort=-creatordate").
-		Arg("--format=%(refname)%00%(objecttype)%00%(contents:subject)").
-		Arg("refs/tags").
-		ToArgv()
+	cmdArgs := NewGitCmd("tag").Arg("--list", "-n", "--sort=-creatordate").ToArgv()
 	tagsOutput, err := self.cmd.New(cmdArgs).DontLog().RunWithOutput()
 	if err != nil {
 		return nil, err
 	}
 
 	split := utils.SplitLines(tagsOutput)
 
-	tags := lo.FilterMap(split, func(line string, _ int) (*models.Tag, bool) {
-		fields := strings.SplitN(line, "\x00", 3)
-		if len(fields) != 3 {
-			return nil, false
+	lineRegex := regexp.MustCompile(`^([^\s]+)(\s+)?(.*)$`)
+
+	tags := lo.Map(split, func(line string, _ int) *models.Tag {
+		matches := lineRegex.FindStringSubmatch(line)
+		tagName := matches[1]
+		message := ""
+		if len(matches) > 3 {
+			message = matches[3]
 		}
-		tagName := fields[0]
-		objectType := fields[1]
-		message := fields[2]
 
 		return &models.Tag{
-			Name:        strings.TrimPrefix(tagName, "refs/tags/"),
-			Message:     message,
-			IsAnnotated: objectType == "tag",
-		}, true
+			Name:    tagName,
+			Message: message,
+		}
 	})
 
 	return tags, nil

pkg/commands/git_commands/tag_loader_test.go

@@ -9,9 +9,10 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-const tagsOutput = "refs/tags/tag1\x00tag\x00this is my message\n" +
-	"refs/tags/tag2\x00commit\x00\n" +
-	"refs/tags/tag3\x00tag\x00this is my other message\n"
+const tagsOutput = `tag1 this is my message
+tag2
+tag3 this is my other message
+`
 
 func TestGetTags(t *testing.T) {
 	type scenario struct {
@@ -25,18 +26,18 @@ func TestGetTags(t *testing.T) {
 		{
 			testName: "should return no tags if there are none",
 			runner: oscommands.NewFakeRunner(t).
-				ExpectGitArgs([]string{"for-each-ref", "--sort=-creatordate", "--format=%(refname)%00%(objecttype)%00%(contents:subject)", "refs/tags"}, "", nil),
+				ExpectGitArgs([]string{"tag", "--list", "-n", "--sort=-creatordate"}, "", nil),
 			expectedTags:  []*models.Tag{},
 			expectedError: nil,
 		},
 		{
 			testName: "should return tags if present",
 			runner: oscommands.NewFakeRunner(t).
-				ExpectGitArgs([]string{"for-each-ref", "--sort=-creatordate", "--format=%(refname)%00%(objecttype)%00%(contents:subject)", "refs/tags"}, tagsOutput, nil),
+				ExpectGitArgs([]string{"tag", "--list", "-n", "--sort=-creatordate"}, tagsOutput, nil),
 			expectedTags: []*models.Tag{
-				{Name: "tag1", Message: "this is my message", IsAnnotated: true},
-				{Name: "tag2", Message: "", IsAnnotated: false},
-				{Name: "tag3", Message: "this is my other message", IsAnnotated: true},
+				{Name: "tag1", Message: "this is my message"},
+				{Name: "tag2", Message: ""},
+				{Name: "tag3", Message: "this is my other message"},
 			},
 			expectedError: nil,
 		},

pkg/commands/models/tag.go

@@ -3,13 +3,9 @@ package models
 // Tag : A git tag
 type Tag struct {
 	Name string
-
 	// this is either the first line of the message of an annotated tag, or the
 	// first line of a commit message for a lightweight tag
 	Message string
-
-	// true if this is an annotated tag, false if it's a lightweight tag
-	IsAnnotated bool
 }
 
 func (t *Tag) FullRefName() string {

pkg/gui/controllers/tags_controller.go

@@ -117,7 +117,12 @@ func (self *TagsController) GetOnRenderToMain() func() {
 }
 
 func (self *TagsController) getTagInfo(tag *models.Tag) string {
-	if tag.IsAnnotated {
+	tagIsAnnotated, err := self.c.Git().Tag.IsTagAnnotated(tag.Name)
+	if err != nil {
+		self.c.Log.Warnf("Error checking if tag is annotated: %v", err)
+	}
+
+	if tagIsAnnotated {
 		info := fmt.Sprintf("%s: %s", self.c.Tr.AnnotatedTag, style.AttrBold.Sprint(style.FgYellow.Sprint(tag.Name)))
 		output, err := self.c.Git().Tag.ShowAnnotationInfo(tag.Name)
 		if err == nil {

pkg/integration/tests/tag/crud_annotated.go

@@ -32,6 +32,18 @@ var CrudAnnotated = NewIntegrationTest(NewIntegrationTestArgs{
 			Lines(
 				MatchesRegexp(`new-tag.*message`).IsSelected(),
 			).
+			Tap(func() {
+				t.Views().Main().ContainsLines(
+					Equals("Annotated tag: new-tag"),
+					Equals(""),
+					Contains("Tagger:"),
+					Contains("TaggerDate:"),
+					Equals(""),
+					Equals("message"),
+					Equals(""),
+					Equals("---"),
+				)
+			}).
 			Press(keys.Universal.Push).
 			Tap(func() {
 				t.ExpectPopup().Prompt().

pkg/integration/tests/tag/crud_lightweight.go

@@ -28,6 +28,13 @@ var CrudLightweight = NewIntegrationTest(NewIntegrationTestArgs{
 			Lines(
 				MatchesRegexp(`new-tag.*initial commit`).IsSelected(),
 			).
+			Tap(func() {
+				t.Views().Main().ContainsLines(
+					Equals("Lightweight tag: new-tag"),
+					Equals(""),
+					Equals("---"),
+				)
+			}).
 			PressEnter().
 			Tap(func() {
 				// view the commits of the tag