Show divergence from base branch in branches list

Author: stefanhaller

docs/Config.md

@@ -187,6 +187,10 @@ gui:
   # If true, show commit hashes alongside branch names in the branches view.
   showBranchCommitHash: false
 
+  # Whether to show the divergence from the base branch in the branches view.
+  # One of: 'none' | 'onlyArrow'  | 'arrowAndNumber'
+  showDivergenceFromBaseBranch: none
+
   # Height of the command log view
   commandLogSize: 8
 

pkg/commands/git_commands/branch_loader.go

@@ -5,6 +5,7 @@ import (
 	"regexp"
 	"strconv"
 	"strings"
+	"time"
 
 	"github.com/jesseduffield/generics/set"
 	"github.com/jesseduffield/go-git/v5/config"
@@ -14,6 +15,7 @@ import (
 	"github.com/jesseduffield/lazygit/pkg/utils"
 	"github.com/samber/lo"
 	"golang.org/x/exp/slices"
+	"golang.org/x/sync/errgroup"
 )
 
 // context:
@@ -63,7 +65,13 @@ func NewBranchLoader(
 }
 
 // Load the list of branches for the current repo
-func (self *BranchLoader) Load(reflogCommits []*models.Commit) ([]*models.Branch, error) {
+func (self *BranchLoader) Load(reflogCommits []*models.Commit,
+	mainBranches *MainBranches,
+	oldBranches []*models.Branch,
+	loadBehindCounts bool,
+	onWorker func(func() error),
+	renderFunc func(),
+) ([]*models.Branch, error) {
 	branches := self.obtainBranches(self.version.IsAtLeast(2, 22, 0))
 
 	if self.AppState.LocalBranchSortOrder == "recency" {
@@ -122,11 +130,75 @@ func (self *BranchLoader) Load(reflogCommits []*models.Commit) ([]*models.Branch
 			branch.UpstreamRemote = match.Remote
 			branch.UpstreamBranch = match.Merge.Short()
 		}
+
+		// If the branch already existed, take over its BehindBaseBranch value
+		// to reduce flicker
+		if oldBranch, found := lo.Find(oldBranches, func(b *models.Branch) bool {
+			return b.Name == branch.Name
+		}); found {
+			branch.BehindBaseBranch.Store(oldBranch.BehindBaseBranch.Load())
+		}
+	}
+
+	if loadBehindCounts && self.UserConfig.Gui.ShowDivergenceFromBaseBranch != "none" {
+		onWorker(func() error {
+			return self.GetBehindBaseBranchValuesForAllBranches(branches, mainBranches, renderFunc)
+		})
 	}
 
 	return branches, nil
 }
 
+func (self *BranchLoader) GetBehindBaseBranchValuesForAllBranches(
+	branches []*models.Branch,
+	mainBranches *MainBranches,
+	renderFunc func(),
+) error {
+	mainBranchRefs := mainBranches.Get()
+	if len(mainBranchRefs) == 0 {
+		return nil
+	}
+
+	t := time.Now()
+	errg := errgroup.Group{}
+
+	for _, branch := range branches {
+		errg.Go(func() error {
+			baseBranch, err := self.GetBaseBranch(branch, mainBranches)
+			if err != nil {
+				return err
+			}
+			behind := 0 // prime it in case something below fails
+			if baseBranch != "" {
+				output, err := self.cmd.New(
+					NewGitCmd("rev-list").
+						Arg("--left-right").
+						Arg("--count").
+						Arg(fmt.Sprintf("%s...%s", branch.FullRefName(), baseBranch)).
+						ToArgv(),
+				).DontLog().RunWithOutput()
+				if err != nil {
+					return err
+				}
+				// The format of the output is "<ahead>\t<behind>"
+				aheadBehindStr := strings.Split(strings.TrimSpace(output), "\t")
+				if len(aheadBehindStr) == 2 {
+					if value, err := strconv.Atoi(aheadBehindStr[1]); err == nil {
+						behind = value
+					}
+				}
+			}
+			branch.BehindBaseBranch.Store(int32(behind))
+			return nil
+		})
+	}
+
+	err := errg.Wait()
+	self.Log.Debugf("time to get behind base branch values for all branches: %s", time.Since(t))
+	renderFunc()
+	return err
+}
+
 // Find the base branch for the given branch (i.e. the main branch that the
 // given branch was forked off of)
 //

pkg/commands/models/branch.go

@@ -1,6 +1,9 @@
 package models
 
-import "fmt"
+import (
+	"fmt"
+	"sync/atomic"
+)
 
 // Branch : A git branch
 // duplicating this for now
@@ -32,6 +35,11 @@ type Branch struct {
 	Subject string
 	// commit hash
 	CommitHash string
+
+	// How far we have fallen behind our base branch. 0 means either not
+	// determined yet, or up to date with base branch. (We don't need to
+	// distinguish the two, as we don't draw anything in both cases.)
+	BehindBaseBranch atomic.Int32
 }
 
 func (b *Branch) FullRefName() string {

pkg/config/user_config.go

@@ -129,6 +129,9 @@ type GuiConfig struct {
 	CommitHashLength int `yaml:"commitHashLength" jsonschema:"minimum=0"`
 	// If true, show commit hashes alongside branch names in the branches view.
 	ShowBranchCommitHash bool `yaml:"showBranchCommitHash"`
+	// Whether to show the divergence from the base branch in the branches view.
+	// One of: 'none' | 'onlyArrow'  | 'arrowAndNumber'
+	ShowDivergenceFromBaseBranch string `yaml:"showDivergenceFromBaseBranch" jsonschema:"enum=none,enum=onlyArrow,enum=arrowAndNumber"`
 	// Height of the command log view
 	CommandLogSize int `yaml:"commandLogSize" jsonschema:"minimum=0"`
 	// Whether to split the main window when viewing file changes.
@@ -673,27 +676,28 @@ func GetDefaultConfig() *UserConfig {
 				UnstagedChangesColor:       []string{"red"},
 				DefaultFgColor:             []string{"default"},
 			},
-			CommitLength:              CommitLengthConfig{Show: true},
-			SkipNoStagedFilesWarning:  false,
-			ShowListFooter:            true,
-			ShowCommandLog:            true,
-			ShowBottomLine:            true,
-			ShowPanelJumps:            true,
-			ShowFileTree:              true,
-			ShowRandomTip:             true,
-			ShowIcons:                 false,
-			NerdFontsVersion:          "",
-			ShowFileIcons:             true,
-			CommitHashLength:          8,
-			ShowBranchCommitHash:      false,
-			CommandLogSize:            8,
-			SplitDiff:                 "auto",
-			SkipRewordInEditorWarning: false,
-			WindowSize:                "normal",
-			Border:                    "rounded",
-			AnimateExplosion:          true,
-			PortraitMode:              "auto",
-			FilterMode:                "substring",
+			CommitLength:                 CommitLengthConfig{Show: true},
+			SkipNoStagedFilesWarning:     false,
+			ShowListFooter:               true,
+			ShowCommandLog:               true,
+			ShowBottomLine:               true,
+			ShowPanelJumps:               true,
+			ShowFileTree:                 true,
+			ShowRandomTip:                true,
+			ShowIcons:                    false,
+			NerdFontsVersion:             "",
+			ShowFileIcons:                true,
+			CommitHashLength:             8,
+			ShowBranchCommitHash:         false,
+			ShowDivergenceFromBaseBranch: "none",
+			CommandLogSize:               8,
+			SplitDiff:                    "auto",
+			SkipRewordInEditorWarning:    false,
+			WindowSize:                   "normal",
+			Border:                       "rounded",
+			AnimateExplosion:             true,
+			PortraitMode:                 "auto",
+			FilterMode:                   "substring",
 			Spinner: SpinnerConfig{
 				Frames: []string{"|", "/", "-", "\\"},
 				Rate:   50,

pkg/config/user_config_validation.go

@@ -7,7 +7,12 @@ import (
 )
 
 func (config *UserConfig) Validate() error {
-	if err := validateEnum("gui.statusPanelView", config.Gui.StatusPanelView, []string{"dashboard", "allBranchesLog"}); err != nil {
+	if err := validateEnum("gui.statusPanelView", config.Gui.StatusPanelView,
+		[]string{"dashboard", "allBranchesLog"}); err != nil {
+		return err
+	}
+	if err := validateEnum("gui.showDivergenceFromBaseBranch", config.Gui.ShowDivergenceFromBaseBranch,
+		[]string{"none", "onlyArrow", "arrowAndNumber"}); err != nil {
 		return err
 	}
 	return nil

pkg/gui/controllers/helpers/refresh_helper.go

@@ -130,7 +130,7 @@ func (self *RefreshHelper) Refresh(options types.RefreshOptions) error {
 			if self.c.AppState.LocalBranchSortOrder == "recency" {
 				refresh("reflog and branches", func() { self.refreshReflogAndBranches(includeWorktreesWithBranches, options.KeepBranchSelectionIndex) })
 			} else {
-				refresh("branches", func() { self.refreshBranches(includeWorktreesWithBranches, options.KeepBranchSelectionIndex) })
+				refresh("branches", func() { self.refreshBranches(includeWorktreesWithBranches, options.KeepBranchSelectionIndex, true) })
 				refresh("reflog", func() { _ = self.refreshReflogCommits() })
 			}
 		} else if scopeSet.Includes(types.REBASE_COMMITS) {
@@ -256,7 +256,7 @@ func (self *RefreshHelper) refreshReflogCommitsConsideringStartup() {
 	case types.INITIAL:
 		self.c.OnWorker(func(_ gocui.Task) error {
 			_ = self.refreshReflogCommits()
-			self.refreshBranches(false, true)
+			self.refreshBranches(false, true, true)
 			self.c.State().GetRepoState().SetStartupStage(types.COMPLETE)
 			return nil
 		})
@@ -269,7 +269,7 @@ func (self *RefreshHelper) refreshReflogCommitsConsideringStartup() {
 func (self *RefreshHelper) refreshReflogAndBranches(refreshWorktrees bool, keepBranchSelectionIndex bool) {
 	self.refreshReflogCommitsConsideringStartup()
 
-	self.refreshBranches(refreshWorktrees, keepBranchSelectionIndex)
+	self.refreshBranches(refreshWorktrees, keepBranchSelectionIndex, false)
 }
 
 func (self *RefreshHelper) refreshCommitsAndCommitFiles() {
@@ -438,7 +438,7 @@ func (self *RefreshHelper) refreshStateSubmoduleConfigs() error {
 
 // self.refreshStatus is called at the end of this because that's when we can
 // be sure there is a State.Model.Branches array to pick the current branch from
-func (self *RefreshHelper) refreshBranches(refreshWorktrees bool, keepBranchSelectionIndex bool) {
+func (self *RefreshHelper) refreshBranches(refreshWorktrees bool, keepBranchSelectionIndex bool, loadBehindCounts bool) {
 	self.c.Mutexes().RefreshingBranchesMutex.Lock()
 	defer self.c.Mutexes().RefreshingBranchesMutex.Unlock()
 
@@ -457,7 +457,25 @@ func (self *RefreshHelper) refreshBranches(refreshWorktrees bool, keepBranchSele
 		}
 	}
 
-	branches, err := self.c.Git().Loaders.BranchLoader.Load(reflogCommits)
+	branches, err := self.c.Git().Loaders.BranchLoader.Load(
+		reflogCommits,
+		self.c.Model().MainBranches,
+		self.c.Model().Branches,
+		loadBehindCounts,
+		func(f func() error) {
+			self.c.OnWorker(func(_ gocui.Task) error {
+				return f()
+			})
+		},
+		func() {
+			self.c.OnUIThread(func() error {
+				if err := self.c.Contexts().Branches.HandleRender(); err != nil {
+					self.c.Log.Error(err)
+				}
+				self.refreshStatus()
+				return nil
+			})
+		})
 	if err != nil {
 		self.c.Log.Error(err)
 	}

pkg/gui/presentation/branches.go

@@ -155,32 +155,38 @@ func BranchStatus(
 		return style.FgCyan.Sprintf("%s %s", itemOperationStr, utils.Loader(now, userConfig.Gui.Spinner))
 	}
 
-	if !branch.IsTrackingRemote() {
-		return ""
-	}
-
-	if branch.UpstreamGone {
-		return style.FgRed.Sprint(tr.UpstreamGone)
-	}
-
-	if branch.MatchesUpstream() {
-		return style.FgGreen.Sprint("✓")
-	}
-	if branch.RemoteBranchNotStoredLocally() {
-		return style.FgMagenta.Sprint("?")
-	}
-
-	if branch.IsBehindForPull() && branch.IsAheadForPull() {
-		return style.FgYellow.Sprintf("↓%s↑%s", branch.BehindForPull, branch.AheadForPull)
-	}
-	if branch.IsBehindForPull() {
-		return style.FgYellow.Sprintf("↓%s", branch.BehindForPull)
-	}
-	if branch.IsAheadForPull() {
-		return style.FgYellow.Sprintf("↑%s", branch.AheadForPull)
-	}
-
-	return ""
+	result := ""
+	if branch.IsTrackingRemote() {
+		if branch.UpstreamGone {
+			result = style.FgRed.Sprint(tr.UpstreamGone)
+		} else if branch.MatchesUpstream() {
+			result = style.FgGreen.Sprint("✓")
+		} else if branch.RemoteBranchNotStoredLocally() {
+			result = style.FgMagenta.Sprint("?")
+		} else if branch.IsBehindForPull() && branch.IsAheadForPull() {
+			result = style.FgYellow.Sprintf("↓%s↑%s", branch.BehindForPull, branch.AheadForPull)
+		} else if branch.IsBehindForPull() {
+			result = style.FgYellow.Sprintf("↓%s", branch.BehindForPull)
+		} else if branch.IsAheadForPull() {
+			result = style.FgYellow.Sprintf("↑%s", branch.AheadForPull)
+		}
+	}
+
+	if userConfig.Gui.ShowDivergenceFromBaseBranch != "none" {
+		behind := branch.BehindBaseBranch.Load()
+		if behind != 0 {
+			if result != "" {
+				result += " "
+			}
+			if userConfig.Gui.ShowDivergenceFromBaseBranch == "arrowAndNumber" {
+				result += style.FgCyan.Sprintf("↓%d", behind)
+			} else {
+				result += style.FgCyan.Sprintf("↓")
+			}
+		}
+	}
+
+	return result
 }
 
 func SetCustomBranches(customBranchColors map[string]string) {