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mirror of https://github.com/jesseduffield/lazygit.git synced 2024-12-16 11:37:01 +02:00
lazygit/pkg/gui/presentation/graph/graph.go
2022-03-24 20:14:41 +11:00

401 lines
9.8 KiB
Go

package graph
import (
"runtime"
"strings"
"sync"
"github.com/jesseduffield/generics/slices"
"github.com/jesseduffield/lazygit/pkg/commands/models"
"github.com/jesseduffield/lazygit/pkg/gui/style"
"github.com/jesseduffield/lazygit/pkg/utils"
)
type PipeKind uint8
const (
TERMINATES PipeKind = iota
STARTS
CONTINUES
)
type Pipe struct {
fromPos int
toPos int
fromSha string
toSha string
kind PipeKind
style style.TextStyle
}
var highlightStyle = style.FgLightWhite.SetBold()
func ContainsCommitSha(pipes []*Pipe, sha string) bool {
for _, pipe := range pipes {
if equalHashes(pipe.fromSha, sha) {
return true
}
}
return false
}
func (self Pipe) left() int {
return utils.Min(self.fromPos, self.toPos)
}
func (self Pipe) right() int {
return utils.Max(self.fromPos, self.toPos)
}
func RenderCommitGraph(commits []*models.Commit, selectedCommitSha string, getStyle func(c *models.Commit) style.TextStyle) []string {
pipeSets := GetPipeSets(commits, getStyle)
if len(pipeSets) == 0 {
return nil
}
lines := RenderAux(pipeSets, commits, selectedCommitSha)
return lines
}
func GetPipeSets(commits []*models.Commit, getStyle func(c *models.Commit) style.TextStyle) [][]*Pipe {
if len(commits) == 0 {
return nil
}
pipes := []*Pipe{{fromPos: 0, toPos: 0, fromSha: "START", toSha: commits[0].Sha, kind: STARTS, style: style.FgDefault}}
pipeSets := [][]*Pipe{}
for _, commit := range commits {
pipes = getNextPipes(pipes, commit, getStyle)
pipeSets = append(pipeSets, pipes)
}
return pipeSets
}
func RenderAux(pipeSets [][]*Pipe, commits []*models.Commit, selectedCommitSha string) []string {
maxProcs := runtime.GOMAXPROCS(0)
lines := make([]string, 0, len(pipeSets))
// splitting up the rendering of the graph into multiple goroutines allows us to render the graph in parallel
chunks := make([][]string, maxProcs)
perProc := len(pipeSets) / maxProcs
wg := sync.WaitGroup{}
wg.Add(maxProcs)
for i := 0; i < maxProcs; i++ {
i := i
go func() {
from := i * perProc
to := (i + 1) * perProc
if i == maxProcs-1 {
to = len(pipeSets)
}
innerLines := make([]string, 0, to-from)
for j, pipeSet := range pipeSets[from:to] {
k := from + j
var prevCommit *models.Commit
if k > 0 {
prevCommit = commits[k-1]
}
line := renderPipeSet(pipeSet, selectedCommitSha, prevCommit)
innerLines = append(innerLines, line)
}
chunks[i] = innerLines
wg.Done()
}()
}
wg.Wait()
for _, chunk := range chunks {
lines = append(lines, chunk...)
}
return lines
}
func getNextPipes(prevPipes []*Pipe, commit *models.Commit, getStyle func(c *models.Commit) style.TextStyle) []*Pipe {
currentPipes := make([]*Pipe, 0, len(prevPipes))
maxPos := 0
for _, pipe := range prevPipes {
// a pipe that terminated in the previous line has no bearing on the current line
// so we'll filter those out
if pipe.kind != TERMINATES {
currentPipes = append(currentPipes, pipe)
}
maxPos = utils.Max(maxPos, pipe.toPos)
}
newPipes := make([]*Pipe, 0, len(currentPipes)+len(commit.Parents))
// start by assuming that we've got a brand new commit not related to any preceding commit.
// (this only happens when we're doing `git log --all`). These will be tacked onto the far end.
pos := maxPos + 1
for _, pipe := range currentPipes {
if equalHashes(pipe.toSha, commit.Sha) {
// turns out this commit does have a descendant so we'll place it right under the first instance
pos = pipe.toPos
break
}
}
// a taken spot is one where a current pipe is ending on
takenSpots := make(map[int]bool)
// a traversed spot is one where a current pipe is starting on, ending on, or passing through
traversedSpots := make(map[int]bool)
if len(commit.Parents) > 0 {
newPipes = append(newPipes, &Pipe{
fromPos: pos,
toPos: pos,
fromSha: commit.Sha,
toSha: commit.Parents[0],
kind: STARTS,
style: getStyle(commit),
})
}
traversedSpotsForContinuingPipes := make(map[int]bool)
for _, pipe := range currentPipes {
if !equalHashes(pipe.toSha, commit.Sha) {
traversedSpotsForContinuingPipes[pipe.toPos] = true
}
}
getNextAvailablePosForContinuingPipe := func() int {
i := 0
for {
if !traversedSpots[i] {
return i
}
i++
}
}
getNextAvailablePosForNewPipe := func() int {
i := 0
for {
// a newly created pipe is not allowed to end on a spot that's already taken,
// nor on a spot that's been traversed by a continuing pipe.
if !takenSpots[i] && !traversedSpotsForContinuingPipes[i] {
return i
}
i++
}
}
traverse := func(from, to int) {
left, right := from, to
if left > right {
left, right = right, left
}
for i := left; i <= right; i++ {
traversedSpots[i] = true
}
takenSpots[to] = true
}
for _, pipe := range currentPipes {
if equalHashes(pipe.toSha, commit.Sha) {
// terminating here
newPipes = append(newPipes, &Pipe{
fromPos: pipe.toPos,
toPos: pos,
fromSha: pipe.fromSha,
toSha: pipe.toSha,
kind: TERMINATES,
style: pipe.style,
})
traverse(pipe.toPos, pos)
} else if pipe.toPos < pos {
// continuing here
availablePos := getNextAvailablePosForContinuingPipe()
newPipes = append(newPipes, &Pipe{
fromPos: pipe.toPos,
toPos: availablePos,
fromSha: pipe.fromSha,
toSha: pipe.toSha,
kind: CONTINUES,
style: pipe.style,
})
traverse(pipe.toPos, availablePos)
}
}
if commit.IsMerge() {
for _, parent := range commit.Parents[1:] {
availablePos := getNextAvailablePosForNewPipe()
// need to act as if continuing pipes are going to continue on the same line.
newPipes = append(newPipes, &Pipe{
fromPos: pos,
toPos: availablePos,
fromSha: commit.Sha,
toSha: parent,
kind: STARTS,
style: getStyle(commit),
})
takenSpots[availablePos] = true
}
}
for _, pipe := range currentPipes {
if !equalHashes(pipe.toSha, commit.Sha) && pipe.toPos > pos {
// continuing on, potentially moving left to fill in a blank spot
last := pipe.toPos
for i := pipe.toPos; i > pos; i-- {
if takenSpots[i] || traversedSpots[i] {
break
} else {
last = i
}
}
newPipes = append(newPipes, &Pipe{
fromPos: pipe.toPos,
toPos: last,
fromSha: pipe.fromSha,
toSha: pipe.toSha,
kind: CONTINUES,
style: pipe.style,
})
traverse(pipe.toPos, last)
}
}
// not efficient but doing it for now: sorting my pipes by toPos, then by kind
slices.SortFunc(newPipes, func(a, b *Pipe) bool {
if a.toPos == b.toPos {
return a.kind < b.kind
}
return a.toPos < b.toPos
})
return newPipes
}
func renderPipeSet(
pipes []*Pipe,
selectedCommitSha string,
prevCommit *models.Commit,
) string {
maxPos := 0
commitPos := 0
startCount := 0
for _, pipe := range pipes {
if pipe.kind == STARTS {
startCount++
commitPos = pipe.fromPos
} else if pipe.kind == TERMINATES {
commitPos = pipe.toPos
}
if pipe.right() > maxPos {
maxPos = pipe.right()
}
}
isMerge := startCount > 1
cells := make([]*Cell, maxPos+1)
for i := range cells {
cells[i] = &Cell{cellType: CONNECTION, style: style.FgDefault}
}
renderPipe := func(pipe *Pipe, style style.TextStyle, overrideRightStyle bool) {
left := pipe.left()
right := pipe.right()
if left != right {
for i := left + 1; i < right; i++ {
cells[i].setLeft(style).setRight(style, overrideRightStyle)
}
cells[left].setRight(style, overrideRightStyle)
cells[right].setLeft(style)
}
if pipe.kind == STARTS || pipe.kind == CONTINUES {
cells[pipe.toPos].setDown(style)
}
if pipe.kind == TERMINATES || pipe.kind == CONTINUES {
cells[pipe.fromPos].setUp(style)
}
}
// we don't want to highlight two commits if they're contiguous. We only want
// to highlight multiple things if there's an actual visible pipe involved.
highlight := true
if prevCommit != nil && equalHashes(prevCommit.Sha, selectedCommitSha) {
highlight = false
for _, pipe := range pipes {
if equalHashes(pipe.fromSha, selectedCommitSha) && (pipe.kind != TERMINATES || pipe.fromPos != pipe.toPos) {
highlight = true
}
}
}
// so we have our commit pos again, now it's time to build the cells.
// we'll handle the one that's sourced from our selected commit last so that it can override the other cells.
selectedPipes := []*Pipe{}
// pre-allocating this one because most of the time we'll only have non-selected pipes
nonSelectedPipes := make([]*Pipe, 0, len(pipes))
for _, pipe := range pipes {
if highlight && equalHashes(pipe.fromSha, selectedCommitSha) {
selectedPipes = append(selectedPipes, pipe)
} else {
nonSelectedPipes = append(nonSelectedPipes, pipe)
}
}
for _, pipe := range nonSelectedPipes {
if pipe.kind == STARTS {
renderPipe(pipe, pipe.style, true)
}
}
for _, pipe := range nonSelectedPipes {
if pipe.kind != STARTS && !(pipe.kind == TERMINATES && pipe.fromPos == commitPos && pipe.toPos == commitPos) {
renderPipe(pipe, pipe.style, false)
}
}
for _, pipe := range selectedPipes {
for i := pipe.left(); i <= pipe.right(); i++ {
cells[i].reset()
}
}
for _, pipe := range selectedPipes {
renderPipe(pipe, highlightStyle, true)
if pipe.toPos == commitPos {
cells[pipe.toPos].setStyle(highlightStyle)
}
}
cType := COMMIT
if isMerge {
cType = MERGE
}
cells[commitPos].setType(cType)
// using a string builder here for the sake of performance
writer := &strings.Builder{}
writer.Grow(len(cells) * 2)
for _, cell := range cells {
cell.render(writer)
}
return writer.String()
}
func equalHashes(a, b string) bool {
// if our selectedCommitSha is an empty string we treat that as meaning there is no selected commit sha
if a == "" || b == "" {
return false
}
length := utils.Min(len(a), len(b))
// parent hashes are only stored up to 20 characters for some reason so we'll truncate to that for comparison
return a[:length] == b[:length]
}