Move gitgraph from modules to services layer (#33527)

Just move, no code change.

(cherry picked from commit 466cc725bc69d9222abf17d7a22d86e7dbe991ac)

services/repository/gitgraph/graph.go

@@ -0,0 +1,116 @@
+// Copyright 2016 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package gitgraph
+
+import (
+	"bufio"
+	"bytes"
+	"context"
+	"os"
+	"strings"
+
+	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/setting"
+)
+
+// GetCommitGraph return a list of commit (GraphItems) from all branches
+func GetCommitGraph(r *git.Repository, page, maxAllowedColors int, hidePRRefs bool, branches, files []string) (*Graph, error) {
+	format := "DATA:%D|%H|%aD|%h|%s"
+
+	if page == 0 {
+		page = 1
+	}
+
+	graphCmd := git.NewCommand(r.Ctx, "log", "--graph", "--date-order", "--decorate=full")
+
+	if hidePRRefs {
+		graphCmd.AddArguments("--exclude=" + git.PullPrefix + "*")
+	}
+
+	if len(branches) == 0 {
+		graphCmd.AddArguments("--all")
+	}
+
+	graphCmd.AddArguments("-C", "-M", "--date=iso").
+		AddOptionFormat("-n %d", setting.UI.GraphMaxCommitNum*page).
+		AddOptionFormat("--pretty=format:%s", format)
+
+	if len(branches) > 0 {
+		graphCmd.AddDynamicArguments(branches...)
+	}
+	if len(files) > 0 {
+		graphCmd.AddDashesAndList(files...)
+	}
+	graph := NewGraph()
+
+	stderr := new(strings.Builder)
+	stdoutReader, stdoutWriter, err := os.Pipe()
+	if err != nil {
+		return nil, err
+	}
+	commitsToSkip := setting.UI.GraphMaxCommitNum * (page - 1)
+
+	scanner := bufio.NewScanner(stdoutReader)
+
+	if err := graphCmd.Run(&git.RunOpts{
+		Dir:    r.Path,
+		Stdout: stdoutWriter,
+		Stderr: stderr,
+		PipelineFunc: func(ctx context.Context, cancel context.CancelFunc) error {
+			_ = stdoutWriter.Close()
+			defer stdoutReader.Close()
+			parser := &Parser{}
+			parser.firstInUse = -1
+			parser.maxAllowedColors = maxAllowedColors
+			if maxAllowedColors > 0 {
+				parser.availableColors = make([]int, maxAllowedColors)
+				for i := range parser.availableColors {
+					parser.availableColors[i] = i + 1
+				}
+			} else {
+				parser.availableColors = []int{1, 2}
+			}
+			for commitsToSkip > 0 && scanner.Scan() {
+				line := scanner.Bytes()
+				dataIdx := bytes.Index(line, []byte("DATA:"))
+				if dataIdx < 0 {
+					dataIdx = len(line)
+				}
+				starIdx := bytes.IndexByte(line, '*')
+				if starIdx >= 0 && starIdx < dataIdx {
+					commitsToSkip--
+				}
+				parser.ParseGlyphs(line[:dataIdx])
+			}
+
+			row := 0
+
+			// Skip initial non-commit lines
+			for scanner.Scan() {
+				line := scanner.Bytes()
+				if bytes.IndexByte(line, '*') >= 0 {
+					if err := parser.AddLineToGraph(graph, row, line); err != nil {
+						cancel()
+						return err
+					}
+					break
+				}
+				parser.ParseGlyphs(line)
+			}
+
+			for scanner.Scan() {
+				row++
+				line := scanner.Bytes()
+				if err := parser.AddLineToGraph(graph, row, line); err != nil {
+					cancel()
+					return err
+				}
+			}
+			return scanner.Err()
+		},
+	}); err != nil {
+		return graph, err
+	}
+	return graph, nil
+}