Sync branches into databases (#22743)

Related #14180
Related #25233 
Related #22639
Close #19786
Related #12763 

This PR will change all the branches retrieve method from reading git
data to read database to reduce git read operations.

- [x] Sync git branches information into database when push git data
- [x] Create a new table `Branch`, merge some columns of `DeletedBranch`
into `Branch` table and drop the table `DeletedBranch`.
- [x] Read `Branch` table when visit `code` -> `branch` page
- [x] Read `Branch` table when list branch names in `code` page dropdown
- [x] Read `Branch` table when list git ref compare page
- [x] Provide a button in admin page to manually sync all branches.
- [x] Sync branches if repository is not empty but database branches are
empty when visiting pages with branches list
- [x] Use `commit_time desc` as the default FindBranch order by to keep
consistent as before and deleted branches will be always at the end.

---------

Co-authored-by: Jason Song <i@wolfogre.com>

models/git/branch_list.go

@@ -0,0 +1,132 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package git
+
+import (
+	"context"
+
+	"code.gitea.io/gitea/models/db"
+	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/container"
+	"code.gitea.io/gitea/modules/util"
+
+	"xorm.io/builder"
+	"xorm.io/xorm"
+)
+
+type BranchList []*Branch
+
+func (branches BranchList) LoadDeletedBy(ctx context.Context) error {
+	ids := container.Set[int64]{}
+	for _, branch := range branches {
+		if !branch.IsDeleted {
+			continue
+		}
+		ids.Add(branch.DeletedByID)
+	}
+	usersMap := make(map[int64]*user_model.User, len(ids))
+	if err := db.GetEngine(ctx).In("id", ids.Values()).Find(&usersMap); err != nil {
+		return err
+	}
+	for _, branch := range branches {
+		if !branch.IsDeleted {
+			continue
+		}
+		branch.DeletedBy = usersMap[branch.DeletedByID]
+		if branch.DeletedBy == nil {
+			branch.DeletedBy = user_model.NewGhostUser()
+		}
+	}
+	return nil
+}
+
+func (branches BranchList) LoadPusher(ctx context.Context) error {
+	ids := container.Set[int64]{}
+	for _, branch := range branches {
+		if branch.PusherID > 0 { // pusher_id maybe zero because some branches are sync by backend with no pusher
+			ids.Add(branch.PusherID)
+		}
+	}
+	usersMap := make(map[int64]*user_model.User, len(ids))
+	if err := db.GetEngine(ctx).In("id", ids.Values()).Find(&usersMap); err != nil {
+		return err
+	}
+	for _, branch := range branches {
+		if branch.PusherID <= 0 {
+			continue
+		}
+		branch.Pusher = usersMap[branch.PusherID]
+		if branch.Pusher == nil {
+			branch.Pusher = user_model.NewGhostUser()
+		}
+	}
+	return nil
+}
+
+const (
+	BranchOrderByNameAsc        = "name ASC"
+	BranchOrderByCommitTimeDesc = "commit_time DESC"
+)
+
+type FindBranchOptions struct {
+	db.ListOptions
+	RepoID             int64
+	ExcludeBranchNames []string
+	IsDeletedBranch    util.OptionalBool
+	OrderBy            string
+}
+
+func (opts *FindBranchOptions) Cond() builder.Cond {
+	cond := builder.NewCond()
+	if opts.RepoID > 0 {
+		cond = cond.And(builder.Eq{"repo_id": opts.RepoID})
+	}
+
+	if len(opts.ExcludeBranchNames) > 0 {
+		cond = cond.And(builder.NotIn("name", opts.ExcludeBranchNames))
+	}
+	if !opts.IsDeletedBranch.IsNone() {
+		cond = cond.And(builder.Eq{"is_deleted": opts.IsDeletedBranch.IsTrue()})
+	}
+	return cond
+}
+
+func CountBranches(ctx context.Context, opts FindBranchOptions) (int64, error) {
+	return db.GetEngine(ctx).Where(opts.Cond()).Count(&Branch{})
+}
+
+func orderByBranches(sess *xorm.Session, opts FindBranchOptions) *xorm.Session {
+	if !opts.IsDeletedBranch.IsFalse() { // if deleted branch included, put them at the end
+		sess = sess.OrderBy("is_deleted ASC")
+	}
+
+	if opts.OrderBy == "" {
+		opts.OrderBy = BranchOrderByCommitTimeDesc
+	}
+	return sess.OrderBy(opts.OrderBy)
+}
+
+func FindBranches(ctx context.Context, opts FindBranchOptions) (BranchList, error) {
+	sess := db.GetEngine(ctx).Where(opts.Cond())
+	if opts.PageSize > 0 && !opts.IsListAll() {
+		sess = db.SetSessionPagination(sess, &opts.ListOptions)
+	}
+	sess = orderByBranches(sess, opts)
+
+	var branches []*Branch
+	return branches, sess.Find(&branches)
+}
+
+func FindBranchNames(ctx context.Context, opts FindBranchOptions) ([]string, error) {
+	sess := db.GetEngine(ctx).Select("name").Where(opts.Cond())
+	if opts.PageSize > 0 && !opts.IsListAll() {
+		sess = db.SetSessionPagination(sess, &opts.ListOptions)
+	}
+	sess = orderByBranches(sess, opts)
+	var branches []string
+	if err := sess.Table("branch").Find(&branches); err != nil {
+		return nil, err
+	}
+	return branches, nil
+}