1 files changed, 115 insertions, 0 deletions
diff --git a/modules/repository/push.go b/modules/repository/push.go
new file mode 100644
index 0000000000..04dd63a2cc
--- /dev/null
+++ b/modules/repository/push.go
@@ -0,0 +1,115 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package repository
+
+import (
+	"path/filepath"
+	"strings"
+
+	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/setting"
+)
+
+// PushUpdateOptions defines the push update options
+type PushUpdateOptions struct {
+	PusherID     int64
+	PusherName   string
+	RepoUserName string
+	RepoName     string
+	RefFullName  string // branch, tag or other name to push
+	OldCommitID  string
+	NewCommitID  string
+}
+
+// IsNewRef return true if it's a first-time push to a branch, tag or etc.
+func (opts PushUpdateOptions) IsNewRef() bool {
+	return opts.OldCommitID == git.EmptySHA
+}
+
+// IsDelRef return true if it's a deletion to a branch or tag
+func (opts PushUpdateOptions) IsDelRef() bool {
+	return opts.NewCommitID == git.EmptySHA
+}
+
+// IsUpdateRef return true if it's an update operation
+func (opts PushUpdateOptions) IsUpdateRef() bool {
+	return !opts.IsNewRef() && !opts.IsDelRef()
+}
+
+// IsTag return true if it's an operation to a tag
+func (opts PushUpdateOptions) IsTag() bool {
+	return strings.HasPrefix(opts.RefFullName, git.TagPrefix)
+}
+
+// IsNewTag return true if it's a creation to a tag
+func (opts PushUpdateOptions) IsNewTag() bool {
+	return opts.IsTag() && opts.IsNewRef()
+}
+
+// IsDelTag return true if it's a deletion to a tag
+func (opts PushUpdateOptions) IsDelTag() bool {
+	return opts.IsTag() && opts.IsDelRef()
+}
+
+// IsBranch return true if it's a push to branch
+func (opts PushUpdateOptions) IsBranch() bool {
+	return strings.HasPrefix(opts.RefFullName, git.BranchPrefix)
+}
+
+// IsNewBranch return true if it's the first-time push to a branch
+func (opts PushUpdateOptions) IsNewBranch() bool {
+	return opts.IsBranch() && opts.IsNewRef()
+}
+
+// IsUpdateBranch return true if it's not the first push to a branch
+func (opts PushUpdateOptions) IsUpdateBranch() bool {
+	return opts.IsBranch() && opts.IsUpdateRef()
+}
+
+// IsDelBranch return true if it's a deletion to a branch
+func (opts PushUpdateOptions) IsDelBranch() bool {
+	return opts.IsBranch() && opts.IsDelRef()
+}
+
+// TagName returns simple tag name if it's an operation to a tag
+func (opts PushUpdateOptions) TagName() string {
+	return opts.RefFullName[len(git.TagPrefix):]
+}
+
+// BranchName returns simple branch name if it's an operation to branch
+func (opts PushUpdateOptions) BranchName() string {
+	return opts.RefFullName[len(git.BranchPrefix):]
+}
+
+// RefName returns simple name for ref
+func (opts PushUpdateOptions) RefName() string {
+	if strings.HasPrefix(opts.RefFullName, git.TagPrefix) {
+		return opts.RefFullName[len(git.TagPrefix):]
+	} else if strings.HasPrefix(opts.RefFullName, git.BranchPrefix) {
+		return opts.RefFullName[len(git.BranchPrefix):]
+	}
+	return ""
+}
+
+// RepoFullName returns repo full name
+func (opts PushUpdateOptions) RepoFullName() string {
+	return opts.RepoUserName + "/" + opts.RepoName
+}
+
+// IsForcePush detect if a push is a force push
+func IsForcePush(opts *PushUpdateOptions) (bool, error) {
+	if !opts.IsUpdateBranch() {
+		return false, nil
+	}
+
+	output, err := git.NewCommand("rev-list", "--max-count=1", opts.OldCommitID, "^"+opts.NewCommitID).
+		RunInDir(filepath.Join(setting.RepoRootPath, opts.RepoUserName, opts.RepoName))
+	if err != nil {
+		return false, err
+	} else if len(output) > 0 {
+		return true, nil
+	}
+	return false, nil
+}