Use native git variants by default with go-git variants as build tag (#13673)

* Move last commit cache back into modules/git

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Remove go-git from the interface for last commit cache

Signed-off-by: Andrew Thornton <art27@cantab.net>

* move cacheref to last_commit_cache

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Remove go-git from routers/private/hook

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Move FindLFSFiles to pipeline

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Make no-go-git variants

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Submodule RefID

Signed-off-by: Andrew Thornton <art27@cantab.net>

* fix issue with GetCommitsInfo

Signed-off-by: Andrew Thornton <art27@cantab.net>

* fix GetLastCommitForPaths

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Improve efficiency

Signed-off-by: Andrew Thornton <art27@cantab.net>

* More efficiency

Signed-off-by: Andrew Thornton <art27@cantab.net>

* even faster

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Reduce duplication

* As per @lunny

Signed-off-by: Andrew Thornton <art27@cantab.net>

* attempt to fix drone

Signed-off-by: Andrew Thornton <art27@cantab.net>

* fix test-tags

Signed-off-by: Andrew Thornton <art27@cantab.net>

* default to use no-go-git variants and add gogit build tag

Signed-off-by: Andrew Thornton <art27@cantab.net>

* placate lint

Signed-off-by: Andrew Thornton <art27@cantab.net>

* as per @6543

Signed-off-by: Andrew Thornton <art27@cantab.net>

Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>

modules/git/tree_entry_gogit.go

@@ -0,0 +1,96 @@
+// Copyright 2015 The Gogs Authors. All rights reserved.
+// Copyright 2019 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.
+
+// +build gogit
+
+package git
+
+import (
+	"github.com/go-git/go-git/v5/plumbing"
+	"github.com/go-git/go-git/v5/plumbing/filemode"
+	"github.com/go-git/go-git/v5/plumbing/object"
+)
+
+// TreeEntry the leaf in the git tree
+type TreeEntry struct {
+	ID SHA1
+
+	gogitTreeEntry *object.TreeEntry
+	ptree          *Tree
+
+	size     int64
+	sized    bool
+	fullName string
+}
+
+// Name returns the name of the entry
+func (te *TreeEntry) Name() string {
+	if te.fullName != "" {
+		return te.fullName
+	}
+	return te.gogitTreeEntry.Name
+}
+
+// Mode returns the mode of the entry
+func (te *TreeEntry) Mode() EntryMode {
+	return EntryMode(te.gogitTreeEntry.Mode)
+}
+
+// Size returns the size of the entry
+func (te *TreeEntry) Size() int64 {
+	if te.IsDir() {
+		return 0
+	} else if te.sized {
+		return te.size
+	}
+
+	file, err := te.ptree.gogitTree.TreeEntryFile(te.gogitTreeEntry)
+	if err != nil {
+		return 0
+	}
+
+	te.sized = true
+	te.size = file.Size
+	return te.size
+}
+
+// IsSubModule if the entry is a sub module
+func (te *TreeEntry) IsSubModule() bool {
+	return te.gogitTreeEntry.Mode == filemode.Submodule
+}
+
+// IsDir if the entry is a sub dir
+func (te *TreeEntry) IsDir() bool {
+	return te.gogitTreeEntry.Mode == filemode.Dir
+}
+
+// IsLink if the entry is a symlink
+func (te *TreeEntry) IsLink() bool {
+	return te.gogitTreeEntry.Mode == filemode.Symlink
+}
+
+// IsRegular if the entry is a regular file
+func (te *TreeEntry) IsRegular() bool {
+	return te.gogitTreeEntry.Mode == filemode.Regular
+}
+
+// IsExecutable if the entry is an executable file (not necessarily binary)
+func (te *TreeEntry) IsExecutable() bool {
+	return te.gogitTreeEntry.Mode == filemode.Executable
+}
+
+// Blob returns the blob object the entry
+func (te *TreeEntry) Blob() *Blob {
+	encodedObj, err := te.ptree.repo.gogitRepo.Storer.EncodedObject(plumbing.AnyObject, te.gogitTreeEntry.Hash)
+	if err != nil {
+		return nil
+	}
+
+	return &Blob{
+		ID:              te.gogitTreeEntry.Hash,
+		gogitEncodedObj: encodedObj,
+		name:            te.Name(),
+	}
+}