Improve listing performance by using go-git (#6478)

* Use go-git for tree reading and commit info lookup.

Signed-off-by: Filip Navara <navara@emclient.com>

* Use TreeEntry.IsRegular() instead of ObjectType that was removed.

Signed-off-by: Filip Navara <navara@emclient.com>

* Use the treePath to optimize commit info search.

Signed-off-by: Filip Navara <navara@emclient.com>

* Extract the latest commit at treePath along with the other commits.

Signed-off-by: Filip Navara <navara@emclient.com>

* Fix listing commit info for a directory that was created in one commit and never modified after.

Signed-off-by: Filip Navara <navara@emclient.com>

* Avoid nearly all external 'git' invocations when doing directory listing (.editorconfig code path is still hit).

Signed-off-by: Filip Navara <navara@emclient.com>

* Use go-git for reading blobs.

Signed-off-by: Filip Navara <navara@emclient.com>

* Make SHA1 type alias for plumbing.Hash in go-git.

Signed-off-by: Filip Navara <navara@emclient.com>

* Make Signature type alias for object.Signature in go-git.

Signed-off-by: Filip Navara <navara@emclient.com>

* Fix GetCommitsInfo for repository with only one commit.

Signed-off-by: Filip Navara <navara@emclient.com>

* Fix PGP signature verification.

Signed-off-by: Filip Navara <navara@emclient.com>

* Fix issues with walking commit graph across merges.

Signed-off-by: Filip Navara <navara@emclient.com>

* Fix typo in condition.

Signed-off-by: Filip Navara <navara@emclient.com>

* Speed up loading branch list by keeping the repository reference (and thus all the loaded packfile indexes).

Signed-off-by: Filip Navara <navara@emclient.com>

* Fix lising submodules.

Signed-off-by: Filip Navara <navara@emclient.com>

* Fix build

Signed-off-by: Filip Navara <navara@emclient.com>

* Add back commit cache because of name-rev

Signed-off-by: Filip Navara <navara@emclient.com>

* Fix tests

Signed-off-by: Filip Navara <navara@emclient.com>

* Fix code style

* Fix spelling

* Address PR feedback

Signed-off-by: Filip Navara <navara@emclient.com>

* Update vendor module list

Signed-off-by: Filip Navara <navara@emclient.com>

* Fix getting trees by commit id

Signed-off-by: Filip Navara <navara@emclient.com>

* Fix remaining unit test failures

* Fix GetTreeBySHA

* Avoid running `git name-rev` if not necessary

Signed-off-by: Filip Navara <navara@emclient.com>

* Move Branch code to git module

* Clean up GPG signature verification and fix it for tagged commits

* Address PR feedback (import formatting, copyright headers)

* Make blob lookup by SHA working

* Update tests to use public API

* Allow getting content from any type of object through the blob interface

* Change test to actually expect the object content that is in the GIT repository

* Change one more test to actually expect the object content that is in the GIT repository

* Add comments

1 files changed, 4 insertions, 25 deletions

diff --git a/modules/git/sha1.go b/modules/git/sha1.go
index 6c9d53949d..57b06fe738 100644
--- a/modules/git/sha1.go
+++ b/modules/git/sha1.go
@@ -1,44 +1,23 @@
 // 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.
 
 package git
 
 import (
-	"bytes"
 	"encoding/hex"
 	"fmt"
 	"strings"
+
+	"gopkg.in/src-d/go-git.v4/plumbing"
 )
 
 // EmptySHA defines empty git SHA
 const EmptySHA = "0000000000000000000000000000000000000000"
 
 // SHA1 a git commit name
-type SHA1 [20]byte
-
-// Equal returns true if s has the same SHA1 as caller.
-// Support 40-length-string, []byte, SHA1.
-func (id SHA1) Equal(s2 interface{}) bool {
-	switch v := s2.(type) {
-	case string:
-		if len(v) != 40 {
-			return false
-		}
-		return v == id.String()
-	case []byte:
-		return bytes.Equal(v, id[:])
-	case SHA1:
-		return v == id
-	default:
-		return false
-	}
-}
-
-// String returns string (hex) representation of the Oid.
-func (id SHA1) String() string {
-	return hex.EncodeToString(id[:])
-}
+type SHA1 = plumbing.Hash
 
 // MustID always creates a new SHA1 from a [20]byte array with no validation of input.
 func MustID(b []byte) SHA1 {