1 files changed, 62 insertions, 0 deletions
diff --git a/modules/git/sha1_nogogit.go b/modules/git/sha1_nogogit.go
new file mode 100644
index 0000000000..09b5baacd5
--- /dev/null
+++ b/modules/git/sha1_nogogit.go
@@ -0,0 +1,62 @@
+// 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 (
+	"crypto/sha1"
+	"encoding/hex"
+	"hash"
+	"strconv"
+)
+
+// SHA1 a git commit name
+type SHA1 [20]byte
+
+// String returns a string representation of the SHA
+func (s SHA1) String() string {
+	return hex.EncodeToString(s[:])
+}
+
+// IsZero returns whether this SHA1 is all zeroes
+func (s SHA1) IsZero() bool {
+	var empty SHA1
+	return s == empty
+}
+
+// ComputeBlobHash compute the hash for a given blob content
+func ComputeBlobHash(content []byte) SHA1 {
+	return ComputeHash(ObjectBlob, content)
+}
+
+// ComputeHash compute the hash for a given ObjectType and content
+func ComputeHash(t ObjectType, content []byte) SHA1 {
+	h := NewHasher(t, int64(len(content)))
+	_, _ = h.Write(content)
+	return h.Sum()
+}
+
+// Hasher is a struct that will generate a SHA1
+type Hasher struct {
+	hash.Hash
+}
+
+// NewHasher takes an object type and size and creates a hasher to generate a SHA
+func NewHasher(t ObjectType, size int64) Hasher {
+	h := Hasher{sha1.New()}
+	_, _ = h.Write(t.Bytes())
+	_, _ = h.Write([]byte(" "))
+	_, _ = h.Write([]byte(strconv.FormatInt(size, 10)))
+	_, _ = h.Write([]byte{0})
+	return h
+}
+
+// Sum generates a SHA1 for the provided hash
+func (h Hasher) Sum() (sha1 SHA1) {
+	copy(sha1[:], h.Hash.Sum(nil))
+	return
+}