142 lines
2.9 KiB
Go
142 lines
2.9 KiB
Go
// Copyright 2023 The Gitea Authors. All rights reserved.
|
|
// SPDX-License-Identifier: MIT
|
|
|
|
package git
|
|
|
|
import (
|
|
"bytes"
|
|
"encoding/hex"
|
|
"errors"
|
|
"fmt"
|
|
"hash"
|
|
"strconv"
|
|
"strings"
|
|
)
|
|
|
|
type ObjectID interface {
|
|
String() string
|
|
IsZero() bool
|
|
RawValue() []byte
|
|
Type() ObjectFormat
|
|
}
|
|
|
|
type Sha1Hash [20]byte
|
|
|
|
func (h *Sha1Hash) String() string {
|
|
return hex.EncodeToString(h[:])
|
|
}
|
|
|
|
func (h *Sha1Hash) IsZero() bool {
|
|
empty := Sha1Hash{}
|
|
return bytes.Equal(empty[:], h[:])
|
|
}
|
|
func (h *Sha1Hash) RawValue() []byte { return h[:] }
|
|
func (*Sha1Hash) Type() ObjectFormat { return &Sha1ObjectFormat{} }
|
|
|
|
func NewSha1() *Sha1Hash {
|
|
return &Sha1Hash{}
|
|
}
|
|
|
|
// NewHash is for generic implementations
|
|
func NewHash(hash string) (ObjectID, error) {
|
|
hash = strings.ToLower(hash)
|
|
switch hash {
|
|
case "sha1":
|
|
return &Sha1Hash{}, nil
|
|
}
|
|
|
|
return nil, errors.New("unsupported hash type")
|
|
}
|
|
|
|
func IDFromRaw(h ObjectFormat, b []byte) (ObjectID, error) {
|
|
if len(b) != h.FullLength()/2 {
|
|
return h.Empty(), fmt.Errorf("length must be %d: %v", h.FullLength(), b)
|
|
}
|
|
return h.MustID(b), nil
|
|
}
|
|
|
|
func MustIDFromString(h ObjectFormat, s string) ObjectID {
|
|
b, _ := hex.DecodeString(s)
|
|
return h.MustID(b)
|
|
}
|
|
|
|
func genericIDFromString(h ObjectFormat, s string) (ObjectID, error) {
|
|
s = strings.TrimSpace(s)
|
|
if len(s) != h.FullLength() {
|
|
return h.Empty(), fmt.Errorf("length must be %d: %s", h.FullLength(), s)
|
|
}
|
|
b, err := hex.DecodeString(s)
|
|
if err != nil {
|
|
return h.Empty(), err
|
|
}
|
|
return h.NewID(b)
|
|
}
|
|
|
|
func IDFromString(hexHash string) (ObjectID, error) {
|
|
switch len(hexHash) {
|
|
case 40:
|
|
hashType := Sha1ObjectFormat{}
|
|
h, err := hashType.NewIDFromString(hexHash)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return h, nil
|
|
}
|
|
|
|
return nil, fmt.Errorf("invalid hash hex string: '%s' len: %d", hexHash, len(hexHash))
|
|
}
|
|
|
|
func IsEmptyCommitID(commitID string) bool {
|
|
if commitID == "" {
|
|
return true
|
|
}
|
|
|
|
id, err := IDFromString(commitID)
|
|
if err != nil {
|
|
return false
|
|
}
|
|
|
|
return id.IsZero()
|
|
}
|
|
|
|
// HasherInterface is a struct that will generate a Hash
|
|
type HasherInterface interface {
|
|
hash.Hash
|
|
|
|
HashSum() ObjectID
|
|
}
|
|
|
|
type Sha1Hasher struct {
|
|
hash.Hash
|
|
}
|
|
|
|
// ComputeBlobHash compute the hash for a given blob content
|
|
func ComputeBlobHash(hashType ObjectFormat, content []byte) ObjectID {
|
|
return ComputeHash(hashType, ObjectBlob, content)
|
|
}
|
|
|
|
// ComputeHash compute the hash for a given ObjectType and content
|
|
func ComputeHash(hashType ObjectFormat, t ObjectType, content []byte) ObjectID {
|
|
h := hashType.NewHasher()
|
|
_, _ = h.Write(t.Bytes())
|
|
_, _ = h.Write([]byte(" "))
|
|
_, _ = h.Write([]byte(strconv.FormatInt(int64(len(content)), 10)))
|
|
_, _ = h.Write([]byte{0})
|
|
return h.HashSum()
|
|
}
|
|
|
|
// HashSum generates a SHA1 for the provided hash
|
|
func (h *Sha1Hasher) HashSum() ObjectID {
|
|
var sha1 Sha1Hash
|
|
copy(sha1[:], h.Hash.Sum(nil))
|
|
return &sha1
|
|
}
|
|
|
|
type ErrInvalidSHA struct {
|
|
SHA string
|
|
}
|
|
|
|
func (err ErrInvalidSHA) Error() string {
|
|
return fmt.Sprintf("invalid sha: %s", err.SHA)
|
|
}
|