forgejo/modules/git/object_id.go
Lunny Xiao 4eb2a29910
Improve ObjectFormat interface (#28496)
The 4 functions are duplicated, especially as interface methods. I think
we just need to keep `MustID` the only one and remove other 3.

```
MustID(b []byte) ObjectID
MustIDFromString(s string) ObjectID
NewID(b []byte) (ObjectID, error)
NewIDFromString(s string) (ObjectID, error)
```

Introduced the new interfrace method `ComputeHash` which will replace
the interface `HasherInterface`. Now we don't need to keep two
interfaces.

Reintroduced `git.NewIDFromString` and `git.MustIDFromString`. The new
function will detect the hash length to decide which objectformat of it.
If it's 40, then it's SHA1. If it's 64, then it's SHA256. This will be
right if the commitID is a full one. So the parameter should be always a
full commit id.

@AdamMajer Please review.
2023-12-19 07:20:47 +00:00

90 lines
1.8 KiB
Go

// Copyright 2023 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package git
import (
"bytes"
"encoding/hex"
"fmt"
)
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 }
var _ ObjectID = &Sha1Hash{}
func MustIDFromString(hexHash string) ObjectID {
id, err := NewIDFromString(hexHash)
if err != nil {
panic(err)
}
return id
}
func NewIDFromString(hexHash string) (ObjectID, error) {
var theObjectFormat ObjectFormat
for _, objectFormat := range SupportedObjectFormats {
if len(hexHash) == objectFormat.FullLength() {
theObjectFormat = objectFormat
break
}
}
if theObjectFormat == nil {
return nil, fmt.Errorf("length %d has no matched object format: %s", len(hexHash), hexHash)
}
b, err := hex.DecodeString(hexHash)
if err != nil {
return nil, err
}
if len(b) != theObjectFormat.FullLength()/2 {
return theObjectFormat.EmptyObjectID(), fmt.Errorf("length must be %d: %v", theObjectFormat.FullLength(), b)
}
return theObjectFormat.MustID(b), nil
}
func IsEmptyCommitID(commitID string) bool {
if commitID == "" {
return true
}
id, err := NewIDFromString(commitID)
if err != nil {
return false
}
return id.IsZero()
}
// ComputeBlobHash compute the hash for a given blob content
func ComputeBlobHash(hashType ObjectFormat, content []byte) ObjectID {
return hashType.ComputeHash(ObjectBlob, content)
}
type ErrInvalidSHA struct {
SHA string
}
func (err ErrInvalidSHA) Error() string {
return fmt.Sprintf("invalid sha: %s", err.SHA)
}