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package id
import (
"encoding/hex"
"fmt"
"hash"
)
// HexLen returns the encoded hexadecimal length.
func (objectFormat ObjectFormat) HexLen() int {
return objectFormat.Size() * 2
}
// Size returns the hash size in bytes.
func (objectFormat ObjectFormat) Size() int {
return objectFormat.details().size
}
// New returns a new hash.Hash for this object format.
func (objectFormat ObjectFormat) New() (hash.Hash, error) {
newFn := objectFormat.details().new
if newFn == nil {
return nil, ErrInvalidObjectFormat
}
return newFn(), nil
}
// FromBytes builds an object ID from raw bytes for this object format.
func (objectFormat ObjectFormat) FromBytes(b []byte) (ObjectID, error) {
var id ObjectID
if objectFormat.Size() == 0 {
return id, ErrInvalidObjectFormat
}
if len(b) != objectFormat.Size() {
return id, fmt.Errorf("%w: got %d bytes, expected %d", ErrInvalidObjectID, len(b), objectFormat.Size())
}
copy(id.data[:], b)
id.objectFormat = objectFormat
return id, nil
}
// FromString parses an object ID from its canonical hex representation.
func (objectFormat ObjectFormat) FromString(s string) (ObjectID, error) {
var id ObjectID
if objectFormat.Size() == 0 {
return id, ErrInvalidObjectFormat
}
if len(s)&1 != 0 {
return id, fmt.Errorf("%w: odd hex length %d", ErrInvalidObjectID, len(s))
}
if len(s) != objectFormat.HexLen() {
return id, fmt.Errorf("%w: got %d chars, expected %d", ErrInvalidObjectID, len(s), objectFormat.HexLen())
}
decoded, err := hex.DecodeString(s)
if err != nil {
return id, fmt.Errorf("%w: decode: %w", ErrInvalidObjectID, err)
}
copy(id.data[:], decoded)
id.objectFormat = objectFormat
return id, nil
}
// String returns the canonical object format name.
func (objectFormat ObjectFormat) String() string {
return objectFormat.details().name
}
// Sum computes an object ID from raw data using the selected object format.
func (objectFormat ObjectFormat) Sum(data []byte) ObjectID {
return objectFormat.details().sum(data)
}
// Zero returns the all-zero object ID for this object format.
func (objectFormat ObjectFormat) Zero() ObjectID {
return ObjectID{
objectFormat: objectFormat,
data: [maxObjectIDSize]byte{},
}
}
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