frostfs-sdk-go/object/transformer/fmt.go
Evgenii Stratonikov 1c94309d7a [#19] transformer: Simplify AccessIdentifiers
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
2023-03-15 05:39:09 +00:00

117 lines
2.5 KiB
Go

package transformer
import (
"crypto/ecdsa"
"fmt"
"github.com/TrueCloudLab/frostfs-sdk-go/object"
oid "github.com/TrueCloudLab/frostfs-sdk-go/object/id"
"github.com/TrueCloudLab/frostfs-sdk-go/session"
"github.com/TrueCloudLab/frostfs-sdk-go/version"
)
type formatter struct {
prm *FormatterParams
obj *object.Object
sz uint64
}
type EpochSource interface {
CurrentEpoch() uint64
}
// FormatterParams groups NewFormatTarget parameters.
type FormatterParams struct {
Key *ecdsa.PrivateKey
NextTarget ObjectTarget
SessionToken *session.Object
NetworkState EpochSource
}
// NewFormatTarget returns ObjectTarget instance that finalizes object structure
// and writes it to the next target.
//
// Chunks must be written before the WriteHeader call.
//
// Object changes:
// - sets version to current SDK version;
// - sets payload size to the total length of all written chunks;
// - sets session token;
// - sets number of creation epoch;
// - calculates and sets verification fields (ID, Signature).
func NewFormatTarget(p *FormatterParams) ObjectTarget {
return &formatter{
prm: p,
}
}
func (f *formatter) WriteHeader(obj *object.Object) error {
f.obj = obj
return nil
}
func (f *formatter) Write(p []byte) (n int, err error) {
n, err = f.prm.NextTarget.Write(p)
f.sz += uint64(n)
return
}
func (f *formatter) Close() (*AccessIdentifiers, error) {
curEpoch := f.prm.NetworkState.CurrentEpoch()
ver := version.Current()
f.obj.SetVersion(&ver)
f.obj.SetPayloadSize(f.sz)
f.obj.SetSessionToken(f.prm.SessionToken)
f.obj.SetCreationEpoch(curEpoch)
var (
parID *oid.ID
parHdr *object.Object
)
if par := f.obj.Parent(); par != nil && par.Signature() == nil {
rawPar := object.NewFromV2(par.ToV2())
rawPar.SetSessionToken(f.prm.SessionToken)
rawPar.SetCreationEpoch(curEpoch)
if err := object.SetIDWithSignature(*f.prm.Key, rawPar); err != nil {
return nil, fmt.Errorf("could not finalize parent object: %w", err)
}
id, _ := rawPar.ID()
parID = &id
parHdr = rawPar
f.obj.SetParent(parHdr)
}
if err := object.SetIDWithSignature(*f.prm.Key, f.obj); err != nil {
return nil, fmt.Errorf("could not finalize object: %w", err)
}
if err := f.prm.NextTarget.WriteHeader(f.obj); err != nil {
return nil, fmt.Errorf("could not write header to next target: %w", err)
}
if _, err := f.prm.NextTarget.Close(); err != nil {
return nil, fmt.Errorf("could not close next target: %w", err)
}
id, _ := f.obj.ID()
return &AccessIdentifiers{
ParentID: parID,
SelfID: id,
ParentHeader: parHdr,
}, nil
}