frostfs-sdk-go/object/erasurecode/split.go
Evgenii Stratonikov bd2d350b09 [#205] object: Initial EC implementation
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
2024-03-22 10:14:12 +00:00

69 lines
1.5 KiB
Go

package erasurecode
import (
"crypto/ecdsa"
objectSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
)
// Split splits fully formed object into multiple chunks.
func (c *Constructor) Split(obj *objectSDK.Object, key *ecdsa.PrivateKey) ([]*objectSDK.Object, error) {
c.clear()
header, err := obj.CutPayload().Marshal()
if err != nil {
return nil, err
}
headerShards, err := c.encodeRaw(header)
if err != nil {
return nil, err
}
payloadShards, err := c.encodeRaw(obj.Payload())
if err != nil {
return nil, err
}
parts := make([]*objectSDK.Object, len(payloadShards))
parent, _ := obj.ID()
for i := range parts {
chunk := objectSDK.New()
copyRequiredFields(chunk, obj)
chunk.SetPayload(payloadShards[i])
chunk.SetPayloadSize(uint64(len(payloadShards[i])))
ec := objectSDK.NewECHeader(parent, uint32(i), uint32(len(payloadShards)), headerShards[i], uint32(len(header)))
chunk.SetECHeader(ec)
if err := setIDWithSignature(chunk, key); err != nil {
return nil, err
}
parts[i] = chunk
}
return parts, nil
}
func setIDWithSignature(obj *objectSDK.Object, key *ecdsa.PrivateKey) error {
if err := objectSDK.CalculateAndSetID(obj); err != nil {
return err
}
objectSDK.CalculateAndSetPayloadChecksum(obj)
if key == nil {
return nil
}
return objectSDK.CalculateAndSetSignature(*key, obj)
}
func (c *Constructor) encodeRaw(data []byte) ([][]byte, error) {
shards, err := c.enc.Split(data)
if err != nil {
return nil, err
}
if err := c.enc.Encode(shards); err != nil {
return nil, err
}
return shards, nil
}