frostfs-node/pkg/local_object_storage/metabase/get.go
Leonard Lyubich 590745204c [#237] metabase: Structure parameters and results of all operations
All parameters and resulting values of all metabase operations are
structured in new types. The most popular scenarios for using operations are
moved to auxiliary functions.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
2020-12-11 17:19:37 +03:00

134 lines
3.1 KiB
Go

package meta
import (
"fmt"
"github.com/nspcc-dev/neofs-api-go/pkg/container"
objectSDK "github.com/nspcc-dev/neofs-api-go/pkg/object"
"github.com/nspcc-dev/neofs-node/pkg/core/object"
"go.etcd.io/bbolt"
)
// GetPrm groups the parameters of Get operation.
type GetPrm struct {
addr *objectSDK.Address
}
// GetRes groups resulting values of Get operation.
type GetRes struct {
hdr *object.Object
}
// WithAddress is a Get option to set the address of the requested object.
//
// Option is required.
func (p *GetPrm) WithAddress(addr *objectSDK.Address) *GetPrm {
if p != nil {
p.addr = addr
}
return p
}
// Header returns the requested object header.
func (r *GetRes) Header() *object.Object {
return r.hdr
}
// Get read the object from DB.
func Get(db *DB, addr *objectSDK.Address) (*object.Object, error) {
r, err := db.Get(new(GetPrm).WithAddress(addr))
if err != nil {
return nil, err
}
return r.Header(), nil
}
// Get returns object header for specified address.
func (db *DB) Get(prm *GetPrm) (res *GetRes, err error) {
res = new(GetRes)
err = db.boltDB.View(func(tx *bbolt.Tx) error {
res.hdr, err = db.get(tx, prm.addr, true)
return err
})
return
}
func (db *DB) get(tx *bbolt.Tx, addr *objectSDK.Address, checkGraveyard bool) (*object.Object, error) {
obj := object.New()
key := objectKey(addr.ObjectID())
cid := addr.ContainerID()
if checkGraveyard && inGraveyard(tx, addr) {
return nil, object.ErrAlreadyRemoved
}
// check in primary index
data := getFromBucket(tx, primaryBucketName(cid), key)
if len(data) != 0 {
return obj, obj.Unmarshal(data)
}
// if not found then check in tombstone index
data = getFromBucket(tx, tombstoneBucketName(cid), key)
if len(data) != 0 {
return obj, obj.Unmarshal(data)
}
// if not found then check in storage group index
data = getFromBucket(tx, storageGroupBucketName(cid), key)
if len(data) != 0 {
return obj, obj.Unmarshal(data)
}
// if not found then check if object is a virtual
return getVirtualObject(tx, cid, key)
}
func getFromBucket(tx *bbolt.Tx, name, key []byte) []byte {
bkt := tx.Bucket(name)
if bkt == nil {
return nil
}
return bkt.Get(key)
}
func getVirtualObject(tx *bbolt.Tx, cid *container.ID, key []byte) (*object.Object, error) {
parentBucket := tx.Bucket(parentBucketName(cid))
if parentBucket == nil {
return nil, object.ErrNotFound
}
relativeLst, err := decodeList(parentBucket.Get(key))
if err != nil {
return nil, err
}
if len(relativeLst) == 0 { // this should never happen though
return nil, object.ErrNotFound
}
// pick last item, for now there is not difference which address to pick
// but later list might be sorted so first or last value can be more
// prioritized to choose
virtualOID := relativeLst[len(relativeLst)-1]
data := getFromBucket(tx, primaryBucketName(cid), virtualOID)
child := object.New()
err = child.Unmarshal(data)
if err != nil {
return nil, fmt.Errorf("can't unmarshal child with parent: %w", err)
}
if child.GetParent() == nil { // this should never happen though
return nil, object.ErrNotFound
}
return child.GetParent(), nil
}