frostfs-node/pkg/local_object_storage/engine/head.go
Leonard Lyubich 09750484f9 [#176] localstore: Draft storage engine structure and ops
Implement the primary structure and operation of the local object
storage engine.

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

78 lines
1.7 KiB
Go

package engine
import (
objectSDK "github.com/nspcc-dev/neofs-api-go/pkg/object"
"github.com/nspcc-dev/neofs-node/pkg/core/object"
"github.com/nspcc-dev/neofs-node/pkg/local_object_storage/shard"
"github.com/pkg/errors"
"go.uber.org/zap"
)
// HeadPrm groups the parameters of Head operation.
type HeadPrm struct {
addr *objectSDK.Address
}
// HeadRes groups resulting values of Head operation.
type HeadRes struct {
head *object.Object
}
// WithAddress is a Head option to set the address of the requested object.
//
// Option is required.
func (p *HeadPrm) WithAddress(addr *objectSDK.Address) *HeadPrm {
if p != nil {
p.addr = addr
}
return p
}
// Header returns the requested object header.
//
// Instance has empty payload.
func (r *HeadRes) Header() *object.Object {
return r.head
}
// Head reads object header from local storage.
//
// Returns any error encountered that
// did not allow to completely read the object header.
//
// Returns ErrObjectNotFound if requested object is missing in local storage.
func (e *StorageEngine) Head(prm *HeadPrm) (*HeadRes, error) {
e.mtx.RLock()
defer e.mtx.RUnlock()
var head *object.Object
shPrm := new(shard.GetPrm).
WithAddress(prm.addr)
e.iterateOverSortedShards(prm.addr, func(sh *shard.Shard) (stop bool) {
res, err := sh.Get(shPrm)
if err != nil {
if !errors.Is(err, shard.ErrObjectNotFound) {
// TODO: smth wrong with shard, need to be processed
e.log.Warn("could not get object from shard",
zap.Stringer("shard", sh.ID()),
zap.String("error", err.Error()),
)
}
} else {
head = res.Object()
}
return err == nil
})
if head == nil {
return nil, ErrObjectNotFound
}
return &HeadRes{
head: head,
}, nil
}