frostfs-node/pkg/local_object_storage/shard/head.go

package shard

import (
	"context"

	meta "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/metabase"
	"git.frostfs.info/TrueCloudLab/frostfs-observability/tracing"
	objectSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/trace"
)

// HeadPrm groups the parameters of Head operation.
type HeadPrm struct {
	addr          oid.Address
	raw           bool
	ShardLooksBad bool
}

// HeadRes groups the resulting values of Head operation.
type HeadRes struct {
	obj *objectSDK.Object
}

// SetAddress is a Head option to set the address of the requested object.
//
// Option is required.
func (p *HeadPrm) SetAddress(addr oid.Address) {
	p.addr = addr
}

// SetRaw is a Head option to set raw flag value. If flag is unset, then Head
// returns header of virtual object, otherwise it returns SplitInfo of virtual
// object.
func (p *HeadPrm) SetRaw(raw bool) {
	p.raw = raw
}

// Object returns the requested object header.
func (r HeadRes) Object() *objectSDK.Object {
	return r.obj
}

// Head reads header of the object from the shard.
//
// Returns any error encountered.
//
// Returns an error of type apistatus.ObjectNotFound if object is missing in Shard.
// Returns an error of type apistatus.ObjectAlreadyRemoved if the requested object has been marked as removed in shard.
// Returns the object.ErrObjectIsExpired if the object is presented but already expired.
func (s *Shard) Head(ctx context.Context, prm HeadPrm) (HeadRes, error) {
	ctx, span := tracing.StartSpanFromContext(ctx, "Shard.Head",
		trace.WithAttributes(
			attribute.String("shard_id", s.ID().String()),
			attribute.String("address", prm.addr.EncodeToString()),
			attribute.Bool("raw", prm.raw),
		))
	defer span.End()

	var obj *objectSDK.Object
	var err error
	mode := s.GetMode()
	if mode.NoMetabase() || (mode.ReadOnly() && prm.ShardLooksBad) {
		var getPrm GetPrm
		getPrm.SetAddress(prm.addr)
		getPrm.SetIgnoreMeta(true)

		var res GetRes
		res, err = s.Get(ctx, getPrm)
		obj = res.Object()
	} else {
		var headParams meta.GetPrm
		headParams.SetAddress(prm.addr)
		headParams.SetRaw(prm.raw)

		var res meta.GetRes
		res, err = s.metaBase.Get(ctx, headParams)
		obj = res.Header()
	}

	return HeadRes{
		obj: obj,
	}, err
}