frostfs-node/pkg/local_object_storage/engine/range.go
Leonard Lyubich 1d23483828 [#235] services/object: Implement new GetRange algorithm
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
2020-12-11 17:19:37 +03:00

121 lines
2.7 KiB
Go

package engine
import (
"errors"
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"
"go.uber.org/zap"
)
// RngPrm groups the parameters of GetRange operation.
type RngPrm struct {
off, ln uint64
addr *objectSDK.Address
}
// GetRes groups resulting values of GetRange operation.
type RngRes struct {
obj *object.Object
}
// WithAddress is a GetRng option to set the address of the requested object.
//
// Option is required.
func (p *RngPrm) WithAddress(addr *objectSDK.Address) *RngPrm {
if p != nil {
p.addr = addr
}
return p
}
// WithPayloadRange is a GetRange option to set range of requested payload data.
//
// Missing an option or calling with zero length is equivalent
// to getting the full payload range.
func (p *RngPrm) WithPayloadRange(rng *objectSDK.Range) *RngPrm {
if p != nil {
p.off, p.ln = rng.GetOffset(), rng.GetLength()
}
return p
}
// Object returns the requested object part.
//
// Instance payload contains the requested range of the original object.
func (r *RngRes) Object() *object.Object {
return r.obj
}
// GetRange reads part of an object from local storage.
//
// Returns any error encountered that
// did not allow to completely read the object part.
//
// Returns ErrNotFound if requested object is missing in local storage.
func (e *StorageEngine) GetRange(prm *RngPrm) (*RngRes, error) {
var (
obj *object.Object
siErr *objectSDK.SplitInfoError
outError = object.ErrNotFound
)
shPrm := new(shard.RngPrm).
WithAddress(prm.addr).
WithRange(prm.off, prm.ln)
e.iterateOverSortedShards(prm.addr, func(_ int, sh *shard.Shard) (stop bool) {
res, err := sh.GetRange(shPrm)
if err != nil {
switch {
case errors.Is(err, object.ErrNotFound):
return false // ignore, go to next shard
case
errors.Is(err, object.ErrAlreadyRemoved),
errors.As(err, &siErr):
outError = err
return true // stop, return it back
default:
// TODO: smth wrong with shard, need to be processed, but
// still go to next shard
e.log.Warn("could not get object from shard",
zap.Stringer("shard", sh.ID()),
zap.String("error", err.Error()),
)
return false
}
}
obj = res.Object()
return true
})
if obj == nil {
return nil, outError
}
return &RngRes{
obj: obj,
}, nil
}
// GetRange reads object payload range from local storage by provided address.
func GetRange(storage *StorageEngine, addr *objectSDK.Address, rng *objectSDK.Range) ([]byte, error) {
res, err := storage.GetRange(new(RngPrm).
WithAddress(addr).
WithPayloadRange(rng),
)
if err != nil {
return nil, err
}
return res.Object().Payload(), nil
}