frostfs-node/pkg/local_object_storage/engine/get.go

103 lines
2.3 KiB
Go
Raw Normal View History

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"
)
// GetPrm groups the parameters of Get operation.
type GetPrm struct {
off, ln uint64
addr *objectSDK.Address
}
// GetRes groups resulting values of Get operation.
type GetRes struct {
obj *object.Object
}
// ErrObjectNotFound is returns on read operations requested on a missing object.
var ErrObjectNotFound = errors.New("object not found")
// 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
}
// WithPayloadRange is a Get 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 *GetPrm) WithPayloadRange(off, ln uint64) *GetPrm {
if p != nil {
p.off, p.ln = off, ln
}
return p
}
// Object returns the requested object part.
//
// Instance payload contains the requested range of the original object.
func (r *GetRes) Object() *object.Object {
return r.obj
}
// Get reads part of an object from local storage.
//
// Returns any error encountered that
// did not allow to completely read the object part.
//
// Returns ErrObjectNotFound if requested object is missing in local storage.
func (e *StorageEngine) Get(prm *GetPrm) (*GetRes, error) {
e.mtx.RLock()
defer e.mtx.RUnlock()
var obj *object.Object
shPrm := new(shard.GetPrm).
WithAddress(prm.addr)
if prm.ln == 0 {
shPrm = shPrm.WithFullRange()
} else {
shPrm = shPrm.WithRange(prm.off, int64(prm.ln))
}
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 {
obj = res.Object()
}
return err == nil
})
if obj == nil {
return nil, ErrObjectNotFound
}
return &GetRes{
obj: obj,
}, nil
}