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

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package blobstor
import (
"io/ioutil"
"os"
objectSDK "github.com/nspcc-dev/neofs-api-go/pkg/object"
"github.com/nspcc-dev/neofs-node/pkg/core/object"
"github.com/pkg/errors"
)
// GetPrm groups the parameters of Get operation.
type GetPrm struct {
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
}
// Object returns the requested object.
func (r *GetRes) Object() *object.Object {
return r.obj
}
// Get reads the object from BLOB storage.
//
// Returns any error encountered that
// did not allow to completely read the object part.
func (b *BlobStor) Get(prm *GetPrm) (*GetRes, error) {
b.mtx.RLock()
defer b.mtx.RUnlock()
// get compressed object data
data, err := b.fsTree.get(prm.addr)
if err != nil {
if errors.Is(err, errFileNotFound) {
return nil, ErrObjectNotFound
}
return nil, errors.Wrap(err, "could not read object from fs tree")
}
data, err = b.decompressor(data)
if err != nil {
return nil, errors.Wrap(err, "could not decompress object data")
}
// unmarshal the object
obj := object.New()
if err := obj.Unmarshal(data); err != nil {
return nil, errors.Wrap(err, "could not unmarshal the object")
}
return &GetRes{
obj: obj,
}, nil
}
func (t *fsTree) get(addr *objectSDK.Address) ([]byte, error) {
p := t.treePath(addr)
if _, err := os.Stat(p); os.IsNotExist(err) {
return nil, errFileNotFound
}
return ioutil.ReadFile(p)
}