frostfs-node/pkg/local_object_storage/writecache/get.go
Elizaveta Chichindaeva cc7a723d77 [#1320] English Check
Signed-off-by: Elizaveta Chichindaeva <elizaveta@nspcc.ru>
2022-05-11 10:40:02 +03:00

86 lines
2.1 KiB
Go

package writecache
import (
apistatus "github.com/nspcc-dev/neofs-sdk-go/client/status"
objectSDK "github.com/nspcc-dev/neofs-sdk-go/object"
addressSDK "github.com/nspcc-dev/neofs-sdk-go/object/address"
"go.etcd.io/bbolt"
)
// Get returns object from write-cache.
//
// Returns an error of type apistatus.ObjectNotFound if the requested object is missing in write-cache.
func (c *cache) Get(addr *addressSDK.Address) (*objectSDK.Object, error) {
saddr := addr.String()
c.mtx.RLock()
for i := range c.mem {
if saddr == c.mem[i].addr {
data := c.mem[i].data
c.mtx.RUnlock()
// We unmarshal object instead of using cached value to avoid possibility
// of unintentional object corruption by caller.
// It is safe to unmarshal without mutex, as storage under `c.mem[i].data` slices is not reused.
obj := objectSDK.New()
return obj, obj.Unmarshal(data)
}
}
c.mtx.RUnlock()
value, err := Get(c.db, []byte(saddr))
if err == nil {
obj := objectSDK.New()
c.flushed.Get(saddr)
return obj, obj.Unmarshal(value)
}
data, err := c.fsTree.Get(addr)
if err != nil {
var errNotFound apistatus.ObjectNotFound
return nil, errNotFound
}
obj := objectSDK.New()
if err := obj.Unmarshal(data); err != nil {
return nil, err
}
c.flushed.Get(saddr)
return obj, nil
}
// Head returns object header from write-cache.
//
// Returns an error of type apistatus.ObjectNotFound if the requested object is missing in write-cache.
func (c *cache) Head(addr *addressSDK.Address) (*objectSDK.Object, error) {
obj, err := c.Get(addr)
if err != nil {
return nil, err
}
return obj.CutPayload(), nil
}
// Get fetches object from the underlying database.
// Key should be a stringified address.
//
// Returns an error of type apistatus.ObjectNotFound if the requested object is missing in db.
func Get(db *bbolt.DB, key []byte) ([]byte, error) {
var value []byte
err := db.View(func(tx *bbolt.Tx) error {
b := tx.Bucket(defaultBucket)
if b == nil {
return ErrNoDefaultBucket
}
value = b.Get(key)
if value == nil {
var errNotFound apistatus.ObjectNotFound
return errNotFound
}
value = cloneBytes(value)
return nil
})
return value, err
}