xk6-frostfs/internal/registry/obj_selector.go
Vladimir Domnich b1ec6d562c [#19] Stop object iteration after all objects were processed
At the moment we don't need logic that swings back to beginning of registry when
all objects have been processed. So, for now we can stop iterating and return an
error when selector reaches the end of registry.

Signed-off-by: Vladimir Domnich <v.domnich@yadro.com>
2022-09-23 13:36:27 +03:00

69 lines
1.6 KiB
Go

package registry
import (
"encoding/json"
"errors"
"sync"
"go.etcd.io/bbolt"
)
type ObjSelector struct {
boltDB *bbolt.DB
mu sync.Mutex
lastId uint64
objStatus string
}
func (o *ObjSelector) NextObject() (*ObjectInfo, error) {
var foundObj *ObjectInfo
err := o.boltDB.View(func(tx *bbolt.Tx) error {
b := tx.Bucket([]byte(bucketName))
if b == nil {
return nil
}
c := b.Cursor()
// We use mutex so that multiple VUs won't attempt to modify lastId simultaneously
// TODO: consider singleton channel that will produce those ids on demand
o.mu.Lock()
defer o.mu.Unlock()
// Establish the start position for searching the next object:
// If we should go from the beginning (lastId=0), then we start from the first element
// Otherwise we start from the key right after the lastId
var keyBytes, objBytes []byte
if o.lastId == 0 {
keyBytes, objBytes = c.First()
} else {
c.Seek(encodeId(o.lastId))
keyBytes, objBytes = c.Next()
}
// Iterate over objects to find the next object in the target status
var obj ObjectInfo
for ; keyBytes != nil; keyBytes, objBytes = c.Next() {
if objBytes != nil {
if err := json.Unmarshal(objBytes, &obj); err != nil {
// Ignore malformed objects for now. Maybe it should be panic?
continue
}
// If we reached an object in the target status, stop iterating
if obj.Status == o.objStatus {
foundObj = &obj
break
}
}
}
// Update the last key
if keyBytes != nil {
o.lastId = decodeId(keyBytes)
return nil
}
return errors.New("no objects are available")
})
return foundObj, err
}