func (db *LevelDB) metadataExists() (bool, error) {
var ctx storage.MetadataContext
keyBeg, keyEnd := ctx.KeyRange()
dvid.StartCgo()
ro := levigo.NewReadOptions()
it := db.ldb.NewIterator(ro)
defer func() {
it.Close()
dvid.StopCgo()
}()
it.Seek(keyBeg)
for {
if it.Valid() {
// Did we pass the final key?
if bytes.Compare(it.Key(), keyEnd) > 0 {
break
}
return true, nil
}
break
}
if err := it.GetError(); err != nil {
return false, err
}
dvid.Infof("No metadata found for %s...\n", db)
return false, nil
}
// check if any metadata has been written into this store.
func (db *KVAutobus) metadataExists() (bool, error) {
var ctx storage.MetadataContext
kStart, kEnd := ctx.KeyRange()
b64key1 := encodeKey(kStart)
b64key2 := encodeKey(kEnd)
url := fmt.Sprintf("%s/kvautobus/api/key_range/%s/%s/%s/", db.host, db.collection, b64key1, b64key2)
dvid.Infof("metdataExists: doing GET on %s\n", url)
timedLog := dvid.NewTimeLog()
resp, err := db.client.Get(url)
if err != nil {
return false, err
}
defer resp.Body.Close()
if resp.StatusCode == http.StatusNotFound {
return true, nil // Handle no keys found.
}
r := msgp.NewReader(bufio.NewReader(resp.Body))
var mks Ks
if err := mks.DecodeMsg(r); err != nil {
return false, err
}
timedLog.Infof("PROXY key_range metadata to %s returned %d (%d keys)\n", db.host, resp.StatusCode, len(mks))
if len(mks) == 0 {
return false, nil
}
return true, nil
}
func (db *BigTable) metadataExists() (bool, error) {
if db == nil {
return false, fmt.Errorf("Can't call metadataExists() on nil BigTable")
}
var ctx storage.MetadataContext
unvKeyBeg, unvKeyEnd := ctx.KeyRange()
rr := api.NewRange(encodeKey(unvKeyBeg), encodeKey(unvKeyEnd))
var found bool
err := tbl.ReadRows(db.ctx, rr, func(r api.Row) bool {
found = true
return false
})
return found, err
}