allocate ec shards to volume servers

weed/topology/data_node_ec.go

@@ -30,11 +30,11 @@ func (dn *DataNode) UpdateEcShards(actualShards []*erasure_coding.EcVolumeInfo)
 		} else {
 			// found, but maybe the actual shard could be missing
 			a := actualEcShards.Minus(ecShards)
-			if len(a.ShardIds()) > 0 {
+			if a.ShardIdCount() > 0 {
 				newShards = append(newShards, a)
 			}
 			d := ecShards.Minus(actualEcShards)
-			if len(d.ShardIds()) > 0 {
+			if d.ShardIdCount() > 0 {
 				deletedShards = append(deletedShards, d)
 			}
 		}

weed/topology/topology_ec.go

@@ -7,11 +7,9 @@ import (
 	"github.com/chrislusf/seaweedfs/weed/storage/needle"
 )
 
-const shardCount = erasure_coding.DataShardsCount + erasure_coding.ParityShardsCount
-
 type EcShardLocations struct {
 	Collection string
-	locations  [shardCount][]*DataNode
+	locations  [erasure_coding.TotalShardsCount][]*DataNode
 }
 
 func (t *Topology) SyncDataNodeEcShards(shardInfos []*master_pb.VolumeEcShardInformationMessage, dn *DataNode) (newShards, deletedShards []*erasure_coding.EcVolumeInfo) {