chore:(weed/worker/tasks/erasure_coding): Prune Unused and Untested Functions (#8761)

* chore(weed/worker/tasks/erasure_coding): prune unused findVolumeReplicas()

* chore(weed/worker/tasks/erasure_coding): prune unused isDiskSuitableForEC()

* chore(weed/worker/tasks/erasure_coding): prune unused selectBestECDestinations()

* chore(weed/worker/tasks/erasure_coding): prune unused candidatesToDiskInfos()

weed/worker/tasks/erasure_coding/detection.go

@@ -786,40 +786,6 @@ func createECTaskParams(multiPlan *topology.MultiDestinationPlan) *worker_pb.Era
 	}
 }
 
-// selectBestECDestinations selects multiple disks for EC shard placement with diversity
-// Uses the consolidated placement package for proper rack/server/disk spreading
-func selectBestECDestinations(disks []*topology.DiskInfo, sourceRack, sourceDC string, shardsNeeded int) []*topology.DiskInfo {
-	if len(disks) == 0 {
-		return nil
-	}
-
-	// Convert topology.DiskInfo to placement.DiskCandidate
-	candidates := diskInfosToCandidates(disks)
-	if len(candidates) == 0 {
-		return nil
-	}
-
-	// Configure placement for EC shards
-	config := placement.PlacementRequest{
-		ShardsNeeded:           shardsNeeded,
-		MaxShardsPerServer:     0, // No hard limit, but prefer spreading
-		MaxShardsPerRack:       0, // No hard limit, but prefer spreading
-		MaxTaskLoad:            topology.MaxTaskLoadForECPlacement,
-		PreferDifferentServers: true,
-		PreferDifferentRacks:   true,
-	}
-
-	// Use the shared placement algorithm
-	result, err := placement.SelectDestinations(candidates, config)
-	if err != nil {
-		glog.V(2).Infof("EC placement failed: %v", err)
-		return nil
-	}
-
-	// Convert back to topology.DiskInfo
-	return candidatesToDiskInfos(result.SelectedDisks, disks)
-}
-
 // diskInfosToCandidates converts topology.DiskInfo slice to placement.DiskCandidate slice
 func diskInfosToCandidates(disks []*topology.DiskInfo) []*placement.DiskCandidate {
 	var candidates []*placement.DiskCandidate
@@ -860,25 +826,6 @@ func diskInfosToCandidates(disks []*topology.DiskInfo) []*placement.DiskCandidat
 	return candidates
 }
 
-// candidatesToDiskInfos converts placement results back to topology.DiskInfo
-func candidatesToDiskInfos(candidates []*placement.DiskCandidate, originalDisks []*topology.DiskInfo) []*topology.DiskInfo {
-	// Create a map for quick lookup
-	diskMap := make(map[string]*topology.DiskInfo)
-	for _, disk := range originalDisks {
-		key := fmt.Sprintf("%s:%d", disk.NodeID, disk.DiskID)
-		diskMap[key] = disk
-	}
-
-	var result []*topology.DiskInfo
-	for _, candidate := range candidates {
-		key := fmt.Sprintf("%s:%d", candidate.NodeID, candidate.DiskID)
-		if disk, ok := diskMap[key]; ok {
-			result = append(result, disk)
-		}
-	}
-	return result
-}
-
 // calculateECScoreCandidate calculates placement score for EC operations.
 // Used for logging and plan metadata.
 func calculateECScoreCandidate(disk *placement.DiskCandidate, sourceRack, sourceDC string) float64 {
@@ -900,22 +847,6 @@ func calculateECScoreCandidate(disk *placement.DiskCandidate, sourceRack, source
 	return score
 }
 
-// isDiskSuitableForEC checks if a disk is suitable for EC placement
-// Note: This is kept for backward compatibility but the placement package
-// handles filtering internally
-func isDiskSuitableForEC(disk *topology.DiskInfo) bool {
-	if disk.DiskInfo == nil {
-		return false
-	}
-
-	// Check if disk is not overloaded with tasks
-	if disk.LoadCount > topology.MaxTaskLoadForECPlacement {
-		return false
-	}
-
-	return true
-}
-
 // findVolumeReplicaLocations finds all replica locations (server + disk) for the specified volume
 // Uses O(1) indexed lookup for optimal performance on large clusters.
 func findVolumeReplicaLocations(activeTopology *topology.ActiveTopology, volumeID uint32, collection string) []topology.VolumeReplica {
@@ -933,35 +864,3 @@ func findExistingECShards(activeTopology *topology.ActiveTopology, volumeID uint
 	}
 	return activeTopology.GetECShardLocations(volumeID, collection)
 }
-
-// findVolumeReplicas finds all servers that have replicas of the specified volume
-func findVolumeReplicas(activeTopology *topology.ActiveTopology, volumeID uint32, collection string) []string {
-	if activeTopology == nil {
-		return []string{}
-	}
-
-	topologyInfo := activeTopology.GetTopologyInfo()
-	if topologyInfo == nil {
-		return []string{}
-	}
-
-	var replicaServers []string
-
-	// Iterate through all nodes to find volume replicas
-	for _, dc := range topologyInfo.DataCenterInfos {
-		for _, rack := range dc.RackInfos {
-			for _, nodeInfo := range rack.DataNodeInfos {
-				for _, diskInfo := range nodeInfo.DiskInfos {
-					for _, volumeInfo := range diskInfo.VolumeInfos {
-						if volumeInfo.Id == volumeID && volumeInfo.Collection == collection {
-							replicaServers = append(replicaServers, nodeInfo.Id)
-							break // Found volume on this node, move to next node
-						}
-					}
-				}
-			}
-		}
-	}
-
-	return replicaServers
-}