chore: remove ~50k lines of unreachable dead code (#8913)

* chore: remove unreachable dead code across the codebase

Remove ~50,000 lines of unreachable code identified by static analysis.

Major removals:
- weed/filer/redis_lua: entire unused Redis Lua filer store implementation
- weed/wdclient/net2, resource_pool: unused connection/resource pool packages
- weed/plugin/worker/lifecycle: unused lifecycle plugin worker
- weed/s3api: unused S3 policy templates, presigned URL IAM, streaming copy,
  multipart IAM, key rotation, and various SSE helper functions
- weed/mq/kafka: unused partition mapping, compression, schema, and protocol functions
- weed/mq/offset: unused SQL storage and migration code
- weed/worker: unused registry, task, and monitoring functions
- weed/query: unused SQL engine, parquet scanner, and type functions
- weed/shell: unused EC proportional rebalance functions
- weed/storage/erasure_coding/distribution: unused distribution analysis functions
- Individual unreachable functions removed from 150+ files across admin,
  credential, filer, iam, kms, mount, mq, operation, pb, s3api, server,
  shell, storage, topology, and util packages

* fix(s3): reset shared memory store in IAM test to prevent flaky failure

TestLoadIAMManagerFromConfig_EmptyConfigWithFallbackKey was flaky because
the MemoryStore credential backend is a singleton registered via init().
Earlier tests that create anonymous identities pollute the shared store,
causing LookupAnonymous() to unexpectedly return true.

Fix by calling Reset() on the memory store before the test runs.

* style: run gofmt on changed files

* fix: restore KMS functions used by integration tests

* fix(plugin): prevent panic on send to closed worker session channel

The Plugin.sendToWorker method could panic with "send on closed channel"
when a worker disconnected while a message was being sent. The race was
between streamSession.close() closing the outgoing channel and sendToWorker
writing to it concurrently.

Add a done channel to streamSession that is closed before the outgoing
channel, and check it in sendToWorker's select to safely detect closed
sessions without panicking.

weed/storage/erasure_coding/placement/placement.go

@@ -64,18 +64,6 @@ type PlacementRequest struct {
 	PreferDifferentRacks bool
 }
 
-// DefaultPlacementRequest returns the default placement configuration
-func DefaultPlacementRequest() PlacementRequest {
-	return PlacementRequest{
-		ShardsNeeded:           14,
-		MaxShardsPerServer:     0,
-		MaxShardsPerRack:       0,
-		MaxTaskLoad:            5,
-		PreferDifferentServers: true,
-		PreferDifferentRacks:   true,
-	}
-}
-
 // PlacementResult contains the selected destinations for EC shards
 type PlacementResult struct {
 	SelectedDisks []*DiskCandidate
@@ -270,15 +258,6 @@ func groupDisksByRack(disks []*DiskCandidate) map[string][]*DiskCandidate {
 	return result
 }
 
-// groupDisksByServer groups disks by their server
-func groupDisksByServer(disks []*DiskCandidate) map[string][]*DiskCandidate {
-	result := make(map[string][]*DiskCandidate)
-	for _, disk := range disks {
-		result[disk.NodeID] = append(result[disk.NodeID], disk)
-	}
-	return result
-}
-
 // getRackKey returns the unique key for a rack (dc:rack)
 func getRackKey(disk *DiskCandidate) string {
 	return fmt.Sprintf("%s:%s", disk.DataCenter, disk.Rack)
@@ -393,28 +372,3 @@ func addDiskToResult(result *PlacementResult, disk *DiskCandidate,
 	result.ShardsPerRack[rackKey]++
 	result.ShardsPerDC[disk.DataCenter]++
 }
-
-// VerifySpread checks if the placement result meets diversity requirements
-func VerifySpread(result *PlacementResult, minServers, minRacks int) error {
-	if result.ServersUsed < minServers {
-		return fmt.Errorf("only %d servers used, need at least %d", result.ServersUsed, minServers)
-	}
-	if result.RacksUsed < minRacks {
-		return fmt.Errorf("only %d racks used, need at least %d", result.RacksUsed, minRacks)
-	}
-	return nil
-}
-
-// CalculateIdealDistribution returns the ideal number of shards per server
-// when we have a certain number of shards and servers
-func CalculateIdealDistribution(totalShards, numServers int) (min, max int) {
-	if numServers <= 0 {
-		return 0, totalShards
-	}
-	min = totalShards / numServers
-	max = min
-	if totalShards%numServers != 0 {
-		max = min + 1
-	}
-	return
-}

weed/storage/erasure_coding/placement/placement_test.go

@@ -1,517 +0,0 @@
-package placement
-
-import (
-	"testing"
-)
-
-// Helper function to create disk candidates for testing
-func makeDisk(nodeID string, diskID uint32, dc, rack string, freeSlots int) *DiskCandidate {
-	return &DiskCandidate{
-		NodeID:         nodeID,
-		DiskID:         diskID,
-		DataCenter:     dc,
-		Rack:           rack,
-		VolumeCount:    0,
-		MaxVolumeCount: 100,
-		ShardCount:     0,
-		FreeSlots:      freeSlots,
-		LoadCount:      0,
-	}
-}
-
-func TestSelectDestinations_SingleRack(t *testing.T) {
-	// Test: 3 servers in same rack, each with 2 disks, need 6 shards
-	// Expected: Should spread across all 6 disks (one per disk)
-	disks := []*DiskCandidate{
-		makeDisk("server1", 0, "dc1", "rack1", 10),
-		makeDisk("server1", 1, "dc1", "rack1", 10),
-		makeDisk("server2", 0, "dc1", "rack1", 10),
-		makeDisk("server2", 1, "dc1", "rack1", 10),
-		makeDisk("server3", 0, "dc1", "rack1", 10),
-		makeDisk("server3", 1, "dc1", "rack1", 10),
-	}
-
-	config := PlacementRequest{
-		ShardsNeeded:           6,
-		PreferDifferentServers: true,
-		PreferDifferentRacks:   true,
-	}
-
-	result, err := SelectDestinations(disks, config)
-	if err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-
-	if len(result.SelectedDisks) != 6 {
-		t.Errorf("expected 6 selected disks, got %d", len(result.SelectedDisks))
-	}
-
-	// Verify all 3 servers are used
-	if result.ServersUsed != 3 {
-		t.Errorf("expected 3 servers used, got %d", result.ServersUsed)
-	}
-
-	// Verify each disk is unique
-	diskSet := make(map[string]bool)
-	for _, disk := range result.SelectedDisks {
-		key := getDiskKey(disk)
-		if diskSet[key] {
-			t.Errorf("disk %s selected multiple times", key)
-		}
-		diskSet[key] = true
-	}
-}
-
-func TestSelectDestinations_MultipleRacks(t *testing.T) {
-	// Test: 2 racks with 2 servers each, each server has 2 disks
-	// Need 8 shards
-	// Expected: Should spread across all 8 disks
-	disks := []*DiskCandidate{
-		makeDisk("server1", 0, "dc1", "rack1", 10),
-		makeDisk("server1", 1, "dc1", "rack1", 10),
-		makeDisk("server2", 0, "dc1", "rack1", 10),
-		makeDisk("server2", 1, "dc1", "rack1", 10),
-		makeDisk("server3", 0, "dc1", "rack2", 10),
-		makeDisk("server3", 1, "dc1", "rack2", 10),
-		makeDisk("server4", 0, "dc1", "rack2", 10),
-		makeDisk("server4", 1, "dc1", "rack2", 10),
-	}
-
-	config := PlacementRequest{
-		ShardsNeeded:           8,
-		PreferDifferentServers: true,
-		PreferDifferentRacks:   true,
-	}
-
-	result, err := SelectDestinations(disks, config)
-	if err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-
-	if len(result.SelectedDisks) != 8 {
-		t.Errorf("expected 8 selected disks, got %d", len(result.SelectedDisks))
-	}
-
-	// Verify all 4 servers are used
-	if result.ServersUsed != 4 {
-		t.Errorf("expected 4 servers used, got %d", result.ServersUsed)
-	}
-
-	// Verify both racks are used
-	if result.RacksUsed != 2 {
-		t.Errorf("expected 2 racks used, got %d", result.RacksUsed)
-	}
-}
-
-func TestSelectDestinations_PrefersDifferentServers(t *testing.T) {
-	// Test: 4 servers with 4 disks each, need 4 shards
-	// Expected: Should use one disk from each server
-	disks := []*DiskCandidate{
-		makeDisk("server1", 0, "dc1", "rack1", 10),
-		makeDisk("server1", 1, "dc1", "rack1", 10),
-		makeDisk("server1", 2, "dc1", "rack1", 10),
-		makeDisk("server1", 3, "dc1", "rack1", 10),
-		makeDisk("server2", 0, "dc1", "rack1", 10),
-		makeDisk("server2", 1, "dc1", "rack1", 10),
-		makeDisk("server2", 2, "dc1", "rack1", 10),
-		makeDisk("server2", 3, "dc1", "rack1", 10),
-		makeDisk("server3", 0, "dc1", "rack1", 10),
-		makeDisk("server3", 1, "dc1", "rack1", 10),
-		makeDisk("server3", 2, "dc1", "rack1", 10),
-		makeDisk("server3", 3, "dc1", "rack1", 10),
-		makeDisk("server4", 0, "dc1", "rack1", 10),
-		makeDisk("server4", 1, "dc1", "rack1", 10),
-		makeDisk("server4", 2, "dc1", "rack1", 10),
-		makeDisk("server4", 3, "dc1", "rack1", 10),
-	}
-
-	config := PlacementRequest{
-		ShardsNeeded:           4,
-		PreferDifferentServers: true,
-		PreferDifferentRacks:   true,
-	}
-
-	result, err := SelectDestinations(disks, config)
-	if err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-
-	if len(result.SelectedDisks) != 4 {
-		t.Errorf("expected 4 selected disks, got %d", len(result.SelectedDisks))
-	}
-
-	// Verify all 4 servers are used (one shard per server)
-	if result.ServersUsed != 4 {
-		t.Errorf("expected 4 servers used, got %d", result.ServersUsed)
-	}
-
-	// Each server should have exactly 1 shard
-	for server, count := range result.ShardsPerServer {
-		if count != 1 {
-			t.Errorf("server %s has %d shards, expected 1", server, count)
-		}
-	}
-}
-
-func TestSelectDestinations_SpilloverToMultipleDisksPerServer(t *testing.T) {
-	// Test: 2 servers with 4 disks each, need 6 shards
-	// Expected: First pick one from each server (2 shards), then one more from each (4 shards),
-	//           then fill remaining from any server (6 shards)
-	disks := []*DiskCandidate{
-		makeDisk("server1", 0, "dc1", "rack1", 10),
-		makeDisk("server1", 1, "dc1", "rack1", 10),
-		makeDisk("server1", 2, "dc1", "rack1", 10),
-		makeDisk("server1", 3, "dc1", "rack1", 10),
-		makeDisk("server2", 0, "dc1", "rack1", 10),
-		makeDisk("server2", 1, "dc1", "rack1", 10),
-		makeDisk("server2", 2, "dc1", "rack1", 10),
-		makeDisk("server2", 3, "dc1", "rack1", 10),
-	}
-
-	config := PlacementRequest{
-		ShardsNeeded:           6,
-		PreferDifferentServers: true,
-		PreferDifferentRacks:   true,
-	}
-
-	result, err := SelectDestinations(disks, config)
-	if err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-
-	if len(result.SelectedDisks) != 6 {
-		t.Errorf("expected 6 selected disks, got %d", len(result.SelectedDisks))
-	}
-
-	// Both servers should be used
-	if result.ServersUsed != 2 {
-		t.Errorf("expected 2 servers used, got %d", result.ServersUsed)
-	}
-
-	// Each server should have exactly 3 shards (balanced)
-	for server, count := range result.ShardsPerServer {
-		if count != 3 {
-			t.Errorf("server %s has %d shards, expected 3", server, count)
-		}
-	}
-}
-
-func TestSelectDestinations_MaxShardsPerServer(t *testing.T) {
-	// Test: 2 servers with 4 disks each, need 6 shards, max 2 per server
-	// Expected: Should only select 4 shards (2 per server limit)
-	disks := []*DiskCandidate{
-		makeDisk("server1", 0, "dc1", "rack1", 10),
-		makeDisk("server1", 1, "dc1", "rack1", 10),
-		makeDisk("server1", 2, "dc1", "rack1", 10),
-		makeDisk("server1", 3, "dc1", "rack1", 10),
-		makeDisk("server2", 0, "dc1", "rack1", 10),
-		makeDisk("server2", 1, "dc1", "rack1", 10),
-		makeDisk("server2", 2, "dc1", "rack1", 10),
-		makeDisk("server2", 3, "dc1", "rack1", 10),
-	}
-
-	config := PlacementRequest{
-		ShardsNeeded:           6,
-		MaxShardsPerServer:     2,
-		PreferDifferentServers: true,
-		PreferDifferentRacks:   true,
-	}
-
-	result, err := SelectDestinations(disks, config)
-	if err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-
-	// Should only get 4 shards due to server limit
-	if len(result.SelectedDisks) != 4 {
-		t.Errorf("expected 4 selected disks (limit 2 per server), got %d", len(result.SelectedDisks))
-	}
-
-	// No server should exceed the limit
-	for server, count := range result.ShardsPerServer {
-		if count > 2 {
-			t.Errorf("server %s has %d shards, exceeds limit of 2", server, count)
-		}
-	}
-}
-
-func TestSelectDestinations_14ShardsAcross7Servers(t *testing.T) {
-	// Test: Real-world EC scenario - 14 shards across 7 servers with 2 disks each
-	// Expected: Should spread evenly (2 shards per server)
-	var disks []*DiskCandidate
-	for i := 1; i <= 7; i++ {
-		serverID := "server" + string(rune('0'+i))
-		disks = append(disks, makeDisk(serverID, 0, "dc1", "rack1", 10))
-		disks = append(disks, makeDisk(serverID, 1, "dc1", "rack1", 10))
-	}
-
-	config := PlacementRequest{
-		ShardsNeeded:           14,
-		PreferDifferentServers: true,
-		PreferDifferentRacks:   true,
-	}
-
-	result, err := SelectDestinations(disks, config)
-	if err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-
-	if len(result.SelectedDisks) != 14 {
-		t.Errorf("expected 14 selected disks, got %d", len(result.SelectedDisks))
-	}
-
-	// All 7 servers should be used
-	if result.ServersUsed != 7 {
-		t.Errorf("expected 7 servers used, got %d", result.ServersUsed)
-	}
-
-	// Each server should have exactly 2 shards
-	for server, count := range result.ShardsPerServer {
-		if count != 2 {
-			t.Errorf("server %s has %d shards, expected 2", server, count)
-		}
-	}
-}
-
-func TestSelectDestinations_FewerServersThanShards(t *testing.T) {
-	// Test: Only 3 servers but need 6 shards
-	// Expected: Should distribute evenly (2 per server)
-	disks := []*DiskCandidate{
-		makeDisk("server1", 0, "dc1", "rack1", 10),
-		makeDisk("server1", 1, "dc1", "rack1", 10),
-		makeDisk("server1", 2, "dc1", "rack1", 10),
-		makeDisk("server2", 0, "dc1", "rack1", 10),
-		makeDisk("server2", 1, "dc1", "rack1", 10),
-		makeDisk("server2", 2, "dc1", "rack1", 10),
-		makeDisk("server3", 0, "dc1", "rack1", 10),
-		makeDisk("server3", 1, "dc1", "rack1", 10),
-		makeDisk("server3", 2, "dc1", "rack1", 10),
-	}
-
-	config := PlacementRequest{
-		ShardsNeeded:           6,
-		PreferDifferentServers: true,
-		PreferDifferentRacks:   true,
-	}
-
-	result, err := SelectDestinations(disks, config)
-	if err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-
-	if len(result.SelectedDisks) != 6 {
-		t.Errorf("expected 6 selected disks, got %d", len(result.SelectedDisks))
-	}
-
-	// All 3 servers should be used
-	if result.ServersUsed != 3 {
-		t.Errorf("expected 3 servers used, got %d", result.ServersUsed)
-	}
-
-	// Each server should have exactly 2 shards
-	for server, count := range result.ShardsPerServer {
-		if count != 2 {
-			t.Errorf("server %s has %d shards, expected 2", server, count)
-		}
-	}
-}
-
-func TestSelectDestinations_NoSuitableDisks(t *testing.T) {
-	// Test: All disks have no free slots
-	disks := []*DiskCandidate{
-		{NodeID: "server1", DiskID: 0, DataCenter: "dc1", Rack: "rack1", FreeSlots: 0},
-		{NodeID: "server2", DiskID: 0, DataCenter: "dc1", Rack: "rack1", FreeSlots: 0},
-	}
-
-	config := PlacementRequest{
-		ShardsNeeded:           4,
-		PreferDifferentServers: true,
-		PreferDifferentRacks:   true,
-	}
-
-	_, err := SelectDestinations(disks, config)
-	if err == nil {
-		t.Error("expected error for no suitable disks, got nil")
-	}
-}
-
-func TestSelectDestinations_EmptyInput(t *testing.T) {
-	config := DefaultPlacementRequest()
-	_, err := SelectDestinations([]*DiskCandidate{}, config)
-	if err == nil {
-		t.Error("expected error for empty input, got nil")
-	}
-}
-
-func TestSelectDestinations_FiltersByLoad(t *testing.T) {
-	// Test: Some disks have too high load
-	disks := []*DiskCandidate{
-		{NodeID: "server1", DiskID: 0, DataCenter: "dc1", Rack: "rack1", FreeSlots: 10, LoadCount: 10},
-		{NodeID: "server2", DiskID: 0, DataCenter: "dc1", Rack: "rack1", FreeSlots: 10, LoadCount: 2},
-		{NodeID: "server3", DiskID: 0, DataCenter: "dc1", Rack: "rack1", FreeSlots: 10, LoadCount: 1},
-	}
-
-	config := PlacementRequest{
-		ShardsNeeded:           2,
-		MaxTaskLoad:            5,
-		PreferDifferentServers: true,
-		PreferDifferentRacks:   true,
-	}
-
-	result, err := SelectDestinations(disks, config)
-	if err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-
-	// Should only select from server2 and server3 (server1 has too high load)
-	for _, disk := range result.SelectedDisks {
-		if disk.NodeID == "server1" {
-			t.Errorf("disk from server1 should not be selected (load too high)")
-		}
-	}
-}
-
-func TestCalculateDiskScore(t *testing.T) {
-	// Test that score calculation works as expected
-	lowUtilDisk := &DiskCandidate{
-		VolumeCount:    10,
-		MaxVolumeCount: 100,
-		ShardCount:     0,
-		LoadCount:      0,
-	}
-
-	highUtilDisk := &DiskCandidate{
-		VolumeCount:    90,
-		MaxVolumeCount: 100,
-		ShardCount:     5,
-		LoadCount:      5,
-	}
-
-	lowScore := calculateDiskScore(lowUtilDisk)
-	highScore := calculateDiskScore(highUtilDisk)
-
-	if lowScore <= highScore {
-		t.Errorf("low utilization disk should have higher score: low=%f, high=%f", lowScore, highScore)
-	}
-}
-
-func TestCalculateIdealDistribution(t *testing.T) {
-	tests := []struct {
-		totalShards int
-		numServers  int
-		expectedMin int
-		expectedMax int
-	}{
-		{14, 7, 2, 2},  // Even distribution
-		{14, 4, 3, 4},  // Uneven: 14/4 = 3 remainder 2
-		{6, 3, 2, 2},   // Even distribution
-		{7, 3, 2, 3},   // Uneven: 7/3 = 2 remainder 1
-		{10, 0, 0, 10}, // Edge case: no servers
-		{0, 5, 0, 0},   // Edge case: no shards
-	}
-
-	for _, tt := range tests {
-		min, max := CalculateIdealDistribution(tt.totalShards, tt.numServers)
-		if min != tt.expectedMin || max != tt.expectedMax {
-			t.Errorf("CalculateIdealDistribution(%d, %d) = (%d, %d), want (%d, %d)",
-				tt.totalShards, tt.numServers, min, max, tt.expectedMin, tt.expectedMax)
-		}
-	}
-}
-
-func TestVerifySpread(t *testing.T) {
-	result := &PlacementResult{
-		ServersUsed: 3,
-		RacksUsed:   2,
-	}
-
-	// Should pass
-	if err := VerifySpread(result, 3, 2); err != nil {
-		t.Errorf("unexpected error: %v", err)
-	}
-
-	// Should fail - not enough servers
-	if err := VerifySpread(result, 4, 2); err == nil {
-		t.Error("expected error for insufficient servers")
-	}
-
-	// Should fail - not enough racks
-	if err := VerifySpread(result, 3, 3); err == nil {
-		t.Error("expected error for insufficient racks")
-	}
-}
-
-func TestSelectDestinations_MultiDC(t *testing.T) {
-	// Test: 2 DCs, each with 2 racks, each rack has 2 servers
-	disks := []*DiskCandidate{
-		// DC1, Rack1
-		makeDisk("dc1-r1-s1", 0, "dc1", "rack1", 10),
-		makeDisk("dc1-r1-s1", 1, "dc1", "rack1", 10),
-		makeDisk("dc1-r1-s2", 0, "dc1", "rack1", 10),
-		makeDisk("dc1-r1-s2", 1, "dc1", "rack1", 10),
-		// DC1, Rack2
-		makeDisk("dc1-r2-s1", 0, "dc1", "rack2", 10),
-		makeDisk("dc1-r2-s1", 1, "dc1", "rack2", 10),
-		makeDisk("dc1-r2-s2", 0, "dc1", "rack2", 10),
-		makeDisk("dc1-r2-s2", 1, "dc1", "rack2", 10),
-		// DC2, Rack1
-		makeDisk("dc2-r1-s1", 0, "dc2", "rack1", 10),
-		makeDisk("dc2-r1-s1", 1, "dc2", "rack1", 10),
-		makeDisk("dc2-r1-s2", 0, "dc2", "rack1", 10),
-		makeDisk("dc2-r1-s2", 1, "dc2", "rack1", 10),
-		// DC2, Rack2
-		makeDisk("dc2-r2-s1", 0, "dc2", "rack2", 10),
-		makeDisk("dc2-r2-s1", 1, "dc2", "rack2", 10),
-		makeDisk("dc2-r2-s2", 0, "dc2", "rack2", 10),
-		makeDisk("dc2-r2-s2", 1, "dc2", "rack2", 10),
-	}
-
-	config := PlacementRequest{
-		ShardsNeeded:           8,
-		PreferDifferentServers: true,
-		PreferDifferentRacks:   true,
-	}
-
-	result, err := SelectDestinations(disks, config)
-	if err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-
-	if len(result.SelectedDisks) != 8 {
-		t.Errorf("expected 8 selected disks, got %d", len(result.SelectedDisks))
-	}
-
-	// Should use all 4 racks
-	if result.RacksUsed != 4 {
-		t.Errorf("expected 4 racks used, got %d", result.RacksUsed)
-	}
-
-	// Should use both DCs
-	if result.DCsUsed != 2 {
-		t.Errorf("expected 2 DCs used, got %d", result.DCsUsed)
-	}
-}
-
-func TestSelectDestinations_SameRackDifferentDC(t *testing.T) {
-	// Test: Same rack name in different DCs should be treated as different racks
-	disks := []*DiskCandidate{
-		makeDisk("dc1-s1", 0, "dc1", "rack1", 10),
-		makeDisk("dc2-s1", 0, "dc2", "rack1", 10),
-	}
-
-	config := PlacementRequest{
-		ShardsNeeded:           2,
-		PreferDifferentServers: true,
-		PreferDifferentRacks:   true,
-	}
-
-	result, err := SelectDestinations(disks, config)
-	if err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-
-	// Should use 2 racks (dc1:rack1 and dc2:rack1 are different)
-	if result.RacksUsed != 2 {
-		t.Errorf("expected 2 racks used (different DCs), got %d", result.RacksUsed)
-	}
-}