fix(build): move EstimateBackupSize to platform-independent file

Fixes Windows, OpenBSD, and NetBSD builds by extracting
EstimateBackupSize from disk_check.go (which has build tags
excluding those platforms) to a new estimate.go file.

internal/checks/disk_check.go

@@ -109,28 +109,3 @@ func FormatDiskSpaceMessage(check *DiskSpaceCheck) string {
 
 	return msg
 }
-
-// EstimateBackupSize estimates backup size based on database size
-func EstimateBackupSize(databaseSize uint64, compressionLevel int) uint64 {
-	// Typical compression ratios:
-	// Level 0 (no compression): 1.0x
-	// Level 1-3 (fast): 0.4-0.6x
-	// Level 4-6 (balanced): 0.3-0.4x
-	// Level 7-9 (best): 0.2-0.3x
-
-	var compressionRatio float64
-	if compressionLevel == 0 {
-		compressionRatio = 1.0
-	} else if compressionLevel <= 3 {
-		compressionRatio = 0.5
-	} else if compressionLevel <= 6 {
-		compressionRatio = 0.35
-	} else {
-		compressionRatio = 0.25
-	}
-
-	estimated := uint64(float64(databaseSize) * compressionRatio)
-
-	// Add 10% buffer for metadata, indexes, etc.
-	return uint64(float64(estimated) * 1.1)
-}

internal/checks/estimate.go

@@ -0,0 +1,26 @@
+package checks
+
+// EstimateBackupSize estimates backup size based on database size
+func EstimateBackupSize(databaseSize uint64, compressionLevel int) uint64 {
+	// Typical compression ratios:
+	// Level 0 (no compression): 1.0x
+	// Level 1-3 (fast): 0.4-0.6x
+	// Level 4-6 (balanced): 0.3-0.4x
+	// Level 7-9 (best): 0.2-0.3x
+
+	var compressionRatio float64
+	if compressionLevel == 0 {
+		compressionRatio = 1.0
+	} else if compressionLevel <= 3 {
+		compressionRatio = 0.5
+	} else if compressionLevel <= 6 {
+		compressionRatio = 0.35
+	} else {
+		compressionRatio = 0.25
+	}
+
+	estimated := uint64(float64(databaseSize) * compressionRatio)
+
+	// Add 10% buffer for metadata, indexes, etc.
+	return uint64(float64(estimated) * 1.1)
+}

internal/engine/binlog/file_target.go

@@ -16,12 +16,12 @@ type FileTarget struct {
 	basePath   string
 	rotateSize int64
 
-	mu       sync.Mutex
-	current  *os.File
-	written  int64
-	fileNum  int
-	healthy  bool
-	lastErr  error
+	mu      sync.Mutex
+	current *os.File
+	written int64
+	fileNum int
+	healthy bool
+	lastErr error
 }
 
 // NewFileTarget creates a new file target
@@ -165,13 +165,13 @@ type CompressedFileTarget struct {
 	basePath   string
 	rotateSize int64
 
-	mu        sync.Mutex
-	file      *os.File
-	gzWriter  *gzip.Writer
-	written   int64
-	fileNum   int
-	healthy   bool
-	lastErr   error
+	mu       sync.Mutex
+	file     *os.File
+	gzWriter *gzip.Writer
+	written  int64
+	fileNum  int
+	healthy  bool
+	lastErr  error
 }
 
 // NewCompressedFileTarget creates a gzip-compressed file target

internal/engine/binlog/s3_target.go

@@ -22,17 +22,17 @@ type S3Target struct {
 	region   string
 	partSize int64
 
-	mu          sync.Mutex
-	buffer      *bytes.Buffer
-	bufferSize  int
-	currentKey  string
-	uploadID    string
-	parts       []types.CompletedPart
-	partNumber  int32
-	fileNum     int
-	healthy     bool
-	lastErr     error
-	lastWrite   time.Time
+	mu         sync.Mutex
+	buffer     *bytes.Buffer
+	bufferSize int
+	currentKey string
+	uploadID   string
+	parts      []types.CompletedPart
+	partNumber int32
+	fileNum    int
+	healthy    bool
+	lastErr    error
+	lastWrite  time.Time
 }
 
 // NewS3Target creates a new S3 target
@@ -204,8 +204,8 @@ func (s *S3Target) Healthy() bool {
 // S3StreamingTarget supports larger files with resumable uploads
 type S3StreamingTarget struct {
 	*S3Target
-	rotateSize   int64
-	currentSize  int64
+	rotateSize  int64
+	currentSize int64
 }
 
 // NewS3StreamingTarget creates an S3 target with file rotation

internal/engine/binlog/streamer.go

@@ -106,11 +106,11 @@ type Filter struct {
 
 // StreamerState holds the current state of the streamer
 type StreamerState struct {
-	Position     Position  `json:"position"`
-	EventCount   uint64    `json:"event_count"`
-	ByteCount    uint64    `json:"byte_count"`
-	LastUpdate   time.Time `json:"last_update"`
-	StartTime    time.Time `json:"start_time"`
+	Position     Position       `json:"position"`
+	EventCount   uint64         `json:"event_count"`
+	ByteCount    uint64         `json:"byte_count"`
+	LastUpdate   time.Time      `json:"last_update"`
+	StartTime    time.Time      `json:"start_time"`
 	TargetStatus []TargetStatus `json:"targets"`
 }
 
@@ -125,17 +125,17 @@ type TargetStatus struct {
 
 // Event represents a parsed binlog event
 type Event struct {
-	Type      string                 `json:"type"` // "write", "update", "delete", "query", "gtid", etc.
-	Timestamp time.Time              `json:"timestamp"`
-	Database  string                 `json:"database,omitempty"`
-	Table     string                 `json:"table,omitempty"`
-	Position  Position               `json:"position"`
-	GTID      string                 `json:"gtid,omitempty"`
-	Query     string                 `json:"query,omitempty"` // For query events
-	Rows      []map[string]any       `json:"rows,omitempty"`  // For row events
-	OldRows   []map[string]any       `json:"old_rows,omitempty"` // For update events
-	RawData   []byte                 `json:"-"` // Raw binlog data for replay
-	Extra     map[string]any         `json:"extra,omitempty"`
+	Type      string           `json:"type"` // "write", "update", "delete", "query", "gtid", etc.
+	Timestamp time.Time        `json:"timestamp"`
+	Database  string           `json:"database,omitempty"`
+	Table     string           `json:"table,omitempty"`
+	Position  Position         `json:"position"`
+	GTID      string           `json:"gtid,omitempty"`
+	Query     string           `json:"query,omitempty"`    // For query events
+	Rows      []map[string]any `json:"rows,omitempty"`     // For row events
+	OldRows   []map[string]any `json:"old_rows,omitempty"` // For update events
+	RawData   []byte           `json:"-"`                  // Raw binlog data for replay
+	Extra     map[string]any   `json:"extra,omitempty"`
 }
 
 // Target interface for binlog output destinations

internal/engine/binlog/streamer_test.go

@@ -77,18 +77,18 @@ func TestEvent(t *testing.T) {
 
 func TestConfig(t *testing.T) {
 	cfg := Config{
-		Host:           "localhost",
-		Port:           3306,
-		User:           "repl",
-		Password:       "secret",
-		ServerID:       99999,
-		Flavor:         "mysql",
-		BatchMaxEvents: 1000,
-		BatchMaxBytes:  10 * 1024 * 1024,
-		BatchMaxWait:   time.Second,
+		Host:              "localhost",
+		Port:              3306,
+		User:              "repl",
+		Password:          "secret",
+		ServerID:          99999,
+		Flavor:            "mysql",
+		BatchMaxEvents:    1000,
+		BatchMaxBytes:     10 * 1024 * 1024,
+		BatchMaxWait:      time.Second,
 		CheckpointEnabled: true,
 		CheckpointFile:    "/var/lib/dbbackup/checkpoint",
-		UseGTID:        true,
+		UseGTID:           true,
 	}
 
 	if cfg.Host != "localhost" {

internal/engine/selector_test.go

@@ -12,7 +12,7 @@ func TestSelectorConfig(t *testing.T) {
 		User:            "root",
 		DataDir:         "/var/lib/mysql",
 		CloneMinVersion: "8.0.17",
-		CloneMinSize:    1024 * 1024 * 1024, // 1GB
+		CloneMinSize:    1024 * 1024 * 1024,      // 1GB
 		SnapshotMinSize: 10 * 1024 * 1024 * 1024, // 10GB
 		PreferClone:     true,
 		AllowMysqldump:  true,
@@ -111,9 +111,9 @@ func TestSelectionReason(t *testing.T) {
 func TestEngineScoring(t *testing.T) {
 	// Test that scores are calculated correctly
 	tests := []struct {
-		name           string
-		info           DatabaseInfo
-		expectedBest   string
+		name         string
+		info         DatabaseInfo
+		expectedBest string
 	}{
 		{
 			name: "large DB with clone plugin",

internal/engine/snapshot/btrfs.go

@@ -110,12 +110,12 @@ func (b *BtrfsBackend) CreateSnapshot(ctx context.Context, opts SnapshotOptions)
 	}
 
 	return &Snapshot{
-		ID:        fullPath,
-		Backend:   "btrfs",
-		Source:    b.config.Subvolume,
-		Name:      snapName,
+		ID:         fullPath,
+		Backend:    "btrfs",
+		Source:     b.config.Subvolume,
+		Name:       snapName,
 		MountPoint: fullPath, // Btrfs snapshots are immediately accessible
-		CreatedAt: time.Now(),
+		CreatedAt:  time.Now(),
 		Metadata: map[string]string{
 			"subvolume":     b.config.Subvolume,
 			"snapshot_path": snapPath,
@@ -279,12 +279,12 @@ func (b *BtrfsBackend) ListSnapshots(ctx context.Context) ([]*Snapshot, error) {
 		}
 
 		snapshots = append(snapshots, &Snapshot{
-			ID:        fullPath,
-			Backend:   "btrfs",
-			Name:      name,
-			Source:    b.config.Subvolume,
+			ID:         fullPath,
+			Backend:    "btrfs",
+			Name:       name,
+			Source:     b.config.Subvolume,
 			MountPoint: fullPath,
-			CreatedAt: createdAt,
+			CreatedAt:  createdAt,
 			Metadata: map[string]string{
 				"subvolume": b.config.Subvolume,
 			},
@@ -322,12 +322,12 @@ func (b *BtrfsBackend) listSnapshotsFromDir(ctx context.Context, snapPath string
 		}
 
 		snapshots = append(snapshots, &Snapshot{
-			ID:        fullPath,
-			Backend:   "btrfs",
-			Name:      entry.Name(),
-			Source:    b.config.Subvolume,
+			ID:         fullPath,
+			Backend:    "btrfs",
+			Name:       entry.Name(),
+			Source:     b.config.Subvolume,
 			MountPoint: fullPath,
-			CreatedAt: createdAt,
+			CreatedAt:  createdAt,
 			Metadata: map[string]string{
 				"subvolume": b.config.Subvolume,
 			},

internal/engine/snapshot_engine.go

@@ -378,10 +378,10 @@ func (e *SnapshotEngine) streamSnapshot(ctx context.Context, sourcePath, destFil
 			// Report progress
 			if progressFunc != nil && totalFiles > 0 {
 				progressFunc(&Progress{
-					Stage:      "STREAMING",
-					Percent:    30 + float64(fileCount)/float64(totalFiles)*60,
-					BytesDone:  countWriter.count,
-					Message:    fmt.Sprintf("Processed %d/%d files (%s)", fileCount, totalFiles, formatBytes(countWriter.count)),
+					Stage:     "STREAMING",
+					Percent:   30 + float64(fileCount)/float64(totalFiles)*60,
+					BytesDone: countWriter.count,
+					Message:   fmt.Sprintf("Processed %d/%d files (%s)", fileCount, totalFiles, formatBytes(countWriter.count)),
 				})
 			}
 		}

internal/engine/streaming.go

@@ -13,10 +13,10 @@ import (
 
 // StreamingBackupEngine wraps a backup engine with streaming capability
 type StreamingBackupEngine struct {
-	engine    BackupEngine
-	cloudCfg  parallel.Config
-	log       logger.Logger
-	
+	engine   BackupEngine
+	cloudCfg parallel.Config
+	log      logger.Logger
+
 	mu        sync.Mutex
 	streamer  *parallel.CloudStreamer
 	pipe      *io.PipeWriter
@@ -28,19 +28,19 @@ type StreamingBackupEngine struct {
 // StreamingConfig holds streaming configuration
 type StreamingConfig struct {
 	// Cloud configuration
-	Bucket    string
-	Key       string
-	Region    string
-	Endpoint  string
-	
+	Bucket   string
+	Key      string
+	Region   string
+	Endpoint string
+
 	// Performance
 	PartSize    int64
 	WorkerCount int
-	
+
 	// Security
-	Encryption   string
-	KMSKeyID     string
-	
+	Encryption string
+	KMSKeyID   string
+
 	// Progress callback
 	OnProgress func(progress parallel.Progress)
 }
@@ -56,7 +56,7 @@ func NewStreamingBackupEngine(engine BackupEngine, cfg StreamingConfig, log logg
 	cloudCfg.Key = cfg.Key
 	cloudCfg.Region = cfg.Region
 	cloudCfg.Endpoint = cfg.Endpoint
-	
+
 	if cfg.PartSize > 0 {
 		cloudCfg.PartSize = cfg.PartSize
 	}
@@ -199,23 +199,23 @@ type DirectBackupConfig struct {
 	// Database
 	DBType string
 	DSN    string
-	
+
 	// Cloud
-	CloudURI    string  // s3://bucket/path or gs://bucket/path
-	Region      string
-	Endpoint    string
-	
+	CloudURI string // s3://bucket/path or gs://bucket/path
+	Region   string
+	Endpoint string
+
 	// Engine selection
-	PreferredEngine string  // clone, snapshot, dump
-	
+	PreferredEngine string // clone, snapshot, dump
+
 	// Performance
 	PartSize    int64
 	WorkerCount int
-	
+
 	// Options
-	Compression    bool
-	Encryption     string
-	EncryptionKey  string
+	Compression   bool
+	Encryption    string
+	EncryptionKey string
 }
 
 // Backup performs a direct backup to cloud