CI: Apply Go linter recommendations to "thumb" package #5330

Signed-off-by: Michael Mayer <michael@photoprism.app>

internal/thumb/color.go

@@ -2,6 +2,7 @@ package thumb
 
 import "github.com/photoprism/photoprism/pkg/clean"
 
+// ColorSpace represents a thumbnail color profile preference.
 type ColorSpace = string
 
 // Supported thumbnail color profile settings.

internal/thumb/errors.go

@@ -5,5 +5,6 @@ import (
 )
 
 var (
+	// ErrNotCached indicates a requested thumbnail is not present in cache.
 	ErrNotCached = errors.New("not cached")
 )

internal/thumb/fileinfo.go

@@ -3,14 +3,14 @@ package thumb
 import (
 	"fmt"
 	"image"
-	_ "image/gif"
-	_ "image/jpeg"
-	_ "image/png"
+	_ "image/gif"  // register GIF decoder for config reads
+	_ "image/jpeg" // register JPEG decoder for config reads
+	_ "image/png"  // register PNG decoder for config reads
 	"os"
 	"runtime/debug"
 
-	_ "golang.org/x/image/bmp"
-	_ "golang.org/x/image/webp"
+	_ "golang.org/x/image/bmp"  // register BMP decoder for config reads
+	_ "golang.org/x/image/webp" // register WEBP decoder for config reads
 
 	"github.com/photoprism/photoprism/pkg/clean"
 	"github.com/photoprism/photoprism/pkg/fs"
@@ -29,7 +29,7 @@ func FileInfo(fileName string) (info image.Config, err error) {
 		return info, err
 	}
 
-	file, err := os.Open(fileName)
+	file, err := os.Open(fileName) //nolint:gosec // fileName is resolved path provided by caller; reading images is expected
 
 	if err != nil || file == nil {
 		return info, err

internal/thumb/generator.go

@@ -1,5 +1,6 @@
 package thumb
 
+// Lib identifies the image processing backend.
 type Lib = string
 
 // Supported image processing libraries.

internal/thumb/init.go

@@ -3,19 +3,29 @@ package thumb
 import "github.com/dustin/go-humanize/english"
 
 const (
-	MiB               = 1024 * 1024
-	GiB               = 1024 * MiB
-	DefaultCacheMem   = 128 * MiB
-	DefaultCacheSize  = 128
+	// MiB represents one mebibyte.
+	MiB = 1024 * 1024
+	// GiB represents one gibibyte.
+	GiB = 1024 * MiB
+	// DefaultCacheMem specifies the default libvips cache memory limit.
+	DefaultCacheMem = 128 * MiB
+	// DefaultCacheSize is the default number of cached operations.
+	DefaultCacheSize = 128
+	// DefaultCacheFiles is the default number of cached files.
 	DefaultCacheFiles = 16
-	DefaultWorkers    = 1
+	// DefaultWorkers is the default worker count when not specified.
+	DefaultWorkers = 1
 )
 
 var (
-	MaxCacheMem   = DefaultCacheMem
-	MaxCacheSize  = DefaultCacheSize
+	// MaxCacheMem is the maximum memory libvips may use for caching.
+	MaxCacheMem = DefaultCacheMem
+	// MaxCacheSize limits the number of cached operations.
+	MaxCacheSize = DefaultCacheSize
+	// MaxCacheFiles limits the number of cached files.
 	MaxCacheFiles = DefaultCacheFiles
-	NumWorkers    = DefaultWorkers
+	// NumWorkers defines the number of libvips worker threads.
+	NumWorkers = DefaultWorkers
 )
 
 // Init initializes the package config based on the available memory,
@@ -38,14 +48,12 @@ func Init(availableMemory uint64, maxWorkers int, imgLib string) {
 	}
 
 	// Set the number of worker threads that libvips can use.
-	if maxWorkers > 0 {
-		// Using the specified number of workers.
-		NumWorkers = maxWorkers
-	} else if maxWorkers < 0 {
-		// Using built-in default.
-		NumWorkers = 0
-	} else {
-		// Default to one worker.
+	switch {
+	case maxWorkers > 0:
+		NumWorkers = maxWorkers // explicitly configured
+	case maxWorkers < 0:
+		NumWorkers = 0 // use libvips default
+	default:
 		NumWorkers = DefaultWorkers
 	}
 

internal/thumb/memsize.go

@@ -57,5 +57,5 @@ func MemSize(img image.Image) Bytes {
 		bytesPerPixel = 8
 	}
 
-	return Bytes(pixels * bytesPerPixel)
+	return Bytes(uint64(pixels) * uint64(bytesPerPixel)) //nolint:gosec // pixels and bytesPerPixel are non-negative and bounded by image dimensions
 }

internal/thumb/open_jpeg.go

@@ -49,7 +49,7 @@ func OpenJpeg(fileName string, orientation int) (image.Image, error) {
 	logName := clean.Log(filepath.Base(fileName))
 
 	// Open file.
-	fileReader, err := os.Open(fileName)
+	fileReader, err := os.Open(fileName) //nolint:gosec // fileName is provided by caller and validated earlier
 	if err != nil {
 		return nil, err
 	}
@@ -76,8 +76,7 @@ func OpenJpeg(fileName string, orientation int) (image.Image, error) {
 			log.Tracef("thumb: %s has no color profile", logName)
 		} else if profile, err := iccProfile.Description(); err == nil && profile != "" {
 			log.Tracef("thumb: %s has color profile %s", logName, clean.Log(profile))
-			switch {
-			case colors.ProfileDisplayP3.Equal(profile):
+			if colors.ProfileDisplayP3.Equal(profile) {
 				img = colors.ToSRGB(img, colors.ProfileDisplayP3)
 			}
 		}

internal/thumb/options.go

@@ -4,6 +4,7 @@ import (
 	"github.com/photoprism/photoprism/pkg/fs"
 )
 
+// ResampleOption enumerates thumbnail resampling strategies.
 const (
 	ResampleFillCenter ResampleOption = iota
 	ResampleFillTopLeft
@@ -15,6 +16,7 @@ const (
 	ResamplePng
 )
 
+// ResampleMethods maps resample options to their string identifiers.
 var ResampleMethods = map[ResampleOption]string{
 	ResampleFillCenter:      "center",
 	ResampleFillTopLeft:     "left",

internal/thumb/resample.go

@@ -12,15 +12,16 @@ func Resample(img image.Image, width, height int, opts ...ResampleOption) image.
 
 	method, filter, _ := ResampleOptions(opts...)
 
-	if method == ResampleFit {
+	switch method {
+	case ResampleFit:
 		resImg = imaging.Fit(img, width, height, filter.Imaging())
-	} else if method == ResampleFillCenter {
+	case ResampleFillCenter:
 		resImg = imaging.Fill(img, width, height, imaging.Center, filter.Imaging())
-	} else if method == ResampleFillTopLeft {
+	case ResampleFillTopLeft:
 		resImg = imaging.Fill(img, width, height, imaging.TopLeft, filter.Imaging())
-	} else if method == ResampleFillBottomRight {
+	case ResampleFillBottomRight:
 		resImg = imaging.Fill(img, width, height, imaging.BottomRight, filter.Imaging())
-	} else if method == ResampleResize {
+	case ResampleResize:
 		resImg = imaging.Resize(img, width, height, filter.Imaging())
 	}
 

internal/thumb/rotate.go

@@ -6,16 +6,17 @@ import (
 	"github.com/disintegration/imaging"
 )
 
+// EXIF orientation values.
 const (
 	OrientationUnspecified int = 0
-	OrientationNormal          = 1
-	OrientationFlipH           = 2
-	OrientationRotate180       = 3
-	OrientationFlipV           = 4
-	OrientationTranspose       = 5
-	OrientationRotate270       = 6
-	OrientationTransverse      = 7
-	OrientationRotate90        = 8
+	OrientationNormal      int = 1
+	OrientationFlipH       int = 2
+	OrientationRotate180   int = 3
+	OrientationFlipV       int = 4
+	OrientationTranspose   int = 5
+	OrientationRotate270   int = 6
+	OrientationTransverse  int = 7
+	OrientationRotate90    int = 8
 )
 
 // Rotate rotates an image based on the Exif orientation.

internal/thumb/sizes.go

@@ -33,11 +33,12 @@ func (m SizeMap) All() SizeList {
 	}
 
 	slices.SortStableFunc(result, func(a, b Size) int {
-		if a.Width < b.Width {
+		switch {
+		case a.Width < b.Width:
 			return -1
-		} else if a.Width > b.Width {
+		case a.Width > b.Width:
 			return 1
-		} else {
+		default:
 			return 0
 		}
 	})
@@ -45,6 +46,7 @@ func (m SizeMap) All() SizeList {
 	return result
 }
 
+// Size presets used throughout the application.
 var (
 	SizeColors   = Size{Colors, Fit720, "Color Detection", 3, 3, false, false, false, true, Options{ResampleResize, ResampleNearestNeighbor, ResamplePng}}
 	SizeTile50   = Size{Tile50, Fit720, "List View", 50, 50, false, false, false, true, Options{ResampleFillCenter, ResampleDefault}}
@@ -103,6 +105,7 @@ var Sizes = SizeMap{
 // All contains all thumbnail sizes sorted by width.
 var All = Sizes.All()
 
+// ParseSize returns a Size by name or the zero value if unknown.
 func ParseSize(s string) Size {
 	return Sizes[Name(s)]
 }

internal/thumb/thumb.go

@@ -26,14 +26,14 @@ package thumb
 
 import (
 	"fmt"
-	_ "image/gif"
-	_ "image/jpeg"
-	_ "image/png"
+	_ "image/gif"  // register GIF decoder for thumbnail generation
+	_ "image/jpeg" // register JPEG decoder for thumbnail generation
+	_ "image/png"  // register PNG decoder for thumbnail generation
 	"math"
 
-	_ "golang.org/x/image/bmp"
-	_ "golang.org/x/image/tiff"
-	_ "golang.org/x/image/webp"
+	_ "golang.org/x/image/bmp"  // register BMP decoder for thumbnail generation
+	_ "golang.org/x/image/tiff" // register TIFF decoder for thumbnail generation
+	_ "golang.org/x/image/webp" // register WEBP decoder for thumbnail generation
 
 	"github.com/photoprism/photoprism/internal/event"
 )

internal/thumb/video.go

@@ -14,15 +14,13 @@ var VideoSizes = SizeList{
 
 // VideoSize returns the largest video size type for the given width limit.
 func VideoSize(limit int) Size {
-	if limit < 0 {
-		// Return maximum size.
-		return Sizes[Fit7680]
-	} else if limit == 0 {
-		// Return default size.
-		return Sizes[Fit4096]
-	} else if limit <= 720 {
-		// Return minimum size.
-		return Sizes[Fit720]
+	switch {
+	case limit < 0:
+		return Sizes[Fit7680] // maximum
+	case limit == 0:
+		return Sizes[Fit4096] // default
+	case limit <= 720:
+		return Sizes[Fit720] // minimum
 	}
 
 	// Find match.

internal/thumb/vips.go

@@ -62,16 +62,17 @@ func Vips(imageName string, imageBuffer []byte, hash, thumbPath string, width, h
 
 	// Choose thumbnail crop.
 	var crop vips.Interesting
-	if method == ResampleFillTopLeft {
+	switch method {
+	case ResampleFillTopLeft:
 		crop = vips.InterestingLow
 		size = vips.SizeBoth
-	} else if method == ResampleFillBottomRight {
+	case ResampleFillBottomRight:
 		crop = vips.InterestingHigh
 		size = vips.SizeBoth
-	} else if method == ResampleFit {
+	case ResampleFit:
 		crop = vips.InterestingNone
 		size = vips.SizeDown
-	} else if method == ResampleFillCenter || method == ResampleResize {
+	case ResampleFillCenter, ResampleResize:
 		crop = vips.InterestingCentre
 		size = vips.SizeBoth
 	}

internal/thumb/vips_init.go

@@ -29,7 +29,7 @@ func VipsShutdown() {
 
 // vipsInit calls vips.Startup() to initialize libvips.
 func vipsInit() {
-	if vipsStarted == true {
+	if vipsStarted {
 		log.Warnf("vips: already initialized - you may have found a bug")
 		return
 	}