Feat: improve thumbnails proformance and GC for local policy (#1044)

* thumb generating improvement

Replace "github.com/nfnt/resize" with "golang.org/x/image/draw". Add thumb task queue to avoid oom when batch thumb operation

* thumb improvement

* Add some tests for thumbnail generation

pkg/conf/conf.go

@@ -70,9 +70,13 @@ type redis struct {
 
 // 缩略图 配置
 type thumb struct {
-	MaxWidth   uint
-	MaxHeight  uint
-	FileSuffix string `validate:"min=1"`
+	MaxWidth      uint
+	MaxHeight     uint
+	FileSuffix    string `validate:"min=1"`
+	MaxTaskCount  int
+	EncodeMethod  string `validate:"eq=jpg|eq=png"`
+	EncodeQuality int    `validate:"gte=1,lte=100"`
+	GCAfterGen    bool
 }
 
 // 跨域配置

pkg/conf/defaults.go

@@ -51,9 +51,13 @@ var CORSConfig = &cors{
 
 // ThumbConfig 缩略图配置
 var ThumbConfig = &thumb{
-	MaxWidth:   400,
-	MaxHeight:  300,
-	FileSuffix: "._thumb",
+	MaxWidth:      400,
+	MaxHeight:     300,
+	FileSuffix:    "._thumb",
+	MaxTaskCount:  -1,
+	EncodeMethod:  "jpg",
+	GCAfterGen:    false,
+	EncodeQuality: 85,
 }
 
 // SlaveConfig 从机配置

pkg/filesystem/image.go

@@ -4,6 +4,9 @@ import (
 	"context"
 	"fmt"
 	"strconv"
+	"sync"
+
+	"runtime"
 
 	model "github.com/cloudreve/Cloudreve/v3/models"
 	"github.com/cloudreve/Cloudreve/v3/pkg/conf"
@@ -35,18 +38,53 @@ func (fs *FileSystem) GetThumb(ctx context.Context, id uint) (*response.ContentR
 	ctx = context.WithValue(ctx, fsctx.ThumbSizeCtx, [2]uint{w, h})
 	ctx = context.WithValue(ctx, fsctx.FileModelCtx, fs.FileTarget[0])
 	res, err := fs.Handler.Thumb(ctx, fs.FileTarget[0].SourceName)
-	if err == nil && conf.SystemConfig.Mode == "master" {
-		res.MaxAge = model.GetIntSetting("preview_timeout", 60)
-	}
 
 	// 本地存储策略出错时重新生成缩略图
 	if err != nil && fs.Policy.Type == "local" {
 		fs.GenerateThumbnail(ctx, &fs.FileTarget[0])
+		res, err = fs.Handler.Thumb(ctx, fs.FileTarget[0].SourceName)
+	}
+
+	if err == nil && conf.SystemConfig.Mode == "master" {
+		res.MaxAge = model.GetIntSetting("preview_timeout", 60)
 	}
 
 	return res, err
 }
 
+// thumbPool 要使用的任务池
+var thumbPool *Pool
+var once sync.Once
+
+// Pool 带有最大配额的任务池
+type Pool struct {
+	// 容量
+	worker chan int
+}
+
+// Init 初始化任务池
+func getThumbWorker() *Pool {
+	once.Do(func() {
+		maxWorker := conf.ThumbConfig.MaxTaskCount
+		if maxWorker <= 0 {
+			maxWorker = runtime.GOMAXPROCS(0)
+		}
+		thumbPool = &Pool{
+			worker: make(chan int, maxWorker),
+		}
+		util.Log().Debug("初始化Thumb任务队列，WorkerNum = %d", maxWorker)
+	})
+	return thumbPool
+}
+func (pool *Pool) addWorker() {
+	pool.worker <- 1
+	util.Log().Debug("Thumb任务队列，addWorker")
+}
+func (pool *Pool) releaseWorker() {
+	util.Log().Debug("Thumb任务队列，releaseWorker")
+	<-pool.worker
+}
+
 // GenerateThumbnail 尝试为本地策略文件生成缩略图并获取图像原始大小
 // TODO 失败时，如果之前还有图像信息，则清除
 func (fs *FileSystem) GenerateThumbnail(ctx context.Context, file *model.File) {
@@ -65,6 +103,8 @@ func (fs *FileSystem) GenerateThumbnail(ctx context.Context, file *model.File) {
 		return
 	}
 	defer source.Close()
+	getThumbWorker().addWorker()
+	defer getThumbWorker().releaseWorker()
 
 	image, err := thumb.NewThumbFromFile(source, file.Name)
 	if err != nil {
@@ -79,6 +119,12 @@ func (fs *FileSystem) GenerateThumbnail(ctx context.Context, file *model.File) {
 	image.GetThumb(fs.GenerateThumbnailSize(w, h))
 	// 保存到文件
 	err = image.Save(util.RelativePath(file.SourceName + conf.ThumbConfig.FileSuffix))
+	image = nil
+	if conf.ThumbConfig.GCAfterGen {
+		util.Log().Debug("GenerateThumbnail runtime.GC")
+		runtime.GC()
+	}
+
 	if err != nil {
 		util.Log().Warning("无法保存缩略图：%s", err)
 		return

pkg/filesystem/image_test.go

@@ -38,3 +38,12 @@ func TestFileSystem_GetThumb(t *testing.T) {
 		asserts.EqualValues(50, res.MaxAge)
 	}
 }
+
+func TestFileSystem_ThumbWorker(t *testing.T) {
+	asserts := assert.New(t)
+
+	asserts.NotPanics(func() {
+		getThumbWorker().addWorker()
+		getThumbWorker().releaseWorker()
+	})
+}

pkg/thumb/image.go

@@ -12,9 +12,11 @@ import (
 	"strings"
 
 	model "github.com/cloudreve/Cloudreve/v3/models"
+	"github.com/cloudreve/Cloudreve/v3/pkg/conf"
 	"github.com/cloudreve/Cloudreve/v3/pkg/util"
 
-	"github.com/nfnt/resize"
+	//"github.com/nfnt/resize"
+	"golang.org/x/image/draw"
 )
 
 // Thumb 缩略图
@@ -58,7 +60,8 @@ func NewThumbFromFile(file io.Reader, name string) (*Thumb, error) {
 
 // GetThumb 生成给定最大尺寸的缩略图
 func (image *Thumb) GetThumb(width, height uint) {
-	image.src = resize.Thumbnail(width, height, image.src, resize.Lanczos3)
+	//image.src = resize.Thumbnail(width, height, image.src, resize.Lanczos3)
+	image.src = Thumbnail(width, height, image.src)
 }
 
 // GetSize 获取图像尺寸
@@ -75,12 +78,59 @@ func (image *Thumb) Save(path string) (err error) {
 		return err
 	}
 	defer out.Close()
+	switch conf.ThumbConfig.EncodeMethod {
+	case "png":
+		err = png.Encode(out, image.src)
+	default:
+		err = jpeg.Encode(out, image.src, &jpeg.Options{Quality: conf.ThumbConfig.EncodeQuality})
+	}
 
-	err = png.Encode(out, image.src)
 	return err
 
 }
 
+// Thumbnail will downscale provided image to max width and height preserving
+// original aspect ratio and using the interpolation function interp.
+// It will return original image, without processing it, if original sizes
+// are already smaller than provided constraints.
+func Thumbnail(maxWidth, maxHeight uint, img image.Image) image.Image {
+	origBounds := img.Bounds()
+	origWidth := uint(origBounds.Dx())
+	origHeight := uint(origBounds.Dy())
+	newWidth, newHeight := origWidth, origHeight
+
+	// Return original image if it have same or smaller size as constraints
+	if maxWidth >= origWidth && maxHeight >= origHeight {
+		return img
+	}
+
+	// Preserve aspect ratio
+	if origWidth > maxWidth {
+		newHeight = uint(origHeight * maxWidth / origWidth)
+		if newHeight < 1 {
+			newHeight = 1
+		}
+		newWidth = maxWidth
+	}
+
+	if newHeight > maxHeight {
+		newWidth = uint(newWidth * maxHeight / newHeight)
+		if newWidth < 1 {
+			newWidth = 1
+		}
+		newHeight = maxHeight
+	}
+	return Resize(newWidth, newHeight, img)
+}
+
+func Resize(newWidth, newHeight uint, img image.Image) image.Image {
+	// Set the expected size that you want:
+	dst := image.NewRGBA(image.Rect(0, 0, int(newWidth), int(newHeight)))
+	// Resize:
+	draw.BiLinear.Scale(dst, dst.Rect, img, img.Bounds(), draw.Src, nil)
+	return dst
+}
+
 // CreateAvatar 创建头像
 func (image *Thumb) CreateAvatar(uid uint) error {
 	// 读取头像相关设定
@@ -92,7 +142,8 @@ func (image *Thumb) CreateAvatar(uid uint) error {
 	// 生成头像缩略图
 	src := image.src
 	for k, size := range []int{s, m, l} {
-		image.src = resize.Resize(uint(size), uint(size), src, resize.Lanczos3)
+		//image.src = resize.Resize(uint(size), uint(size), src, resize.Lanczos3)
+		image.src = Resize(uint(size), uint(size), src)
 		err := image.Save(filepath.Join(savePath, fmt.Sprintf("avatar_%d_%d.png", uid, k)))
 		if err != nil {
 			return err

pkg/thumb/image_test.go

@@ -86,6 +86,30 @@ func TestThumb_GetThumb(t *testing.T) {
 	})
 }
 
+func TestThumb_Thumbnail(t *testing.T) {
+	asserts := assert.New(t)
+	{
+		img := image.NewRGBA(image.Rect(0, 0, 500, 200))
+		thumb := Thumbnail(100, 100, img)
+		asserts.Equal(thumb.Bounds(), image.Rect(0, 0, 100, 40))
+	}
+	{
+		img := image.NewRGBA(image.Rect(0, 0, 200, 200))
+		thumb := Thumbnail(100, 100, img)
+		asserts.Equal(thumb.Bounds(), image.Rect(0, 0, 100, 100))
+	}
+	{
+		img := image.NewRGBA(image.Rect(0, 0, 500, 500))
+		thumb := Thumbnail(100, 100, img)
+		asserts.Equal(thumb.Bounds(), image.Rect(0, 0, 100, 100))
+	}
+	{
+		img := image.NewRGBA(image.Rect(0, 0, 200, 500))
+		thumb := Thumbnail(100, 100, img)
+		asserts.Equal(thumb.Bounds(), image.Rect(0, 0, 40, 100))
+	}
+}
+
 func TestThumb_Save(t *testing.T) {
 	asserts := assert.New(t)
 	file := CreateTestImage()