image-storage/internal/convert/service.go

package convert

import (
	"github.com/davidbyttow/govips/v2/vips"
	"io"
)

type service struct{}

func newService() *service {
	return &service{}
}

func (s *service) ConvertAndSave(imageData []byte, fullWriter, thumbWriter io.Writer) error {
	img, err := vips.NewImageFromBuffer(imageData)
	if err != nil {
		return err
	}
	defer img.Close()

	//force convert even it is already a jpeg image
	converted, _, err := img.ExportJpeg(&vips.JpegExportParams{
		StripMetadata: true,
		Quality:       90,
	})

	if _, err = fullWriter.Write(converted); err != nil {
		return err
	}

	if err = img.Thumbnail(300, 300, vips.InterestingNone); err != nil {
		return err
	}

	thumbnail, _, err := img.ExportJpeg(&vips.JpegExportParams{
		StripMetadata: true,
		Quality:       80,
	})
	if err != nil {
		return err
	}

	if _, err = thumbWriter.Write(thumbnail); err != nil {
		return err
	}

	return nil
}