implement thumbnail support for txt files

changelog/unreleased/thumbnails-for-txt.md

@@ -0,0 +1,5 @@
+Enhancement: Support thumbnails for txt files
+
+Implemented support for thumbnails for txt files in the thumbnails service.
+
+https://github.com/owncloud/ocis/pull/1988

ocis/go.sum

@@ -669,6 +669,7 @@ github.com/gogo/protobuf v1.2.1/go.mod h1:hp+jE20tsWTFYpLwKvXlhS1hjn+gTNwPg2I6zV
 github.com/gogo/protobuf v1.3.1 h1:DqDEcV5aeaTmdFBePNpYsp3FlcVH/2ISVVM9Qf8PSls=
 github.com/gogo/protobuf v1.3.1/go.mod h1:SlYgWuQ5SjCEi6WLHjHCa1yvBfUnHcTbrrZtXPKa29o=
 github.com/goji/httpauth v0.0.0-20160601135302-2da839ab0f4d/go.mod h1:nnjvkQ9ptGaCkuDUx6wNykzzlUixGxvkme+H/lnzb+A=
+github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0 h1:DACJavvAHhabrF08vX0COfcOBJRhZ8lUbR+ZWIs0Y5g=
 github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0/go.mod h1:E/TSTwGwJL78qG/PmXZO1EjYhfJinVAhrmmHX6Z8B9k=
 github.com/golang/gddo v0.0.0-20180828051604-96d2a289f41e/go.mod h1:xEhNfoBDX1hzLm2Nf80qUvZ2sVwoMZ8d6IE2SrsQfh4=
 github.com/golang/gddo v0.0.0-20190904175337-72a348e765d2/go.mod h1:xEhNfoBDX1hzLm2Nf80qUvZ2sVwoMZ8d6IE2SrsQfh4=

ocs/go.mod

@@ -22,14 +22,14 @@ require (
 	github.com/owncloud/ocis/proxy v0.0.0-20210412105747-9b95e9b1191b
 	github.com/owncloud/ocis/settings v0.0.0-20210413063522-955bd60edf33
 	github.com/owncloud/ocis/store v0.0.0-20210413063522-955bd60edf33
-	github.com/pkg/errors v0.9.1 // indirect
+	github.com/pkg/errors v0.9.1
 	github.com/prometheus/client_golang v1.10.0
 	github.com/spf13/viper v1.7.1
 	github.com/stretchr/testify v1.7.0
 	github.com/thejerf/suture/v4 v4.0.0
 	go.opencensus.io v0.23.0
 	google.golang.org/genproto v0.0.0-20210207032614-bba0dbe2a9ea
-	google.golang.org/grpc v1.37.0 // indirect
+	google.golang.org/grpc v1.37.0
 	google.golang.org/protobuf v1.26.0
 )
 

tests/acceptance/expected-failures-API-on-OCIS-storage.md

@@ -801,16 +801,14 @@ cannot share a folder with create permission
 #### [Previews via webDAV API tests fail on OCIS](https://github.com/owncloud/ocis/issues/187)
 
 -   [apiWebdavPreviews/previews.feature:15](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L15)
--   [apiWebdavPreviews/previews.feature:16](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L16)
 -   [apiWebdavPreviews/previews.feature:17](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L17)
 -   [apiWebdavPreviews/previews.feature:18](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L18)
 -   [apiWebdavPreviews/previews.feature:19](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L19)
--   [apiWebdavPreviews/previews.feature:56](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L56)
--   [apiWebdavPreviews/previews.feature:87](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L87)
 -   [apiWebdavPreviews/previews.feature:95](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L95)
 -   [apiWebdavPreviews/previews.feature:104](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L104)
 -   [apiWebdavPreviews/previews.feature:113](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L113)
--   [apiWebdavPreviews/previews.feature:163](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L163)
+-   [apiWebdavPreviews/previews.feature:127](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L127)
+-   [apiWebdavPreviews/previews.feature:135](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L135)
 -   [apiWebdavPreviews/previews.feature:164](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L164)
 -   [apiWebdavPreviews/previews.feature:165](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L165)
 -   [apiWebdavPreviews/previews.feature:166](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L166)

tests/acceptance/expected-failures-API-on-OWNCLOUD-storage.md

@@ -825,16 +825,14 @@ cannot share a folder with create permission
 #### [Previews via webDAV API tests fail on OCIS](https://github.com/owncloud/ocis/issues/187)
 
 -   [apiWebdavPreviews/previews.feature:15](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L15)
--   [apiWebdavPreviews/previews.feature:16](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L16)
 -   [apiWebdavPreviews/previews.feature:17](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L17)
 -   [apiWebdavPreviews/previews.feature:18](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L18)
 -   [apiWebdavPreviews/previews.feature:19](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L19)
--   [apiWebdavPreviews/previews.feature:56](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L56)
--   [apiWebdavPreviews/previews.feature:87](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L87)
 -   [apiWebdavPreviews/previews.feature:95](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L95)
 -   [apiWebdavPreviews/previews.feature:104](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L104)
 -   [apiWebdavPreviews/previews.feature:113](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L113)
--   [apiWebdavPreviews/previews.feature:163](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L163)
+-   [apiWebdavPreviews/previews.feature:127](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L127)
+-   [apiWebdavPreviews/previews.feature:135](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L135)
 -   [apiWebdavPreviews/previews.feature:164](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L164)
 -   [apiWebdavPreviews/previews.feature:165](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L165)
 -   [apiWebdavPreviews/previews.feature:166](https://github.com/owncloud/core/blob/master/tests/acceptance/features/apiWebdavPreviews/previews.feature#L166)

tests/acceptance/features/apiBugDemonstration/apiWebdavPreviews-previews.feature

@@ -36,15 +36,6 @@ Feature: previews of files downloaded through the webdav API
       | A      |
       | %2F    |
 
-  @issue-ocis-187
-  # after fixing all issues delete this Scenario and use the one from oC10 core
-  Scenario: download previews of image after renaming it
-    Given user "Alice" has uploaded file "filesForUpload/testavatar.jpg" to "/testimage.jpg"
-    When user "Alice" moves file "/testimage.jpg" to "/testimage.txt" using the WebDAV API
-    And user "Alice" downloads the preview of "/testimage.txt" with width "32" and height "32" using the WebDAV API
-    Then the HTTP status code should be "404"
-    # And the downloaded image should be "1240" pixels wide and "648" pixels high
-
   @issue-ocis-thumbnails-191 @skipOnOcis-EOS-Storage @issue-ocis-reva-308
   # after fixing all issues delete this Scenario and use the one from oC10 core
   Scenario: download previews of other users files
@@ -66,7 +57,7 @@ Feature: previews of files downloaded through the webdav API
     Given the administrator has updated system config key "enable_previews" with value "false" and type "boolean"
     And user "Alice" has uploaded file "filesForUpload/lorem.txt" to "/parent.txt"
     When user "Alice" downloads the preview of "/parent.txt" with width "32" and height "32" using the WebDAV API
-    Then the HTTP status code should be "404"
+    Then the HTTP status code should be "200"
 
   @issue-ocis-193
   # after fixing all issues delete this Scenario and use the one from oC10 core
@@ -75,7 +66,7 @@ Feature: previews of files downloaded through the webdav API
     And the administrator has updated system config key "preview_max_x" with value "null"
     And the administrator has updated system config key "preview_max_y" with value "null"
     When user "Alice" downloads the preview of "/parent.txt" with width "32" and height "32" using the WebDAV API
-    Then the HTTP status code should be "404"
+    Then the HTTP status code should be "200"
 
   @issue-ocis-193
   # after fixing all issues delete this Scenario and use the one from oC10 core

thumbnails/go.mod

@@ -10,6 +10,7 @@ require (
 	github.com/cs3org/go-cs3apis v0.0.0-20210325133324-32b03d75a535
 	github.com/cs3org/reva v1.6.1-0.20210414111318-a4b5148cbfb2
 	github.com/disintegration/imaging v1.6.2
+	github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0
 	github.com/golang/protobuf v1.5.2
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.2.0
 	github.com/micro/cli/v2 v2.1.2
@@ -23,6 +24,7 @@ require (
 	github.com/stretchr/testify v1.7.0
 	github.com/thejerf/suture/v4 v4.0.0
 	go.opencensus.io v0.23.0
+	golang.org/x/image v0.0.0-20191009234506-e7c1f5e7dbb8
 	google.golang.org/grpc v1.37.0
 	google.golang.org/protobuf v1.26.0
 )

thumbnails/go.sum

@@ -665,6 +665,7 @@ github.com/gogo/protobuf v1.2.1/go.mod h1:hp+jE20tsWTFYpLwKvXlhS1hjn+gTNwPg2I6zV
 github.com/gogo/protobuf v1.3.1 h1:DqDEcV5aeaTmdFBePNpYsp3FlcVH/2ISVVM9Qf8PSls=
 github.com/gogo/protobuf v1.3.1/go.mod h1:SlYgWuQ5SjCEi6WLHjHCa1yvBfUnHcTbrrZtXPKa29o=
 github.com/goji/httpauth v0.0.0-20160601135302-2da839ab0f4d/go.mod h1:nnjvkQ9ptGaCkuDUx6wNykzzlUixGxvkme+H/lnzb+A=
+github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0 h1:DACJavvAHhabrF08vX0COfcOBJRhZ8lUbR+ZWIs0Y5g=
 github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0/go.mod h1:E/TSTwGwJL78qG/PmXZO1EjYhfJinVAhrmmHX6Z8B9k=
 github.com/golang/gddo v0.0.0-20180828051604-96d2a289f41e/go.mod h1:xEhNfoBDX1hzLm2Nf80qUvZ2sVwoMZ8d6IE2SrsQfh4=
 github.com/golang/gddo v0.0.0-20190904175337-72a348e765d2/go.mod h1:xEhNfoBDX1hzLm2Nf80qUvZ2sVwoMZ8d6IE2SrsQfh4=

thumbnails/pkg/preprocessor/preprocessor.go

@@ -0,0 +1,106 @@
+package preprocessor
+
+import (
+	"bufio"
+	"github.com/golang/freetype"
+	"github.com/golang/freetype/truetype"
+	"github.com/pkg/errors"
+	"golang.org/x/image/font"
+	"golang.org/x/image/font/gofont/goregular"
+	"image"
+	"image/draw"
+	"io"
+	"mime"
+	"strings"
+)
+
+const (
+	fontSize         = 12
+	spacing  float64 = 1.5
+)
+
+type FileConverter interface {
+	Convert(r io.Reader) (image.Image, error)
+}
+
+type ImageDecoder struct{}
+
+func (i ImageDecoder) Convert(r io.Reader) (image.Image, error) {
+	img, _, err := image.Decode(r)
+	if err != nil {
+		return nil, errors.Wrap(err, `could not decode the image`)
+	}
+	return img, nil
+}
+
+type TxtToImageConverter struct{}
+
+func (t TxtToImageConverter) Convert(r io.Reader) (image.Image, error) {
+	img := image.NewRGBA(image.Rect(0, 0, 640, 480))
+	draw.Draw(img, img.Bounds(), image.White, image.Point{}, draw.Src)
+
+	c := freetype.NewContext()
+	// Ignoring the error since we are using the embedded Golang font.
+	// This shouldn't return an error.
+	f, _ := truetype.Parse(goregular.TTF)
+	c.SetFont(f)
+	c.SetFontSize(fontSize)
+	c.SetClip(img.Bounds())
+	c.SetDst(img)
+	c.SetSrc(image.Black)
+	c.SetHinting(font.HintingFull)
+	pt := freetype.Pt(10, 10+int(c.PointToFixed(fontSize)>>6))
+
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		txt := scanner.Text()
+		cs := chunks(txt, 80)
+		for _, s := range cs {
+			_, err := c.DrawString(strings.TrimSpace(s), pt)
+			if err != nil {
+				return nil, err
+			}
+			pt.Y += c.PointToFixed(fontSize * spacing)
+			if pt.Y.Round() >= img.Bounds().Dy() {
+				return img, scanner.Err()
+			}
+		}
+
+	}
+	return img, scanner.Err()
+}
+
+// Code from https://stackoverflow.com/a/61469854
+// Written By Igor Mikushkin
+func chunks(s string, chunkSize int) []string {
+	if chunkSize >= len(s) {
+		return []string{s}
+	}
+	var chunks []string
+	chunk := make([]rune, chunkSize)
+	length := 0
+	for _, r := range s {
+		chunk[length] = r
+		length++
+		if length == chunkSize {
+			chunks = append(chunks, string(chunk))
+			length = 0
+		}
+	}
+	if length > 0 {
+		chunks = append(chunks, string(chunk[:length]))
+	}
+	return chunks
+}
+
+func ForType(mimeType string) FileConverter {
+	// We can ignore the error here because we parse it in IsMimeTypeSupported before and if it fails
+	// return the service call. So we should only get here when the mimeType parses fine.
+	mimeType, _, _ = mime.ParseMediaType(mimeType)
+	switch mimeType {
+	case "text/plain":
+		return TxtToImageConverter{}
+	default:
+		return ImageDecoder{}
+	}
+}

thumbnails/pkg/service/v0/service.go

@@ -8,6 +8,7 @@ import (
 	provider "github.com/cs3org/go-cs3apis/cs3/storage/provider/v1beta1"
 	"github.com/cs3org/reva/pkg/token"
 	"github.com/owncloud/ocis/ocis-pkg/log"
+	"github.com/owncloud/ocis/thumbnails/pkg/preprocessor"
 	v0proto "github.com/owncloud/ocis/thumbnails/pkg/proto/v0"
 	"github.com/owncloud/ocis/thumbnails/pkg/thumbnail"
 	"github.com/owncloud/ocis/thumbnails/pkg/thumbnail/imgsource"
@@ -105,12 +106,15 @@ func (g Thumbnail) handleCS3Source(ctx context.Context, req *v0proto.GetThumbnai
 	}
 
 	ctx = imgsource.ContextSetAuthorization(ctx, src.Authorization)
-	img, err := g.cs3Source.Get(ctx, src.Path)
+	r, err := g.cs3Source.Get(ctx, src.Path)
 	if err != nil {
 		return nil, merrors.InternalServerError(g.serviceID, "could not get image from source: %s", err.Error())
 	}
-	if img == nil {
-		return nil, merrors.InternalServerError(g.serviceID, "could not get image from source")
+	defer r.Close() // nolint:errcheck
+	pp := preprocessor.ForType(sRes.GetInfo().GetMimeType())
+	img, err := pp.Convert(r)
+	if img == nil || err != nil {
+		return nil, merrors.InternalServerError(g.serviceID, "could not get image")
 	}
 	if thumb, err = g.manager.Generate(tr, img); err != nil {
 		return nil, err
@@ -176,12 +180,15 @@ func (g Thumbnail) handleWebdavSource(ctx context.Context, req *v0proto.GetThumb
 		ctx = imgsource.ContextSetAuthorization(ctx, src.WebdavAuthorization)
 	}
 	imgURL.RawQuery = ""
-	img, err := g.webdavSource.Get(ctx, imgURL.String())
+	r, err := g.webdavSource.Get(ctx, imgURL.String())
 	if err != nil {
 		return nil, merrors.InternalServerError(g.serviceID, "could not get image from source: %s", err.Error())
 	}
-	if img == nil {
-		return nil, merrors.InternalServerError(g.serviceID, "could not get image from source")
+	defer r.Close() // nolint:errcheck
+	pp := preprocessor.ForType(sRes.GetInfo().GetMimeType())
+	img, err := pp.Convert(r)
+	if img == nil || err != nil {
+		return nil, merrors.InternalServerError(g.serviceID, "could not get image")
 	}
 	if thumb, err = g.manager.Generate(tr, img); err != nil {
 		return nil, err
@@ -223,8 +230,5 @@ func (g Thumbnail) stat(path, auth string) (*provider.StatResponse, error) {
 	if !thumbnail.IsMimeTypeSupported(rsp.Info.MimeType) {
 		return nil, merrors.NotFound(g.serviceID, "Unsupported file type")
 	}
-
-
-
 	return rsp, nil
 }

thumbnails/pkg/thumbnail/imgsource/cs3.go

@@ -11,7 +11,7 @@ import (
 	"github.com/cs3org/reva/pkg/token"
 	"github.com/pkg/errors"
 	"google.golang.org/grpc/metadata"
-	"image"
+	"io"
 	"net/http"
 )
 
@@ -25,7 +25,9 @@ func NewCS3Source(c gateway.GatewayAPIClient) CS3 {
 	}
 }
 
-func (s CS3) Get(ctx context.Context, path string) (image.Image, error) {
+// Get downloads the file from a cs3 service
+// The caller MUST make sure to close the returned ReadCloser
+func (s CS3) Get(ctx context.Context, path string) (io.ReadCloser, error) {
 	auth, ok := ContextGetAuthorization(ctx)
 	if !ok {
 		return nil, errors.New("cs3source: authorization missing")
@@ -63,19 +65,14 @@ func (s CS3) Get(ctx context.Context, path string) (image.Image, error) {
 	http.DefaultTransport.(*http.Transport).TLSClientConfig = &tls.Config{InsecureSkipVerify: true} //nolint:gosec
 	client := &http.Client{}
 
-	resp, err := client.Do(httpReq)
+	resp, err := client.Do(httpReq) // nolint:bodyclose
 	if err != nil {
 		return nil, err
 	}
-	defer resp.Body.Close() //nolint:errcheck
 
 	if resp.StatusCode != http.StatusOK {
 		return nil, fmt.Errorf("could not get the image \"%s\". Request returned with statuscode %d ", path, resp.StatusCode)
 	}
 
-	img, _, err := image.Decode(resp.Body)
-	if err != nil {
-		return nil, errors.Wrapf(err, `could not decode the image "%s"`, path)
-	}
-	return img, nil
+	return resp.Body, nil
 }

thumbnails/pkg/thumbnail/imgsource/filesystem.go

@@ -2,7 +2,7 @@ package imgsource
 
 import (
 	"context"
-	"image"
+	"io"
 	"os"
 	"path/filepath"
 
@@ -23,17 +23,12 @@ type FileSystem struct {
 }
 
 // Get retrieves an image from the filesystem.
-func (s FileSystem) Get(ctx context.Context, file string) (image.Image, error) {
+func (s FileSystem) Get(ctx context.Context, file string) (io.ReadCloser, error) {
 	imgPath := filepath.Join(s.basePath, file)
 	f, err := os.Open(filepath.Clean(imgPath))
 	if err != nil {
 		return nil, errors.Wrapf(err, "failed to load the file %s from %s", file, imgPath)
 	}
 
-	img, _, err := image.Decode(f)
-	if err != nil {
-		return nil, errors.Wrap(err, "Get: Decode:")
-	}
-
-	return img, nil
+	return f, nil
 }

thumbnails/pkg/thumbnail/imgsource/imgsource.go

@@ -2,7 +2,7 @@ package imgsource
 
 import (
 	"context"
-	"image"
+	"io"
 )
 
 type key int
@@ -13,7 +13,7 @@ const (
 
 // Source defines the interface for image sources
 type Source interface {
-	Get(ctx context.Context, path string) (image.Image, error)
+	Get(ctx context.Context, path string) (io.ReadCloser, error)
 }
 
 // ContextSetAuthorization puts the authorization in the context.