implement thumbnail support for txt files

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.

thumbnails/pkg/thumbnail/imgsource/webdav.go

@@ -6,10 +6,10 @@ import (
 	"fmt"
 	"github.com/owncloud/ocis/thumbnails/pkg/config"
 	"github.com/pkg/errors"
-	"image"
 	_ "image/gif"  // Import the gif package so that image.Decode can understand gifs
 	_ "image/jpeg" // Import the jpeg package so that image.Decode can understand jpegs
 	_ "image/png"  // Import the png package so that image.Decode can understand pngs
+	"io"
 	"net/http"
 )
 
@@ -26,7 +26,8 @@ type WebDav struct {
 }
 
 // Get downloads the file from a webdav service
-func (s WebDav) Get(ctx context.Context, url string) (image.Image, error) {
+// The caller MUST make sure to close the returned ReadCloser
+func (s WebDav) Get(ctx context.Context, url string) (io.ReadCloser, error) {
 	req, err := http.NewRequest(http.MethodGet, url, nil)
 	if err != nil {
 		return nil, errors.Wrapf(err, `could not get the image "%s"`, url)
@@ -39,19 +40,14 @@ func (s WebDav) Get(ctx context.Context, url string) (image.Image, error) {
 	}
 
 	client := &http.Client{}
-	resp, err := client.Do(req)
+	resp, err := client.Do(req) // nolint:bodyclose
 	if err != nil {
 		return nil, errors.Wrapf(err, `could not get the image "%s"`, url)
 	}
-	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 ", url, resp.StatusCode)
 	}
 
-	img, _, err := image.Decode(resp.Body)
-	if err != nil {
-		return nil, errors.Wrapf(err, `could not decode the image "%s"`, url)
-	}
-	return img, nil
+	return resp.Body, nil
 }

thumbnails/pkg/thumbnail/thumbnail.go

@@ -6,6 +6,7 @@ import (
 	"github.com/owncloud/ocis/ocis-pkg/log"
 	"github.com/owncloud/ocis/thumbnails/pkg/thumbnail/storage"
 	"image"
+	"mime"
 	"strings"
 )
 
@@ -15,6 +16,7 @@ var (
 		"image/jpg",
 		"image/jpeg",
 		"image/gif",
+		"text/plain",
 	}
 )
 
@@ -90,8 +92,12 @@ func mapToStorageRequest(r Request) storage.Request {
 }
 
 func IsMimeTypeSupported(m string) bool {
+	mimeType, _, err := mime.ParseMediaType(m)
+	if err != nil {
+		return false
+	}
 	for _, mt := range SupportedMimeTypes {
-		if strings.EqualFold(mt, m) {
+		if strings.EqualFold(mt, mimeType) {
 			return true
 		}
 	}