Merge pull request #4 from rtio/rtio/add-strip-metadata

Add strip metadata

exif.go

@@ -145,3 +145,19 @@ func makeExifDatumIterator(data *ExifData, cIter *C.Exiv2ExifDatumIterator) *Exi
 func (i *Image) ExifStripKey(key string) error {
 	return i.StripKey(EXIF, key)
 }
+
+func (i *Image) ExifStripMetadata(unless []string) error {
+	exifData := i.GetExifData()
+	for iter := exifData.Iterator(); iter.HasNext(); {
+		key := iter.Next().Key()
+		// Skip unless
+		if contains(key, unless) {
+			continue
+		}
+		err := i.StripKey(EXIF, key)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}

exiv.go

@@ -258,3 +258,30 @@ func (i *Image) StripKey(f MetadataFormat, key string) error {
 
 	return nil
 }
+
+func (i *Image) StripMetadata(unless []string) error {
+	var err error
+	err = i.ExifStripMetadata(unless)
+	if err != nil {
+		return err
+	}
+	err = i.IptcStripMetadata(unless)
+	if err != nil {
+		return err
+	}
+	err = i.XmpStripMetadata(unless)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// contains checks if a string is present in a string slice
+func contains(needle string, haystack []string) bool {
+	for _, s := range haystack {
+		if s == needle {
+			return true
+		}
+	}
+	return false
+}

exiv_test.go

@@ -522,6 +522,138 @@ func TestXmpStripKey(t *testing.T) {
 	require.Error(t, err)
 }
 
+func TestExifStrip(t *testing.T) {
+	img, err := goexiv.Open("testdata/pixel.jpg")
+	require.NoError(t, err)
+
+	// add two strings to the EXIF data
+	err = img.SetExifString("Exif.Photo.UserComment", "123")
+	require.NoError(t, err)
+
+	err = img.SetExifString("Exif.Photo.DateTimeOriginal", "123")
+	require.NoError(t, err)
+
+	err = img.ExifStripMetadata([]string{"Exif.Photo.UserComment"})
+	require.NoError(t, err)
+
+	err = img.ReadMetadata()
+	require.NoError(t, err)
+
+	data := img.GetExifData()
+
+	_, err = data.GetString("Exif.Photo.UserComment")
+	require.NoError(t, err)
+
+	_, err = data.GetString("Exif.Photo.DateTimeOriginal")
+	require.Error(t, err)
+}
+
+func TestIptcStrip(t *testing.T) {
+	img, err := goexiv.Open("testdata/pixel.jpg")
+	require.NoError(t, err)
+
+	// add two strings to the IPTC data
+	err = img.SetIptcString("Iptc.Application2.Caption", "123")
+	require.NoError(t, err)
+
+	err = img.SetIptcString("Iptc.Application2.Keywords", "123")
+	require.NoError(t, err)
+
+	err = img.IptcStripMetadata([]string{"Iptc.Application2.Caption"})
+	require.NoError(t, err)
+
+	err = img.ReadMetadata()
+	require.NoError(t, err)
+
+	data := img.GetIptcData()
+
+	_, err = data.GetString("Iptc.Application2.Caption")
+	require.NoError(t, err)
+
+	_, err = data.GetString("Iptc.Application2.Keywords")
+	require.Error(t, err)
+}
+
+func TestXmpStrip(t *testing.T) {
+	img, err := goexiv.Open("testdata/pixel.jpg")
+	require.NoError(t, err)
+
+	// add two strings to the XMP data
+	err = img.SetXmpString("Xmp.dc.description", "123")
+	require.NoError(t, err)
+
+	err = img.SetXmpString("Xmp.dc.subject", "123")
+	require.NoError(t, err)
+
+	err = img.XmpStripMetadata([]string{"Xmp.dc.description"})
+	require.NoError(t, err)
+
+	err = img.ReadMetadata()
+	require.NoError(t, err)
+
+	data := img.GetXmpData()
+
+	_, err = data.GetString("Xmp.dc.description")
+	require.NoError(t, err)
+
+	_, err = data.GetString("Xmp.dc.subject")
+	require.Error(t, err)
+}
+
+func TestStripMetadata(t *testing.T) {
+	img, err := goexiv.Open("testdata/pixel.jpg")
+	require.NoError(t, err)
+
+	// add two strings to the EXIF data
+	err = img.SetExifString("Exif.Photo.UserComment", "123")
+	require.NoError(t, err)
+
+	err = img.SetExifString("Exif.Photo.DateTimeOriginal", "123")
+	require.NoError(t, err)
+
+	// add two strings to the IPTC data
+	err = img.SetIptcString("Iptc.Application2.Caption", "123")
+	require.NoError(t, err)
+
+	err = img.SetIptcString("Iptc.Application2.Keywords", "123")
+	require.NoError(t, err)
+
+	// add two strings to the XMP data
+	err = img.SetXmpString("Xmp.dc.description", "123")
+	require.NoError(t, err)
+
+	err = img.SetXmpString("Xmp.dc.subject", "123")
+	require.NoError(t, err)
+
+	err = img.StripMetadata([]string{"Exif.Photo.UserComment", "Iptc.Application2.Caption", "Xmp.dc.description"})
+	require.NoError(t, err)
+
+	err = img.ReadMetadata()
+	require.NoError(t, err)
+
+	exifData := img.GetExifData()
+	iptcData := img.GetIptcData()
+	xmpData := img.GetXmpData()
+
+	_, err = exifData.GetString("Exif.Photo.UserComment")
+	require.NoError(t, err)
+
+	_, err = exifData.GetString("Exif.Photo.DateTimeOriginal")
+	require.Error(t, err)
+
+	_, err = iptcData.GetString("Iptc.Application2.Caption")
+	require.NoError(t, err)
+
+	_, err = iptcData.GetString("Iptc.Application2.Keywords")
+	require.Error(t, err)
+
+	_, err = xmpData.GetString("Xmp.dc.description")
+	require.NoError(t, err)
+
+	_, err = xmpData.GetString("Xmp.dc.subject")
+	require.Error(t, err)
+}
+
 func BenchmarkImage_GetBytes_KeepAlive(b *testing.B) {
 	bytes, err := ioutil.ReadFile("testdata/stripped_pixel.jpg")
 	require.NoError(b, err)

helper.cpp

@@ -23,6 +23,14 @@ DEFINE_STRUCT(Exiv2Image, Exiv2::Image::AutoPtr, image);
 
 DEFINE_STRUCT(Exiv2XmpData, const Exiv2::XmpData&, data);
 DEFINE_STRUCT(Exiv2XmpDatum, const Exiv2::Xmpdatum&, datum);
+struct _Exiv2XmpDatumIterator {
+	_Exiv2XmpDatumIterator(Exiv2::XmpMetadata::const_iterator i, Exiv2::XmpMetadata::const_iterator e) : it(i), end(e) {}
+	Exiv2::XmpMetadata::const_iterator it;
+	Exiv2::XmpMetadata::const_iterator end;
+
+	bool has_next() const;
+	Exiv2XmpDatum* next();
+};
 
 DEFINE_STRUCT(Exiv2ExifData, const Exiv2::ExifData&, data);
 DEFINE_STRUCT(Exiv2ExifDatum, const Exiv2::Exifdatum&, datum);
@@ -46,6 +54,7 @@ struct _Exiv2IptcDatumIterator {
 	Exiv2IptcDatum* next();
 };
 
+DEFINE_FREE_FUNCTION(exiv2_xmp_datum_iterator, Exiv2XmpDatumIterator*);
 DEFINE_FREE_FUNCTION(exiv2_iptc_datum_iterator, Exiv2IptcDatumIterator*);
 DEFINE_FREE_FUNCTION(exiv2_exif_datum_iterator, Exiv2ExifDatumIterator*);
 
@@ -275,8 +284,41 @@ exiv2_xmp_data_find_key(const Exiv2XmpData *data, const char *key, Exiv2Error **
 	}
 }
 
+Exiv2XmpDatumIterator* exiv2_xmp_data_iterator(const Exiv2XmpData *data)
+{
+	return new Exiv2XmpDatumIterator(data->data.begin(), data->data.end());
+}
+
+bool Exiv2XmpDatumIterator::has_next() const
+{
+	return it != end;
+}
+
+int exiv2_xmp_data_iterator_has_next(const Exiv2XmpDatumIterator *iter)
+{
+	return iter->has_next() ? 1 : 0;
+}
+
+Exiv2XmpDatum* Exiv2XmpDatumIterator::next()
+{
+	if (it == end) {
+		return 0;
+	}
+	return new Exiv2XmpDatum(*it++);
+}
+
+Exiv2XmpDatum* exiv2_xmp_datum_iterator_next(Exiv2XmpDatumIterator *iter)
+{
+	return iter->next();
+}
+
 DEFINE_FREE_FUNCTION(exiv2_xmp_data, Exiv2XmpData*);
 
+const char* exiv2_xmp_datum_key(const Exiv2XmpDatum *datum)
+{
+	return strdup(datum->datum.key().c_str());
+}
+
 char*
 exiv2_xmp_datum_to_string(const Exiv2XmpDatum *datum)
 {

helper.h

@@ -8,6 +8,7 @@ DECLARE_STRUCT(Exiv2ImageFactory);
 DECLARE_STRUCT(Exiv2Image);
 DECLARE_STRUCT(Exiv2XmpData);
 DECLARE_STRUCT(Exiv2XmpDatum);
+DECLARE_STRUCT(Exiv2XmpDatumIterator);
 DECLARE_STRUCT(Exiv2IptcData);
 DECLARE_STRUCT(Exiv2IptcDatum);
 DECLARE_STRUCT(Exiv2IptcDatumIterator);
@@ -16,6 +17,7 @@ DECLARE_STRUCT(Exiv2ExifDatum);
 DECLARE_STRUCT(Exiv2ExifDatumIterator);
 DECLARE_STRUCT(Exiv2Error);
 
+void exiv2_xmp_datum_iterator_free(Exiv2XmpDatumIterator *datum);
 void exiv2_iptc_datum_iterator_free(Exiv2IptcDatumIterator *datum);
 void exiv2_exif_datum_iterator_free(Exiv2ExifDatumIterator *datum);
 
@@ -38,9 +40,13 @@ int exiv2_image_get_pixel_height(Exiv2Image *img);
 
 Exiv2XmpData* exiv2_image_get_xmp_data(const Exiv2Image *img);
 void exiv2_xmp_data_free(Exiv2XmpData *data);
+const char* exiv2_xmp_datum_key(const Exiv2XmpDatum *datum);
 char* exiv2_xmp_datum_to_string(const Exiv2XmpDatum *datum);
 void exiv2_xmp_datum_free(Exiv2XmpDatum *datum);
 Exiv2XmpDatum* exiv2_xmp_data_find_key(const Exiv2XmpData *data, const char *key, Exiv2Error **error);
+Exiv2XmpDatumIterator* exiv2_xmp_data_iterator(const Exiv2XmpData *data);
+int exiv2_xmp_data_iterator_has_next(const Exiv2XmpDatumIterator *iter);
+Exiv2XmpDatum* exiv2_xmp_datum_iterator_next(Exiv2XmpDatumIterator *iter);
 
 Exiv2IptcData* exiv2_image_get_iptc_data(const Exiv2Image *img);
 void exiv2_iptc_data_free(Exiv2IptcData *data);

iptc.go

@@ -149,3 +149,19 @@ func makeIptcDatumIterator(data *IptcData, cIter *C.Exiv2IptcDatumIterator) *Ipt
 func (i *Image) IptcStripKey(key string) error {
 	return i.StripKey(IPTC, key)
 }
+
+func (i *Image) IptcStripMetadata(unless []string) error {
+	iptcData := i.GetIptcData()
+	for iter := iptcData.Iterator(); iter.HasNext(); {
+		key := iter.Next().Key()
+		// Skip unless
+		if contains(key, unless) {
+			continue
+		}
+		err := i.StripKey(IPTC, key)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}

xmp.go

@@ -22,6 +22,12 @@ type XmpDatum struct {
 	datum *C.Exiv2XmpDatum
 }
 
+// XmpDatumIterator wraps the respective C++ structure.
+type XmpDatumIterator struct {
+	data *XmpData
+	iter *C.Exiv2XmpDatumIterator
+}
+
 func makeXmpData(img *Image, cdata *C.Exiv2XmpData) *XmpData {
 	data := &XmpData{
 		img,
@@ -105,3 +111,49 @@ func (d *XmpData) GetString(key string) (string, error) {
 
 	return datum.String(), nil
 }
+
+func (i *Image) XmpStripMetadata(unless []string) error {
+	xmpData := i.GetXmpData()
+	for iter := xmpData.Iterator(); iter.HasNext(); {
+		key := iter.Next().Key()
+		// Skip unless
+		if contains(key, unless) {
+			continue
+		}
+		err := i.StripKey(XMP, key)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// Iterator returns a new XmpDatumIterator to iterate over all IPTC data.
+func (d *XmpData) Iterator() *XmpDatumIterator {
+	return makeXmpDatumIterator(d, C.exiv2_xmp_data_iterator(d.data))
+}
+
+// HasNext returns true as long as the iterator has another datum to deliver.
+func (i *XmpDatumIterator) HasNext() bool {
+	return C.exiv2_xmp_data_iterator_has_next(i.iter) != 0
+}
+
+// Next returns the next XmpDatum of the iterator or nil if iterator has reached the end.
+func (i *XmpDatumIterator) Next() *XmpDatum {
+	return makeXmpDatum(i.data, C.exiv2_xmp_datum_iterator_next(i.iter))
+}
+
+func makeXmpDatumIterator(data *XmpData, cIter *C.Exiv2XmpDatumIterator) *XmpDatumIterator {
+	datum := &XmpDatumIterator{data, cIter}
+
+	runtime.SetFinalizer(datum, func(i *XmpDatumIterator) {
+		C.exiv2_xmp_datum_iterator_free(i.iter)
+	})
+
+	return datum
+}
+
+// Key returns the XMP key of the datum.
+func (d *XmpDatum) Key() string {
+	return C.GoString(C.exiv2_xmp_datum_key(d.datum))
+}