Refactor fiv_thumbnail_extract()

1 files changed, 108 insertions, 76 deletions

diff --git a/fiv-thumbnail.c b/fiv-thumbnail.c
index 0f6d264..51e53b2 100644
--- a/fiv-thumbnail.c
+++ b/fiv-thumbnail.c
@@ -240,71 +240,68 @@ orient_thumbnail(cairo_surface_t *surface, FivIoOrientation orientation)
 	return oriented;
 }
 
-cairo_surface_t *
-fiv_thumbnail_extract(GFile *target, FivThumbnailSize max_size, GError **error)
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+#ifdef HAVE_LIBRAW
+
+static cairo_surface_t *
+extract_libraw_bitmap(
+	libraw_data_t *iprc, libraw_processed_image_t *image, GError **error)
 {
-	const char *path = g_file_peek_path(target);
-	if (!path) {
-		set_error(error, "thumbnails will only be extracted from local files");
+	// Anything else is extremely rare.
+	if (image->colors != 3 || image->bits != 8) {
+		set_error(error, "unsupported bitmap thumbnail");
 		return NULL;
 	}
 
-	GMappedFile *mf = g_mapped_file_new(path, FALSE, error);
-	if (!mf)
-		return NULL;
-
-	// Bitmap thumbnails generally need rotating, e.g.:
-	//  - Hasselblad/H4D-50/2-9-2017_street_0012.fff
-	//  - OnePlus/One/IMG_20150729_201116.dng (and more DNGs in general)
-	// Though it's apparent LibRaw doesn't adjust the thumbnails to match
-	// the main image's "flip" field (it just happens to match up often), e.g.:
-	//  - Phase One/H 25/H25_Outdoor_.IIQ (correct Orientation in IFD0)
-	//  - Phase One/H 25/H25_IT8.7-2_Card.TIF (correctly missing in IFD0)
-	//
-	// JPEG thumbnails generally have the right rotation in their Exif, e.g.:
-	//  - Canon/EOS-1Ds Mark II/RAW_CANON_1DSM2.CR2
-	//  - Leica/C (Typ 112)/Leica_-_C_(Typ_112)-_3:2.RWL
-	//  - Nikon/1 S2/RAW_NIKON_1S2.NEF
-	//  - Panasonic/DMC-FZ18/RAW_PANASONIC_LUMIX_FZ18.RAW
-	//  - Panasonic/DMC-FZ70/P1000836.RW2
-	//  - Samsung/NX200/2013-05-08-194524__sam6589.srw
-	//  - Sony/DSC-HX95/DSC00018.ARW
-	//
-	// Some files are problematic and we won't bother with special-casing:
-	//  - Leaf/Aptus 22/L_003172.mos (JPEG)'s thumbnail wrongly contains
-	//    Exif Orientation 6, and sizes.flip also contains 6.
-	//  - Nokia/Lumia 1020/RAW_NOKIA_LUMIA_1020.DNG (bitmap) has wrong color.
-	//  - Ricoh/GXR/R0017428.DNG (JPEG) seems to be plainly invalid.
-	FivIoOrientation orientation = FivIoOrientationUnknown;
-	cairo_surface_t *surface = NULL;
-#ifndef HAVE_LIBRAW
-	// TODO(p): Implement our own thumbnail extractors.
-	set_error(error, "unsupported file");
-#else  // HAVE_LIBRAW
-	// In this case, g_mapped_file_get_contents() returns NULL, causing issues.
-	if (!g_mapped_file_get_length(mf)) {
-		set_error(error, "empty file");
-		goto fail;
+	cairo_surface_t *surface = cairo_image_surface_create(
+		CAIRO_FORMAT_RGB24, image->width, image->height);
+	guint32 *out = (guint32 *) cairo_image_surface_get_data(surface);
+	const unsigned char *in = image->data;
+	for (guint64 i = 0; i < image->width * image->height; in += 3)
+		out[i++] = in[0] << 16 | in[1] << 8 | in[2];
+	cairo_surface_mark_dirty(surface);
+
+	// LibRaw actually turns an 8 to 5, so follow the documentation.
+	FivIoOrientation orient = FivIoOrientationUnknown;
+	switch (iprc->sizes.flip) {
+	break; case 3:
+		orient = FivIoOrientation180;
+	break; case 5:
+		orient = FivIoOrientation270;
+	break; case 6:
+		orient = FivIoOrientation90;
+	break; default:
+		return surface;
 	}
 
+	cairo_surface_set_user_data(
+		surface, &fiv_io_key_orientation, (void *) (intptr_t) orient, NULL);
+	return surface;
+}
+
+static cairo_surface_t *
+extract_libraw(GFile *target, GMappedFile *mf, GError **error)
+{
+	cairo_surface_t *surface = NULL;
 	libraw_data_t *iprc = libraw_init(
 		LIBRAW_OPIONS_NO_MEMERR_CALLBACK | LIBRAW_OPIONS_NO_DATAERR_CALLBACK);
 	if (!iprc) {
 		set_error(error, "failed to obtain a LibRaw handle");
-		goto fail;
+		return NULL;
 	}
 
 	int err = 0;
 	if ((err = libraw_open_buffer(iprc, (void *) g_mapped_file_get_contents(mf),
 			 g_mapped_file_get_length(mf)))) {
 		set_error(error, libraw_strerror(err));
-		goto fail_libraw;
+		goto fail;
 	}
 
 #if LIBRAW_VERSION >= LIBRAW_MAKE_VERSION(0, 21, 0)
 	if (!iprc->thumbs_list.thumbcount) {
 		set_error(error, "no thumbnails found");
-		goto fail_libraw;
+		goto fail;
 	}
 
 	// The old libraw_unpack_thumb() goes for the largest thumbnail,
@@ -323,66 +320,101 @@ fiv_thumbnail_extract(GFile *target, FivThumbnailSize max_size, GError **error)
 	}
 	if ((err = libraw_unpack_thumb_ex(iprc, best_index))) {
 		set_error(error, libraw_strerror(err));
-		goto fail_libraw;
+		goto fail;
 	}
-#else
+#else  // LIBRAW_VERSION < LIBRAW_MAKE_VERSION(0, 21, 0)
 	if ((err = libraw_unpack_thumb(iprc))) {
 		set_error(error, libraw_strerror(err));
-		goto fail_libraw;
+		goto fail;
 	}
-#endif
+#endif  // LIBRAW_VERSION < LIBRAW_MAKE_VERSION(0, 21, 0)
 
 	libraw_processed_image_t *image = libraw_dcraw_make_mem_thumb(iprc, &err);
 	if (!image) {
 		set_error(error, libraw_strerror(err));
-		goto fail_libraw;
+		goto fail;
 	}
 
-	gboolean dummy = FALSE;
+	// Bitmap thumbnails generally need rotating, e.g.:
+	//  - Hasselblad/H4D-50/2-9-2017_street_0012.fff
+	//  - OnePlus/One/IMG_20150729_201116.dng (and more DNGs in general)
+	// Though it's apparent LibRaw doesn't adjust the thumbnails to match
+	// the main image's "flip" field (it just happens to match up often), e.g.:
+	//  - Phase One/H 25/H25_Outdoor_.IIQ (correct Orientation in IFD0)
+	//  - Phase One/H 25/H25_IT8.7-2_Card.TIF (correctly missing in IFD0)
+	//
+	// JPEG thumbnails generally have the right rotation in their Exif, e.g.:
+	//  - Canon/EOS-1Ds Mark II/RAW_CANON_1DSM2.CR2
+	//  - Leica/C (Typ 112)/Leica_-_C_(Typ_112)-_3:2.RWL
+	//  - Nikon/1 S2/RAW_NIKON_1S2.NEF
+	//  - Panasonic/DMC-FZ18/RAW_PANASONIC_LUMIX_FZ18.RAW
+	//  - Panasonic/DMC-FZ70/P1000836.RW2
+	//  - Samsung/NX200/2013-05-08-194524__sam6589.srw
+	//  - Sony/DSC-HX95/DSC00018.ARW
+	//
+	// Some files are problematic and we won't bother with special-casing:
+	//  - Leaf/Aptus 22/L_003172.mos (JPEG)'s thumbnail wrongly contains
+	//    Exif Orientation 6, and sizes.flip also contains 6.
+	//  - Nokia/Lumia 1020/RAW_NOKIA_LUMIA_1020.DNG (bitmap) has wrong color.
+	//  - Ricoh/GXR/R0017428.DNG (JPEG) seems to be plainly invalid.
 	switch (image->type) {
+		gboolean dummy;
 	case LIBRAW_IMAGE_JPEG:
 		surface = render(
 			target, g_bytes_new(image->data, image->data_size), &dummy, error);
-		orientation = (int) (intptr_t) cairo_surface_get_user_data(
-			surface, &fiv_io_key_orientation);
 		break;
 	case LIBRAW_IMAGE_BITMAP:
-		// Anything else is extremely rare.
-		if (image->colors != 3 || image->bits != 8) {
-			set_error(error, "unsupported bitmap thumbnail");
-			break;
-		}
-
-		surface = cairo_image_surface_create(
-			CAIRO_FORMAT_RGB24, image->width, image->height);
-		guint32 *out = (guint32 *) cairo_image_surface_get_data(surface);
-		const unsigned char *in = image->data;
-		for (guint64 i = 0; i < image->width * image->height; in += 3)
-			out[i++] = in[0] << 16 | in[1] << 8 | in[2];
-		cairo_surface_mark_dirty(surface);
-
-		// LibRaw actually turns an 8 to 5, so follow the documentation.
-		switch (iprc->sizes.flip) {
-		break; case 3: orientation = FivIoOrientation180;
-		break; case 5: orientation = FivIoOrientation270;
-		break; case 6: orientation = FivIoOrientation90;
-		}
+		surface = extract_libraw_bitmap(iprc, image, error);
 		break;
 	default:
 		set_error(error, "unsupported embedded thumbnail");
 	}
 
 	libraw_dcraw_clear_mem(image);
-fail_libraw:
+fail:
 	libraw_close(iprc);
+	return surface;
+}
+
 #endif  // HAVE_LIBRAW
 
-fail:
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+cairo_surface_t *
+fiv_thumbnail_extract(GFile *target, FivThumbnailSize max_size, GError **error)
+{
+	const char *path = g_file_peek_path(target);
+	if (!path) {
+		set_error(error, "thumbnails will only be extracted from local files");
+		return NULL;
+	}
+
+	GMappedFile *mf = g_mapped_file_new(path, FALSE, error);
+	if (!mf)
+		return NULL;
+
+	// In this case, g_mapped_file_get_contents() returns NULL, causing issues.
+	if (!g_mapped_file_get_length(mf)) {
+		set_error(error, "empty file");
+		return NULL;
+	}
+
+	cairo_surface_t *surface = NULL;
+#ifdef HAVE_LIBRAW
+	surface = extract_libraw(target, mf, error);
+#else  // ! HAVE_LIBRAW
+	// TODO(p): Implement our own thumbnail extractors.
+	set_error(error, "unsupported file");
+#endif  // ! HAVE_LIBRAW
 	g_mapped_file_unref(mf);
 
-	// This hardcodes Exif orientation before adjust_thumbnail() might do so,
+	// Hardcode Exif orientation before adjust_thumbnail() might do so,
 	// before the early return below.
-	surface = orient_thumbnail(surface, orientation);
+	if (surface) {
+		int orientation = (intptr_t) cairo_surface_get_user_data(
+			surface, &fiv_io_key_orientation);
+		surface = orient_thumbnail(surface, orientation);
+	}
 	if (!surface || max_size < FIV_THUMBNAIL_SIZE_MIN ||
 		max_size > FIV_THUMBNAIL_SIZE_MAX)
 		return surface;