[gdk-pixbuf] thumbnailer: Simplify the code by reusing existing GdkPixbuf API

[Debarshi Ray <debarshir src gnome org>]

commit dd1f222f78eed2b7d70a5e8507199c78e3f9e12b
Author: Debarshi Ray <debarshir gnome org>
Date:   Sun Feb 12 02:43:19 2017 +0100

    thumbnailer: Simplify the code by reusing existing GdkPixbuf API
    
    Existing GdkPixbuf API like gdk_pixbuf_new_from_file_at_size and
    gdk_pixbuf_get_file_info have grown smarter since this code was
    written. They are now better at selecting the best GdkPixbufLoader for
    a given file.
    
    As a side-effect, this also prevents leaking the GFile and its URI,
    but those are minor issues since the thumbnailer has a very short life
    span
    
    https://bugzilla.gnome.org/show_bug.cgi?id=778517

 thumbnailer/gdk-pixbuf-thumbnailer.c |  209 ++--------------------------------
 1 files changed, 8 insertions(+), 201 deletions(-)
---
diff --git a/thumbnailer/gdk-pixbuf-thumbnailer.c b/thumbnailer/gdk-pixbuf-thumbnailer.c
index 85df4b3..d50ede8 100644
--- a/thumbnailer/gdk-pixbuf-thumbnailer.c
+++ b/thumbnailer/gdk-pixbuf-thumbnailer.c
@@ -24,225 +24,32 @@
 
 #include "gnome-thumbnailer-skeleton.h"
 
-typedef struct {
-    gint size;
-    gint input_width;
-    gint input_height;
-} SizePrepareContext;
-
-#define LOAD_BUFFER_SIZE 65536
-
-static void
-size_prepared_cb (GdkPixbufLoader *loader, 
-                 int              width,
-                 int              height,
-                 gpointer         data)
-{
-  SizePrepareContext *info = data;
-  
-  g_return_if_fail (width > 0 && height > 0);
-  
-  info->input_width = width;
-  info->input_height = height;
-  
-  if (width < info->size && height < info->size) return;
-  if (info->size <= 0) return;
-  
-  if (height > width) {
-    width = 0.5 + (double)width * (double)info->size / (double)height;
-    height = info->size;
-  } else {
-    height = 0.5 + (double)height * (double)info->size / (double)width;
-    width = info->size;
-  }
-  
-  gdk_pixbuf_loader_set_size (loader, width, height);
-}
-
-static GdkPixbufLoader *
-create_loader (GFile        *file,
-               const guchar *data,
-               gsize         size)
-{
-  GdkPixbufLoader *loader;
-  GError *error = NULL;
-  char *mime_type;
-  char *filename;
-
-  loader = NULL;
-
-  /* need to specify the type here because the gdk_pixbuf_loader_write
-     doesn't have access to the filename in order to correct detect
-     the image type. */
-  filename = g_file_get_basename (file);
-  mime_type = g_content_type_guess (filename, data, size, NULL);
-  g_free (filename);
-
-  if (mime_type != NULL) {
-    loader = gdk_pixbuf_loader_new_with_mime_type (mime_type, &error);
-  }
-
-  if (loader == NULL) {
-    g_debug ("Unable to create loader for mime type %s: %s", mime_type,
-             (error != NULL) ? error->message : "(null)");
-    g_clear_error (&error);
-    loader = gdk_pixbuf_loader_new ();
-  }
-  g_free (mime_type);
-
-  return loader;
-}
-
-static GdkPixbuf *
-_gdk_pixbuf_new_from_uri_at_scale (const char  *uri,
-                                  gint         size,
-                                  GError     **error)
-{
-    gboolean result;
-    guchar buffer[LOAD_BUFFER_SIZE];
-    gssize bytes_read;
-    GdkPixbufLoader *loader = NULL;
-    GdkPixbuf *pixbuf; 
-    GdkPixbufAnimation *animation;
-    GdkPixbufAnimationIter *iter;
-    gboolean has_frame;
-    SizePrepareContext info;
-    GFile *file;
-    GInputStream *input_stream;
-
-    g_return_val_if_fail (uri != NULL, NULL);
-
-    file = g_file_new_for_uri (uri);
-
-    input_stream = G_INPUT_STREAM (g_file_read (file, NULL, error));
-    if (input_stream == NULL) {
-        g_object_unref (file);
-        return NULL;
-    }
-
-    has_frame = FALSE;
-
-    result = FALSE;
-    while (!has_frame) {
-
-       bytes_read = g_input_stream_read (input_stream,
-                                         buffer,
-                                         sizeof (buffer),
-                                         NULL,
-                                         error);
-        if (bytes_read == -1) {
-            break;
-        }
-       result = TRUE;
-       if (bytes_read == 0) {
-           break;
-       }
-
-        if (loader == NULL) {
-            loader = create_loader (file, buffer, bytes_read);
-            if (1 <= size) {
-              info.size = size;
-              info.input_width = info.input_height = 0;
-              g_signal_connect (loader, "size-prepared", G_CALLBACK (size_prepared_cb), &info);
-            }
-            g_assert (loader != NULL);
-        }
-
-       if (!gdk_pixbuf_loader_write (loader,
-                                     (unsigned char *)buffer,
-                                     bytes_read,
-                                     error)) {
-           result = FALSE;
-           break;
-       }
-
-       animation = gdk_pixbuf_loader_get_animation (loader);
-       if (animation) {
-               iter = gdk_pixbuf_animation_get_iter (animation, NULL);
-               if (!gdk_pixbuf_animation_iter_on_currently_loading_frame (iter)) {
-                       has_frame = TRUE;
-               }
-               g_object_unref (iter);
-       }
-    }
-
-    if (loader == NULL) {
-        /* This can happen if the above loop was exited due to the
-         * g_input_stream_read() call failing. */
-        result = FALSE;
-    } else if (*error != NULL) {
-        gdk_pixbuf_loader_close (loader, NULL);
-        result = FALSE;
-    } else if (gdk_pixbuf_loader_close (loader, error) == FALSE) {
-        if (!g_error_matches (*error, GDK_PIXBUF_ERROR, GDK_PIXBUF_ERROR_INCOMPLETE_ANIMATION))
-          result = FALSE;
-        else
-          g_clear_error (error);
-    }
-
-    if (!result) {
-        g_clear_object (&loader);
-       g_input_stream_close (input_stream, NULL, NULL);
-       g_object_unref (input_stream);
-       g_object_unref (file);
-       return NULL;
-    }
-
-    g_input_stream_close (input_stream, NULL, NULL);
-    g_object_unref (input_stream);
-    g_object_unref (file);
-
-    pixbuf = gdk_pixbuf_loader_get_pixbuf (loader);
-    if (pixbuf != NULL) {
-       g_object_ref (G_OBJECT (pixbuf));
-       g_object_set_data (G_OBJECT (pixbuf), "gnome-original-width",
-                          GINT_TO_POINTER (info.input_width));
-       g_object_set_data (G_OBJECT (pixbuf), "gnome-original-height",
-                          GINT_TO_POINTER (info.input_height));
-    }
-    g_object_unref (G_OBJECT (loader));
-
-    return pixbuf;
-}
-
 GdkPixbuf *
 file_to_pixbuf (const char  *path,
                guint        destination_size,
                GError     **error)
 {
        GdkPixbuf *pixbuf, *tmp_pixbuf;
-       GFile *file;
-       char *uri;
-       int original_width, original_height;
+       const char *original_width_str, *original_height_str;
 
-       file = g_file_new_for_path (path);
-       uri = g_file_get_uri (file);
-       pixbuf = _gdk_pixbuf_new_from_uri_at_scale (uri, destination_size, error);
+       pixbuf = gdk_pixbuf_new_from_file_at_size (path, destination_size, destination_size, error);
        if (pixbuf == NULL)
                return NULL;
 
-        original_width = GPOINTER_TO_INT (g_object_get_data (G_OBJECT (pixbuf),
-                                                             "gnome-original-width"));
-        original_height = GPOINTER_TO_INT (g_object_get_data (G_OBJECT (pixbuf),
-                                                              "gnome-original-height"));
-
        tmp_pixbuf = gdk_pixbuf_apply_embedded_orientation (pixbuf);
        gdk_pixbuf_copy_options (pixbuf, tmp_pixbuf);
        gdk_pixbuf_remove_option (tmp_pixbuf, "orientation");
        g_object_unref (pixbuf);
        pixbuf = tmp_pixbuf;
 
-       if (original_width > 0 && original_height > 0) {
-               char *tmp;
+       original_width_str = gdk_pixbuf_get_option (pixbuf, "original-width");
+       original_height_str = gdk_pixbuf_get_option (pixbuf, "original-height");
 
-               tmp = g_strdup_printf ("%d", original_width);
-               gdk_pixbuf_set_option (pixbuf, "tEXt::Thumb::Image::Width", tmp);
-               g_free (tmp);
+       if (original_width_str != NULL)
+               gdk_pixbuf_set_option (pixbuf, "tEXt::Thumb::Image::Width", original_width_str);
 
-               tmp = g_strdup_printf ("%d", original_height);
-               gdk_pixbuf_set_option (pixbuf, "tEXt::Thumb::Image::Height", tmp);
-               g_free (tmp);
-       }
+       if (original_height_str != NULL)
+               gdk_pixbuf_set_option (pixbuf, "tEXt::Thumb::Image::Height", original_height_str);
 
        return pixbuf;
 }