fix delayed write to foreign via "w"

also added vips_foreign_find_save_options()/
vips_foreign_find_load_options()

ChangeLog

@@ -1,5 +1,7 @@
 30/1/12 started 7.28.0
 - version bump
+- added vips_foreign_find_save_options()/vips_foreign_find_load_options()
+- delayed write to foreign via a "w" image was not working
 
 20/8/11 started 7.27.0
 - version bump for new dev cycle

TODO

@@ -1,22 +1,6 @@
 - swig is not wrapping ops which return more than one arg by reference
   correctly .. eg. im_correl()
 
-- try/bench/vips.py is broken
-
-
-	(gdb) run vips.py wtc_tiled_small.tif x.tif
-	Starting program: /usr/bin/python vips.py wtc_tiled_small.tif x.tif
-	[Thread debugging using libthread_db enabled]
-
-	(vips.py:28339): GLib-GObject-CRITICAL **: g_object_ref: assertion
-	`G_IS_OBJECT (object)' failed
-
-	Program received signal SIGSEGV, Segmentation fault.
-	vips_foreign_convert_saveable (save=0xeac800) at foreign.c:899
-	899		if( in->Coding != VIPS_CODING_NONE &&
-	(gdb) p in
-	$1 = (VipsImage *) 0x0
-
 
 
 

libvips/foreign/foreign.c

@@ -482,13 +482,13 @@ vips_foreign_load_new_from_foreign_sub( VipsForeignLoadClass *load_class,
 
 /**
  * vips_foreign_find_load:
- * @filename: file to find a file for
+ * @filename: file to find a loader for
  *
- * Searches for an operation you could use to load a file. 
+ * Searches for an operation you could use to load @filename. 
  *
  * See also: vips_foreign_read().
  *
- * Returns: the nmae of an operation on success, %NULL on error
+ * Returns: the name of an operation on success, %NULL on error
  */
 const char *
 vips_foreign_find_load( const char *filename )
@@ -513,6 +513,40 @@ vips_foreign_find_load( const char *filename )
 	return( G_OBJECT_CLASS_NAME( load_class ) );
 }
 
+/**
+ * vips_foreign_find_load_options:
+ * @filename: file to find a loader for
+ *
+ * Searches for an operation you could use to load @filename. 
+ *
+ * Arguments to the loader may be embedded in the filename using the usual
+ * syntax.
+ *
+ * See also: vips_foreign_load().
+ *
+ * Returns: 0 on success, -1 on error
+ */
+const char *
+vips_foreign_find_load_options( const char *filename )
+{
+	VipsObjectClass *oclass = g_type_class_ref( VIPS_TYPE_FOREIGN_LOAD );
+	VipsObject *object;
+	const char *type_name;
+
+	/* This will use vips_foreign_load_new_from_string() to pick a loader,
+	 * then set options from the tail of the filename. This is rather slow
+	 * :-( 
+	 */
+	if( !(object = vips_object_new_from_string( oclass, filename )) )
+		return( NULL );
+
+	type_name = G_OBJECT_TYPE_NAME( object );
+
+	g_object_unref( object );
+
+	return( type_name );
+}
+
 /**
  * vips_foreign_is_a:
  * @loader: name of loader to use for test
@@ -834,9 +868,12 @@ vips_foreign_find_save_sub( VipsForeignSaveClass *save_class,
 
 /**
  * vips_foreign_find_save:
- * @filename: name to find a file for
+ * @filename: name to find a saver for
  *
- * Searches for an operation you could use to save a file.
+ * Searches for an operation you could use to write to @filename.
+ *
+ * @filename may not contain embedded options. See
+ * vips_foreign_find_save_options() if your filename may have options in.
  *
  * See also: vips_foreign_write().
  *
@@ -860,6 +897,40 @@ vips_foreign_find_save( const char *filename )
 	return( G_OBJECT_CLASS_NAME( save_class ) );
 }
 
+/**
+ * vips_foreign_find_save_options:
+ * @filename: name to find a saver for
+ *
+ * Searches for an operation you could use to write to @filename.
+ *
+ * @filename may contain embedded options. See
+ * vips_foreign_find_save() if your filename does not options in.
+ *
+ * See also: vips_foreign_write().
+ *
+ * Returns: 0 on success, -1 on error
+ */
+const char *
+vips_foreign_find_save_options( const char *filename )
+{
+	VipsObjectClass *oclass = g_type_class_ref( VIPS_TYPE_FOREIGN_SAVE );
+	VipsObject *object;
+	const char *type_name;
+
+	/* This will use vips_foreign_save_new_from_string() to pick a saver,
+	 * then set options from the tail of the filename. This is rather slow
+	 * :-( 
+	 */
+	if( !(object = vips_object_new_from_string( oclass, filename )) )
+		return( NULL );
+
+	type_name = G_OBJECT_TYPE_NAME( object );
+
+	g_object_unref( object );
+
+	return( type_name );
+}
+
 static VipsObject *
 vips_foreign_save_new_from_string( const char *string )
 {
@@ -1139,7 +1210,8 @@ vips_foreign_save_build( VipsObject *object )
 {
 	VipsForeignSave *save = VIPS_FOREIGN_SAVE( object );
 
-	if( vips_foreign_convert_saveable( save ) )
+	if( save->in &&
+		vips_foreign_convert_saveable( save ) )
 		return( -1 );
 
 	if( VIPS_OBJECT_CLASS( vips_foreign_save_parent_class )->
@@ -1222,7 +1294,8 @@ vips_foreign_load( const char *filename, VipsImage **out, ... )
  * @...: %NULL-terminated list of optional named arguments
  *
  * Saves @in to @filename using the saver recommended by
- * vips_foreign_find_save().
+ * vips_foreign_find_save(). Options are not in @filename but must be given
+ * as a NULL-terminated list of name-value pairs.
  *
  * See also: vips_foreign_load().
  *
@@ -1302,7 +1375,10 @@ vips_foreign_load_options( const char *filename, VipsImage **out )
  * @filename: file to write to
  *
  * Saves @in to @filename using the saver recommended by
- * vips_foreign_find_save().
+ * vips_foreign_find_save(). 
+ *
+ * Arguments to the saver may be embedded in the filename using the usual
+ * syntax.
  *
  * See also: vips_foreign_save().
  *

libvips/include/vips/foreign.h

@@ -189,6 +189,7 @@ typedef struct _VipsForeignLoadClass {
 GType vips_foreign_load_get_type( void );
 
 const char *vips_foreign_find_load( const char *filename );
+const char *vips_foreign_find_load_options( const char *filename );
 
 VipsForeignFlags vips_foreign_flags( const char *loader, const char *filename );
 gboolean vips_foreign_is_a( const char *loader, const char *filename );
@@ -277,6 +278,7 @@ typedef struct _VipsForeignSaveClass {
 GType vips_foreign_save_get_type( void );
 
 const char *vips_foreign_find_save( const char *filename );
+const char *vips_foreign_find_save_options( const char *filename );
 
 /* Read/write an image convenience functions.
  */

libvips/iofuncs/image.c

@@ -503,12 +503,12 @@ vips_image_rewind( VipsObject *object )
  * to a "p" and on "written" do im_vips2tiff() or whatever. 
  */
 
-/* From "written" callback: invoke a delayed save by building the write object..
+/* From "written" callback: save to image->filename using VipsForeign.
  */
 static void
-vips_image_save_cb( VipsImage *image, int *result, VipsObject *write )
+vips_image_save_cb( VipsImage *image, int *result )
 {
-	if( vips_object_build( write ) )
+	if( vips_foreign_save_options( image, image->filename ) )
 		*result = -1;
 }
 
@@ -669,36 +669,27 @@ vips_image_build( VipsObject *object )
 
 	case 'w':
 {
-		VipsObjectClass *oclass = 
-			g_type_class_ref( VIPS_TYPE_FOREIGN_SAVE );
-		VipsObject *object;
-
-		/* This will use vips_foreign_save_new_from_string() to pick a 
-		 * saver, then set options from the tail of the filename.
-		 */
-		if( !(object = vips_object_new_from_string( oclass, 
-			filename )) )
-			return( -1 );
-		vips_object_local( image, object );
+		const char *file_op;
 
 		/* Make sure the vips saver is there ... strange things will
-		 * happen if that type is renamed or removed.
+		 * happen if this type is renamed or removed.
 		 */
 		g_assert( g_type_from_name( "VipsForeignSaveVips" ) );
 
-		/* If this ia the vips saver, just save directly ourselves.
-		 * Otherwise trigger a _build() and save when the image has
-		 * been written to.
+		if( !(file_op = vips_foreign_find_save_options( filename )) )
+			return( -1 );
+
+		/* If this is the vips saver, just save directly ourselves.
+		 * Otherwise save with VipsForeign when the image has been 
+		 * written to.
 		 */
-		if( G_TYPE_CHECK_INSTANCE_TYPE( object, 
-			g_type_from_name( "VipsForeignSaveVips" ) ) ) {
+		if( strcmp( file_op, "VipsForeignSaveVips" ) == 0 )
 			image->dtype = VIPS_IMAGE_OPENOUT;
-		}
 		else {
 			image->dtype = VIPS_IMAGE_PARTIAL;
 			g_signal_connect( image, "written", 
 				G_CALLBACK( vips_image_save_cb ), 
-				object );
+				NULL );
 		}
 }
         	break;