Moved stuff to keep reference to input buffer

The typedefs and macros belong with the INPUT_BUFFER_RO macro, so it
makes sense to define them together.

Author: jim-easterbrook

src/interface/image.i

@@ -56,25 +56,13 @@ UNIQUE_PTR(Exiv2::Image);
 %thread Exiv2::ImageFactory::open;
 
 // ImageFactory can open image or get type from a buffer
-INPUT_BUFFER_RO(const Exiv2::byte* data, long size)
-INPUT_BUFFER_RO(const Exiv2::byte* data, size_t size)
-// Keep reference to memoryview of buffer until it can be released
-%{
-#define KEEPREF_VIEW_ImageFactory_open
-#define KEEPREF_VIEW_ImageFactory_createIo
-%}
-%typemap(argout, fragment="private_data")
-        (const Exiv2::byte* data, long size),
-        (const Exiv2::byte* data, size_t size) %{
-#ifdef KEEPREF_VIEW_$symname
-    private_store_set(resultobj, "using_view", _global_view);
-#endif
-%}
+INPUT_BUFFER_RO(const Exiv2::byte* data, long size,
+                ImageFactory_open, ImageFactory_createIo)
+INPUT_BUFFER_RO(const Exiv2::byte* data, size_t size,
+                ImageFactory_open, ImageFactory_createIo)
 
 // Release memory buffer after writeMetadata, as it creates its own copy
-%typemap(ret, fragment="private_data") void writeMetadata %{
-    private_store_del(self, "using_view");
-%}
+RELEASE_BUFFER(void writeMetadata)
 
 // Convert path encoding on Windows
 WINDOWS_PATH(const std::string& path)

src/interface/shared/buffers.i

@@ -16,8 +16,18 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 
+// Recursive macro to output #define statements for list of functions
+%define _HOLD_BUFFER(hold_func, remainder...)
+%{#define KEEPREF_VIEW_##hold_func%}
+#if #remainder != ""
+_HOLD_BUFFER(remainder)
+#endif
+%enddef
+
 // Macro for input read only byte buffer
-%define INPUT_BUFFER_RO(buf_type, len_type)
+// hold_funcs is a list of functions that don't read the input data
+// immediately, so keep a reference to the Python object
+%define INPUT_BUFFER_RO(buf_type, len_type, hold_funcs...)
 %typemap(doctype) buf_type ":py:term:`bytes-like object`";
 %typemap(in) (buf_type, len_type) (PyObject* _global_view = NULL) {
     _global_view = PyMemoryView_GetContiguous($input, PyBUF_READ, 'A');
@@ -36,8 +46,23 @@
 %typemap(typecheck, precedence=SWIG_TYPECHECK_CHAR_PTR) buf_type %{
     $1 = PyObject_CheckBuffer($input) ? 1 : 0;
 %}
+
+#if #hold_funcs != ""
+_HOLD_BUFFER(hold_funcs)
+%typemap(argout, fragment="private_data") (buf_type, len_type) {
+%#ifdef KEEPREF_VIEW_$symname
+    private_store_set(resultobj, "using_view", _global_view);
+%#endif
+}
+#endif
 %enddef // INPUT_BUFFER_RO
 
+// Macro for functions to release the held reference
+%define RELEASE_BUFFER(signature)
+%typemap(ret, fragment="private_data") signature %{
+    private_store_del(self, "using_view");
+%}
+%enddef
 
 // Macro for output writeable byte buffer
 %define OUTPUT_BUFFER_RW(buf_type, count_type)

src/swig-0_27_7/image_wrap.cxx

@@ -4379,10 +4379,10 @@ static void _set_python_exception() {
 #define EXV_ENABLE_FILESYSTEM
 #endif
 
-
 #define KEEPREF_VIEW_ImageFactory_open
 #define KEEPREF_VIEW_ImageFactory_createIo
-
+#define KEEPREF_VIEW_ImageFactory_open
+#define KEEPREF_VIEW_ImageFactory_createIo
 
 static bool enableBMFF(bool enable) {
     // deprecated since 2024-08-01
@@ -6539,11 +6539,11 @@ SWIGINTERN PyObject *_wrap_ImageFactory_open__SWIG_1(PyObject *self, Py_ssize_t
 
   resultobj = SWIG_NewPointerObj((&result)->release(), SWIGTYPE_p_Exiv2__Image, SWIG_POINTER_OWN |  0 );
 
-  
+  {
 #ifdef KEEPREF_VIEW_ImageFactory_open
-  private_store_set(resultobj, "using_view", _global_view);
+    private_store_set(resultobj, "using_view", _global_view);
 #endif
-  
+  }
 
   Py_XDECREF(_global_view);
 
@@ -6810,11 +6810,11 @@ SWIGINTERN PyObject *_wrap_ImageFactory_getType__SWIG_1(PyObject *self, Py_ssize
     if (!resultobj)
     SWIG_fail;
   }
-  
+  {
 #ifdef KEEPREF_VIEW_ImageFactory_getType
-  private_store_set(resultobj, "using_view", _global_view);
+    private_store_set(resultobj, "using_view", _global_view);
 #endif
-  
+  }
 
   Py_XDECREF(_global_view);
 
@@ -7051,11 +7051,11 @@ SWIGINTERN PyObject *_wrap_ImageFactory_createIo__SWIG_1(PyObject *self, Py_ssiz
 
   resultobj = SWIG_NewPointerObj((&result)->release(), SWIGTYPE_p_Exiv2__BasicIo, SWIG_POINTER_OWN |  0 );
 
-  
+  {
 #ifdef KEEPREF_VIEW_ImageFactory_createIo
-  private_store_set(resultobj, "using_view", _global_view);
+    private_store_set(resultobj, "using_view", _global_view);
 #endif
-  
+  }
 
   Py_XDECREF(_global_view);
 

src/swig-0_28_5/image_wrap.cxx

@@ -4377,10 +4377,10 @@ static void _set_python_exception() {
 #define EXV_ENABLE_FILESYSTEM
 #endif
 
-
 #define KEEPREF_VIEW_ImageFactory_open
 #define KEEPREF_VIEW_ImageFactory_createIo
-
+#define KEEPREF_VIEW_ImageFactory_open
+#define KEEPREF_VIEW_ImageFactory_createIo
 
 static bool enableBMFF(bool enable) {
     // deprecated since 2024-08-01
@@ -6537,11 +6537,11 @@ SWIGINTERN PyObject *_wrap_ImageFactory_open__SWIG_1(PyObject *self, Py_ssize_t
 
   resultobj = SWIG_NewPointerObj((&result)->release(), SWIGTYPE_p_Exiv2__Image, SWIG_POINTER_OWN |  0 );
 
-  
+  {
 #ifdef KEEPREF_VIEW_ImageFactory_open
-  private_store_set(resultobj, "using_view", _global_view);
+    private_store_set(resultobj, "using_view", _global_view);
 #endif
-  
+  }
 
   Py_XDECREF(_global_view);
 
@@ -6812,11 +6812,11 @@ SWIGINTERN PyObject *_wrap_ImageFactory_getType__SWIG_1(PyObject *self, Py_ssize
     if (!resultobj)
     SWIG_fail;
   }
-  
+  {
 #ifdef KEEPREF_VIEW_ImageFactory_getType
-  private_store_set(resultobj, "using_view", _global_view);
+    private_store_set(resultobj, "using_view", _global_view);
 #endif
-  
+  }
 
   Py_XDECREF(_global_view);
 
@@ -7053,11 +7053,11 @@ SWIGINTERN PyObject *_wrap_ImageFactory_createIo__SWIG_1(PyObject *self, Py_ssiz
 
   resultobj = SWIG_NewPointerObj((&result)->release(), SWIGTYPE_p_Exiv2__BasicIo, SWIG_POINTER_OWN |  0 );
 
-  
+  {
 #ifdef KEEPREF_VIEW_ImageFactory_createIo
-  private_store_set(resultobj, "using_view", _global_view);
+    private_store_set(resultobj, "using_view", _global_view);
 #endif
-  
+  }
 
   Py_XDECREF(_global_view);