Better "struct dict" initialisation

Author: jim-easterbrook

src/interface/datasets.i

@@ -77,3 +77,5 @@ STRUCT_DICT(Exiv2::DataSet, false, true)
 %immutable;
 %include "exiv2/datasets.hpp"
 %mutable;
+
+INIT_STRUCT_DICT(Exiv2::DataSet)

src/interface/preview.i

@@ -111,3 +111,5 @@ STRUCT_DICT(Exiv2::PreviewProperties, false, true)
 %include "exiv2/preview.hpp"
 %mutable;
 #undef EXV_ENABLE_FILESYSTEM
+
+INIT_STRUCT_DICT(Exiv2::PreviewProperties)

src/interface/properties.i

@@ -128,3 +128,6 @@ STRUCT_DICT(Exiv2::XmpNsInfo, false, true)
 %immutable;
 %include "exiv2/properties.hpp"
 %mutable;
+
+INIT_STRUCT_DICT(Exiv2::XmpPropertyInfo)
+INIT_STRUCT_DICT(Exiv2::XmpNsInfo)

src/interface/shared/struct_dict.i

@@ -29,8 +29,6 @@ typedef struct {
 }
 %fragment("init_struct_info", "header", fragment="struct_info_type") {
 static void init_struct_info(struct_info& info, swig_type_info* type) {
-    if (!info.members.empty())
-        return;
     PyGetSetDef* getset =
         ((SwigPyClientData*)type->clientdata)->pytype->tp_getset;
     while (getset->name) {
@@ -156,64 +154,53 @@ Python interface uses names without underscores."
     %fragment("values_struct");
     %fragment("items_struct");
     static PyObject* keys() {
-        init_info_%mangle(struct_type)();
         return keys_struct(info_%mangle(struct_type));
     }
     PyObject* values(PyObject* py_self) {
-        init_info_%mangle(struct_type)();
         return values_struct(info_%mangle(struct_type), py_self);
     }
     PyObject* items(PyObject* py_self) {
-        init_info_%mangle(struct_type)();
         return items_struct(info_%mangle(struct_type), py_self);
     }
     static PyObject* __iter__() {
         // Deprecated since 2025-09-11
         PyErr_WarnEx(PyExc_DeprecationWarning,
              "Please iterate over keys() function output", 1);
-        init_info_%mangle(struct_type)();
         PyObject* seq = keys_struct(info_%mangle(struct_type));
         PyObject* result = PySeqIter_New(seq);
         Py_DECREF(seq);
         return result;
     }
 }
 %fragment("struct_info"{struct_type}, "header",
-          fragment="init_struct_info") {
+          fragment="struct_info_type") {
 static struct_info info_%mangle(struct_type);
-static void init_info_%mangle(struct_type)() {
-    init_struct_info(info_%mangle(struct_type), $descriptor(struct_type*));
-};
 }
 %fragment("get_item"{struct_type}, "header",
           fragment="struct_info"{struct_type}, fragment="get_attr_struct") {
 static PyObject* get_item_%mangle(struct_type)(PyObject* obj,
                                                PyObject* key) {
-    init_info_%mangle(struct_type)();
     return get_attr_struct(info_%mangle(struct_type), true, obj, key);
 };
 }
 %fragment("get_attr"{struct_type}, "header",
           fragment="struct_info"{struct_type}, fragment="get_attr_struct") {
 static PyObject* get_attr_%mangle(struct_type)(PyObject* obj,
                                                PyObject* name) {
-    init_info_%mangle(struct_type)();
     return get_attr_struct(info_%mangle(struct_type), false, obj, name);
 };
 }
 %fragment("set_item"{struct_type}, "header",
           fragment="struct_info"{struct_type}, fragment="set_attr_struct") {
 static int set_item_%mangle(struct_type)(
         PyObject* obj, PyObject* key, PyObject* value) {
-    init_info_%mangle(struct_type)();
     return set_attr_struct(info_%mangle(struct_type), true, obj, key, value);
 };
 }
 %fragment("set_attr"{struct_type}, "header",
           fragment="struct_info"{struct_type}, fragment="set_attr_struct") {
 static int set_attr_%mangle(struct_type)(
         PyObject* obj, PyObject* name, PyObject* value) {
-    init_info_%mangle(struct_type)();
     return set_attr_struct(
         info_%mangle(struct_type), false, obj, name, value);
 };
@@ -237,3 +224,20 @@ static int set_attr_%mangle(struct_type)(
 #endif
 #endif // mutable
 %enddef // STRUCT_DICT
+
+
+// Put this at the end of a .i file, after the struct_type type object
+// has been initialised.
+%define INIT_STRUCT_DICT(struct_type)
+%fragment("init_struct_dict"{struct_type}, "init",
+          fragment="struct_info"{struct_type},
+          fragment="init_struct_info") {
+init_struct_info(info_%mangle(struct_type), $descriptor(struct_type*));
+if (info_%mangle(struct_type).aliases.empty()) {
+    PyErr_SetString(
+        PyExc_RuntimeError, "Failed to initialise struct_type info");
+    return INIT_ERROR_RETURN;
+}
+}
+%fragment("init_struct_dict"{struct_type});
+%enddef // INIT_STRUCT_DICT

src/interface/tags.i

@@ -122,3 +122,6 @@ public:
 %immutable;
 %include "exiv2/tags.hpp"
 %mutable;
+
+INIT_STRUCT_DICT(Exiv2::GroupInfo)
+INIT_STRUCT_DICT(Exiv2::TagInfo)

src/interface/value.i

@@ -553,3 +553,6 @@ VALUETYPE(LongValue, int32_t, Exiv2::signedLong)
 VALUETYPE(RationalValue, Exiv2::Rational, Exiv2::signedRational)
 VALUETYPE(FloatValue, float, Exiv2::tiffFloat)
 VALUETYPE(DoubleValue, double, Exiv2::tiffDouble)
+
+INIT_STRUCT_DICT(Exiv2::DateValue::Date)
+INIT_STRUCT_DICT(Exiv2::TimeValue::Time)

src/swig-0_27_7/datasets_wrap.cxx

@@ -4358,31 +4358,7 @@ typedef struct {
 } struct_info;
 
 
-static void init_struct_info(struct_info& info, swig_type_info* type) {
-    if (!info.members.empty())
-        return;
-    PyGetSetDef* getset =
-        ((SwigPyClientData*)type->clientdata)->pytype->tp_getset;
-    while (getset->name) {
-        // __dict__ is also in the getset list
-        if (getset->name[0] != '_') {
-            info.members.push_back(getset->name);
-            std::string alias = getset->name;
-            if (alias.back() == '_') {
-                alias.pop_back();
-                info.aliased = true;
-            }
-            info.aliases.push_back(alias);
-        }
-        getset++;
-    }
-};
-
-
 static struct_info info_Exiv2_DataSet;
-static void init_info_Exiv2_DataSet() {
-    init_struct_info(info_Exiv2_DataSet, SWIGTYPE_p_Exiv2__DataSet);
-};
 
 
 static PyObject* get_attr_struct(struct_info& info, bool as_item,
@@ -4400,14 +4376,12 @@ static PyObject* get_attr_struct(struct_info& info, bool as_item,
 
 static PyObject* get_item_Exiv2_DataSet(PyObject* obj,
                                                PyObject* key) {
-    init_info_Exiv2_DataSet();
     return get_attr_struct(info_Exiv2_DataSet, true, obj, key);
 };
 
 
 static PyObject* get_attr_Exiv2_DataSet(PyObject* obj,
                                                PyObject* name) {
-    init_info_Exiv2_DataSet();
     return get_attr_struct(info_Exiv2_DataSet, false, obj, name);
 };
 
@@ -4475,22 +4449,18 @@ SWIGINTERNINLINE PyObject*
 static PyObject* Python_Exiv2_TypeId = NULL;
 
 SWIGINTERN PyObject *Exiv2_DataSet_keys(){
-        init_info_Exiv2_DataSet();
         return keys_struct(info_Exiv2_DataSet);
     }
 SWIGINTERN PyObject *Exiv2_DataSet_values(Exiv2::DataSet *self,PyObject *py_self){
-        init_info_Exiv2_DataSet();
         return values_struct(info_Exiv2_DataSet, py_self);
     }
 SWIGINTERN PyObject *Exiv2_DataSet_items(Exiv2::DataSet *self,PyObject *py_self){
-        init_info_Exiv2_DataSet();
         return items_struct(info_Exiv2_DataSet, py_self);
     }
 SWIGINTERN PyObject *Exiv2_DataSet___iter__(){
         // Deprecated since 2025-09-11
         PyErr_WarnEx(PyExc_DeprecationWarning,
              "Please iterate over keys() function output", 1);
-        init_info_Exiv2_DataSet();
         PyObject* seq = keys_struct(info_Exiv2_DataSet);
         PyObject* result = PySeqIter_New(seq);
         Py_DECREF(seq);
@@ -4794,6 +4764,25 @@ static PyObject* pointer_to_list(Exiv2::DataSet* ptr) {
     return list;
 };
 
+
+static void init_struct_info(struct_info& info, swig_type_info* type) {
+    PyGetSetDef* getset =
+        ((SwigPyClientData*)type->clientdata)->pytype->tp_getset;
+    while (getset->name) {
+        // __dict__ is also in the getset list
+        if (getset->name[0] != '_') {
+            info.members.push_back(getset->name);
+            std::string alias = getset->name;
+            if (alias.back() == '_') {
+                alias.pop_back();
+                info.aliased = true;
+            }
+            info.aliases.push_back(alias);
+        }
+        getset++;
+    }
+};
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -7956,6 +7945,14 @@ SWIG_init(void) {
   PyModule_AddObject(m, "IptcKey", (PyObject *)builtin_pytype);
   SwigPyBuiltin_AddPublicSymbol(public_interface, "IptcKey");
   d = md;
+  
+  init_struct_info(info_Exiv2_DataSet, SWIGTYPE_p_Exiv2__DataSet);
+  if (info_Exiv2_DataSet.aliases.empty()) {
+    PyErr_SetString(
+      PyExc_RuntimeError, "Failed to initialise Exiv2::DataSet info");
+    return INIT_ERROR_RETURN;
+  }
+  
 #if PY_VERSION_HEX >= 0x03000000
   return m;
 #else

src/swig-0_27_7/preview_wrap.cxx

@@ -5447,31 +5447,7 @@ typedef struct {
 } struct_info;
 
 
-static void init_struct_info(struct_info& info, swig_type_info* type) {
-    if (!info.members.empty())
-        return;
-    PyGetSetDef* getset =
-        ((SwigPyClientData*)type->clientdata)->pytype->tp_getset;
-    while (getset->name) {
-        // __dict__ is also in the getset list
-        if (getset->name[0] != '_') {
-            info.members.push_back(getset->name);
-            std::string alias = getset->name;
-            if (alias.back() == '_') {
-                alias.pop_back();
-                info.aliased = true;
-            }
-            info.aliases.push_back(alias);
-        }
-        getset++;
-    }
-};
-
-
 static struct_info info_Exiv2_PreviewProperties;
-static void init_info_Exiv2_PreviewProperties() {
-    init_struct_info(info_Exiv2_PreviewProperties, SWIGTYPE_p_Exiv2__PreviewProperties);
-};
 
 
 static PyObject* get_attr_struct(struct_info& info, bool as_item,
@@ -5489,14 +5465,12 @@ static PyObject* get_attr_struct(struct_info& info, bool as_item,
 
 static PyObject* get_item_Exiv2_PreviewProperties(PyObject* obj,
                                                PyObject* key) {
-    init_info_Exiv2_PreviewProperties();
     return get_attr_struct(info_Exiv2_PreviewProperties, true, obj, key);
 };
 
 
 static PyObject* get_attr_Exiv2_PreviewProperties(PyObject* obj,
                                                PyObject* name) {
-    init_info_Exiv2_PreviewProperties();
     return get_attr_struct(info_Exiv2_PreviewProperties, false, obj, name);
 };
 
@@ -5550,22 +5524,18 @@ SWIGINTERNINLINE PyObject*
 }
 
 SWIGINTERN PyObject *Exiv2_PreviewProperties_keys(){
-        init_info_Exiv2_PreviewProperties();
         return keys_struct(info_Exiv2_PreviewProperties);
     }
 SWIGINTERN PyObject *Exiv2_PreviewProperties_values(Exiv2::PreviewProperties *self,PyObject *py_self){
-        init_info_Exiv2_PreviewProperties();
         return values_struct(info_Exiv2_PreviewProperties, py_self);
     }
 SWIGINTERN PyObject *Exiv2_PreviewProperties_items(Exiv2::PreviewProperties *self,PyObject *py_self){
-        init_info_Exiv2_PreviewProperties();
         return items_struct(info_Exiv2_PreviewProperties, py_self);
     }
 SWIGINTERN PyObject *Exiv2_PreviewProperties___iter__(){
         // Deprecated since 2025-09-11
         PyErr_WarnEx(PyExc_DeprecationWarning,
              "Please iterate over keys() function output", 1);
-        init_info_Exiv2_PreviewProperties();
         PyObject* seq = keys_struct(info_Exiv2_PreviewProperties);
         PyObject* result = PySeqIter_New(seq);
         Py_DECREF(seq);
@@ -5918,6 +5888,25 @@ namespace swig {
 	};
       }
 
+
+static void init_struct_info(struct_info& info, swig_type_info* type) {
+    PyGetSetDef* getset =
+        ((SwigPyClientData*)type->clientdata)->pytype->tp_getset;
+    while (getset->name) {
+        // __dict__ is also in the getset list
+        if (getset->name[0] != '_') {
+            info.members.push_back(getset->name);
+            std::string alias = getset->name;
+            if (alias.back() == '_') {
+                alias.pop_back();
+                info.aliased = true;
+            }
+            info.aliases.push_back(alias);
+        }
+        getset++;
+    }
+};
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -8831,6 +8820,14 @@ SWIG_init(void) {
   PyModule_AddObject(m, "PreviewManager", (PyObject *)builtin_pytype);
   SwigPyBuiltin_AddPublicSymbol(public_interface, "PreviewManager");
   d = md;
+  
+  init_struct_info(info_Exiv2_PreviewProperties, SWIGTYPE_p_Exiv2__PreviewProperties);
+  if (info_Exiv2_PreviewProperties.aliases.empty()) {
+    PyErr_SetString(
+      PyExc_RuntimeError, "Failed to initialise Exiv2::PreviewProperties info");
+    return INIT_ERROR_RETURN;
+  }
+  
 #if PY_VERSION_HEX >= 0x03000000
   return m;
 #else