PYTHON-5737 - BSON encoding/decoding performance improvements

bson/_cbsonmodule.c

@@ -711,13 +711,19 @@ static long _type_marker(PyObject* object, PyObject* _type_marker_str) {
     PyObject* type_marker = NULL;
     long type = 0;
 
-    if (PyObject_HasAttr(object, _type_marker_str)) {
-        type_marker = PyObject_GetAttr(object, _type_marker_str);
-        if (type_marker == NULL) {
+    #if PY_VERSION_HEX >= 0x030D0000
+        // 3.13
+        if (PyObject_GetOptionalAttr(object, _type_marker_str, &type_marker) == -1) {
             return -1;
         }
-    }
-
+    # else
+        if (PyObject_HasAttr(object, _type_marker_str)) {
+            type_marker = PyObject_GetAttr(object, _type_marker_str);
+            if (type_marker == NULL) {
+                return -1;
+            }
+        }
+    #endif
     /*
      * Python objects with broken __getattr__ implementations could return
      * arbitrary types for a call to PyObject_GetAttrString. For example
@@ -814,6 +820,7 @@ int convert_codec_options(PyObject* self, PyObject* options_obj, codec_options_t
     }
 
     options->is_raw_bson = (101 == type_marker);
+    options->is_dict_class = (options->document_class == (PyObject*)&PyDict_Type);
     options->options_obj = options_obj;
 
     Py_INCREF(options->options_obj);
@@ -1013,10 +1020,20 @@ static int _write_element_to_buffer(PyObject* self, buffer_t buffer,
     }
     /*
      * Use _type_marker attribute instead of PyObject_IsInstance for better perf.
+     *
+     * Skip _type_marker lookup for common built-in types
+     * that we know don't have a _type_marker attribute. This avoids the overhead
+     * of PyObject_HasAttr/PyObject_GetAttr calls for the most common cases.
      */
-    type = _type_marker(value, state->_type_marker_str);
-    if (type < 0) {
-        return 0;
+    if (PyUnicode_CheckExact(value) || PyLong_CheckExact(value) || PyFloat_CheckExact(value) ||
+        PyBool_Check(value) || PyDict_CheckExact(value) || PyList_CheckExact(value) ||
+        PyTuple_CheckExact(value) || PyBytes_CheckExact(value) || value == Py_None) {
+        type = 0;
+    } else {
+        type = _type_marker(value, state->_type_marker_str);
+        if (type < 0) {
+            return 0;
+        }
     }
 
     switch (type) {
@@ -2716,11 +2733,20 @@ static PyObject* _elements_to_dict(PyObject* self, const char* string,
                                    unsigned max,
                                    const codec_options_t* options) {
     unsigned position = 0;
-    PyObject* dict = PyObject_CallObject(options->document_class, NULL);
+    PyObject* dict;
+    int raw_array = 0;
+
+    /* Use PyDict_New() directly when document_class is dict.
+     * This avoids the overhead of PyObject_CallObject() for the common case. */
+    if (options->is_dict_class) {
+        dict = PyDict_New();
+    } else {
+        dict = PyObject_CallObject(options->document_class, NULL);
+    }
     if (!dict) {
         return NULL;
     }
-    int raw_array = 0;
+
     while (position < max) {
         PyObject* name = NULL;
         PyObject* value = NULL;
@@ -2735,7 +2761,24 @@ static PyObject* _elements_to_dict(PyObject* self, const char* string,
             position = (unsigned)new_position;
         }
 
-        PyObject_SetItem(dict, name, value);
+        /* Use PyDict_SetItem() when document_class is dict.
+         * PyDict_SetItem() is faster than PyObject_SetItem() because it
+         * avoids method lookup overhead. */
+        if (options->is_dict_class) {
+            if (PyDict_SetItem(dict, name, value) < 0) {
+                Py_DECREF(name);
+                Py_DECREF(value);
+                Py_DECREF(dict);
+                return NULL;
+            }
+        } else {
+            if (PyObject_SetItem(dict, name, value) < 0) {
+                Py_DECREF(name);
+                Py_DECREF(value);
+                Py_DECREF(dict);
+                return NULL;
+            }
+        }
         Py_DECREF(name);
         Py_DECREF(value);
     }

bson/_cbsonmodule.h

@@ -72,6 +72,7 @@ typedef struct codec_options_t {
     unsigned char datetime_conversion;
     PyObject* options_obj;
     unsigned char is_raw_bson;
+    unsigned char is_dict_class;
 } codec_options_t;
 
 /* C API functions */