Merge pull request #377 from Distributive-Network/philippe/376-copy

Implement the copy protocol for string proxies

Author: philippedistributive

include/JSStringProxy.hh

@@ -36,6 +36,35 @@ public:
    * @param self - The JSStringProxy to be free'd
    */
   static void JSStringProxy_dealloc(JSStringProxy *self);
+
+   /**
+   * @brief copy protocol method for both copy and deepcopy
+   *
+   * @param self - The JSObjectProxy
+   * @return a copy of the string
+   */
+  static PyObject *JSStringProxy_copy_method(JSStringProxy *self);
+};
+
+// docs for methods, copied from cpython
+PyDoc_STRVAR(stringproxy_deepcopy__doc__,
+  "__deepcopy__($self, memo, /)\n"
+"--\n"
+"\n");
+
+PyDoc_STRVAR(stringproxy_copy__doc__,
+"__copy__($self, /)\n"
+"--\n"
+"\n");
+
+/**
+ * @brief Struct for the other methods
+ *
+ */
+static PyMethodDef JSStringProxy_methods[] = {
+  {"__deepcopy__", (PyCFunction)JSStringProxyMethodDefinitions::JSStringProxy_copy_method, METH_O, stringproxy_deepcopy__doc__}, // ignores any memo argument
+  {"__copy__", (PyCFunction)JSStringProxyMethodDefinitions::JSStringProxy_copy_method, METH_NOARGS, stringproxy_copy__doc__},
+  {NULL, NULL}                  /* sentinel */
 };
 
 /**

include/StrType.hh

@@ -37,6 +37,8 @@ public:
   static PyObject *getPyObject(JSContext *cx, JS::HandleValue str);
 
   static const char *getValue(JSContext *cx, JS::HandleValue str);
+
+  static PyObject *proxifyString(JSContext *cx, JS::HandleValue str);
 };
 
 #endif

src/JSStringProxy.cc

@@ -1,6 +1,6 @@
 /**
  * @file JSStringProxy.cc
- * @author Caleb Aikens ([email protected])
+ * @author Caleb Aikens ([email protected]) and Philippe Laporte ([email protected])
  * @brief JSStringProxy is a custom C-implemented python type that derives from str. It acts as a proxy for JSStrings from Spidermonkey, and behaves like a str would.
  * @date 2024-05-15
  *
@@ -10,7 +10,19 @@
 
 #include "include/JSStringProxy.hh"
 
+#include "include/StrType.hh"
+
+
+extern JSContext *GLOBAL_CX;
+
+
 void JSStringProxyMethodDefinitions::JSStringProxy_dealloc(JSStringProxy *self)
 {
   delete self->jsString;
+}
+
+PyObject *JSStringProxyMethodDefinitions::JSStringProxy_copy_method(JSStringProxy *self) {
+  JS::RootedString selfString(GLOBAL_CX, ((JSStringProxy *)self)->jsString->toString());
+  JS::RootedValue selfStringValue(GLOBAL_CX, JS::StringValue(selfString));
+  return StrType::proxifyString(GLOBAL_CX, selfStringValue);
 }

src/StrType.cc

@@ -95,7 +95,7 @@ static PyObject *asUCS4(PyObject *pyString) {
   return ret;
 }
 
-static PyObject *processString(JSContext *cx, JS::HandleValue strVal) {
+PyObject *StrType::proxifyString(JSContext *cx, JS::HandleValue strVal) {
   JS::RootedString str(cx, strVal.toString());
   JSLinearString *lstr = JS_EnsureLinearString(cx, str);
   JS::AutoCheckCannotGC nogc;
@@ -189,11 +189,11 @@ PyObject *StrType::getPyObject(JSContext *cx, JS::HandleValue str) {
     }
   }
 
-  return processString(cx, str);
+  return proxifyString(cx, str);
 }
 
 const char *StrType::getValue(JSContext *cx, JS::HandleValue str) {
-  PyObject *pyString = processString(cx, str);
+  PyObject *pyString = proxifyString(cx, str);
   const char *value = PyUnicode_AsUTF8(pyString);
   Py_DECREF(pyString);
   return value;

src/modules/pythonmonkey/pythonmonkey.cc

@@ -130,7 +130,8 @@ PyTypeObject JSStringProxyType = {
   .tp_basicsize = sizeof(JSStringProxy),
   .tp_dealloc = (destructor)JSStringProxyMethodDefinitions::JSStringProxy_dealloc,
   .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_UNICODE_SUBCLASS,
-  .tp_doc = PyDoc_STR("Javascript String value"),
+  .tp_doc = PyDoc_STR("Javascript String proxy"),
+  .tp_methods = JSStringProxy_methods,
   .tp_base = &PyUnicode_Type
 };
 

tests/python/test_strings.py

@@ -1,6 +1,7 @@
 import pythonmonkey as pm
 import gc
 import random
+import copy
 
 
 def test_identity():
@@ -271,3 +272,21 @@ def test_eval_boxed_ucs4_string_fuzztest():
 
       string1 = string2
     assert INITIAL_STRING == string1  # strings should still match after a bunch of iterations through JS
+
+
+def test_string_proxy_copy():
+  world = pm.eval('(function() {return "World"})')
+  say = pm.eval('(function(who) { return `Hello ${who}`})')
+  who = world()
+  hello_world = say(copy.copy(who))
+  assert hello_world == "Hello World"
+  assert hello_world is not who
+
+def test_string_proxy_deepcopy():
+  world = pm.eval('(function() {return "World"})')
+  say = pm.eval('(function(who) { return `Hello ${who}`})')
+  who = world()
+  hello_world = say(copy.deepcopy(who))
+  assert hello_world == "Hello World"
+  assert hello_world is not who
+