Mercurial > cpython-lru_cache-weakref
view Python/structmember.c @ 87690:66c1c9f32567 default tip
Add use_weakref option to functools.lru_cache
The use_weakref option makes lru_cache create weak references to the function
arguments when creating the cache key, which prevents them from staying in the
memory forever even after all other references to them are gone.
This is a proof of concept for http://bugs.python.org/issue19859
| author | Radomir Dopieralski <devel@sheep.art.pl> |
|---|---|
| date | Tue, 03 Dec 2013 16:02:48 +0100 |
| parents | afe55cd04119 |
| children |
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/* Map C struct members to Python object attributes */ #include "Python.h" #include "structmember.h" PyObject * PyMember_GetOne(const char *addr, PyMemberDef *l) { PyObject *v; addr += l->offset; switch (l->type) { case T_BOOL: v = PyBool_FromLong(*(char*)addr); break; case T_BYTE: v = PyLong_FromLong(*(char*)addr); break; case T_UBYTE: v = PyLong_FromUnsignedLong(*(unsigned char*)addr); break; case T_SHORT: v = PyLong_FromLong(*(short*)addr); break; case T_USHORT: v = PyLong_FromUnsignedLong(*(unsigned short*)addr); break; case T_INT: v = PyLong_FromLong(*(int*)addr); break; case T_UINT: v = PyLong_FromUnsignedLong(*(unsigned int*)addr); break; case T_LONG: v = PyLong_FromLong(*(long*)addr); break; case T_ULONG: v = PyLong_FromUnsignedLong(*(unsigned long*)addr); break; case T_PYSSIZET: v = PyLong_FromSsize_t(*(Py_ssize_t*)addr); break; case T_FLOAT: v = PyFloat_FromDouble((double)*(float*)addr); break; case T_DOUBLE: v = PyFloat_FromDouble(*(double*)addr); break; case T_STRING: if (*(char**)addr == NULL) { Py_INCREF(Py_None); v = Py_None; } else v = PyUnicode_FromString(*(char**)addr); break; case T_STRING_INPLACE: v = PyUnicode_FromString((char*)addr); break; case T_CHAR: v = PyUnicode_FromStringAndSize((char*)addr, 1); break; case T_OBJECT: v = *(PyObject **)addr; if (v == NULL) v = Py_None; Py_INCREF(v); break; case T_OBJECT_EX: v = *(PyObject **)addr; if (v == NULL) PyErr_SetString(PyExc_AttributeError, l->name); Py_XINCREF(v); break; #ifdef HAVE_LONG_LONG case T_LONGLONG: v = PyLong_FromLongLong(*(PY_LONG_LONG *)addr); break; case T_ULONGLONG: v = PyLong_FromUnsignedLongLong(*(unsigned PY_LONG_LONG *)addr); break; #endif /* HAVE_LONG_LONG */ case T_NONE: v = Py_None; Py_INCREF(v); break; default: PyErr_SetString(PyExc_SystemError, "bad memberdescr type"); v = NULL; } return v; } #define WARN(msg) \ do { \ if (PyErr_WarnEx(PyExc_RuntimeWarning, msg, 1) < 0) \ return -1; \ } while (0) int PyMember_SetOne(char *addr, PyMemberDef *l, PyObject *v) { PyObject *oldv; addr += l->offset; if ((l->flags & READONLY)) { PyErr_SetString(PyExc_AttributeError, "readonly attribute"); return -1; } if (v == NULL) { if (l->type == T_OBJECT_EX) { /* Check if the attribute is set. */ if (*(PyObject **)addr == NULL) { PyErr_SetString(PyExc_AttributeError, l->name); return -1; } } else if (l->type != T_OBJECT) { PyErr_SetString(PyExc_TypeError, "can't delete numeric/char attribute"); return -1; } } switch (l->type) { case T_BOOL:{ if (!PyBool_Check(v)) { PyErr_SetString(PyExc_TypeError, "attribute value type must be bool"); return -1; } if (v == Py_True) *(char*)addr = (char) 1; else *(char*)addr = (char) 0; break; } case T_BYTE:{ long long_val = PyLong_AsLong(v); if ((long_val == -1) && PyErr_Occurred()) return -1; *(char*)addr = (char)long_val; /* XXX: For compatibility, only warn about truncations for now. */ if ((long_val > CHAR_MAX) || (long_val < CHAR_MIN)) WARN("Truncation of value to char"); break; } case T_UBYTE:{ long long_val = PyLong_AsLong(v); if ((long_val == -1) && PyErr_Occurred()) return -1; *(unsigned char*)addr = (unsigned char)long_val; if ((long_val > UCHAR_MAX) || (long_val < 0)) WARN("Truncation of value to unsigned char"); break; } case T_SHORT:{ long long_val = PyLong_AsLong(v); if ((long_val == -1) && PyErr_Occurred()) return -1; *(short*)addr = (short)long_val; if ((long_val > SHRT_MAX) || (long_val < SHRT_MIN)) WARN("Truncation of value to short"); break; } case T_USHORT:{ long long_val = PyLong_AsLong(v); if ((long_val == -1) && PyErr_Occurred()) return -1; *(unsigned short*)addr = (unsigned short)long_val; if ((long_val > USHRT_MAX) || (long_val < 0)) WARN("Truncation of value to unsigned short"); break; } case T_INT:{ long long_val = PyLong_AsLong(v); if ((long_val == -1) && PyErr_Occurred()) return -1; *(int *)addr = (int)long_val; if ((long_val > INT_MAX) || (long_val < INT_MIN)) WARN("Truncation of value to int"); break; } case T_UINT:{ unsigned long ulong_val = PyLong_AsUnsignedLong(v); if ((ulong_val == (unsigned long)-1) && PyErr_Occurred()) { /* XXX: For compatibility, accept negative int values as well. */ PyErr_Clear(); ulong_val = PyLong_AsLong(v); if ((ulong_val == (unsigned long)-1) && PyErr_Occurred()) return -1; *(unsigned int *)addr = (unsigned int)ulong_val; WARN("Writing negative value into unsigned field"); } else *(unsigned int *)addr = (unsigned int)ulong_val; if (ulong_val > UINT_MAX) WARN("Truncation of value to unsigned int"); break; } case T_LONG:{ *(long*)addr = PyLong_AsLong(v); if ((*(long*)addr == -1) && PyErr_Occurred()) return -1; break; } case T_ULONG:{ *(unsigned long*)addr = PyLong_AsUnsignedLong(v); if ((*(unsigned long*)addr == (unsigned long)-1) && PyErr_Occurred()) { /* XXX: For compatibility, accept negative int values as well. */ PyErr_Clear(); *(unsigned long*)addr = PyLong_AsLong(v); if ((*(unsigned long*)addr == (unsigned long)-1) && PyErr_Occurred()) return -1; WARN("Writing negative value into unsigned field"); } break; } case T_PYSSIZET:{ *(Py_ssize_t*)addr = PyLong_AsSsize_t(v); if ((*(Py_ssize_t*)addr == (Py_ssize_t)-1) && PyErr_Occurred()) return -1; break; } case T_FLOAT:{ double double_val = PyFloat_AsDouble(v); if ((double_val == -1) && PyErr_Occurred()) return -1; *(float*)addr = (float)double_val; break; } case T_DOUBLE: *(double*)addr = PyFloat_AsDouble(v); if ((*(double*)addr == -1) && PyErr_Occurred()) return -1; break; case T_OBJECT: case T_OBJECT_EX: Py_XINCREF(v); oldv = *(PyObject **)addr; *(PyObject **)addr = v; Py_XDECREF(oldv); break; case T_CHAR: { char *string; Py_ssize_t len; string = _PyUnicode_AsStringAndSize(v, &len); if (string == NULL || len != 1) { PyErr_BadArgument(); return -1; } *(char*)addr = string[0]; break; } case T_STRING: case T_STRING_INPLACE: PyErr_SetString(PyExc_TypeError, "readonly attribute"); return -1; #ifdef HAVE_LONG_LONG case T_LONGLONG:{ PY_LONG_LONG value; *(PY_LONG_LONG*)addr = value = PyLong_AsLongLong(v); if ((value == -1) && PyErr_Occurred()) return -1; break; } case T_ULONGLONG:{ unsigned PY_LONG_LONG value; /* ??? PyLong_AsLongLong accepts an int, but PyLong_AsUnsignedLongLong doesn't ??? */ if (PyLong_Check(v)) *(unsigned PY_LONG_LONG*)addr = value = PyLong_AsUnsignedLongLong(v); else *(unsigned PY_LONG_LONG*)addr = value = PyLong_AsLong(v); if ((value == (unsigned PY_LONG_LONG)-1) && PyErr_Occurred()) return -1; break; } #endif /* HAVE_LONG_LONG */ default: PyErr_Format(PyExc_SystemError, "bad memberdescr type for %s", l->name); return -1; } return 0; }
