From 1bcbaab15a38ce23cfa4e5ddfee507b75b7cc0b4 Mon Sep 17 00:00:00 2001 From: Alexander Belopolsky Date: Thu, 14 Oct 2010 17:03:51 +0000 Subject: [PATCH] Issue 9183: Intern UTC timezone. --- Lib/datetime.py | 39 +++++++++++++++++++-------------- Lib/test/datetimetester.py | 4 +++- Misc/NEWS | 3 +++ Modules/_datetimemodule.c | 45 ++++++++++++++++++++++++++------------ 4 files changed, 60 insertions(+), 31 deletions(-) diff --git a/Lib/datetime.py b/Lib/datetime.py index d640f75616b..29ffe246aa4 100644 --- a/Lib/datetime.py +++ b/Lib/datetime.py @@ -1784,24 +1784,31 @@ class timezone(tzinfo): # Sentinel value to disallow None _Omitted = object() - def __init__(self, offset, name=_Omitted): - if name is self._Omitted: + def __new__(cls, offset, name=_Omitted): + if not isinstance(offset, timedelta): + raise TypeError("offset must be a timedelta") + if name is cls._Omitted: + if not offset: + return cls.utc name = None elif not isinstance(name, str): raise TypeError("name must be a string") - if isinstance(offset, timedelta): - if self._minoffset <= offset <= self._maxoffset: - if (offset.microseconds != 0 or - offset.seconds % 60 != 0): - raise ValueError("offset must be whole" - " number of minutes") - self._offset = offset - else: - raise ValueError("offset out of range") - else: - raise TypeError("offset must be timedelta") + if not cls._minoffset <= offset <= cls._maxoffset: + raise ValueError("offset must be a timedelta" + " strictly between -timedelta(hours=24) and" + " timedelta(hours=24).") + if (offset.microseconds != 0 or + offset.seconds % 60 != 0): + raise ValueError("offset must be a timedelta" + " representing a whole number of minutes") + return cls._create(offset, name) + @classmethod + def _create(cls, offset, name=None): + self = tzinfo.__new__(cls) + self._offset = offset self._name = name + return self def __getinitargs__(self): """pickle support""" @@ -1879,9 +1886,9 @@ class timezone(tzinfo): minutes = rest // timedelta(minutes=1) return 'UTC{}{:02d}:{:02d}'.format(sign, hours, minutes) -timezone.utc = timezone(timedelta(0)) -timezone.min = timezone(timezone._minoffset) -timezone.max = timezone(timezone._maxoffset) +timezone.utc = timezone._create(timedelta(0)) +timezone.min = timezone._create(timezone._minoffset) +timezone.max = timezone._create(timezone._maxoffset) """ Some time zone algebra. For a datetime x, let diff --git a/Lib/test/datetimetester.py b/Lib/test/datetimetester.py index 0ee544b1b75..e91eb673a4d 100644 --- a/Lib/test/datetimetester.py +++ b/Lib/test/datetimetester.py @@ -176,7 +176,9 @@ class TestTimeZone(unittest.TestCase): def test_constructor(self): - self.assertEqual(timezone.utc, timezone(timedelta(0))) + self.assertIs(timezone.utc, timezone(timedelta(0))) + self.assertIsNot(timezone.utc, timezone(timedelta(0), 'UTC')) + self.assertEqual(timezone.utc, timezone(timedelta(0), 'UTC')) # invalid offsets for invalid in [timedelta(microseconds=1), timedelta(1, 1), timedelta(seconds=1), timedelta(1), -timedelta(1)]: diff --git a/Misc/NEWS b/Misc/NEWS index 7fb305c2adc..c09e24f714a 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -21,6 +21,9 @@ Core and Builtins Library ------- +- Issue 9183: ``datetime.timezone(datetime.timedelta(0))`` will now + return the same instance as ``datetime.timezone.utc``. + - Issue #7523: Add SOCK_CLOEXEC and SOCK_NONBLOCK to the socket module, where supported by the system. Patch by Nikita Vetoshkin. diff --git a/Modules/_datetimemodule.c b/Modules/_datetimemodule.c index 8c473516327..9a04549787d 100644 --- a/Modules/_datetimemodule.c +++ b/Modules/_datetimemodule.c @@ -767,14 +767,15 @@ typedef struct PyObject *name; } PyDateTime_TimeZone; -PyObject *PyDateTime_TimeZone_UTC; +/* The interned UTC timezone instance */ +static PyObject *PyDateTime_TimeZone_UTC; /* Create new timezone instance checking offset range. This function does not check the name argument. Caller must assure that offset is a timedelta instance and name is either NULL or a unicode object. */ static PyObject * -new_timezone(PyObject *offset, PyObject *name) +create_timezone(PyObject *offset, PyObject *name) { PyDateTime_TimeZone *self; PyTypeObject *type = &PyDateTime_TimeZoneType; @@ -783,6 +784,30 @@ new_timezone(PyObject *offset, PyObject *name) assert(PyDelta_Check(offset)); assert(name == NULL || PyUnicode_Check(name)); + self = (PyDateTime_TimeZone *)(type->tp_alloc(type, 0)); + if (self == NULL) { + return NULL; + } + Py_INCREF(offset); + self->offset = offset; + Py_XINCREF(name); + self->name = name; + return (PyObject *)self; +} + +static int delta_bool(PyDateTime_Delta *self); + +static PyObject * +new_timezone(PyObject *offset, PyObject *name) +{ + assert(offset != NULL); + assert(PyDelta_Check(offset)); + assert(name == NULL || PyUnicode_Check(name)); + + if (name == NULL && delta_bool((PyDateTime_Delta *)offset) == 0) { + Py_INCREF(PyDateTime_TimeZone_UTC); + return PyDateTime_TimeZone_UTC; + } if (GET_TD_MICROSECONDS(offset) != 0 || GET_TD_SECONDS(offset) % 60 != 0) { PyErr_Format(PyExc_ValueError, "offset must be a timedelta" " representing a whole number of minutes"); @@ -796,15 +821,7 @@ new_timezone(PyObject *offset, PyObject *name) return NULL; } - self = (PyDateTime_TimeZone *)(type->tp_alloc(type, 0)); - if (self == NULL) { - return NULL; - } - Py_INCREF(offset); - self->offset = offset; - Py_XINCREF(name); - self->name = name; - return (PyObject *)self; + return create_timezone(offset, name); } /* --------------------------------------------------------------------------- @@ -5156,7 +5173,7 @@ PyInit__datetime(void) delta = new_delta(0, 0, 0, 0); if (delta == NULL) return NULL; - x = new_timezone(delta, NULL); + x = create_timezone(delta, NULL); Py_DECREF(delta); if (x == NULL || PyDict_SetItemString(d, "utc", x) < 0) return NULL; @@ -5165,7 +5182,7 @@ PyInit__datetime(void) delta = new_delta(-1, 60, 0, 1); /* -23:59 */ if (delta == NULL) return NULL; - x = new_timezone(delta, NULL); + x = create_timezone(delta, NULL); Py_DECREF(delta); if (x == NULL || PyDict_SetItemString(d, "min", x) < 0) return NULL; @@ -5174,7 +5191,7 @@ PyInit__datetime(void) delta = new_delta(0, (23 * 60 + 59) * 60, 0, 0); /* +23:59 */ if (delta == NULL) return NULL; - x = new_timezone(delta, NULL); + x = create_timezone(delta, NULL); Py_DECREF(delta); if (x == NULL || PyDict_SetItemString(d, "max", x) < 0) return NULL;