datetime: support big values for some platforms

Before this patch, tarantool.Datetime constructor used
datetime.fromtimestamp function to build a new datetime [1], except for
negative timestamps for Windows platform. This constructor branch is
used on each Tarantool datetime encoding or while building
a tarantool.Datetime object from timestamp. datetime.fromtimestamp have
some drawbacks: it "may raise OverflowError, if the timestamp is out of
the range of values supported by the platform C localtime() or gmtime()
functions, and OSError on localtime() or gmtime() failure. It’s common
for this to be restricted to years in 1970 through 2038.". It had never
happened on supported Unix platforms, but seem to be an issue for
Windows ones. We already workaround this issue for years smaller than
1970 on Windows. After this patch, this workaround will be used for
all platforms and timestamp values, allowing to provide similar
behavior for platforms both restricted to years in 1970 through 2038
with localtime() or gmtime() or not.

1. https://docs.python.org/3/library/datetime.html#datetime.datetime.fromtimestamp

Author: DifferentialOrange

CHANGELOG.md

@@ -8,6 +8,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 - Exception rethrow in crud API (PR #310).
+- Work with timestamps larger than year 2038 for some platforms (like Windows) (PR #311).
+  It covers
+  - building new tarantool.Datetime objects from timestamp,
+  - parsing datetime objects received from Tarantool.
 
 ## 1.1.1 - 2023-07-19
 

tarantool/msgpack_ext/types/datetime.py

@@ -6,7 +6,6 @@
 from calendar import monthrange
 from copy import deepcopy
 from datetime import datetime, timedelta
-import sys
 
 import pytz
 
@@ -314,13 +313,12 @@ def __init__(self, *, timestamp=None, year=None, month=None,
                     timestamp += nsec // NSEC_IN_SEC
                     nsec = nsec % NSEC_IN_SEC
 
-            if (sys.platform.startswith("win")) and (timestamp < 0):
-                # Fails to create a datetime from negative timestamp on Windows.
-                _datetime = _EPOCH + timedelta(seconds=timestamp)
-            else:
-                # Timezone-naive datetime objects are treated by many datetime methods
-                # as local times, so we represent time in UTC explicitly if not provided.
-                _datetime = datetime.fromtimestamp(timestamp, pytz.UTC)
+            # datetime.fromtimestamp may raise OverflowError, if the timestamp
+            # is out of the range of values supported by the platform C localtime()
+            # function, and OSError on localtime() failure. It’s common for this
+            # to be restricted to years from 1970 through 2038, yet we want
+            # to support a wider range.
+            _datetime = _EPOCH + timedelta(seconds=timestamp)
 
             if nsec is not None:
                 _datetime = _datetime.replace(microsecond=nsec // NSEC_IN_MKSEC)

test/suites/test_datetime.py

@@ -153,6 +153,24 @@ def test_datetime_class_api_wth_tz(self):
             'type': ValueError,
             'msg': 'Failed to create datetime with ambiguous timezone "AET"'
         },
+        'under_min_timestamp_1': {
+            'args': [],
+            'kwargs': {'timestamp': -62135596801},
+            'type': OverflowError,
+            'msg': 'date value out of range'
+        },
+        'under_min_timestamp_2': {
+            'args': [],
+            'kwargs': {'timestamp': -62135596800, 'nsec': -1},
+            'type': OverflowError,
+            'msg': 'date value out of range'
+        },
+        'over_max_timestamp': {
+            'args': [],
+            'kwargs': {'timestamp': 253402300800},
+            'type': OverflowError,
+            'msg': 'date value out of range'
+        },
     }
 
     def test_datetime_class_invalid_init(self):
@@ -293,6 +311,28 @@ def test_datetime_class_invalid_init(self):
             'tarantool': r"datetime.new({timestamp=1661969274, nsec=308543321, "
                          r"tz='Europe/Moscow'})",
         },
+        'min_datetime': {  # Python datetime.MINYEAR is 1.
+            'python': tarantool.Datetime(year=1, month=1, day=1, hour=0, minute=0, sec=0),
+            'msgpack': (b'\x00\x09\x6e\x88\xf1\xff\xff\xff'),
+            'tarantool': r"datetime.new({year=1, month=1, day=1, hour=0, min=0, sec=0})",
+        },
+        'max_datetime': {  # Python datetime.MAXYEAR is 9999.
+            'python': tarantool.Datetime(year=9999, month=12, day=31, hour=23, minute=59, sec=59,
+                                         nsec=999999999),
+            'msgpack': (b'\x7f\x41\xf4\xff\x3a\x00\x00\x00\xff\xc9\x9a\x3b\x00\x00\x00\x00'),
+            'tarantool': r"datetime.new({year=9999, month=12, day=31, hour=23, min=59, sec=59,"
+                         r"nsec=999999999})",
+        },
+        'min_datetime_timestamp': {  # Python datetime.MINYEAR is 1.
+            'python': tarantool.Datetime(timestamp=-62135596800),
+            'msgpack': (b'\x00\x09\x6e\x88\xf1\xff\xff\xff'),
+            'tarantool': r"datetime.new({timestamp=-62135596800})",
+        },
+        'max_datetime_timestamp': {  # Python datetime.MAXYEAR is 9999.
+            'python': tarantool.Datetime(timestamp=253402300799, nsec=999999999),
+            'msgpack': (b'\x7f\x41\xf4\xff\x3a\x00\x00\x00\xff\xc9\x9a\x3b\x00\x00\x00\x00'),
+            'tarantool': r"datetime.new({timestamp=253402300799, nsec=999999999})",
+        },
     }
 
     def test_msgpack_decode(self):