feat(datatype, abstime): support abstime

Author: Brooke-white

redshift_connector/__init__.py

@@ -44,6 +44,7 @@
     mask_secure_info_in_props,
 )
 from redshift_connector.utils.type_utils import (
+    ABSTIME,
     BIGINT,
     BIGINTEGER,
     BOOLEAN,
@@ -406,6 +407,7 @@ def connect(
     "PGText",
     "PGVarchar",
     "__version__",
+    "ABSTIME",
     "BIGINT",
     "BIGINTEGER",
     "BOOLEAN",

redshift_connector/utils/type_utils.py

@@ -32,6 +32,7 @@
 )
 
 ANY_ARRAY = 2277
+ABSTIME = 702
 BIGINT = 20
 BIGINT_ARRAY = 1016
 BOOLEAN = 16
@@ -209,6 +210,33 @@ def timestamp_recv_integer(data: bytes, offset: int, length: int) -> typing.Unio
             return Datetime.max
 
 
+def abstime_recv(data: bytes, offset: int, length: int) -> Datetime:
+    """
+    Converts abstime values represented as integer, representing seconds, to Python datetime.Datetime using UTC.
+    """
+    if length != 4:
+        raise Exception("Malformed column value of type abstime received")
+
+    time: float = i_unpack(data, offset)[0]
+    time *= 1000000  # Time in micro secs
+    secs: float = time / 1000000
+    nanos: int = int(time - secs * 1000000)
+    if nanos < 0:
+        secs -= 1
+        nanos += 1000000
+
+    nanos *= 1000
+
+    millis: float = secs * float(1000)
+
+    total_secs: float = (millis / 1e3) + (nanos / 1e9)
+    server_date: Datetime = Datetime.fromtimestamp(total_secs)
+    # As of Version 3.0, times are no longer read and written using Greenwich Mean Time;
+    # the input and output routines default to the local time zone.
+    # Ref https://www.postgresql.org/docs/6.3/c0804.htm#abstime
+    return server_date.astimezone(Timezone.utc)
+
+
 # data is 64-bit integer representing microseconds since 2000-01-01
 def timestamp_send_integer(v: Datetime) -> bytes:
     return q_pack(int((timegm(v.timetuple()) - EPOCH_SECONDS) * 1e6) + v.microsecond)
@@ -588,6 +616,7 @@ def varbytehex_recv(data: bytes, idx: int, length: int) -> str:
 pg_types: typing.DefaultDict[int, typing.Tuple[int, typing.Callable]] = defaultdict(
     lambda: (FC_TEXT, text_recv),
     {
+        ABSTIME: (FC_BINARY, abstime_recv),  # abstime
         BOOLEAN: (FC_BINARY, bool_recv),  # boolean
         # 17: (FC_BINARY, bytea_recv),  # bytea
         NAME: (FC_BINARY, text_recv),  # name type

test/integration/datatype/test_datatypes.py

@@ -2,6 +2,8 @@
 import datetime
 import os
 import typing
+from datetime import datetime as Datetime
+from datetime import timezone
 from math import isclose
 from test.integration.datatype._generate_test_datatype_tables import (  # type: ignore
     DATATYPES_WITH_MS,
@@ -160,3 +162,22 @@ def test_redshift_timetz_client_tz_applied(db_kwargs, _input, client_protocol):
             results: typing.Tuple = cursor.fetchone()
             assert len(results) == 1
             assert results[0] == t_time
+
+
+abstime_vals: typing.List[typing.Tuple[str, Datetime]] = [
+    ("infinity", Datetime(year=2038, month=1, day=19, hour=3, minute=14, second=4, tzinfo=timezone.utc)),
+    ("-infinity", Datetime(year=1901, month=12, day=13, hour=20, minute=45, second=52, tzinfo=timezone.utc)),
+    ("2022-06-10", Datetime(year=2022, month=6, day=10, tzinfo=timezone.utc)),
+]
+
+
+@pytest.mark.parametrize("client_protocol", ClientProtocolVersion.list())
+@pytest.mark.parametrize("_input", abstime_vals)
+def test_abstime(db_kwargs, _input, client_protocol):
+    insert_val, exp_val = _input
+
+    with redshift_connector.connect(**db_kwargs) as conn:
+        with conn.cursor() as cursor:
+            cursor.execute("select '{}'::abstime".format(insert_val))
+            res = cursor.fetchone()
+            assert res[0] == exp_val