Revert "fix: Migrate datetime from float to datetime object"

This reverts commit 1171521.

Author: FullyTyped

src/aws_durable_execution_sdk_python/concurrency.py

@@ -5,11 +5,11 @@
 import heapq
 import logging
 import threading
+import time
 from abc import ABC, abstractmethod
 from collections import Counter
 from concurrent.futures import Future, ThreadPoolExecutor
 from dataclasses import dataclass
-from datetime import UTC, datetime
 from enum import Enum
 from typing import TYPE_CHECKING, Generic, Self, TypeVar
 
@@ -258,7 +258,7 @@ def __init__(self, executable: Executable[CallableType]):
         self.executable = executable
         self._status = BranchStatus.PENDING
         self._future: Future | None = None
-        self._suspend_until: datetime | None = None
+        self._suspend_until: float | None = None
         self._result: ResultType = None  # type: ignore[assignment]
         self._is_result_set: bool = False
         self._error: Exception | None = None
@@ -293,7 +293,7 @@ def error(self) -> Exception:
         return self._error
 
     @property
-    def suspend_until(self) -> datetime | None:
+    def suspend_until(self) -> float | None:
         """Get suspend timestamp."""
         return self._suspend_until
 
@@ -308,7 +308,7 @@ def can_resume(self) -> bool:
         return self._status is BranchStatus.SUSPENDED or (
             self._status is BranchStatus.SUSPENDED_WITH_TIMEOUT
             and self._suspend_until is not None
-            and datetime.now(UTC) >= self._suspend_until
+            and time.time() >= self._suspend_until
         )
 
     @property
@@ -333,7 +333,7 @@ def suspend(self) -> None:
         self._status = BranchStatus.SUSPENDED
         self._suspend_until = None
 
-    def suspend_with_timeout(self, timestamp: datetime) -> None:
+    def suspend_with_timeout(self, timestamp: float) -> None:
         """Transition to SUSPENDED_WITH_TIMEOUT state."""
         self._status = BranchStatus.SUSPENDED_WITH_TIMEOUT
         self._suspend_until = timestamp
@@ -507,11 +507,11 @@ def __exit__(self, exc_type, exc_val, exc_tb) -> None:
         self.shutdown()
 
     def schedule_resume(
-        self, exe_state: ExecutableWithState, resume_time: datetime
+        self, exe_state: ExecutableWithState, resume_time: float
     ) -> None:
         """Schedule a task to resume at the specified time."""
         with self._lock:
-            heapq.heappush(self._pending_resumes, (resume_time.timestamp(), exe_state))
+            heapq.heappush(self._pending_resumes, (resume_time, exe_state))
 
     def shutdown(self) -> None:
         """Shutdown the timer thread and cancel all pending resumes."""
@@ -534,7 +534,7 @@ def _timer_loop(self) -> None:
                 self._shutdown.wait(timeout=0.1)
                 continue
 
-            current_time = datetime.now(UTC).timestamp()
+            current_time = time.time()
             if current_time >= next_resume_time:
                 # Time to resume
                 with self._lock:
@@ -675,7 +675,7 @@ def on_done(future: Future) -> None:
 
     def should_execution_suspend(self) -> SuspendResult:
         """Check if execution should suspend."""
-        earliest_timestamp: datetime | None = None
+        earliest_timestamp: float = float("inf")
         indefinite_suspend_task: (
             ExecutableWithState[CallableType, ResultType] | None
         ) = None
@@ -685,16 +685,16 @@ def should_execution_suspend(self) -> SuspendResult:
                 # Exit here! Still have tasks that can make progress, don't suspend.
                 return SuspendResult.do_not_suspend()
             if exe_state.status is BranchStatus.SUSPENDED_WITH_TIMEOUT:
-                if exe_state.suspend_until and (
-                    earliest_timestamp is None
-                    or exe_state.suspend_until < earliest_timestamp
+                if (
+                    exe_state.suspend_until
+                    and exe_state.suspend_until < earliest_timestamp
                 ):
                     earliest_timestamp = exe_state.suspend_until
             elif exe_state.status is BranchStatus.SUSPENDED:
                 indefinite_suspend_task = exe_state
 
         # All tasks are in final states and at least one of them is a suspend.
-        if earliest_timestamp is not None:
+        if earliest_timestamp != float("inf"):
             return SuspendResult.suspend(
                 TimedSuspendExecution(
                     "All concurrent work complete or suspended pending retry.",

src/aws_durable_execution_sdk_python/exceptions.py

@@ -5,9 +5,13 @@
 
 from __future__ import annotations
 
+import time
 from dataclasses import dataclass
-from datetime import UTC, datetime, timedelta
 from enum import Enum
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    import datetime
 
 
 class TerminationReason(Enum):
@@ -146,10 +150,10 @@ class TimedSuspendExecution(SuspendExecution):
     This is a specialized form of SuspendExecution that includes a scheduled resume time.
 
     Attributes:
-        scheduled_timestamp (datetime): DateTime at which to resume.
+        scheduled_timestamp (float): Unix timestamp in seconds at which to resume.
     """
 
-    def __init__(self, message: str, scheduled_timestamp: datetime):
+    def __init__(self, message: str, scheduled_timestamp: float):
         super().__init__(message)
         self.scheduled_timestamp = scheduled_timestamp
 
@@ -168,23 +172,23 @@ def from_delay(cls, message: str, delay_seconds: int) -> TimedSuspendExecution:
             >>> exception = TimedSuspendExecution.from_delay("Waiting for callback", 30)
             >>> # Will suspend for 30 seconds from now
         """
-        resume_time = datetime.now(UTC) + timedelta(seconds=delay_seconds)
+        resume_time = time.time() + delay_seconds
         return cls(message, scheduled_timestamp=resume_time)
 
     @classmethod
     def from_datetime(
-        cls, message: str, datetime_timestamp: datetime
+        cls, message: str, datetime_timestamp: datetime.datetime
     ) -> TimedSuspendExecution:
         """Create a timed suspension with the delay calculated from now.
 
         Args:
             message: Descriptive message for the suspension
-            datetime_timestamp: DateTime timestamp at which to resume
+            datetime_timestamp: Unix datetime timestamp in seconds at which to resume
 
         Returns:
             TimedSuspendExecution: Instance with calculated resume time
         """
-        return cls(message, scheduled_timestamp=datetime_timestamp)
+        return cls(message, scheduled_timestamp=datetime_timestamp.timestamp())
 
 
 class OrderedLockError(DurableExecutionsError):

src/aws_durable_execution_sdk_python/operation/wait.py

@@ -3,7 +3,7 @@
 from __future__ import annotations
 
 import logging
-from datetime import UTC, datetime, timedelta
+import time
 from typing import TYPE_CHECKING
 
 from aws_durable_execution_sdk_python.exceptions import TimedSuspendExecution
@@ -48,6 +48,6 @@ def wait_handler(
         state.create_checkpoint(operation_update=operation)
 
     # Calculate when to resume
-    resume_time = datetime.now(UTC) + timedelta(seconds=seconds)
+    resume_time = time.time() + seconds
     msg = f"Wait for {seconds} seconds"
     raise TimedSuspendExecution(msg, scheduled_timestamp=resume_time)