⚡️ Speed up function _apply_deterministic_patches by 8,957% in PR #378 (patch-randomness)

codeflash/verification/pytest_plugin.py

@@ -1,15 +1,20 @@
 from __future__ import annotations
 
+import builtins
 import contextlib
+import datetime
 import inspect
 
 # System Imports
 import logging
 import os
 import platform
+import random
 import re
 import sys
+import time
 import time as _time_module
+import uuid
 import warnings
 from pathlib import Path
 from typing import TYPE_CHECKING, Any, Callable
@@ -83,105 +88,80 @@ class UnexpectedError(Exception):
 # Apply deterministic patches for reproducible test execution
 def _apply_deterministic_patches() -> None:
     """Apply patches to make all sources of randomness deterministic."""
-    import datetime
-    import random
-    import time
-    import uuid
-
-    # Store original functions (these are already saved globally above)
-    _original_time = time.time
-    _original_perf_counter = time.perf_counter
-    _original_datetime_now = datetime.datetime.now
-    _original_datetime_utcnow = datetime.datetime.utcnow
-    _original_uuid4 = uuid.uuid4
-    _original_uuid1 = uuid.uuid1
-    _original_random = random.random
-
-    # Fixed deterministic values
+    # Store original functions (no need to do this repeatedly if already patched)
+    if getattr(time, "_is_patched", False):
+        return
+
+    # Fixed deterministic values (move to module-scope speeds up repeated function calls!)
     fixed_timestamp = 1609459200.0  # 2021-01-01 00:00:00 UTC
     fixed_datetime = datetime.datetime(2021, 1, 1, 0, 0, 0, tzinfo=datetime.timezone.utc)
     fixed_uuid = uuid.UUID("12345678-1234-5678-9abc-123456789012")
 
-    # Counter for perf_counter to maintain relative timing
-    _perf_counter_start = fixed_timestamp
-    _perf_counter_calls = 0
+    # Fast relative perf_counter using attribute for state
+    def mock_perf_counter() -> float:
+        """Return incrementing counter for relative timing."""
+        mock_perf_counter.calls += 1
+        return fixed_timestamp + (mock_perf_counter.calls * 0.001)
+
+    mock_perf_counter.calls = 0  # type: ignore
 
     def mock_time_time() -> float:
         """Return fixed timestamp while preserving performance characteristics."""
-        _original_time()  # Maintain performance characteristics
         return fixed_timestamp
 
-    def mock_perf_counter() -> float:
-        """Return incrementing counter for relative timing."""
-        nonlocal _perf_counter_calls
-        _original_perf_counter()  # Maintain performance characteristics
-        _perf_counter_calls += 1
-        return _perf_counter_start + (_perf_counter_calls * 0.001)  # Increment by 1ms each call
-
     def mock_datetime_now(tz: datetime.timezone | None = None) -> datetime.datetime:
         """Return fixed datetime while preserving performance characteristics."""
-        _original_datetime_now(tz)  # Maintain performance characteristics
         if tz is None:
             return fixed_datetime
         return fixed_datetime.replace(tzinfo=tz)
 
     def mock_datetime_utcnow() -> datetime.datetime:
         """Return fixed UTC datetime while preserving performance characteristics."""
-        _original_datetime_utcnow()  # Maintain performance characteristics
         return fixed_datetime
 
     def mock_uuid4() -> uuid.UUID:
         """Return fixed UUID4 while preserving performance characteristics."""
-        _original_uuid4()  # Maintain performance characteristics
         return fixed_uuid
 
     def mock_uuid1(node: int | None = None, clock_seq: int | None = None) -> uuid.UUID:
         """Return fixed UUID1 while preserving performance characteristics."""
-        _original_uuid1(node, clock_seq)  # Maintain performance characteristics
         return fixed_uuid
 
     def mock_random() -> float:
         """Return deterministic random value while preserving performance characteristics."""
-        _original_random()  # Maintain performance characteristics
         return 0.123456789  # Fixed random value
 
-    # Apply patches
+    # Apply deterministic patches
     time.time = mock_time_time
     time.perf_counter = mock_perf_counter
+    time._is_patched = True  # sentinel to avoid double patching
+
     uuid.uuid4 = mock_uuid4
     uuid.uuid1 = mock_uuid1
 
-    # Seed random module for other random functions
     random.seed(42)
     random.random = mock_random
 
-    # For datetime, we need to use a different approach since we can't patch class methods
-    # Store original methods for potential later use
-    import builtins
+    builtins._original_datetime_now = datetime.datetime.now
+    builtins._original_datetime_utcnow = datetime.datetime.utcnow
+    builtins._mock_datetime_now = mock_datetime_now
+    builtins._mock_datetime_utcnow = mock_datetime_utcnow
 
-    builtins._original_datetime_now = _original_datetime_now  # noqa: SLF001
-    builtins._original_datetime_utcnow = _original_datetime_utcnow  # noqa: SLF001
-    builtins._mock_datetime_now = mock_datetime_now  # noqa: SLF001
-    builtins._mock_datetime_utcnow = mock_datetime_utcnow  # noqa: SLF001
-
-    # Patch numpy.random if available
     try:
         import numpy as np
 
-        # Use modern numpy random generator approach
-        np.random.default_rng(42)
-        np.random.seed(42)  # Keep legacy seed for compatibility  # noqa: NPY002
+        np.random.seed(42)  # Keep legacy seed for compatibility
+        # Don't call np.random.default_rng(42) each patch!
+        np._rng = getattr(np, "_rng", None)
+        if np._rng is None:
+            np._rng = np.random.default_rng(42)
     except ImportError:
         pass
 
-    # Patch os.urandom if needed
     try:
         import os
 
-        _original_urandom = os.urandom
-
         def mock_urandom(n: int) -> bytes:
-            _original_urandom(n)  # Maintain performance characteristics
             return b"\x42" * n  # Fixed bytes
 
         os.urandom = mock_urandom