performance: fix a performance regression introduced in #402

src/poetry/core/constraints/version/version_range.py

@@ -12,6 +12,7 @@
     VersionRangeConstraint,
 )
 from poetry.core.constraints.version.version_union import VersionUnion
+from poetry.core.utils._compat import cached_property
 
 
 if TYPE_CHECKING:
@@ -356,14 +357,16 @@ def difference(self, other: VersionConstraint) -> VersionConstraint:
     def flatten(self) -> list[VersionRangeConstraint]:
         return [self]
 
+    @cached_property
     def _single_wildcard_range_string(self) -> str:
-        if not self.is_single_wildcard_range():
+        if not self.is_single_wildcard_range:
             raise ValueError("Not a valid wildcard range")
 
         assert self.min is not None
         assert self.max is not None
         return f"=={_single_wildcard_range_string(self.min, self.max)}"
 
+    @cached_property
     def is_single_wildcard_range(self) -> bool:
         # e.g.
         # - "1.*" equals ">=1.0.dev0, <2" (equivalent to ">=1.0.dev0, <2.0.dev0")
@@ -436,7 +439,7 @@ def _compare_max(self, other: VersionRangeConstraint) -> int:
 
     def __str__(self) -> str:
         with suppress(ValueError):
-            return self._single_wildcard_range_string()
+            return self._single_wildcard_range_string
 
         text = ""
 

src/poetry/core/constraints/version/version_range_constraint.py

@@ -4,6 +4,7 @@
 from typing import TYPE_CHECKING
 
 from poetry.core.constraints.version.version_constraint import VersionConstraint
+from poetry.core.utils._compat import cached_property
 
 
 if TYPE_CHECKING:
@@ -33,9 +34,6 @@ def include_max(self) -> bool:
 
     @property
     def allowed_min(self) -> Version | None:
-        if self.min is None:
-            return None
-
         # That is a bit inaccurate because
         # 1) The exclusive ordered comparison >V MUST NOT allow a post-release
         #    of the given version unless V itself is a post release.
@@ -47,7 +45,7 @@ def allowed_min(self) -> Version | None:
         # the callers of allowed_min.
         return self.min
 
-    @property
+    @cached_property
     def allowed_max(self) -> Version | None:
         if self.max is None:
             return None

src/poetry/core/constraints/version/version_union.py

@@ -14,6 +14,7 @@
 from poetry.core.constraints.version.version_range_constraint import (
     VersionRangeConstraint,
 )
+from poetry.core.utils._compat import cached_property
 
 
 if TYPE_CHECKING:
@@ -92,19 +93,17 @@ def is_any(self) -> bool:
         return False
 
     def is_simple(self) -> bool:
-        return self.excludes_single_version()
+        return self.excludes_single_version
 
     def allows(self, version: Version) -> bool:
-        if self.excludes_single_version():
+        if self.excludes_single_version:
             # when excluded version is local, special handling is required
             # to ensure that a constraint (!=2.0+deadbeef) will allow the
             # provided version (2.0)
-            from poetry.core.constraints.version.version import Version
-            from poetry.core.constraints.version.version_range import VersionRange
 
-            excluded = VersionRange().difference(self)
+            excluded = self._excluded_single_version
 
-            if isinstance(excluded, Version) and excluded.is_local():
+            if excluded.is_local():
                 return excluded != version
 
         return any(constraint.allows(version) for constraint in self._ranges)
@@ -252,12 +251,13 @@ def our_next_range(include_current: bool = True) -> bool:
     def flatten(self) -> list[VersionRangeConstraint]:
         return self.ranges
 
+    @cached_property
     def _exclude_single_wildcard_range_string(self) -> str:
         """
         Helper method to convert this instance into a wild card range
         string.
         """
-        if not self.excludes_single_wildcard_range():
+        if not self.excludes_single_wildcard_range:
             raise ValueError("Not a valid wildcard range")
 
         idx_order = (0, 1) if self._ranges[0].max else (1, 0)
@@ -268,6 +268,7 @@ def _exclude_single_wildcard_range_string(self) -> str:
         assert two.min is not None
         return f"!={_single_wildcard_range_string(one.max, two.min)}"
 
+    @cached_property
     def excludes_single_wildcard_range(self) -> bool:
         if len(self._ranges) != 2:
             return False
@@ -288,11 +289,25 @@ def excludes_single_wildcard_range(self) -> bool:
 
         return _is_wildcard_candidate(two.min, one.max, inverted=True)
 
+    @cached_property
     def excludes_single_version(self) -> bool:
         from poetry.core.constraints.version.version import Version
+
+        return isinstance(self._inverted, Version)
+
+    @cached_property
+    def _excluded_single_version(self) -> Version:
+        from poetry.core.constraints.version.version import Version
+
+        excluded = self._inverted
+        assert isinstance(excluded, Version)
+        return excluded
+
+    @cached_property
+    def _inverted(self) -> VersionConstraint:
         from poetry.core.constraints.version.version_range import VersionRange
 
-        return isinstance(VersionRange().difference(self), Version)
+        return VersionRange().difference(self)
 
     def __eq__(self, other: object) -> bool:
         if not isinstance(other, VersionUnion):
@@ -304,12 +319,10 @@ def __hash__(self) -> int:
         return reduce(op.xor, map(hash, self._ranges))
 
     def __str__(self) -> str:
-        from poetry.core.constraints.version.version_range import VersionRange
-
-        if self.excludes_single_version():
-            return f"!={VersionRange().difference(self)}"
+        if self.excludes_single_version:
+            return f"!={self._excluded_single_version}"
 
         try:
-            return self._exclude_single_wildcard_range_string()
+            return self._exclude_single_wildcard_range_string
         except ValueError:
             return " || ".join([str(r) for r in self._ranges])

src/poetry/core/packages/dependency.py

@@ -239,8 +239,8 @@ def base_pep_508_name(self) -> str:
         constraint = self.constraint
         if isinstance(constraint, VersionUnion):
             if (
-                constraint.excludes_single_version()
-                or constraint.excludes_single_wildcard_range()
+                constraint.excludes_single_version
+                or constraint.excludes_single_wildcard_range
             ):
                 # This branch is a short-circuit logic for special cases and
                 # avoids having to split and parse constraint again. This has

src/poetry/core/utils/_compat.py

@@ -5,6 +5,14 @@
 
 WINDOWS = sys.platform == "win32"
 
+if sys.version_info < (3, 8):
+    # no caching for python 3.7
+    cached_property = property
+else:
+    import functools
+
+    cached_property = functools.cached_property
+
 if sys.version_info < (3, 11):
     # compatibility for python <3.11
     import tomli as tomllib

tests/constraints/version/test_version_range.py

@@ -672,7 +672,7 @@ def test_is_single_wildcard_range_include_min_include_max(
     version_range = VersionRange(
         Version.parse("1.2.dev0"), Version.parse("1.3"), include_min, include_max
     )
-    assert version_range.is_single_wildcard_range() is expected
+    assert version_range.is_single_wildcard_range is expected
 
 
 @pytest.mark.parametrize(
@@ -721,7 +721,7 @@ def test_is_single_wildcard_range(
         Version.parse(max) if max else None,
         include_min=True,
     )
-    assert version_range.is_single_wildcard_range() is expected
+    assert version_range.is_single_wildcard_range is expected
 
 
 @pytest.mark.parametrize(

tests/constraints/version/test_version_union.py

@@ -83,7 +83,7 @@
 def test_excludes_single_wildcard_range_basics(
     ranges: list[VersionRange], expected: bool
 ) -> None:
-    assert VersionUnion(*ranges).excludes_single_wildcard_range() is expected
+    assert VersionUnion(*ranges).excludes_single_wildcard_range is expected
 
 
 @pytest.mark.parametrize(
@@ -126,7 +126,7 @@ def test_excludes_single_wildcard_range(max: str, min: str, expected: bool) -> N
         VersionRange(max=Version.parse(max)),
         VersionRange(Version.parse(min), include_min=True),
     )
-    assert version_union.excludes_single_wildcard_range() is expected
+    assert version_union.excludes_single_wildcard_range is expected
 
 
 @pytest.mark.parametrize(