Cache parsing of version and names

extracted from pypa/pip#12316

src/packaging/specifiers.py

@@ -24,7 +24,7 @@
 )
 
 from .utils import canonicalize_version
-from .version import Version
+from .version import Version, parse
 
 UnparsedVersion = Union[Version, str]
 UnparsedVersionVar = TypeVar("UnparsedVersionVar", bound=UnparsedVersion)
@@ -33,7 +33,7 @@
 
 def _coerce_version(version: UnparsedVersion) -> Version:
     if not isinstance(version, Version):
-        version = Version(version)
+        return parse(version)
     return version
 
 
@@ -272,7 +272,7 @@ def prereleases(self) -> bool:
 
             # Parse the version, and if it is a pre-release than this
             # specifier allows pre-releases.
-            if Version(version).is_prerelease:
+            if parse(version).is_prerelease:
                 return True
 
         return False
@@ -425,13 +425,13 @@ def _compare_equal(self, prospective: Version, spec: str) -> bool:
             return shortened_prospective == split_spec
         else:
             # Convert our spec string into a Version
-            spec_version = Version(spec)
+            spec_version = parse(spec)
 
             # If the specifier does not have a local segment, then we want to
             # act as if the prospective version also does not have a local
             # segment.
             if not spec_version.local:
-                prospective = Version(prospective.public)
+                prospective = parse(prospective.public)
 
             return prospective == spec_version
 
@@ -443,20 +443,20 @@ def _compare_less_than_equal(self, prospective: Version, spec: str) -> bool:
         # NB: Local version identifiers are NOT permitted in the version
         # specifier, so local version labels can be universally removed from
         # the prospective version.
-        return Version(prospective.public) <= Version(spec)
+        return parse(prospective.public) <= parse(spec)
 
     def _compare_greater_than_equal(self, prospective: Version, spec: str) -> bool:
 
         # NB: Local version identifiers are NOT permitted in the version
         # specifier, so local version labels can be universally removed from
         # the prospective version.
-        return Version(prospective.public) >= Version(spec)
+        return parse(prospective.public) >= parse(spec)
 
     def _compare_less_than(self, prospective: Version, spec_str: str) -> bool:
 
         # Convert our spec to a Version instance, since we'll want to work with
         # it as a version.
-        spec = Version(spec_str)
+        spec = parse(spec_str)
 
         # Check to see if the prospective version is less than the spec
         # version. If it's not we can short circuit and just return False now
@@ -469,7 +469,7 @@ def _compare_less_than(self, prospective: Version, spec_str: str) -> bool:
         # versions for the version mentioned in the specifier (e.g. <3.1 should
         # not match 3.1.dev0, but should match 3.0.dev0).
         if not spec.is_prerelease and prospective.is_prerelease:
-            if Version(prospective.base_version) == Version(spec.base_version):
+            if parse(prospective.base_version) == parse(spec.base_version):
                 return False
 
         # If we've gotten to here, it means that prospective version is both
@@ -481,7 +481,7 @@ def _compare_greater_than(self, prospective: Version, spec_str: str) -> bool:
 
         # Convert our spec to a Version instance, since we'll want to work with
         # it as a version.
-        spec = Version(spec_str)
+        spec = parse(spec_str)
 
         # Check to see if the prospective version is greater than the spec
         # version. If it's not we can short circuit and just return False now
@@ -494,13 +494,13 @@ def _compare_greater_than(self, prospective: Version, spec_str: str) -> bool:
         # post-release versions for the version mentioned in the specifier
         # (e.g. >3.1 should not match 3.0.post0, but should match 3.2.post0).
         if not spec.is_postrelease and prospective.is_postrelease:
-            if Version(prospective.base_version) == Version(spec.base_version):
+            if parse(prospective.base_version) == parse(spec.base_version):
                 return False
 
         # Ensure that we do not allow a local version of the version mentioned
         # in the specifier, which is technically greater than, to match.
         if prospective.local is not None:
-            if Version(prospective.base_version) == Version(spec.base_version):
+            if parse(prospective.base_version) == parse(spec.base_version):
                 return False
 
         # If we've gotten to here, it means that prospective version is both
@@ -924,7 +924,7 @@ def contains(
         """
         # Ensure that our item is a Version instance.
         if not isinstance(item, Version):
-            item = Version(item)
+            item = parse(item)
 
         # Determine if we're forcing a prerelease or not, if we're not forcing
         # one for this particular filter call, then we'll use whatever the
@@ -942,7 +942,7 @@ def contains(
             return False
 
         if installed and item.is_prerelease:
-            item = Version(item.base_version)
+            item = parse(item.base_version)
 
         # We simply dispatch to the underlying specs here to make sure that the
         # given version is contained within all of them.

src/packaging/utils.py

@@ -2,11 +2,12 @@
 # 2.0, and the BSD License. See the LICENSE file in the root of this repository
 # for complete details.
 
+import functools
 import re
 from typing import FrozenSet, NewType, Tuple, Union, cast
 
 from .tags import Tag, parse_tag
-from .version import InvalidVersion, Version
+from .version import InvalidVersion, Version, parse
 
 BuildTag = Union[Tuple[()], Tuple[int, str]]
 NormalizedName = NewType("NormalizedName", str)
@@ -40,6 +41,7 @@ class InvalidSdistFilename(ValueError):
 _build_tag_regex = re.compile(r"(\d+)(.*)")
 
 
+@functools.lru_cache(maxsize=4096)
 def canonicalize_name(name: str, *, validate: bool = False) -> NormalizedName:
     if validate and not _validate_regex.match(name):
         raise InvalidName(f"name is invalid: {name!r}")
@@ -52,6 +54,7 @@ def is_normalized_name(name: str) -> bool:
     return _normalized_regex.match(name) is not None
 
 
+@functools.lru_cache(maxsize=4096)
 def canonicalize_version(
     version: Union[Version, str], *, strip_trailing_zero: bool = True
 ) -> str:
@@ -61,7 +64,7 @@ def canonicalize_version(
     """
     if isinstance(version, str):
         try:
-            parsed = Version(version)
+            parsed = parse(version)
         except InvalidVersion:
             # Legacy versions cannot be normalized
             return version

src/packaging/version.py

@@ -7,6 +7,7 @@
     from packaging.version import parse, Version
 """
 
+import functools
 import itertools
 import re
 from typing import Any, Callable, NamedTuple, Optional, SupportsInt, Tuple, Union
@@ -42,6 +43,7 @@ class _Version(NamedTuple):
     local: Optional[LocalType]
 
 
+@functools.lru_cache(maxsize=4096)
 def parse(version: str) -> "Version":
     """Parse the given version string.
 
@@ -220,6 +222,12 @@ def __init__(self, version: str) -> None:
             self._version.dev,
             self._version.local,
         )
+        # Pre-compute the version string since
+        # its almost always called anyways because
+        # public will stringify the object and
+        # we want to cache it to avoid the cost
+        # of re-computing it.
+        self._str = self._version_string()
 
     def __repr__(self) -> str:
         """A representation of the Version that shows all internal state.
@@ -234,7 +242,11 @@ def __str__(self) -> str:
 
         >>> str(Version("1.0a5"))
         '1.0a5'
-        """
+        """        
+        return self._str
+
+    def _version_string(self) -> str:
+        """Build the version string to be used for __str__."""
         parts = []
 
         # Epoch
@@ -393,7 +405,7 @@ def is_prerelease(self) -> bool:
         >>> Version("1.2.3dev1").is_prerelease
         True
         """
-        return self.dev is not None or self.pre is not None
+        return self._version.dev is not None or self._version.pre is not None
 
     @property
     def is_postrelease(self) -> bool:
@@ -404,7 +416,7 @@ def is_postrelease(self) -> bool:
         >>> Version("1.2.3.post1").is_postrelease
         True
         """
-        return self.post is not None
+        return self._version.post is not None
 
     @property
     def is_devrelease(self) -> bool:
@@ -415,7 +427,7 @@ def is_devrelease(self) -> bool:
         >>> Version("1.2.3.dev1").is_devrelease
         True
         """
-        return self.dev is not None
+        return self._version.dev is not None
 
     @property
     def major(self) -> int: