Remove HashMap and HashSet for known-standard-library detection (#5345)

## Summary

This is a lot more concise and probably much more performant (with fewer
instructions).

Cargo.lock

@@ -2072,10 +2072,6 @@ dependencies = [
 [[package]]
 name = "ruff_python_stdlib"
 version = "0.0.0"
-dependencies = [
- "once_cell",
- "rustc-hash",
-]
 
 [[package]]
 name = "ruff_python_whitespace"

crates/ruff/src/rules/isort/categorize.rs

@@ -8,7 +8,7 @@ use serde::{Deserialize, Serialize};
 use strum_macros::EnumIter;
 
 use ruff_macros::CacheKey;
-use ruff_python_stdlib::sys::KNOWN_STANDARD_LIBRARY;
+use ruff_python_stdlib::sys::is_known_standard_library;
 
 use crate::settings::types::PythonVersion;
 use crate::warn_user_once;
@@ -82,11 +82,7 @@ pub(crate) fn categorize<'a>(
             (&ImportSection::Known(ImportType::Future), Reason::Future)
         } else if let Some((import_type, reason)) = known_modules.categorize(module_name) {
             (import_type, reason)
-        } else if KNOWN_STANDARD_LIBRARY
+        } else if is_known_standard_library(target_version.minor(), module_base) {
-            .get(&target_version.as_tuple())
-            .unwrap()
-            .contains(module_base)
-        {
             (
                 &ImportSection::Known(ImportType::StandardLibrary),
                 Reason::KnownStandardLibrary,

crates/ruff/src/settings/types.rs

@@ -52,6 +52,14 @@ impl PythonVersion {
         }
     }
 
+    pub const fn major(&self) -> u32 {
+        self.as_tuple().0
+    }
+
+    pub const fn minor(&self) -> u32 {
+        self.as_tuple().1
+    }
+
     pub fn get_minimum_supported_version(requires_version: &VersionSpecifiers) -> Option<Self> {
         let mut minimum_version = None;
         for python_version in PythonVersion::iter() {

crates/ruff_python_stdlib/Cargo.toml

@@ -13,5 +13,3 @@ license = { workspace = true }
 [lib]
 
 [dependencies]
-once_cell = { workspace = true }
-rustc-hash = { workspace = true }

scripts/generate_known_standard_library.py

@@ -12,13 +12,14 @@ from pathlib import Path
 from sphinx.ext.intersphinx import fetch_inventory
 
 URL = "https://docs.python.org/{}/objects.inv"
-PATH = Path("crates") / "ruff_python" / "src" / "sys.rs"
+PATH = Path("crates") / "ruff_python_stdlib" / "src" / "sys.rs"
 VERSIONS: list[tuple[int, int]] = [
     (3, 7),
     (3, 8),
     (3, 9),
     (3, 10),
     (3, 11),
+    (3, 12),
 ]
 
 
@@ -37,18 +38,16 @@ with PATH.open("w") as f:
     f.write(
         """\
 //! This file is generated by `scripts/generate_known_standard_library.py`
-use once_cell::sync::Lazy;
-use rustc_hash::{FxHashMap, FxHashSet};
 
-// See: https://pycqa.github.io/isort/docs/configuration/options.html#known-standard-library
+pub fn is_known_standard_library(minor_version: u32, module: &str) -> bool {
-pub static KNOWN_STANDARD_LIBRARY: Lazy<FxHashMap<(u32, u32), FxHashSet<&'static str>>> =
+    matches!((minor_version, module),
-    Lazy::new(|| {
+""",
-        FxHashMap::from_iter([
-""",  # noqa: E501
     )
-    for major, minor in VERSIONS:
+
-        version = f"{major}.{minor}"
+    modules_by_version = {}
-        url = URL.format(version)
+
+    for major_version, minor_version in VERSIONS:
+        url = URL.format(f"{major_version}.{minor_version}")
         invdata = fetch_inventory(FakeApp(), "", url)
 
         modules = {
@@ -60,33 +59,44 @@ pub static KNOWN_STANDARD_LIBRARY: Lazy<FxHashMap<(u32, u32), FxHashSet<&'static
             "sre_compile",
             "sre",
         }
+
         for module in invdata["py:module"]:
             root, *_ = module.split(".")
             if root not in ["__future__", "__main__"]:
                 modules.add(root)
 
-        f.write(
+        modules_by_version[minor_version] = modules
-            f"""\
+
-            (
+    # First, add a case for the modules that are in all versions.
-                ({major}, {minor}),
+    ubiquitous_modules = set.intersection(*modules_by_version.values())
-                FxHashSet::from_iter([
+
-""",
+    f.write("(_, ")
-        )
+    for i, module in enumerate(sorted(ubiquitous_modules)):
-        for module in sorted(modules):
+        if i > 0:
-            f.write(
+            f.write(" | ")
-                f"""\
+        f.write(f'"{module}"')
-                    "{module}",
+    f.write(")")
-""",
+    f.write("\n")
+
+    # Next, add any version-specific modules.
+    for _major_version, minor_version in VERSIONS:
+        version_modules = set.difference(
+            modules_by_version[minor_version],
+            ubiquitous_modules,
         )
+
+        f.write(" | ")
+        f.write(f"({minor_version}, ")
+        for i, module in enumerate(sorted(version_modules)):
+            if i > 0:
+                f.write(" | ")
+            f.write(f'"{module}"')
+        f.write(")")
+        f.write("\n")
+
     f.write(
         """\
-                ]),
+        )
-            ),
+}
-""",
-        )
-    f.write(
-        """\
-        ])
-    });
     """,
     )