Performance enhancements (#527)

tools/isledecomp/isledecomp/compare/lines.py

@@ -2,6 +2,7 @@
 between FUNCTION markers and PDB analysis."""
 import sqlite3
 import logging
+from functools import cache
 from typing import Optional
 from pathlib import Path
 from isledecomp.dir import PathResolver
@@ -22,6 +23,16 @@ _SETUP_SQL = """
 logger = logging.getLogger(__name__)
 
 
+@cache
+def my_samefile(path: str, source_path: str) -> bool:
+    return Path(path).samefile(source_path)
+
+
+@cache
+def my_basename_lower(path: str) -> str:
+    return Path(path).name.lower()
+
+
 class LinesDb:
     def __init__(self, code_dir) -> None:
         self._db = sqlite3.connect(":memory:")
@@ -31,7 +42,7 @@ class LinesDb:
     def add_line(self, path: str, line_no: int, addr: int):
         """To be added from the LINES section of cvdump."""
         sourcepath = self._path_resolver.resolve_cvdump(path)
-        filename = Path(sourcepath).name.lower()
+        filename = my_basename_lower(sourcepath)
 
         self._db.execute(
             "INSERT INTO `lineref` (path, filename, line, addr) VALUES (?,?,?,?)",
@@ -41,13 +52,13 @@ class LinesDb:
     def search_line(self, path: str, line_no: int) -> Optional[int]:
         """Using path and line number from FUNCTION marker,
         get the address of this function in the recomp."""
-        filename = Path(path).name.lower()
+        filename = my_basename_lower(path)
         cur = self._db.execute(
             "SELECT path, addr FROM `lineref` WHERE filename = ? AND line = ?",
             (filename, line_no),
         )
         for source_path, addr in cur.fetchall():
-            if Path(path).samefile(source_path):
+            if my_samefile(path, source_path):
                 return addr
 
         logger.error(