From 83f0dc3d8c0e7c6312313c2832a2739b9516d60c Mon Sep 17 00:00:00 2001
From: Vladimir Chebotarev <vladimir.chebotarev@gmail.com>
Date: Sun, 28 Aug 2022 19:47:50 +0300
Subject: [PATCH] 35% faster than `pathspec` \o/. #24
 cpburnz/python-path-specification#38

---
 gitignorefile/__init__.py | 35 ++++++++++++++++++++++-------------
 tests/test_match.py       |  8 ++++++++
 2 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/gitignorefile/__init__.py b/gitignorefile/__init__.py
index 2fc08a5..df2e17b 100644
--- a/gitignorefile/__init__.py
+++ b/gitignorefile/__init__.py
@@ -198,11 +198,7 @@ def _rule_from_pattern(pattern):
                 pattern = pattern[:i]
         i -= 1
 
-    regexp = _fnmatch_pathname_to_regexp(pattern, directory_only)
-
-    if anchored:
-        regexp = f"^{regexp}"
-
+    regexp = _fnmatch_pathname_to_regexp(pattern, anchored, directory_only)
     return _IgnoreRule(regexp, negation, directory_only)
 
 
@@ -244,19 +240,24 @@ def __init__(self, regexp, negation, directory_only):
         self.__regexp = re.compile(regexp)
         self.__negation = negation
         self.__directory_only = directory_only
+        self.__match = self.__regexp.match
+
+    @property
+    def regexp(self):
+        return self.__regexp
 
     @property
     def negation(self):
         return self.__negation
 
     def match(self, rel_path, is_dir):
-        match = self.__regexp.search(rel_path)
+        m = self.__match(rel_path)
 
         # If we need a directory, check there is something after slash and if there is not, target must be a directory.
         # If there is something after slash then it's a directory irrelevant to type of target.
         # `self.directory_only` implies we have group number 1.
         # N.B. Question mark inside a group without a name can shift indices. :(
-        return match and (not self.__directory_only or match.group(1) is not None or is_dir)
+        return m and (not self.__directory_only or m.group(1) is not None or is_dir)
 
 
 if os.altsep is not None:
@@ -269,14 +270,22 @@ def match(self, rel_path, is_dir):
 
 # Frustratingly, python's fnmatch doesn't provide the FNM_PATHNAME
 # option that `.gitignore`'s behavior depends on.
-def _fnmatch_pathname_to_regexp(pattern, directory_only):
+def _fnmatch_pathname_to_regexp(pattern, anchored, directory_only):
     """
     Implements `fnmatch` style-behavior, as though with `FNM_PATHNAME` flagged;
     the path separator will not match shell-style `*` and `.` wildcards.
     """
+
+    if not pattern:
+        if directory_only:  # Empty name means no path fragment.
+            return "[^/]+(/.+)?$"
+
+        else:
+            return ".*"
+
     i, n = 0, len(pattern)
 
-    res = ["(?:^|/)"] if pattern else []  # Empty name means no path fragment.
+    res = ["(?:^|.+/)" if not anchored else ""]
     while i < n:
         c = pattern[i]
         i += 1
@@ -290,10 +299,10 @@ def _fnmatch_pathname_to_regexp(pattern, directory_only):
                         res.append("/?")
 
                 else:
-                    res.append(f"[^/]*")
+                    res.append("[^/]*")
 
             except IndexError:
-                res.append(f"[^/]*")
+                res.append("[^/]*")
 
         elif c == "?":
             res.append("[^/]")
@@ -322,9 +331,9 @@ def _fnmatch_pathname_to_regexp(pattern, directory_only):
             res.append(re.escape(c))
 
     if directory_only:  # In this case we are interested if there is something after slash.
-        res.append(f"(/.+)?$")
+        res.append("(/.+)?$")
 
     else:
-        res.append(f"(?:/|$)")
+        res.append("(?:/.+)?$")
 
     return "".join(res)
diff --git a/tests/test_match.py b/tests/test_match.py
index 78e8769..a4ccbb9 100644
--- a/tests/test_match.py
+++ b/tests/test_match.py
@@ -108,6 +108,14 @@ def test_second_level_directories_unchained(self):
         self.assertTrue(matches("/home/michael/a/doc/frotz", is_dir=True))
         self.assertFalse(matches("/home/michael/a/b/doc/frotz", is_dir=False))
         self.assertTrue(matches("/home/michael/a/b/doc/frotz", is_dir=True))
+        for is_dir in (False, True):
+            with self.subTest(i=is_dir):
+                self.assertTrue(matches("/home/michael/doc/frotz/file", is_dir=False))
+                self.assertTrue(matches("/home/michael/doc/frotz/file", is_dir=True))
+                self.assertTrue(matches("/home/michael/a/doc/frotz/file", is_dir=False))
+                self.assertTrue(matches("/home/michael/a/doc/frotz/file", is_dir=True))
+                self.assertTrue(matches("/home/michael/a/b/doc/frotz/file", is_dir=False))
+                self.assertTrue(matches("/home/michael/a/b/doc/frotz/file", is_dir=True))
 
     def test_second_level_files(self):
         matches = self.__parse_gitignore_string(["doc/frotz"], fake_base_dir="/home/michael")