Refactor parsing function in code coverage plugin to split the actual parsing...

Refactor parsing function in code coverage plugin to split the actual parsing code from the lookup code.

Cython/Coverage.py

@@ -82,7 +82,7 @@ class Plugin(CoveragePlugin):
             #        is not from the main .pyx file but a file with a different
             #        name than the .c file (which prevents us from finding the
             #        .c file)
-            _, code = self._parse_lines(c_file, filename)
+            _, code = self._read_source_lines(c_file, filename)
             if code is None:
                 return None  # no source found
 
@@ -104,7 +104,7 @@ class Plugin(CoveragePlugin):
             c_file, _ = self._find_source_files(filename)
             if not c_file:
                 return None  # unknown file
-            rel_file_path, code = self._parse_lines(c_file, filename)
+            rel_file_path, code = self._read_source_lines(c_file, filename)
             if code is None:
                 return None  # no source found
         return CythonModuleReporter(c_file, filename, rel_file_path, code)
@@ -170,14 +170,14 @@ class Plugin(CoveragePlugin):
         for filename in os.listdir(dir_path):
             ext = splitext(filename)[1].lower()
             if ext in C_FILE_EXTENSIONS:
-                self._parse_lines(os.path.join(dir_path, filename), source_file)
+                self._read_source_lines(os.path.join(dir_path, filename), source_file)
                 if source_file in self._c_files_map:
                     return
         # not found? then try one package up
         if is_package_dir(dir_path):
             self._find_c_source_files(os.path.dirname(dir_path), source_file)
 
-    def _parse_lines(self, c_file, sourcefile):
+    def _read_source_lines(self, c_file, sourcefile):
         """
         Parse a Cython generated C/C++ source file and find the executable lines.
         Each executable line starts with a comment header that states source file
@@ -188,6 +188,24 @@ class Plugin(CoveragePlugin):
         if c_file in self._parsed_c_files:
             code_lines = self._parsed_c_files[c_file]
         else:
+            code_lines = self._parse_cfile_lines(c_file)
+            self._parsed_c_files[c_file] = code_lines
+
+        if self._c_files_map is None:
+            self._c_files_map = {}
+
+        for filename, code in code_lines.items():
+            abs_path = _find_dep_file_path(c_file, filename)
+            self._c_files_map[abs_path] = (c_file, filename, code)
+
+        if sourcefile not in self._c_files_map:
+            return (None,) * 2  # e.g. shared library file
+        return self._c_files_map[sourcefile][1:]
+
+    def _parse_cfile_lines(self, c_file):
+        """
+        Parse a C file and extract all source file lines that generated executable code.
+        """
         match_source_path_line = re.compile(r' */[*] +"(.*)":([0-9]+)$').match
         match_current_code_line = re.compile(r' *[*] (.*) # <<<<<<+$').match
         match_comment_end = re.compile(r' *[*]/$').match
@@ -202,6 +220,7 @@ class Plugin(CoveragePlugin):
         code_lines = defaultdict(dict)
         executable_lines = defaultdict(set)
         current_filename = None
+
         with open(c_file) as lines:
             lines = iter(lines)
             for line in lines:
@@ -232,19 +251,7 @@ class Plugin(CoveragePlugin):
             dead_lines = set(lines).difference(executable_lines.get(filename, ()))
             for lineno in dead_lines:
                 del lines[lineno]
-
-            self._parsed_c_files[c_file] = code_lines
-
-        if self._c_files_map is None:
-            self._c_files_map = {}
-
-        for filename, code in code_lines.items():
-            abs_path = _find_dep_file_path(c_file, filename)
-            self._c_files_map[abs_path] = (c_file, filename, code)
-
-        if sourcefile not in self._c_files_map:
-            return (None,) * 2  # e.g. shared library file
-        return self._c_files_map[sourcefile][1:]
+        return code_lines
 
 
 class CythonModuleTracer(FileTracer):