readjust _run to contain less code & removal of redundant code

Author: SolitudePy

volatility3/framework/plugins/regexscan.py

@@ -46,12 +46,21 @@ def get_requirements(cls) -> List[interfaces.configuration.RequirementInterface]
             ),
         ]
 
-    def _generator(self, compiled_pattern, raw_pattern, maxsize):
-        vollog.debug(f"RegEx Pattern: {raw_pattern}")
-        layer = self.context.layers[self.config["primary"]]
+    def _generator(self, layer, pattern, maxsize):
+        vollog.debug(f"RegEx Pattern: {pattern}")
+
+        # Convert string pattern to bytes for RegExScanner
+        pattern_bytes = pattern.encode("utf-8")
+
+        # Compile the pattern here to ensure consistency
+        try:
+            compiled_pattern = re.compile(pattern_bytes)
+        except re.error as e:
+            vollog.error(f"Invalid regex pattern: {e}")
+            raise ValueError(f"Invalid regex pattern: {e}")
 
         for offset in layer.scan(
-            context=self.context, scanner=scanners.RegExScanner(raw_pattern)
+            context=self.context, scanner=scanners.RegExScanner(pattern_bytes)
         ):
             result_data = layer.read(offset, maxsize, pad=True)
 
@@ -73,36 +82,14 @@ def _generator(self, compiled_pattern, raw_pattern, maxsize):
 
     def run(self):
         pattern = self.config.get("pattern")
-
-        # Handle pattern encoding robustly
-        if isinstance(pattern, str):
-            try:
-                raw_pattern = pattern.encode("utf-8")
-            except UnicodeEncodeError:
-                raw_pattern = pattern.encode("latin1", errors="replace")
-        else:
-            raw_pattern = pattern
-
-        try:
-            compiled_pattern = re.compile(raw_pattern)
-        except re.error as e:
-            vollog.error(f"Invalid regex pattern: {e}")
-            return renderers.TreeGrid(
-                [
-                    ("Offset", format_hints.Hex),
-                    ("Text", str),
-                    ("Hex", bytes),
-                ],
-                [],
-            )
-
         maxsize = self.config.get("maxsize", self.MAXSIZE_DEFAULT)
+        layer = self.context.layers[self.config["primary"]]
 
         return renderers.TreeGrid(
             [
                 ("Offset", format_hints.Hex),
                 ("Text", str),
                 ("Hex", bytes),
             ],
-            self._generator(compiled_pattern, raw_pattern, maxsize),
+            self._generator(layer, pattern, maxsize),
         )