use 127.0.0.1 instead of localhost, update dump_hierarchy

uiautomator2/__init__.py

@@ -11,12 +11,12 @@
 import re
 import time
 import warnings
-import xml.dom.minidom
 from functools import cached_property
 from typing import Any, Dict, List, Optional, Union
 
 import adbutils
 from deprecated import deprecated
+from lxml import etree
 from retry import retry
 
 from uiautomator2.core import BasicUiautomatorServer
@@ -261,21 +261,39 @@ def screenshot(self, filename: Optional[str] = None, format="pillow"):
         elif format == 'raw':
             return pil_img.tobytes()
 
-    @retry(exceptions=HierarchyEmptyError, tries=3, delay=1)
     def dump_hierarchy(self, compressed=False, pretty=False) -> str:
-        # empty output
-        # '<?xml version=\'1.0\' encoding=\'UTF-8\' standalone=\'yes\' ?>\r\n<hierarchy rotation="0" />'
+        """
+        Dump window hierarchy
+
+        Args:
+            compressed (bool): return compressed xml
+            pretty (bool): pretty print xml
+
+        Returns:
+            xml content
+        """
+        try:
+            content = self._do_dump_hierarchy(compressed)
+        except HierarchyEmptyError:
+            logger.warning("dump empty, return empty xml")
+            content = '<?xml version=\'1.0\' encoding=\'UTF-8\' standalone=\'yes\' ?>\r\n<hierarchy rotation="0" />'
+
+        if pretty:
+            root = etree.fromstring(content.encode("utf-8"))
+            content = etree.tostring(root, pretty_print=True, encoding=str)
+        return content
+
+    @retry(HierarchyEmptyError, tries=3, delay=1)
+    def _do_dump_hierarchy(self, compressed=False) -> str:
         content = self.jsonrpc.dumpWindowHierarchy(compressed, None)
         if content == "":
             raise HierarchyEmptyError("dump hierarchy is empty")
 
+        # '<?xml version=\'1.0\' encoding=\'UTF-8\' standalone=\'yes\' ?>\r\n<hierarchy rotation="0" />'
         if '<hierarchy rotation="0" />' in content:
+            logger.debug("dump empty, call clear_traversed_text and retry")
             self.clear_traversed_text()
             raise HierarchyEmptyError("dump hierarchy is empty with no children")
-
-        if pretty and "\n " not in content:
-            xml_text = xml.dom.minidom.parseString(content.encode("utf-8"))
-            content = xml_text.toprettyxml(indent='  ')
         return content
 
     def implicitly_wait(self, seconds: float = None) -> float:

uiautomator2/core.py

@@ -88,7 +88,9 @@ def _http_request(dev: adbutils.AdbDevice, method: str, path: str, data: Dict[st
         logger.debug("http request %s %s %s", method, path, data)
         lport = dev.forward_port(9008)
         logger.debug("forward tcp:%d -> tcp:9008", lport)
-        url = f"http://localhost:{lport}{path}"
+        # https://stackoverflow.com/questions/2386299/running-sites-on-localhost-is-extremely-slow
+        # so here use 127.0.0.1 instead of localhost
+        url = f"http://127.0.0.1:{lport}{path}"
         if print_request:
             fields = [time.strftime("%H:%M:%S"), f"$ curl -X {method}", url]
             if data: