Reduce string conversion in CaseInsensitiveDict lookups (#173)

bdraco · web-flow · commit 93a9efaa9325 · 2023-08-13T22:02:22.000+02:00
* Implement get on CaseInsensitiveDict get was previously provided by the parent class which had to raise KeyError for missing values. Since try/except is only cheap for the non-exception case the performance was not good when the key was missing similar to python/cpython#106665 but in the HA case we call this even more frequently
diff --git a/async_upnp_client/advertisement.py b/async_upnp_client/advertisement.py
@@ -66,24 +66,26 @@ def __init__(
 
     def _on_data(self, request_line: str, headers: CaseInsensitiveDict) -> None:
         """Handle data."""
-        if headers.get("MAN") == SSDP_DISCOVER:
+        if headers.get_lower("man") == SSDP_DISCOVER:
             # Ignore discover packets.
             return
-        if "NTS" not in headers:
+
+        notification_sub_type = headers.get_lower("nts")
+        if notification_sub_type is None:
             _LOGGER.debug("Got non-advertisement packet: %s, %s", request_line, headers)
             return
 
-        _LOGGER.debug(
-            "Received advertisement, _remote_addr: %s, NT: %s, NTS: %s, USN: %s, location: %s",
-            headers.get("_remote_addr", ""),
-            headers.get("NT", "<no NT>"),
-            headers.get("NTS", "<no NTS>"),
-            headers.get("USN", "<no USN>"),
-            headers.get("location", ""),
-        )
+        if _LOGGER.isEnabledFor(logging.DEBUG):
+            _LOGGER.debug(
+                "Received advertisement, _remote_addr: %s, NT: %s, NTS: %s, USN: %s, location: %s",
+                headers.get_lower("_remote_addr", ""),
+                headers.get_lower("nt", "<no NT>"),
+                headers.get_lower("nts", "<no NTS>"),
+                headers.get_lower("usn", "<no USN>"),
+                headers.get_lower("location", ""),
+            )
 
         headers["_source"] = SsdpSource.ADVERTISEMENT
-        notification_sub_type = headers["NTS"]
         if notification_sub_type == NotificationSubType.SSDP_ALIVE:
             if self.async_on_alive:
                 coro = self.async_on_alive(headers)
diff --git a/async_upnp_client/server.py b/async_upnp_client/server.py
@@ -482,16 +482,20 @@ def _on_data(
         # pylint: disable=too-many-branches
         assert self._transport
 
-        if request_line != "M-SEARCH * HTTP/1.1" or headers.get("MAN") != SSDP_DISCOVER:
+        if (
+            request_line != "M-SEARCH * HTTP/1.1"
+            or headers.get_lower("man") != SSDP_DISCOVER
+        ):
             return
 
-        remote_addr = headers["_remote_addr"]
+        remote_addr = headers.get_lower("_remote_addr")
         _LOGGER.debug("Received M-SEARCH from: %s, headers: %s", remote_addr, headers)
 
         loop = asyncio.get_running_loop()
-        if "MX" in headers:
+        mx_header = headers.get_lower("mx")
+        if mx_header is not None:
             try:
-                delay = int(headers["MX"])
+                delay = int(mx_header)
                 _LOGGER.debug("Deferring response for %d seconds", delay)
             except ValueError:
                 delay = 0
@@ -501,8 +505,9 @@ def _on_data(
 
     def _deferred_on_data(self, headers: CaseInsensitiveDict) -> None:
         # Determine how we should respond, page 1.3.2 of UPnP-arch-DeviceArchitecture-v2.0.
-        remote_addr = headers["_remote_addr"]
-        search_target = headers["st"].lower()
+        remote_addr = headers.get_lower("_remote_addr")
+        st_header: str = headers.get_lower("st", "")
+        search_target = st_header.lower()
         if search_target == SSDP_ST_ALL:
             # 3 + 2d + k (d: embedded device, k: service)
             # global:      ST: upnp:rootdevice
diff --git a/async_upnp_client/ssdp_listener.py b/async_upnp_client/ssdp_listener.py
@@ -41,9 +41,9 @@
 def valid_search_headers(headers: CaseInsensitiveDict) -> bool:
     """Validate if this search is usable."""
     # pylint: disable=invalid-name
-    udn = headers.get("_udn")  # type: Optional[str]
-    st = headers.get("st")  # type: Optional[str]
-    location = headers.get("location", "")  # type: str
+    udn = headers.get_lower("_udn")  # type: Optional[str]
+    st = headers.get_lower("st")  # type: Optional[str]
+    location = headers.get_lower("location", "")  # type: str
     return bool(
         udn
         and st
@@ -60,10 +60,10 @@ def valid_search_headers(headers: CaseInsensitiveDict) -> bool:
 def valid_advertisement_headers(headers: CaseInsensitiveDict) -> bool:
     """Validate if this advertisement is usable for connecting to a device."""
     # pylint: disable=invalid-name
-    udn = headers.get("_udn")  # type: Optional[str]
-    nt = headers.get("nt")  # type: Optional[str]
-    nts = headers.get("nts")  # type: Optional[str]
-    location = headers.get("location", "")  # type: str
+    udn = headers.get_lower("_udn")  # type: Optional[str]
+    nt = headers.get_lower("nt")  # type: Optional[str]
+    nts = headers.get_lower("nts")  # type: Optional[str]
+    location = headers.get_lower("location", "")  # type: str
     return bool(
         udn
         and nt
@@ -81,22 +81,22 @@ def valid_advertisement_headers(headers: CaseInsensitiveDict) -> bool:
 def valid_byebye_headers(headers: CaseInsensitiveDict) -> bool:
     """Validate if this advertisement has required headers for byebye."""
     # pylint: disable=invalid-name
-    udn = headers.get("_udn")  # type: Optional[str]
-    nt = headers.get("nt")  # type: Optional[str]
-    nts = headers.get("nts")  # type: Optional[str]
+    udn = headers.get_lower("_udn")  # type: Optional[str]
+    nt = headers.get_lower("nt")  # type: Optional[str]
+    nts = headers.get_lower("nts")  # type: Optional[str]
     return bool(udn and nt and nts)
 
 
 def extract_valid_to(headers: CaseInsensitiveDict) -> datetime:
     """Extract/create valid to."""
-    cache_control = headers.get("cache-control", "")
+    cache_control = headers.get_lower("cache-control", "")
     match = CACHE_CONTROL_RE.search(cache_control)
     if match:
         max_age = int(match[1])
         uncache_after = timedelta(seconds=max_age)
     else:
         uncache_after = DEFAULT_MAX_AGE
-    timestamp: datetime = headers["_timestamp"]
+    timestamp: datetime = headers.get_lower("_timestamp")
     return timestamp + uncache_after
 
 
@@ -247,7 +247,7 @@ def ip_version_from_location(location: str) -> Optional[int]:
 
 def location_changed(ssdp_device: SsdpDevice, headers: CaseInsensitiveDict) -> bool:
     """Test if location changed for device."""
-    new_location = headers.get("location", "")
+    new_location = headers.get_lower("location", "")
     if not new_location:
         return False
 
@@ -295,14 +295,14 @@ def see_search(
             _LOGGER.debug("Received invalid search headers: %s", headers)
             return False, None, None, None
 
-        udn = headers["_udn"]
+        udn = headers.get_lower("_udn")
         is_new_device = udn not in self.devices
 
         ssdp_device, new_location = self._see_device(headers)
         if not ssdp_device:
             return False, None, None, None
 
-        search_target: SearchTarget = headers["ST"]
+        search_target: SearchTarget = headers.get_lower("st")
         is_new_service = (
             search_target not in ssdp_device.advertisement_headers
             and search_target not in ssdp_device.search_headers
@@ -339,14 +339,14 @@ def see_advertisement(
             _LOGGER.debug("Received invalid advertisement headers: %s", headers)
             return False, None, None
 
-        udn = headers["_udn"]
+        udn = headers.get_lower("_udn")
         is_new_device = udn not in self.devices
 
         ssdp_device, new_location = self._see_device(headers)
         if not ssdp_device:
             return False, None, None
 
-        notification_type: NotificationType = headers["NT"]
+        notification_type: NotificationType = headers.get_lower("nt")
         is_new_service = (
             notification_type not in ssdp_device.advertisement_headers
             and notification_type not in ssdp_device.search_headers
@@ -356,7 +356,7 @@ def see_advertisement(
                 "See new service: %s, type: %s", ssdp_device, notification_type
             )
 
-        notification_sub_type: NotificationSubType = headers["NTS"]
+        notification_sub_type: NotificationSubType = headers.get_lower("nts")
         propagate = (
             notification_sub_type == NotificationSubType.SSDP_UPDATE
             or is_new_device
@@ -407,8 +407,8 @@ def _see_device(
         new_location = location_changed(ssdp_device, headers)
 
         # Update device.
-        ssdp_device.add_location(headers["location"], valid_to)
-        ssdp_device.last_seen = headers["_timestamp"]
+        ssdp_device.add_location(headers.get_lower("location"), valid_to)
+        ssdp_device.last_seen = headers.get_lower("_timestamp")
         if not self.next_valid_to or self.next_valid_to > ssdp_device.valid_to:
             self.next_valid_to = ssdp_device.valid_to
 
@@ -433,7 +433,7 @@ def unsee_advertisement(
         del self.devices[udn]
 
         # Update device before propagating it
-        notification_type: NotificationType = headers["NT"]
+        notification_type: NotificationType = headers.get_lower("nt")
         if notification_type in ssdp_device.advertisement_headers:
             ssdp_device.advertisement_headers[notification_type].replace(headers)
         else:
diff --git a/async_upnp_client/utils.py b/async_upnp_client/utils.py
@@ -41,12 +41,12 @@ def as_lower_dict(self) -> Dict[str, Any]:
         """Return the underlying dict in lowercase."""
         return {k.lower(): v for k, v in self._data.items()}
 
-    def get_lower(self, lower_key: str) -> Any:
+    def get_lower(self, lower_key: str, default: Any = None) -> Any:
         """Get a lower case key."""
         data_key = self._case_map.get(lower_key, _SENTINEL)
         if data_key is not _SENTINEL:
-            return self._data[data_key]
-        return None
+            return self._data.get(data_key, default)
+        return default
 
     def replace(self, new_data: abcMapping) -> None:
         """Replace the underlying dict."""
