feat: speed up processing incoming data (#1167)

bdraco · web-flow · commit fbaaf7bb6ff9 · 2023-05-01T10:20:24.000-05:00
diff --git a/src/zeroconf/_protocol/incoming.pxd b/src/zeroconf/_protocol/incoming.pxd
@@ -54,7 +54,7 @@ cdef class DNSIncoming:
     cdef unsigned int _data_len
     cdef public cython.dict name_cache
     cdef public cython.list questions
-    cdef object _answers
+    cdef cython.list _answers
     cdef public object id
     cdef public cython.uint num_questions
     cdef public cython.uint num_answers
@@ -78,8 +78,6 @@ cdef class DNSIncoming:
 
     cdef _initial_parse(self)
 
-    cdef _unpack(self, object unpacker, object length)
-
     @cython.locals(
         end=cython.uint,
         length=cython.uint
@@ -88,9 +86,6 @@ cdef class DNSIncoming:
 
     cdef _read_questions(self)
 
-    @cython.locals(
-        length=cython.uint
-    )
     cdef bytes _read_character_string(self)
 
     cdef _read_string(self, unsigned int length)
diff --git a/src/zeroconf/_protocol/incoming.py b/src/zeroconf/_protocol/incoming.py
@@ -22,7 +22,7 @@
 
 import struct
 import sys
-from typing import Any, Callable, Dict, List, Optional, Set, Tuple, Union, cast
+from typing import Any, Dict, List, Optional, Set, Tuple, Union
 
 from .._dns import (
     DNSAddress,
@@ -194,10 +194,6 @@ def __repr__(self) -> str:
             ]
         )
 
-    def _unpack(self, unpacker: Callable[[bytes, int], tuple], length: int) -> tuple:
-        self.offset += length
-        return unpacker(self.data, self.offset - length)
-
     def _read_header(self) -> None:
         """Reads header portion of packet"""
         (
@@ -207,7 +203,8 @@ def _read_header(self) -> None:
             self.num_answers,
             self.num_authorities,
             self.num_additionals,
-        ) = self._unpack(UNPACK_6H, 12)
+        ) = UNPACK_6H(self.data)
+        self.offset += 12
 
     def _read_questions(self) -> None:
         """Reads questions section of packet"""
@@ -264,18 +261,24 @@ def _read_record(
     ) -> Optional[DNSRecord]:
         """Read known records types and skip unknown ones."""
         if type_ == _TYPE_A:
-            return DNSAddress(domain, type_, class_, ttl, self._read_string(4), created=self.now)
+            dns_address = DNSAddress(domain, type_, class_, ttl, self._read_string(4))
+            dns_address.created = self.now
+            return dns_address
         if type_ in (_TYPE_CNAME, _TYPE_PTR):
             return DNSPointer(domain, type_, class_, ttl, self._read_name(), self.now)
         if type_ == _TYPE_TXT:
             return DNSText(domain, type_, class_, ttl, self._read_string(length), self.now)
         if type_ == _TYPE_SRV:
+            priority, weight, port = UNPACK_3H(self.data, self.offset)
+            self.offset += 6
             return DNSService(
                 domain,
                 type_,
                 class_,
                 ttl,
-                *cast(Tuple[int, int, int], self._unpack(UNPACK_3H, 6)),
+                priority,
+                weight,
+                port,
                 self._read_name(),
                 self.now,
             )
@@ -285,14 +288,15 @@ def _read_record(
                 type_,
                 class_,
                 ttl,
-                self._read_character_string().decode('utf-8'),
-                self._read_character_string().decode('utf-8'),
+                self._read_character_string().decode('utf-8', 'replace'),
+                self._read_character_string().decode('utf-8', 'replace'),
                 self.now,
             )
         if type_ == _TYPE_AAAA:
-            return DNSAddress(
-                domain, type_, class_, ttl, self._read_string(16), created=self.now, scope_id=self.scope_id
-            )
+            dns_address = DNSAddress(domain, type_, class_, ttl, self._read_string(16))
+            dns_address.created = self.now
+            dns_address.scope_id = self.scope_id
+            return dns_address
         if type_ == _TYPE_NSEC:
             name_start = self.offset
             return DNSNsec(
@@ -384,4 +388,4 @@ def _decode_labels_at_offset(self, off: int, labels: List[str], seen_pointers: S
                 )
             return off + DNS_COMPRESSION_POINTER_LEN
 
-        raise IncomingDecodeError("Corrupt packet received while decoding name from {self.source}")
+        raise IncomingDecodeError(f"Corrupt packet received while decoding name from {self.source}")
