From 07b2e84dff919060fe74c154a7ae4206fe01e814 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Fri, 27 Sep 2024 13:34:13 -0500
Subject: [PATCH] Improve performance of building URLs with authority (#1163)

---
 CHANGES/1163.misc.rst   |  1 +
 tests/test_url_build.py | 25 +++++++++++++++++++++++++
 yarl/_url.py            | 11 ++++++++---
 3 files changed, 34 insertions(+), 3 deletions(-)
 create mode 100644 CHANGES/1163.misc.rst

diff --git a/CHANGES/1163.misc.rst b/CHANGES/1163.misc.rst
new file mode 100644
index 000000000..a4976b747
--- /dev/null
+++ b/CHANGES/1163.misc.rst
@@ -0,0 +1 @@
+Improved performance of calling :py:meth:`~yarl.URL.build` with ``authority`` -- by :user:`bdraco`.
diff --git a/tests/test_url_build.py b/tests/test_url_build.py
index 0b7b9cd73..cc9b15f7e 100644
--- a/tests/test_url_build.py
+++ b/tests/test_url_build.py
@@ -153,6 +153,31 @@ def test_build_with_authority_without_encoding():
     assert str(url) == "http://foo:bar@host.com:8000/path"
 
 
+def test_build_with_authority_empty_host_no_scheme():
+    url = URL.build(authority="", path="path")
+    assert str(url) == "path"
+
+
+def test_build_with_authority_and_only_user():
+    url = URL.build(scheme="https", authority="user:@foo.com", path="/path")
+    assert str(url) == "https://user:@foo.com/path"
+
+
+def test_build_with_authority_with_port():
+    url = URL.build(scheme="https", authority="foo.com:8080", path="/path")
+    assert str(url) == "https://foo.com:8080/path"
+
+
+def test_build_with_authority_with_ipv6():
+    url = URL.build(scheme="https", authority="[::1]", path="/path")
+    assert str(url) == "https://[::1]/path"
+
+
+def test_build_with_authority_with_ipv6_and_port():
+    url = URL.build(scheme="https", authority="[::1]:81", path="/path")
+    assert str(url) == "https://[::1]:81/path"
+
+
 def test_query_str():
     u = URL.build(scheme="http", host="127.0.0.1", path="/", query_string="arg=value1")
     assert str(u) == "http://127.0.0.1/?arg=value1"
diff --git a/yarl/_url.py b/yarl/_url.py
index 25988f81d..65a91bb71 100644
--- a/yarl/_url.py
+++ b/yarl/_url.py
@@ -368,10 +368,15 @@ def build(
             if encoded:
                 netloc = authority
             else:
-                tmp = SplitResult("", authority, "", "", "")
-                port = None if tmp.port == DEFAULT_PORTS.get(scheme) else tmp.port
+                _user, _password, _host, _port = cls._split_netloc(authority)
+                port = None if _port == DEFAULT_PORTS.get(scheme) else _port
+                _host = (
+                    ""
+                    if _host is None
+                    else cls._encode_host(_host, validate_host=False)
+                )
                 netloc = cls._make_netloc(
-                    tmp.username, tmp.password, tmp.hostname, port, encode=True
+                    _user, _password, _host, port, encode=True, encode_host=False
                 )
         elif not user and not password and not host and not port:
             netloc = ""