Download the Arduino core and toolchain archives in parallel

esphome/arduino8266/framework.py

@@ -22,7 +22,7 @@ from esphome.build_helpers.ninja import find_ninja
 from esphome.build_helpers.tools_cache import tools_cache_path
 from esphome.core import EsphomeError, Version
 from esphome.framework_helpers import str_to_lst_of_str
-from esphome.platformio.registry import install_package
+from esphome.platformio.registry import install_package, prefetch_packages
 
 FRAMEWORK_PACKAGE = "framework-arduinoespressif8266"
 TOOLCHAIN_PACKAGE = "toolchain-xtensa"
@@ -101,6 +101,25 @@ def check_and_install(framework_version: Version) -> InstalledPaths:
     package_version = framework_package_version(framework_version)
     framework_path = get_framework_path(package_version)
     downloads_dir = get_arduino8266_tools_path() / "downloads"
+    toolchain_path = get_toolchain_path()
+    # Fetch both archives at once; the installs below verify and extract
+    prefetch_packages(
+        [
+            (
+                FRAMEWORK_PACKAGE,
+                package_version,
+                framework_path,
+                ESPHOME_ARDUINO8266_FRAMEWORK_MIRRORS,
+            ),
+            (
+                TOOLCHAIN_PACKAGE,
+                TOOLCHAIN_VERSION,
+                toolchain_path,
+                ESPHOME_ARDUINO8266_TOOLCHAIN_MIRRORS,
+            ),
+        ],
+        downloads_dir,
+    )
     install_package(
         FRAMEWORK_PACKAGE,
         package_version,
@@ -109,7 +128,6 @@ def check_and_install(framework_version: Version) -> InstalledPaths:
         downloads_dir,
         expect=("cores/esp8266", "tools/sdk", "libraries"),
     )
-    toolchain_path = get_toolchain_path()
     install_package(
         TOOLCHAIN_PACKAGE,
         TOOLCHAIN_VERSION,

tests/unit_tests/test_arduino8266_framework.py

@@ -63,6 +63,7 @@ def test_check_and_install_returns_paths(tmp_path: Path) -> None:
     with (
         patch.dict(os.environ, {"ESPHOME_ARDUINO8266_PREFIX": str(tmp_path)}),
         patch.object(framework, "install_package") as mock_install,
+        patch.object(framework, "prefetch_packages") as mock_prefetch,
         patch.object(framework, "find_ninja", return_value=tmp_path / "ninja"),
     ):
         paths = framework.check_and_install(cv.Version(3, 1, 2))
@@ -89,6 +90,24 @@ def test_check_and_install_returns_paths(tmp_path: Path) -> None:
         tmp_path / "downloads",
     )
     assert tc_call.kwargs["expect"] == ("bin", "xtensa-lx106-elf")
+    # The prefetch sees the same package specs as the installs
+    assert mock_prefetch.call_args.args == (
+        [
+            (
+                framework.FRAMEWORK_PACKAGE,
+                "3.30102.0",
+                tmp_path / "frameworks" / "3.30102.0",
+                framework.ESPHOME_ARDUINO8266_FRAMEWORK_MIRRORS,
+            ),
+            (
+                framework.TOOLCHAIN_PACKAGE,
+                framework.TOOLCHAIN_VERSION,
+                tmp_path / "toolchains" / framework.TOOLCHAIN_VERSION,
+                framework.ESPHOME_ARDUINO8266_TOOLCHAIN_MIRRORS,
+            ),
+        ],
+        tmp_path / "downloads",
+    )
 
 
 def test_get_build_env_prepends_toolchain_bin(tmp_path: Path) -> None: