perf(static-sites): parallelize Bunny transfers

tests/test_static_site.py

@@ -4,6 +4,7 @@ import json
 from pathlib import Path
 import sys
 import tempfile
+import threading
 import unittest
 from unittest import mock
 
@@ -15,11 +16,13 @@ sys.modules[SPEC.name] = static_site
 SPEC.loader.exec_module(static_site)
 
 DeployError = static_site.DeployError
+apply_bunny_plan = static_site.apply_bunny_plan
 bunny_plan = static_site.bunny_plan
 collect_files = static_site.collect_files
 manifest_for = static_site.manifest_for
 parse_manifest = static_site.parse_manifest
 purge_bunny_gateway = static_site.purge_bunny_gateway
+run_concurrently = static_site.run_concurrently
 
 
 def write_site(root: Path) -> None:
@@ -80,6 +83,56 @@ class StaticSiteTests(unittest.TestCase):
             remote = manifest_for(files)["files"]
             self.assertEqual(bunny_plan(files, remote), ([], []))
 
+    def test_bunny_transfers_use_multiple_workers(self) -> None:
+        barrier = threading.Barrier(4)
+        completed: list[int] = []
+
+        def transfer(item: int) -> None:
+            barrier.wait(timeout=2)
+            completed.append(item)
+
+        run_concurrently([1, 2, 3, 4], transfer, workers=4)
+
+        self.assertCountEqual(completed, [1, 2, 3, 4])
+
+    def test_bunny_transfer_order_keeps_documents_and_manifest_safe(self) -> None:
+        with tempfile.TemporaryDirectory() as directory:
+            root = Path(directory)
+            write_site(root)
+            (root / "about.html").write_text("<h1>About</h1>")
+            files = collect_files(root)
+            events: list[tuple[str, str]] = []
+            storage = mock.Mock()
+            storage.upload.side_effect = lambda item: events.append(
+                ("upload", item.path)
+            )
+            storage.delete.side_effect = lambda path: events.append(("delete", path))
+            storage.upload_manifest.side_effect = lambda _manifest: events.append(
+                ("manifest", static_site.MANIFEST_NAME)
+            )
+
+            apply_bunny_plan(
+                storage,
+                files,
+                ["assets/app.js", "about.html", "index.html"],
+                ["stale.css"],
+                workers=2,
+            )
+
+        asset_position = events.index(("upload", "assets/app.js"))
+        document_positions = {
+            events.index(("upload", "about.html")),
+            events.index(("upload", "index.html")),
+        }
+        delete_position = events.index(("delete", "stale.css"))
+        self.assertTrue(
+            all(asset_position < position for position in document_positions)
+        )
+        self.assertTrue(
+            all(position < delete_position for position in document_positions)
+        )
+        self.assertEqual(events[-1], ("manifest", static_site.MANIFEST_NAME))
+
     def test_gateway_requires_a_plain_https_origin(self) -> None:
         invalid = (
             "http://purge.example",
@@ -115,6 +168,25 @@ class StaticSiteTests(unittest.TestCase):
         sleep.assert_called_once_with(1)
         self.assertEqual(urlopen.call_count, 2)
 
+    @mock.patch.object(static_site.time, "sleep")
+    @mock.patch.object(static_site.urllib.request, "urlopen")
+    def test_storage_retries_transient_connection_errors(
+        self, urlopen: mock.Mock, sleep: mock.Mock
+    ) -> None:
+        response = mock.MagicMock()
+        response.__enter__.return_value.read.return_value = b"manifest"
+        urlopen.side_effect = [
+            static_site.urllib.error.URLError("connection reset"),
+            response,
+        ]
+        storage = static_site.BunnyStorage(
+            "example", "storage-password", "storage.example"
+        )
+
+        self.assertEqual(storage.get_manifest(), b"manifest")
+        sleep.assert_called_once_with(1)
+        self.assertEqual(urlopen.call_count, 2)
+
     @mock.patch.object(static_site.urllib.request, "urlopen")
     def test_gateway_reuses_storage_password(self, urlopen: mock.Mock) -> None:
         urlopen.return_value.__enter__.return_value = object()