S8 integrate pinned Palantir formatting through OpenRewrite

tooling/format/benchmark-downloads.py

@@ -0,0 +1,31 @@
+"""Measure dependency resolution separately; run from the root with network access.
+
+A disposable copy replaces the Java executable with /usr/bin/true, keeping the
+pinned exec-plugin dependencies. No formatter/application code executes. The
+second invocation uses the populated repository; neither invocation touches the
+normal Maven cache. Logs and measurements are written under target/.
+"""
+from pathlib import Path
+import json
+import shutil
+import subprocess
+import tempfile
+import time
+
+root = Path(__file__).resolve().parents[2]
+(root / "target").mkdir(exist_ok=True)
+with tempfile.TemporaryDirectory(prefix="s8-resolution-") as temporary:
+    fixture = Path(temporary)
+    shutil.copytree(root / ".mvn", fixture / ".mvn")
+    pom = (root / "pom.xml").read_text().replace("${java.home}/bin/java", "/usr/bin/true")
+    (fixture / "pom.xml").write_text(pom)
+    command = ["mvn", "-N", "-B", "-ntp", "-Dmaven.repo.local=" + str(fixture / "repository"),
+               "org.codehaus.mojo:exec-maven-plugin:3.6.3:exec@format"]
+    for label in ("cold-resolution", "warm-resolution"):
+        start = time.monotonic()
+        result = subprocess.run(command, cwd=fixture, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, text=True)
+        elapsed = time.monotonic() - start
+        (root / "target" / ("s8-" + label + ".log")).write_text(result.stdout)
+        print(json.dumps(dict(label=label, seconds=round(elapsed, 3), exit=result.returncode)), flush=True)
+        if result.returncode:
+            raise RuntimeError(result.stdout)