#!/usr/bin/env python3 """One fixed diagnostic experiment; never a release qualification verdict.""" import argparse import hashlib import json import os from pathlib import Path import re import subprocess import tempfile from datetime import datetime, timezone BASE = '9168d16a32e948665eba80e2899604933292cdc0' CANDIDATE = 'dd388decf5896123b6587b1b16f9aee7c3a747f3' EVIDENCE_CANDIDATE = '4cdf250f474ad9cde6ffb121527f021b7387603f7' TREES = {BASE: '439848bb1d62a8ccf743b923eef89f8b47369edf', CANDIDATE: '1120cce4d631bca5525cafc5b5620251998773f7'} SOURCE_HASHES = { 'http_metrics.go': '916c27ad5ff07e00170dd94df0b75eb509dd329e34288647f5358a0759353d37', 'http_metrics_bench_test.go': '1562ae806264d8b22aece08fdadb7284760ae2374864479c7225b5051b5ba6b2', } LABELS = ('base', 'candidate') SYMBOLS = r'api\.(normalizeRoute|BenchmarkNormalizeRoute)' BENCH = '^BenchmarkNormalizeRoute$/^root$' ROUNDS = 10 def digest(path): with path.open('rb') as stream: return hashlib.file_digest(stream, 'sha256').hexdigest() def run(args, cwd=None): return subprocess.check_output(args, cwd=cwd, text=True, stderr=subprocess.STDOUT) def capture(args, output, cwd=None): # Preserve partial diagnostics on failure as well as successful output. with output.open('w') as stream: subprocess.run(args, cwd=cwd, stdout=stream, stderr=subprocess.STDOUT, check=True) def order(round_number): return LABELS if round_number % 2 else tuple(reversed(LABELS)) def bench_args(binary, warmup=False): return [str(binary), '-test.run=^$', '-test.bench=' + BENCH, '-test.cpu=4', '-test.benchmem', '-test.count=1', '-test.benchtime=' + ('100ms' if warmup else '1s'), '-test.timeout=2m'] def validate_sample(sample): rows = [line for line in sample.splitlines() if line.startswith('Benchmark')] if len(rows) != 1 or not re.fullmatch( r'BenchmarkNormalizeRoute/root-4\s+[1-9][0-9]*\s+[0-9.]+ ns/op\s+' r'[0-9]+ B/op\s+[0-9]+ allocs/op', rows[0]): raise ValueError('missing, duplicate, or out-of-scope benchmark sample') def telemetry(): result = {'affinity': sorted(os.sched_getaffinity(0))} for name in ('/proc/pressure/cpu', '/sys/fs/cgroup/cpu.stat', '/proc/self/cgroup'): try: result[name] = Path(name).read_text() except OSError as exc: result[name] = {'unavailable': type(exc).__name__} return result def execute(repo, output): output.mkdir(parents=True, exist_ok=False) # never overwrite a previous attempt os.environ.update(GOTOOLCHAIN='local', GOMAXPROCS='4', GOFLAGS='-mod=readonly', GOENV='off', GOAMD64='v1', CGO_ENABLED='1') if run(['go', 'version']).strip() != 'go version go1.26.10 linux/amd64': raise ValueError('requires exact hosted experiment toolchain go1.26.10 linux/amd64') metadata = { 'purpose': 'diagnostic-only; no gate disposition or release candidate', 'rounds': ROUNDS, 'gomaxprocs': 4, 'benchtime': '1s', 'original_evidence_candidate': EVIDENCE_CANDIDATE, 'workflow_sha': os.environ.get('GITHUB_SHA'), 'run_id': os.environ.get('GITHUB_RUN_ID'), 'run_attempt': os.environ.get('GITHUB_RUN_ATTEMPT'), 'conditions': {}, 'complete': False, } def save(): (output / 'metadata.json').write_text(json.dumps(metadata, indent=2) + '\n') affinity = sorted(os.sched_getaffinity(0))[:4] if len(affinity) != 4: raise ValueError('requires four available CPUs') os.sched_setaffinity(0, affinity) metadata['affinity'] = affinity save() capture(['go', 'version'], output / 'go-version.txt') capture(['go', 'env', 'GOOS', 'GOARCH', 'GOVERSION', 'GOTOOLCHAIN', 'GOAMD64', 'CGO_ENABLED', 'GOFLAGS'], output / 'go-env.txt') capture(['lscpu'], output / 'cpu.txt') capture(['uname', '-smr'], output / 'kernel.txt') # Both builds complete before warm-up/measurement; no compilation drift. with tempfile.TemporaryDirectory(prefix='root-pair-') as temporary: work = Path(temporary) binaries = {} for label in LABELS: revision = CANDIDATE if label.startswith('candidate') else BASE tree = run(['git', 'rev-parse', revision + '^{tree}'], repo).strip() if tree != TREES[revision]: raise ValueError('unexpected source tree') source = work / label source.mkdir() archive = work / (label + '.tar') subprocess.run(['git', 'archive', '-o', str(archive), revision], cwd=repo, check=True) subprocess.run(['tar', '-xf', str(archive), '-C', str(source)], check=True) for filename, expected in SOURCE_HASHES.items(): if digest(source / 'internal/api' / filename) != expected: raise ValueError('unexpected HTTP source content') metrics = source / 'internal/api/http_metrics.go' # Exact unmodified source; no layout intervention. (output / (label + '-http_metrics.go')).write_text(metrics.read_text()) stub = source / 'internal/api/frontend-modern/dist/index.html' stub.parent.mkdir(parents=True, exist_ok=True) stub.write_text('ci embed stub\n') binary = work / (label + '.test') capture(['go', 'test', '-c', '-o', str(binary), './internal/api'], output / (label + '-build.txt'), source) capture(['go', 'version', '-m', str(binary)], output / (label + '-build-info.txt')) binaries[label] = binary metadata['conditions'][label] = { 'commit': revision, 'tree': tree, 'binary_sha256': digest(binary), 'experimental': False, 'http_metrics_sha256': digest(metrics), 'embed_stub_sha256': digest(stub), } save() capture(['go', 'tool', 'objdump', '-s', SYMBOLS, str(binary)], output / (label + '-http.asm')) # Restrict retained symbols to the HTTP normaliser experiment. symbols = run(['go', 'tool', 'nm', str(binary)]) (output / (label + '-symbols.txt')).write_text('\n'.join( line for line in symbols.splitlines() if re.search(SYMBOLS, line)) + '\n') for label in LABELS: capture(bench_args(binaries[label], warmup=True), output / (label + '-warmup.txt')) import time time.sleep(10) for round_number in range(1, ROUNDS + 1): for label in order(round_number): with (output / 'order.jsonl').open('a') as log: log.write(json.dumps({'round': round_number, 'condition': label, 'at': datetime.now(timezone.utc).isoformat(), 'load': os.getloadavg(), 'telemetry': telemetry()}) + '\n') sample_path = output / f'{label}-{round_number:02}.txt' capture(bench_args(binaries[label]), sample_path) sample = sample_path.read_text() validate_sample(sample) with (output / 'ends.jsonl').open('a') as log: log.write(json.dumps({'round': round_number, 'condition': label, 'at': datetime.now(timezone.utc).isoformat(), 'telemetry': telemetry()}) + '\n') with (output / (label + '.txt')).open('a') as aggregate: aggregate.write(sample) metadata['complete'] = True save() files = sorted(path for path in output.iterdir() if path.is_file()) (output / 'SHA256SUMS').write_text(''.join(f'{digest(path)} {path.name}\n' for path in files)) if __name__ == '__main__': parser = argparse.ArgumentParser(description=__doc__) parser.add_argument('--output', required=True, type=Path) args = parser.parse_args() execute(Path(__file__).resolve().parents[1], args.output.resolve())