bench.py

#!/usr/bin/env python3

import json
import statistics
import subprocess
import sys

proc = subprocess.Popen(["./mach", "gtest", sys.argv[1]], stdout=subprocess.PIPE)
for line in proc.stdout:
    if line.startswith(b"PERFHERDER_DATA:"):
        data = json.loads(line[len("PERFHERDER_DATA:") :].decode("utf8"))
        for suite in data["suites"]:
            for subtest in suite["subtests"]:
                # pylint --py3k W1619
                print(
                    "%4d.%03d ± %6s ms    %s.%s"
                    % (
                        subtest["value"] / 1000.0,
                        subtest["value"] % 1000,
                        "%.3f" % (statistics.stdev(subtest["replicates"]) / 1000),
                        suite["name"],
                        subtest["name"],
                    )
                )