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#!/usr/bin/env python3
"""Reject directory-wide segment scans on the selected small-object edit path."""
import argparse
import hashlib
import json
from pathlib import Path
import subprocess
import tempfile
HERE = Path(__file__).resolve().parent
def run(*args):
result = subprocess.run([str(value) for value in args], capture_output=True, timeout=20)
if result.returncode:
raise AssertionError((result.args, result.returncode, result.stderr[-500:]))
return result
def main():
parser = argparse.ArgumentParser(description=__doc__)
parser.add_argument('--editor', required=True, type=Path)
parser.add_argument('--output', type=Path)
args = parser.parse_args()
editor = args.editor.resolve()
with tempfile.TemporaryDirectory(prefix='pure-small-scan-') as name:
root = Path(name)
store = root / 'store'
one = root / 'one'
one.write_bytes(b'A')
base = (editor, '--program', HERE / 'examples/editor.pure', '--store', store)
run(*base, 'edit', 'tiny', 0, 0, 0, one)
for index in range(256):
(store / f'unrelated-{index:03d}').write_bytes(b'')
trace = root / 'trace'
run('strace', '-qq', '-e', 'getdents64', '-yy', '-o', trace,
*base, 'edit', 'tiny', 1, 0, 1, one)
scans = [line for line in trace.read_text().splitlines()
if 'getdents64(' in line and str(store) in line]
assert not scans, scans
result = {'small_edit_store_directory_scans': 0,
'unrelated_directory_entries': 256,
'binary_sha256': hashlib.sha256(editor.read_bytes()).hexdigest()}
output = json.dumps(result, indent=2) + '\n'
if args.output:
if args.output.exists():
parser.error('evidence file already exists')
args.output.parent.mkdir(parents=True, exist_ok=True)
args.output.write_text(output)
print(output, end='')
if __name__ == '__main__':
main()
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