codekingpro/portable-devtools

1# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license2 3import importlib.metadata4import itertools5import string6from typing import Dict, List, Tuple7 8 9def _tuple_from_text(version: str) -> Tuple:10    text_parts = version.split(".")11    int_parts = []12    for text_part in text_parts:13        digit_prefix = "".join(14            itertools.takewhile(lambda x: x in string.digits, text_part)15        )16        try:17            int_parts.append(int(digit_prefix))18        except Exception:19            break20    return tuple(int_parts)21 22 23def _version_check(24    requirement: str,25) -> bool:26    """Is the requirement fulfilled?27 28    The requirement must be of the form29 30        package>=version31    """32    package, minimum = requirement.split(">=")33    try:34        version = importlib.metadata.version(package)35    except Exception:36        return False37    t_version = _tuple_from_text(version)38    t_minimum = _tuple_from_text(minimum)39    if t_version < t_minimum:40        return False41    return True42 43 44_cache: Dict[str, bool] = {}45 46 47def have(feature: str) -> bool:48    """Is *feature* available?49 50    This tests if all optional packages needed for the51    feature are available and recent enough.52 53    Returns ``True`` if the feature is available,54    and ``False`` if it is not or if metadata is55    missing.56    """57    value = _cache.get(feature)58    if value is not None:59        return value60    requirements = _requirements.get(feature)61    if requirements is None:62        # we make a cache entry here for consistency not performance63        _cache[feature] = False64        return False65    ok = True66    for requirement in requirements:67        if not _version_check(requirement):68            ok = False69            break70    _cache[feature] = ok71    return ok72 73 74def force(feature: str, enabled: bool) -> None:75    """Force the status of *feature* to be *enabled*.76 77    This method is provided as a workaround for any cases78    where importlib.metadata is ineffective, or for testing.79    """80    _cache[feature] = enabled81 82 83_requirements: Dict[str, List[str]] = {84    ### BEGIN generated requirements85    "dnssec": ["cryptography>=41"],86    "doh": ["httpcore>=1.0.0", "httpx>=0.26.0", "h2>=4.1.0"],87    "doq": ["aioquic>=0.9.25"],88    "idna": ["idna>=3.6"],89    "trio": ["trio>=0.23"],90    "wmi": ["wmi>=1.5.1"],91    ### END generated requirements92}93