pkgs/desktops/gnome/find-latest-version.py

   1 import argparse
   2 import math
   3 import json
   4 import requests
   5 import sys
   6 from enum import Enum
   7 from libversion import Version
   8 from typing import (
   9     Callable,
  10     Iterable,
  11     List,
  12     NamedTuple,
  13     Optional,
  14     Tuple,
  15     TypeVar,
  16     Type,
  17     cast,
  18 )
  19
  20
  21 EnumValue = TypeVar("EnumValue", bound=Enum)
  22
  23
  24 def enum_to_arg(enum: Enum) -> str:
  25     return enum.name.lower().replace("_", "-")
  26
  27
  28 def arg_to_enum(enum_meta: Type[EnumValue], name: str) -> EnumValue:
  29     return enum_meta[name.upper().replace("-", "_")]
  30
  31
  32 def enum_to_arg_choices(enum_meta: Type[EnumValue]) -> Tuple[str, ...]:
  33     return tuple(enum_to_arg(v) for v in cast(Iterable[EnumValue], enum_meta))
  34
  35
  36 class Stability(Enum):
  37     STABLE = "stable"
  38     UNSTABLE = "unstable"
  39
  40
  41 VersionPolicy = Callable[[Version], bool]
  42 VersionPredicate = Callable[[Version, Stability], bool]
  43
  44
  45 class VersionPredicateHolder(NamedTuple):
  46     function: VersionPredicate
  47
  48
  49 def version_to_list(version: str) -> List[int]:
  50     return list(map(int, version.split(".")))
  51
  52
  53 def odd_unstable(version: Version, selected: Stability) -> bool:
  54     try:
  55         version_parts = version_to_list(version.value)
  56     except:
  57         # Failing to parse as a list of numbers likely means the version contains a string tag like “beta”, therefore it is not a stable release.
  58         return selected != Stability.STABLE
  59
  60     if len(version_parts) < 2:
  61         return True
  62
  63     even = version_parts[1] % 2 == 0
  64     prerelease = (version_parts[1] >= 90 and version_parts[1] < 100) or (version_parts[1] >= 900 and version_parts[1] < 1000)
  65     stable = even and not prerelease
  66     if selected == Stability.STABLE:
  67         return stable
  68     else:
  69         return True
  70
  71
  72 def tagged(version: Version, selected: Stability) -> bool:
  73     if selected == Stability.STABLE:
  74         return not ("alpha" in version.value or "beta" in version.value or "rc" in version.value)
  75     else:
  76         return True
  77
  78
  79 def no_policy(version: Version, selected: Stability) -> bool:
  80     return True
  81
  82
  83 class VersionPolicyKind(Enum):
  84     # HACK: Using function as values directly would make Enum
  85     # think they are methods and skip them.
  86     ODD_UNSTABLE = VersionPredicateHolder(odd_unstable)
  87     TAGGED = VersionPredicateHolder(tagged)
  88     NONE = VersionPredicateHolder(no_policy)
  89
  90
  91 def make_version_policy(
  92     version_policy_kind: VersionPolicyKind,
  93     selected: Stability,
  94     upper_bound: Optional[Version],
  95 ) -> VersionPolicy:
  96     version_predicate = version_policy_kind.value.function
  97     if not upper_bound:
  98         return lambda version: version_predicate(version, selected)
  99     else:
 100         return lambda version: version_predicate(version, selected) and version < upper_bound
 101
 102
 103 def find_versions(package_name: str, version_policy: VersionPolicy) -> List[Version]:
 104     # The structure of cache.json: https://gitlab.gnome.org/Infrastructure/sysadmin-bin/blob/master/ftpadmin#L762
 105     cache = json.loads(requests.get(f"https://ftp.gnome.org/pub/GNOME/sources/{package_name}/cache.json").text)
 106     if type(cache) != list or cache[0] != 4:
 107         raise Exception("Unknown format of cache.json file.")
 108
 109     versions: Iterable[Version] = map(Version, cache[2][package_name])
 110     versions = sorted(filter(version_policy, versions))
 111
 112     return versions
 113
 114
 115 parser = argparse.ArgumentParser(
 116     description="Find latest version for a GNOME package by crawling their release server.",
 117 )
 118 parser.add_argument(
 119     "package-name",
 120     help="Name of the directory in https://ftp.gnome.org/pub/GNOME/sources/ containing the package.",
 121 )
 122 parser.add_argument(
 123     "version-policy",
 124     help="Policy determining which versions are considered stable. GNOME packages usually denote stability by alpha/beta/rc tag in the version. For older packages, odd minor versions are unstable but there are exceptions.",
 125     choices=enum_to_arg_choices(VersionPolicyKind),
 126     nargs="?",
 127     default=enum_to_arg(VersionPolicyKind.TAGGED),
 128 )
 129 parser.add_argument(
 130     "requested-release",
 131     help="Most of the time, we will want to update to stable version but sometimes it is useful to test.",
 132     choices=enum_to_arg_choices(Stability),
 133     nargs="?",
 134     default=enum_to_arg(Stability.STABLE),
 135 )
 136 parser.add_argument(
 137     "--upper-bound",
 138     dest="upper-bound",
 139     help="Only look for versions older than this one (useful for pinning dependencies).",
 140 )
 141
 142
 143 if __name__ == "__main__":
 144     args = parser.parse_args()
 145
 146     package_name = getattr(args, "package-name")
 147     requested_release = arg_to_enum(Stability, getattr(args, "requested-release"))
 148     upper_bound = getattr(args, "upper-bound")
 149     if upper_bound is not None:
 150         upper_bound = Version(upper_bound)
 151     version_policy_kind = arg_to_enum(VersionPolicyKind, getattr(args, "version-policy"))
 152     version_policy = make_version_policy(version_policy_kind, requested_release, upper_bound)
 153
 154     try:
 155         versions = find_versions(package_name, version_policy)
 156     except Exception as error:
 157         print(error, file=sys.stderr)
 158         sys.exit(1)
 159
 160     if len(versions) == 0:
 161         print("No versions matched.", file=sys.stderr)
 162         sys.exit(1)
 163
 164     print(versions[-1].value)