Split detection heuristics from platform definition

extra_platforms/detection.py

@@ -0,0 +1,348 @@
+# Copyright Kevin Deldycke <[email protected]> and contributors.
+#
+# This program is Free Software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+"""Heuristics to detect each platform.
+
+All these heuristics can be hard-cached as the underlying system is not changing
+between code execution.
+
+We mostly rely on `distro <https://github.com/python-distro/distro>`_ to detect the
+Linux distribution, has it is the recommended replacement for Python's original
+``platform.linux_distribution`` function (which was removed in Python 3.8).
+
+We then fill in the gaps with ``sys.platform`` and environment variables to detect
+systems not covered by ``distro``.
+
+This collection of heuristics is designed as a set of separate function with minimal
+logic and dependencies. That way we can double-check during execution that no
+heuristics are conflicting or matching multiple systems at the same time.
+
+.. note::
+
+    Heuristics for unrecognized platforms can be transplanted from `Rust's sysinfo
+    crate <https://github.com/stanislav-tkach/os_info/tree/master/os_info/src>`_.
+"""
+
+from __future__ import annotations
+
+import platform
+import sys
+from os import environ
+
+if sys.version_info >= (3, 9):
+    from functools import cache
+else:
+    from functools import lru_cache
+
+    def cache(user_function):
+        """Simple lightweight unbounded cache. Sometimes called "memoize".
+
+        .. important::
+
+            This is a straight `copy of the functools.cache implementation
+            <https://github.com/python/cpython/blob/55a26de/Lib/functools.py#L647-L653>`_,
+            which is only `available in the standard library starting with Python v3.9
+            <https://docs.python.org/3/library/functools.html?highlight=caching#functools.cache>`.
+        """
+        return lru_cache(maxsize=None)(user_function)
+
+
+import distro
+
+
+@cache
+def is_aix() -> bool:
+    """Return `True` only if current platform is AIX."""
+    return sys.platform.startswith("aix") or distro.id() == "aix"
+
+
+@cache
+def is_altlinux() -> bool:
+    """Return `True` only if current platform is ALT Linux."""
+    return distro.id() == "altlinux"
+
+
+@cache
+def is_amzn() -> bool:
+    """Return `True` only if current platform is Amazon Linux."""
+    return distro.id() == "amzn"
+
+
+@cache
+def is_android() -> bool:
+    """Return `True` only if current platform is Android.
+
+    Source: https://github.com/kivy/kivy/blob/master/kivy/utils.py#L429
+    """
+    return "ANDROID_ROOT" in environ or "P4A_BOOTSTRAP" in environ
+
+
+@cache
+def is_arch() -> bool:
+    """Return `True` only if current platform is Arch Linux."""
+    return distro.id() == "arch"
+
+
+@cache
+def is_buildroot() -> bool:
+    """Return `True` only if current platform is Buildroot."""
+    return distro.id() == "buildroot"
+
+
+@cache
+def is_centos() -> bool:
+    """Return `True` only if current platform is CentOS."""
+    return distro.id() == "centos"
+
+
+@cache
+def is_cloudlinux() -> bool:
+    """Return `True` only if current platform is CloudLinux OS."""
+    return distro.id() == "cloudlinux"
+
+
+@cache
+def is_cygwin() -> bool:
+    """Return `True` only if current platform is Cygwin."""
+    return sys.platform.startswith("cygwin")
+
+
+@cache
+def is_debian() -> bool:
+    """Return `True` only if current platform is Debian."""
+    return distro.id() == "debian"
+
+
+@cache
+def is_exherbo() -> bool:
+    """Return `True` only if current platform is Exherbo Linux."""
+    return distro.id() == "exherbo"
+
+
+@cache
+def is_fedora() -> bool:
+    """Return `True` only if current platform is Fedora."""
+    return distro.id() == "fedora"
+
+
+@cache
+def is_freebsd() -> bool:
+    """Return `True` only if current platform is FreeBSD."""
+    return sys.platform.startswith("freebsd") or distro.id() == "freebsd"
+
+
+@cache
+def is_gentoo() -> bool:
+    """Return `True` only if current platform is GenToo Linux."""
+    return distro.id() == "gentoo"
+
+
+@cache
+def is_guix() -> bool:
+    """Return `True` only if current platform is Guix System."""
+    return distro.id() == "guix"
+
+
+@cache
+def is_hurd() -> bool:
+    """Return `True` only if current platform is GNU/Hurd."""
+    return sys.platform.startswith("GNU")
+
+
+@cache
+def is_ibm_powerkvm() -> bool:
+    """Return `True` only if current platform is IBM PowerKVM."""
+    return distro.id() == "ibm_powerkvm"
+
+
+@cache
+def is_kvmibm() -> bool:
+    """Return `True` only if current platform is KVM for IBM z Systems."""
+    return distro.id() == "kvmibm"
+
+
+@cache
+def is_linuxmint() -> bool:
+    """Return `True` only if current platform is Linux Mint."""
+    return distro.id() == "linuxmint"
+
+
+@cache
+def is_macos() -> bool:
+    """Return `True` only if current platform is macOS."""
+    return platform.platform(terse=True).startswith(("macOS", "Darwin"))
+
+
+@cache
+def is_mageia() -> bool:
+    """Return `True` only if current platform is Mageia."""
+    return distro.id() == "mageia"
+
+
+@cache
+def is_mandriva() -> bool:
+    """Return `True` only if current platform is Mandriva Linux."""
+    return distro.id() == "mandriva"
+
+
+@cache
+def is_midnightbsd() -> bool:
+    """Return `True` only if current platform is MidnightBSD."""
+    return sys.platform.startswith("midnightbsd") or distro.id() == "midnightbsd"
+
+
+@cache
+def is_netbsd() -> bool:
+    """Return `True` only if current platform is NetBSD."""
+    return sys.platform.startswith("netbsd") or distro.id() == "netbsd"
+
+
+@cache
+def is_openbsd() -> bool:
+    """Return `True` only if current platform is OpenBSD."""
+    return sys.platform.startswith("openbsd") or distro.id() == "openbsd"
+
+
+@cache
+def is_opensuse() -> bool:
+    """Return `True` only if current platform is openSUSE."""
+    return distro.id() == "opensuse"
+
+
+@cache
+def is_oracle() -> bool:
+    """Return `True` only if current platform is Oracle Linux (and Oracle Enterprise Linux)."""
+    return distro.id() == "oracle"
+
+
+@cache
+def is_parallels() -> bool:
+    """Return `True` only if current platform is Parallels."""
+    return distro.id() == "parallels"
+
+
+@cache
+def is_pidora() -> bool:
+    """Return `True` only if current platform is Pidora."""
+    return distro.id() == "pidora"
+
+
+@cache
+def is_raspbian() -> bool:
+    """Return `True` only if current platform is Raspbian."""
+    return distro.id() == "raspbian"
+
+
+@cache
+def is_rhel() -> bool:
+    """Return `True` only if current platform is RedHat Enterprise Linux."""
+    return distro.id() == "rhel"
+
+
+@cache
+def is_rocky() -> bool:
+    """Return `True` only if current platform is Rocky Linux."""
+    return distro.id() == "rocky"
+
+
+@cache
+def is_scientific() -> bool:
+    """Return `True` only if current platform is Scientific Linux."""
+    return distro.id() == "scientific"
+
+
+@cache
+def is_slackware() -> bool:
+    """Return `True` only if current platform is Slackware."""
+    return distro.id() == "slackware"
+
+
+@cache
+def is_sles() -> bool:
+    """Return `True` only if current platform is SUSE Linux Enterprise Server."""
+    return distro.id() == "sles"
+
+
+@cache
+def is_solaris() -> bool:
+    """Return `True` only if current platform is Solaris."""
+    return platform.platform(aliased=True, terse=True).startswith("Solaris")
+
+
+@cache
+def is_sunos() -> bool:
+    """Return `True` only if current platform is SunOS."""
+    return platform.platform(aliased=True, terse=True).startswith("SunOS")
+
+
+@cache
+def is_ubuntu() -> bool:
+    """Return `True` only if current platform is Ubuntu."""
+    return distro.id() == "ubuntu"
+
+
+@cache
+def is_unknown_linux() -> bool:
+    """Return `True` only if current platform is an unknown Linux.
+
+    Excludes WSL1 and WSL2 from this check to
+    `avoid false positives <https://github.com/kdeldycke/meta-package-manager/issues/944>`_.
+    """
+    return sys.platform.startswith("linux") and not (
+        is_ubuntu() or is_wsl1() or is_wsl2()
+    )
+
+
+@cache
+def is_windows() -> bool:
+    """Return `True` only if current platform is Windows."""
+    return sys.platform.startswith("win32")
+
+
+@cache
+def is_wsl1() -> bool:
+    """Return `True` only if current platform is Windows Subsystem for Linux v1.
+
+    .. caution::
+        The only difference between WSL1 and WSL2 is `the case of the kernel release
+        version <https://github.com/andweeb/presence.nvim/pull/64#issue-1174430662>`_:
+
+        - WSL 1:
+
+          .. code-block:: shell-session
+
+                $ uname -r
+                4.4.0-22572-Microsoft
+
+        - WSL 2:
+
+          .. code-block:: shell-session
+
+                $ uname -r
+                5.10.102.1-microsoft-standard-WSL2
+    """
+    return "Microsoft" in platform.release()
+
+
+@cache
+def is_wsl2() -> bool:
+    """Return `True` only if current platform is Windows Subsystem for Linux v2."""
+    return "microsoft" in platform.release()
+
+
+@cache
+def is_xenserver() -> bool:
+    """Return `True` only if current platform is XenServer."""
+    return distro.id() == "xenserver"