mergerfs/tests/TEST_posix_xattr_matrix

#!/usr/bin/env python3

import errno
import os
import sys
import tempfile

from posix_parity import fail
from posix_parity import join
from posix_parity import touch


def errno_name(err):
    if err is None:
        return "None"
    return errno.errorcode.get(err, str(err))


def invoke(callable_):
    try:
        return True, callable_(), 0
    except OSError as exc:
        return False, None, exc.errno


def compare(name, m_call, n_call, value_cmp=None):
    m_ok, m_val, m_errno = invoke(m_call)
    n_ok, n_val, n_errno = invoke(n_call)

    if m_ok != n_ok:
        return (
            f"{name}: success mismatch mergerfs={m_ok} native={n_ok} "
            f"(mergerfs_errno={m_errno}:{errno_name(m_errno)} native_errno={n_errno}:{errno_name(n_errno)})"
        )
    if m_errno != n_errno:
        return (
            f"{name}: errno mismatch mergerfs={m_errno}:{errno_name(m_errno)} "
            f"native={n_errno}:{errno_name(n_errno)}"
        )
    if m_ok and value_cmp is not None and not value_cmp(m_val, n_val):
        return f"{name}: value mismatch mergerfs={m_val!r} native={n_val!r}"

    return None


def getxattr_cmp(path_m, path_n, xname):
    return compare(
        f"getxattr {xname} {os.path.basename(path_m)}",
        lambda: os.getxattr(path_m, xname),
        lambda: os.getxattr(path_n, xname),
        lambda a, b: a == b,
    )


def list_has_cmp(path_m, path_n, xname):
    return compare(
        f"listxattr has {xname} {os.path.basename(path_m)}",
        lambda: os.listxattr(path_m),
        lambda: os.listxattr(path_n),
        lambda a, b: ((xname in a) == (xname in b)),
    )


def main():
    if len(sys.argv) != 2:
        print("usage: TEST_posix_xattr_matrix <mountpoint>", file=sys.stderr)
        return 1

    mount = sys.argv[1]

    with tempfile.TemporaryDirectory() as native:
        root_m = join(mount, "posix-xattr-matrix")
        root_n = join(native, "posix-xattr-matrix")

        file_m = join(root_m, "file")
        file_n = join(root_n, "file")
        dir_m = join(root_m, "dir")
        dir_n = join(root_n, "dir")
        link_m = join(root_m, "link")
        link_n = join(root_n, "link")

        touch(file_m, b"x")
        touch(file_n, b"x")
        os.makedirs(dir_m, exist_ok=True)
        os.makedirs(dir_n, exist_ok=True)
        try:
            os.unlink(link_m)
        except FileNotFoundError:
            pass
        try:
            os.unlink(link_n)
        except FileNotFoundError:
            pass
        os.symlink("file", link_m)
        os.symlink("file", link_n)

        objs = [
            ("file", file_m, file_n),
            ("dir", dir_m, dir_n),
        ]

        xbase = "user.mergerfs.matrix"

        for obj_name, path_m, path_n in objs:
            xname = f"{xbase}.{obj_name}"

            err = compare(
                f"setxattr default {obj_name}",
                lambda p=path_m, n=xname: os.setxattr(p, n, b"v1"),
                lambda p=path_n, n=xname: os.setxattr(p, n, b"v1"),
            )
            if err:
                return fail(err)

            err = getxattr_cmp(path_m, path_n, xname)
            if err:
                return fail(err)

            err = list_has_cmp(path_m, path_n, xname)
            if err:
                return fail(err)

            if hasattr(os, "XATTR_CREATE"):
                err = compare(
                    f"setxattr CREATE existing {obj_name}",
                    lambda p=path_m, n=xname: os.setxattr(p, n, b"v2", os.XATTR_CREATE),
                    lambda p=path_n, n=xname: os.setxattr(p, n, b"v2", os.XATTR_CREATE),
                )
                if err:
                    return fail(err)

            if hasattr(os, "XATTR_REPLACE"):
                err = compare(
                    f"setxattr REPLACE existing {obj_name}",
                    lambda p=path_m, n=xname: os.setxattr(p, n, b"v3", os.XATTR_REPLACE),
                    lambda p=path_n, n=xname: os.setxattr(p, n, b"v3", os.XATTR_REPLACE),
                )
                if err:
                    return fail(err)

                err = getxattr_cmp(path_m, path_n, xname)
                if err:
                    return fail(err)

            missing_name = f"{xname}.missing"
            if hasattr(os, "XATTR_REPLACE"):
                err = compare(
                    f"setxattr REPLACE missing {obj_name}",
                    lambda p=path_m, n=missing_name: os.setxattr(p, n, b"v", os.XATTR_REPLACE),
                    lambda p=path_n, n=missing_name: os.setxattr(p, n, b"v", os.XATTR_REPLACE),
                )
                if err:
                    return fail(err)

            err = compare(
                f"removexattr existing {obj_name}",
                lambda p=path_m, n=xname: os.removexattr(p, n),
                lambda p=path_n, n=xname: os.removexattr(p, n),
            )
            if err:
                return fail(err)

            err = compare(
                f"removexattr missing {obj_name}",
                lambda p=path_m, n=xname: os.removexattr(p, n),
                lambda p=path_n, n=xname: os.removexattr(p, n),
            )
            if err:
                return fail(err)

        lxname = f"{xbase}.link"
        if all(hasattr(os, fn) for fn in ("lsetxattr", "lgetxattr", "llistxattr", "lremovexattr")):
            err = compare(
                "lsetxattr symlink default",
                lambda: os.lsetxattr(link_m, lxname, b"lv1"),
                lambda: os.lsetxattr(link_n, lxname, b"lv1"),
            )
            if err:
                return fail(err)

            err = compare(
                "lgetxattr symlink",
                lambda: os.lgetxattr(link_m, lxname),
                lambda: os.lgetxattr(link_n, lxname),
                lambda a, b: a == b,
            )
            if err:
                return fail(err)

            err = compare(
                "llistxattr has symlink key",
                lambda: os.llistxattr(link_m),
                lambda: os.llistxattr(link_n),
                lambda a, b: ((lxname in a) == (lxname in b)),
            )
            if err:
                return fail(err)

            err = compare(
                "lremovexattr symlink",
                lambda: os.lremovexattr(link_m, lxname),
                lambda: os.lremovexattr(link_n, lxname),
            )
            if err:
                return fail(err)

        return 0


if __name__ == "__main__":
    raise SystemExit(main())