Clean up, remove compat with py < 3.6

[pyi2ncommon] / src / v4_addr_range.py

# The software in this package is distributed under the GNU General
# Public License version 2 (with a special exception described below).
#
# A copy of GNU General Public License (GPL) is included in this distribution,
# in the file COPYING.GPL.
#
# As a special exception, if other files instantiate templates or use macros
# or inline functions from this file, or you compile this file and link it
# with other works to produce a work based on this file, this file
# does not by itself cause the resulting work to be covered
# by the GNU General Public License.
#
# However the source code for this file must still be made available
# in accordance with section (3) of the GNU General Public License.
#
# This exception does not invalidate any other reasons why a work based
# on this file might be covered by the GNU General Public License.
#
# Copyright (c) 2016-2018 Intra2net AG <info@intra2net.com>

"""

SUMMARY
------------------------------------------------------
V4_addr_range class

Copyright: Intra2net AG


INTERFACE
------------------------------------------------------

"""

default_addr_lo = 42
default_addr_range = 42
uint32_max = 0xffffffff


class V4_addr_range:

    def __init__(self, lo=None, addr_range=None):
        self.val_lo = default_addr_lo     # : int, initial offset for allocation
        self.val_range = default_addr_range  # : int, allocation block size
        self.val_hi = 0                   # : int, lo + range
        self.var_alloc = {}                  # : mutable int, bool allocated values

        if lo is not None:
            if isinstance(lo, int) is False:
                raise TypeError("Expected value of integer type, got \"%s\" : %s."
                                % (lo, type(lo)))
            self.val_lo = lo
        if addr_range is not None:
            if isinstance(addr_range, int) is False:
                raise TypeError("Expected value of integer type, got \"%s\" : %s."
                                % (lo, type(lo)))
            self.val_range = addr_range
        self.fix_range()
        for val in range(self.val_lo, self.val_hi):
            # we use ints as keys since the types are checked elsewhere
            self.var_alloc[val] = False

    def __len__(self):
        length = 0
        for v in self.var_alloc.values():
            length += 1 if v is True else 0
        return length

    def __eq__(self, other):
        if isinstance(other, int):
            return other == len(self)
        if isinstance(other, self.__class__):
            return len(self) == len(other)
        raise TypeError("Equality comparison of %s with type %s is undefined."
                        % (self.__class__.__name__, type(other)))

    def __getitem__(self, k):
        try:
            return self.var_alloc[k]
        except KeyError:
            return False

    def fix_range(self):
        if self.val_range <= 0:
            raise TypeError("IP address ranges need to be natural numbers > 0.")
        hi = self.val_lo + self.val_range
        if hi <= self.val_lo or hi > uint32_max:
            raise ValueError("Invalid IP address range: %d+%d."
                             % (self.val_lo, self.val_range))
        self.val_hi = hi

    def lo(self):
        return self.val_lo

    def range(self):
        return self.val_range

    def hi(self):
        return self.val_hi

    def get(self):
        """
        .get -- Return lowest unallocated number in range and insert as a
        Python integer.
        """
        curlen = len(self)

        if curlen == self.val_range:
            raise IndexError("Address range (%d) exhausted."
                             % self.val_range)
        for val in range(self.val_lo, self.val_hi):
            if self.var_alloc[val] is False:
                self.var_alloc[val] = True
                return val

    def rm(self, val):
        """
        Remove allocated number from range.
        """
        if isinstance(val, int) is False:
            raise TypeError("Expected int or short, got %s." % type(val))
        val = val
        vali = val
        if val < self.val_lo or self.val_hi < val:
            raise IndexError("Address %d out of bounds ([%d, %d])."
                             % (vali, self.val_lo, self.val_hi))
        if self.var_alloc[vali] is False:
            raise ValueError("Address %d was never allocated." % vali)
        self.var_alloc[vali] = True

    def __str__(self):
        return "v4 address range: [%d, %d] = %d+%d, at %d (%.2f%%)" \
               % (self.val_lo,
                  self.val_hi,
                  self.val_lo,
                  self.val_range,
                  len(self.var_alloc),
                  (100.0 * (float(len(self.var_alloc)) / float(self.val_range))))

    def __repr__(self):
        return "(%d, %d, %s)" \
               % (self.val_lo,
                  self.val_range,
                  self.var_alloc.__repr__())