activitypub-academy/app/lib/fast_ip_map.rb

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2020-10-12 23:33:49 +09:00
# frozen_string_literal: true
class FastIpMap
MAX_IPV4_PREFIX = 32
MAX_IPV6_PREFIX = 128
# @param [Enumerable<IPAddr>] addresses
def initialize(addresses)
@fast_lookup = {}
@ranges = []
# Hash look-up is faster but only works for exact matches, so we split
# exact addresses from non-exact ones
addresses.each do |address|
if (address.ipv4? && address.prefix == MAX_IPV4_PREFIX) || (address.ipv6? && address.prefix == MAX_IPV6_PREFIX)
@fast_lookup[address.to_s] = true
else
@ranges << address
end
end
# We're more likely to hit wider-reaching ranges when checking for
# inclusion, so make sure they're sorted first
@ranges.sort_by!(&:prefix)
end
# @param [IPAddr] address
# @return [Boolean]
def include?(address)
@fast_lookup[address.to_s] || @ranges.any? { |cidr| cidr.include?(address) }
end
end