24 lines
775 B
Python
24 lines
775 B
Python
from django.db.models import Count
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from .models import *
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@transaction.atomic
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def get_suitable_pool(subnetwork_size):
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"""
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Find suitable pools for a certain network size.
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First, filter for all pools that offer the requested subnetwork_size.
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Then find those pools that are not fully exhausted:
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The number of available networks in a pool is 2^(subnetwork_size-network_size.
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The number of available networks in a pool is given by the number of VPNNetworkreservations.
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"""
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return VPNPool.objects.annotate(
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num_reservations=Count('vpnnetworkreservation'),
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max_reservations=2**(F('subnetwork_size')-F('network_size'))).filter(
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num_reservations__lt=F('max_reservations'),
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subnetwork_size=subnetwork_size)
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