root / logic / credits.py @ dfd19c2d
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# Business Logic for all Credit related activity
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#
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# Copyright 2010 Greek Research and Technology Network
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#
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from datetime import datetime |
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from db.models import Debit, FlavorCost |
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from django.db import transaction |
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@transaction.commit_on_success
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def debit_account(user , amount, vm, description): |
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"""Charges the user with the specified amount of credits for a vm (resource)"""
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date_now = datetime.now() |
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user.credit = user.credit - amount |
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user.save() |
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# then write the debit entry
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debit = Debit() |
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debit.user = user |
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debit.vm = vm |
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debit.when = date_now |
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debit.description = description |
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debit.save() |
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@transaction.commit_on_success
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def credit_account(self, amount, creditor, description): |
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"""No clue :)"""
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return
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@transaction.commit_on_success
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def charge(vm): |
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"""Charges the owner of this VM.
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Charges the owner of a VM for the period
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from vm.charged to datetime.now(), based on the
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current operating state.
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"""
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charged_states = ('STARTED', 'STOPPED') |
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start_datetime = vm.charged |
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vm.charged = datetime.now() |
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# Only charge for a specific set of states
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if vm.operstate in charged_states: |
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cost_list = [] |
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# remember, we charge only for Started and Stopped
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if vm.operstate == 'STARTED': |
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cost_list = get_cost_active(vm.flavor, start_datetime, vm.charged) |
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elif vm.operstate == 'STOPPED': |
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cost_list = get_cost_inactive(vm.flavor, start_datetime, vm.charged) |
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# find the total vost
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total_cost = sum([x[1] for x in cost_list]) |
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# add the debit entry
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description = "Server = %s, charge = %d for state: %s" % (vm.name, total_cost, vm.operstate)
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debit_account(vm.owner, total_cost, vm, description) |
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vm.save() |
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def get_costs(vm, start_datetime, end_datetime, active): |
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"""Return a list with FlavorCost objects for the specified duration"""
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def between(enh_fc, a_date): |
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"""Checks if a date is between a FlavorCost duration"""
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if enh_fc.effective_from <= a_date and enh_fc.effective_to is None: |
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return True |
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return enh_fc.effective_from <= a_date and enh_fc.effective_to >= a_date |
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# Get the related FlavorCost objects, sorted.
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price_list = FlavorCost.objects.filter(flavor=vm).order_by('effective_from')
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# add the extra field FlavorCost.effective_to
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for idx in range(0, len(price_list)): |
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if idx + 1 == len(price_list): |
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price_list[idx].effective_to = None
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else:
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price_list[idx].effective_to = price_list[idx + 1].effective_from
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price_result = [] |
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found_start = False
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# Find the affected FlavorCost, according to the
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# dates, and put them in price_result
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for p in price_list: |
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if between(p, start_datetime):
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found_start = True
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p.effective_from = start_datetime |
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if between(p, end_datetime):
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p.effective_to = end_datetime |
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price_result.append(p) |
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break
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if found_start:
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price_result.append(p) |
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results = [] |
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# Create the list and the result tuples
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for p in price_result: |
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if active:
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cost = p.cost_active |
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else:
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cost = p.cost_inactive |
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results.append( ( p.effective_from, calculate_cost(p.effective_from, p.effective_to, cost)) ) |
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return results
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def calculate_cost(start_date, end_date, cost): |
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"""Calculate the total cost for the specified duration"""
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td = end_date - start_date |
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sec = float(td.microseconds + (td.seconds + td.days * 24 * 3600) * 10**6) / float(10**6) |
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total_hours = float(sec) / float(60.0*60.0) |
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total_cost = float(cost)*total_hours
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return round(total_cost) |
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def get_cost_active(vm, start_datetime, end_datetime): |
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"""Returns a list with the active costs for the specified duration"""
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return get_costs(vm, start_datetime, end_datetime, True) |
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def get_cost_inactive(vm, start_datetime, end_datetime): |
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"""Returns a list with the inactive costs for the specified duration"""
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return get_costs(vm, start_datetime, end_datetime, False) |