def allocate(self, dates, raster=15, quota=None, partly_available=False,
grouped=False, approve_manually=True,
reservation_quota_limit=0, whole_day=False
):
"""Allocates a spot in the calendar.
An allocation defines a timerange which can be reserved. No
reservations can exist outside of existing allocations. In fact any
reserved slot will link to an allocation.
An allocation may be available as a whole (to reserve all or nothing).
It may also be partly available which means reservations can be made
for parts of the allocation.
If an allocation is partly available a raster defines the granularity
with which a reservation can be made (e.g. a raster of 15min will
ensure that reservations are at least 15 minutes long and start either
at :00, :15, :30 or :45)
The reason for the raster is mainly to ensure that different
reservations trying to reserve overlapping times need the same keys in
the reserved_slots table, ensuring integrity at the database level.
Allocations may have a quota, which determines how many times an
allocation may be reserved. Quotas are enabled using a master-mirrors
relationship.
The master is the first allocation to be created. The mirrors copies of
that allocation. See Scheduler.__doc__
"""
dates = utils.pairs(dates)
group = new_uuid()
quota = quota or 1
# if the allocation is not partly available the raster is set to lowest
# possible raster value
raster = partly_available and raster or MIN_RASTER_VALUE
# the whole day option results in the dates being aligned to
# the beginning of the day / end of it -> not timezone aware!
if whole_day:
for ix, (start, end) in enumerate(dates):
dates[ix] = utils.align_range_to_day(start, end)
# Ensure that the list of dates contains no overlaps inside
for start, end in dates:
if utils.count_overlaps(dates, start, end) > 1:
raise InvalidAllocationError
# Make sure that this span does not overlap another master
for start, end in dates:
start, end = rasterize_span(start, end, raster)
existing = self.allocations_in_range(start, end).first()
if existing:
raise OverlappingAllocationError(start, end, existing)
# Write the master allocations
allocations = []
for start, end in dates:
allocation = Allocation(raster=raster)
allocation.start = start
allocation.end = end
allocation.resource = self.uuid
allocation.quota = quota
allocation.mirror_of = self.uuid
allocation.partly_available = partly_available
allocation.approve_manually = approve_manually
allocation.reservation_quota_limit = reservation_quota_limit
if grouped:
allocation.group = group
else:
allocation.group = new_uuid()
allocations.append(allocation)
Session.add_all(allocations)
return allocations
