def check_availability_and_purchase(customer, event_sku, qty, tier="General"):
"""Check if there is sufficient inventory before making the purchase"""
p = redis.pipeline()
try:
e_key = keynamehelper.create_key_name("event", event_sku)
redis.watch(e_key)
available = int(redis.hget(e_key, "available:" + tier))
price = float(redis.hget(e_key, "price:" + tier))
if available >= qty:
p.hincrby(e_key, "available:" + tier, -qty)
order_id = generate.order_id()
purchase = {
'order_id': order_id,
'customer': customer,
'tier': tier,
'qty': qty,
'cost': qty * price,
'event_sku': event_sku,
'ts': long(time.time())
}
so_key = keynamehelper.create_key_name("sales_order", order_id)
p.hmset(so_key, purchase)
p.execute()
else:
print "Insufficient inventory, have {}, requested {}".format(
available, qty)
except WatchError:
print "Write Conflict check_availability_and_purchase: {}".format(
e_key)
finally:
p.reset()
print "Purchase complete!"
def reservation(event_sku, tier, block_name, first_seat, last_seat):
""" Reserve the required seats. Create an expiring key (i.e. a latch) to
reserve each seat. If that is successful, then an XOR can be executed to
update the seat map, without needed a Watch."""
reserved = False
p = redis.pipeline()
try:
for i in range(first_seat, last_seat + 1):
# Reserve individual seat, raise exception is already reserved
seat_key = keynamehelper.create_key_name("seatres", event_sku,
tier, block_name, str(i))
if redis.set(seat_key, True, px=5000, nx=True) != True:
raise SeatTaken(i, seat_key)
order_id = generate.order_id()
required_block = int(math.pow(2, last_seat - first_seat + 1)) - 1 << (
first_seat - 1)
vals = ["SET", "u32", 0, required_block]
res_key = keynamehelper.create_key_name("seatres", event_sku, tier,
block_name, order_id)
p.execute_command("BITFIELD", res_key, *vals)
p.expire(res_key, 5)
block_key = keynamehelper.create_key_name("seatmap", event_sku, tier,
block_name)
p.bitop("XOR", block_key, block_key, res_key)
p.execute()
reserved = True
except SeatTaken as error:
print "Seat Taken/{}".format(error.message)
finally:
p.reset()
return reserved
def reserve(customer, event_sku, qty, tier="General"):
"""First reserve the inventory and perform a credit authorization. If successful
then confirm the inventory deduction or back the deducation out."""
p = redis.pipeline()
try:
e_key = keynamehelper.create_key_name("event", event_sku)
redis.watch(e_key)
available = int(redis.hget(e_key, "available:" + tier))
if available >= qty:
order_id = generate.order_id()
ts = long(time.time())
price = float(redis.hget(e_key, "price:" + tier))
p.hincrby(e_key, "available:" + tier, -qty)
p.hincrby(e_key, "held:" + tier, qty)
# Create a hash to store the seat hold information
hold_key = keynamehelper.create_key_name("ticket_hold", event_sku)
p.hsetnx(hold_key, "qty:" + order_id, qty)
p.hsetnx(hold_key, "tier:" + order_id, tier)
p.hsetnx(hold_key, "ts:" + order_id, ts)
p.execute()
except WatchError:
print "Write Conflict in reserve: {}".format(e_key)
finally:
p.reset()
if creditcard_auth(customer, qty * price):
try:
purchase = {
'order_id': order_id,
'customer': customer,
'tier': tier,
'qty': qty,
'cost': qty * price,
'event_sku': event_sku,
'ts': long(time.time())
}
redis.watch(e_key)
# Remove the seat hold, since it is no longer needed
p.hdel(
hold_key,
"qty:" + order_id,
)
p.hdel(hold_key, "tier:" + order_id)
p.hdel(hold_key, "ts:" + order_id)
# Update the Event
p.hincrby(e_key, "held:" + tier, -qty)
# Post the Sales Order
so_key = keynamehelper.create_key_name("sales_order", order_id)
p.hmset(so_key, purchase)
p.execute()
except WatchError:
print "Write Conflict in reserve: {}".format(e_key)
finally:
p.reset()
print "Purchase complete!"
else:
print "Auth failure on order {} for customer {} ${}".format(
order_id, customer, price * qty)
backout_hold(event_sku, order_id)
def purchase(event_sku):
"""Simple purchase function, that pushes the sales order for publishing"""
qty = random.randrange(1, 10)
price = 20
order_id = generate.order_id()
s_order = {'who': "Jim", 'qty': qty, 'cost': qty * price,
'order_id': order_id, 'event': event_sku,
'ts': generate.random_time_today()}
post_purchases(order_id, s_order)
def create_purchase(self, customer, event, quantity):
order_id = generate.order_id()
purchase_key = keynamehelper.create_key_name("sales_order", order_id)
purchase = {'state':'RESERVE', 'order_id': order_id,
'customer_id': customer['id'], 'qty': quantity,
'cost': quantity * float(event['price:General']),
'event_sku': event['sku'], 'ts': int(time.time())}
self.redis.hmset(purchase_key, purchase)
return purchase_key
