from thrift import Thrift
from thrift.transport import TTransport
from thrift.transport import TSocket
from thrift.protocol import TBinaryProtocol
from cassandra import Cassandra
from cassandra.ttypes import Column, ConsistencyLevel, SlicePredicate, RowPredicate, Clock
from cassandra.ttypes import SliceRange, ColumnParent, KeyRange
import time

# Boilerplate: change these to match cassandra config
hostname = "cass1.dev.meebo.com"
port = 9160
keyspace = "TestKeySpace"
column_family_name = "TestNormalCF"  # Warning: will be truncated

# Boilerplate: Connect to the server and set the keyspace
socket = TSocket.TSocket(hostname, port)
transport = TTransport.TFramedTransport(socket)
protocol = TBinaryProtocol.TBinaryProtocol(transport)
client = Cassandra.Client(protocol, protocol)
transport.open()
client.set_keyspace(keyspace)

client.truncate(column_family_name) # Empty the target column family

timestamp = int(time.time() * 1e6)  # GMT epoch microseconds
column_parent = ColumnParent(column_family=column_family_name)

# Insert 10 values
keys_inserted = []
for i in xrange(10):
    key = str(i)
    column = Column(name=key, value=key, clock=Clock(timestamp))
    client.insert(key, column_parent, column, ConsistencyLevel.ALL)
    keys_inserted.append(key)

time.sleep(1)

# Read back max of 7 values, works fine
row_predicate = RowPredicate(key_range=KeyRange(start_key="", end_key="", count=7))
slice_predicate = SlicePredicate(slice_range=SliceRange(start="", finish=""))
scan_results = client.scan(column_parent, row_predicate, slice_predicate, ConsistencyLevel.ALL)

keys = [keyslice.key for keyslice in scan_results]
print "%d scan results, keys: %s" % (len(scan_results), keys)

num_results_scan1 = len(scan_results)

# INTERESTING PART BEGINS HERE

# Read back another set of results, starting with last key from the last result selt
scan2_begin_key = scan_results[len(scan_results)-1].key
print "Scanning again starting at %s" % scan2_begin_key
row_predicate = RowPredicate(key_range=KeyRange(start_key=scan2_begin_key, end_key="", count=7))

scan_results = client.scan(column_parent, row_predicate, slice_predicate, ConsistencyLevel.ALL)
keys = [keyslice.key for keyslice in scan_results]
print "%d more scan results, keys: %s" % (len(scan_results), keys)
num_results_scan2 = len(scan_results)

if num_results_scan1 + num_results_scan2 - 1 > 10: # -1 since result sets overlap by one key
    print "Too many results were returned!"