def execute(self):
## first validate data
data_ok, fault = self._validate_data()
if not data_ok:
return (False, fault)
## if data ok, construct InsertCommands
if self.op_type == CassandraQuery.OP_DELETE:
try:
domain = self.data.domain
row_key = self.data.get_pk()
client = db_connection.get_client()
cf = ColumnFamily(client, domain)
## if cascading is enabled, first delete all DBObject and collections comprised in this DBObject
if self.cascade:
pass
## lastly remove data for current element
cf.remove(row_key)
return (True, None)
except Exception, ex:
return (False, ex)
def get_row_key_id(domain):
counter_column, counter_lock = domain_counter_map[domain]
## acquire lock before getting value of
counter_lock.acquire()
try:
client = db_connection.get_client()
cf = ColumnFamily(client, CONFIG_DOMAIN)
## get new key id
id_key = cf.get(CONFIG_ROW, counter_column)[counter_column]
## increment value if not None
if id_key:
new_id_key = id_key + 1
cf.insert(CONFIG_ROW, {counter_column: new_id_key}, write_consistency_level=ConsistencyLevel.ALL)
return id_key
"""
if id_key:
str_id_key = str(id_key)
str_id_key.zfill(MAX_PADDING_RANGE)
return str_id_key
else:
return None
"""
finally:
## release lock before returning from this function
counter_lock.release()
def get_row_key_id(domain):
counter_column, counter_lock = domain_counter_map[domain]
## acquire lock before getting value of
counter_lock.acquire()
try:
client = db_connection.get_client()
cf = ColumnFamily(client, CONFIG_DOMAIN)
## get new key id
id_key = cf.get(CONFIG_ROW, counter_column)[counter_column]
## increment value if not None
if id_key:
new_id_key = id_key + 1
cf.insert(CONFIG_ROW, {counter_column: new_id_key},
write_consistency_level=ConsistencyLevel.ALL)
return id_key
"""
if id_key:
str_id_key = str(id_key)
str_id_key.zfill(MAX_PADDING_RANGE)
return str_id_key
else:
return None
"""
finally:
## release lock before returning from this function
counter_lock.release()
def undo(self):
if type == InsertCommand.INS_BASIC:
## I know that data for a basic insert is of this tuple type
domain, row_key, basic_type_dict = self.data
client = db_connection.get_client()
cf = ColumnFamily(client, domain)
cf.remove(row_key)
elif type == InsertCommand.INS_OBJECT:
## call the save operation for the object
if self.data:
self.data.delete(cascade=False)
elif type == InsertCommand.INS_BATCH:
domain, basic_type_item_dict = self.data
client = db_connection.get_client()
cf = ColumnFamily(client, domain)
b = cf.batch()
for row_key in basic_type_item_dict.keys():
b.remove(row_key)
b.send()
def do(self):
if type == InsertCommand.INS_BASIC:
## I know that data for a basic insert is of this tuple type
domain, row_key, basic_type_dict = self.data
client = db_connection.get_client()
cf = ColumnFamily(client, domain)
cf.insert(row_key, basic_type_dict)
elif type == InsertCommand.INS_OBJECT:
## call the save operation for the object
if self.data:
self.data.save()
elif type == InsertCommand.INS_BATCH:
## Again, I know data for a batch insert will be of the following tuple type
domain, basic_type_item_dict = self.data
client = db_connection.get_client()
cf = ColumnFamily(client, domain)
b = cf.batch()
for row_key in basic_type_item_dict.keys():
b.insert(row_key, basic_type_item_dict[row_key])
b.send()
def execute(self):
client = db_connection.get_client()
cf = ColumnFamily(client, self.domain)
try:
#### SELECT QUERY ####
if self.op_type == CassandraQuery.OP_SELECT:
if not self.where_node:
## treat this as a simple key get query
if self.limit == 1:
result = cf.get(self.offset)
if result:
return (True, result, None)
else:
return (False, None,
DatabaseError("No " + self.domain +
"entry matching row_key: " +
self.offset))
else:
return (False, None,
DatabaseError(
"Limit for SELECT operation must be 1"))
else:
## treat this as an indexed_slices query
if self.limit == 1:
## we consider the assumption that there is only a single AND node with filtering children
index_expressions = []
for field_predicate, value in self.where_node.children:
field_predicate_list = field_predicate.split("__")
field = field_predicate_list[0]
predicate = EQ
if len(field_predicate_list) == 2:
try:
predicate = SelectManager.predicate_map[
field_predicate_list[1]]
except:
predicate = EQ
index_exp = create_index_expression(
field, value, predicate)
index_expressions.append(index_exp)
index_clause = create_index_clause(
index_expressions,
start_key=self.offset,
count=self.limit)
result = cf.get_indexed_slices(index_clause)
if result:
return (True, result, None)
else:
return (False, None,
DatabaseError("No " + self.domain +
"entry matching query: " +
self.where_node))
else:
return (False, None,
DatabaseError(
"Limit for SELECT operation must be 1"))
#### FETCH QUERY ####
elif self.op_type == CassandraQuery.OP_FETCH:
if self.limit > SelectManager.MAX_FETCH_LIMIT:
return (
False, None,
DatabaseError(
"LIMIT for FETCH operation exceeds MAX_FETCH_LIMIT(1000)"
))
if not self.where_node:
## Treat this as a key range query
key_offset = self.offset
limit = self.limit
result = {}
while True:
if limit < SelectManager.REGULAR_FETCH_LIMIT:
res = cf.get_range(key_offset, row_count=limit)
result.update(res)
break
else:
res = cf.get_range(
key_offset,
row_count=SelectManager.REGULAR_FETCH_LIMIT)
result.update(res)
if len(res) < SelectManager.REGULAR_FETCH_LIMIT:
break
else:
max_key = sorted(res.keys(), reverse=True)[0]
key_offset = max_key + 1
limit -= SelectManager.REGULAR_FETCH_LIMIT
return (True, result, None)
else:
## Treat this as a fetch query
## first create index expressions
index_expressions = []
for field_predicate, value in self.where_node.children:
field_predicate_list = field_predicate.split("__")
field = field_predicate_list[0]
predicate = EQ
if len(field_predicate_list) == 2:
try:
predicate = SelectManager.predicate_map[
field_predicate_list[1]]
except:
predicate = EQ
index_exp = create_index_expression(
field, value, predicate)
index_expressions.append(index_exp)
key_offset = self.offset
limit = self.limit
result = {}
while True:
if limit < SelectManager.REGULAR_FETCH_LIMIT:
index_clause = create_index_clause(
index_expressions,
start_key=key_offset,
count=limit)
res = cf.get_indexed_slices(index_clause)
result.update(res)
break
else:
index_clause = create_index_clause(
index_expressions,
start_key=key_offset,
count=SelectManager.REGULAR_FETCH_LIMIT)
res = cf.get_indexed_slices(index_clause)
result.update(res)
if len(res) < SelectManager.REGULAR_FETCH_LIMIT:
break
else:
max_key = sorted(res.keys(), reverse=True)[0]
key_offset = max_key + 1
limit -= SelectManager.REGULAR_FETCH_LIMIT
return (True, result, None)
except Exception, ex:
return (False, None, ex)
