def query(cls, hash_key=None, range_key_condition=None,
request_limit=None, consistent_read=False,
scan_index_forward=True, **kwargs):
'''Query under a given hash_key
:type range_key_condition: dict
:param range_key_condition: A dict where the key is either
a scalar value appropriate for the RangeKey in the schema
of the database or a tuple of such values. The value-
associated with this key in the dict will be one of the
following conditions:
'EQ'|'LE'|'LT'|'GE'|'GT'|'BEGINS_WITH'|'BETWEEN'
The only condition which expects or will accept a tuple
of values is 'BETWEEN', otherwise a scalar value should
be used as the key in the dict.
:type request_limit: int
:param request_limit: The maximum number of items to request from DynamoDB
in one request. This limit helps with preventing over usage of your
read quota.
:type consistent_read: bool
:param consistent_read: If True, a consistent read
request is issued. Otherwise, an eventually consistent
request is issued.
:type scan_index_forward: bool
:param scan_index_forward: Specified forward or backward
traversal of the index. Default is forward (True).
'''
attempt = 0
last_error = None
# Handle Keyword Searches
if kwargs:
from decimal import Decimal
from boto.dynamodb2.table import Table
tbl = Table(cls._table_name)
index_name = []
args = {}
for arg in kwargs:
index_name.append(arg)
args[arg + '__eq'] = kwargs[arg]
index_name.append('index')
index_name = '-'.join(index_name)
for item in tbl.query_2(index=index_name, **args):
# Convert some values out to simple Python values
data = {}
for attr_name in item.keys():
val = item[attr_name]
if isinstance(val, Decimal):
val = int(val)
if isinstance(val, set):
val = list(val)
data[attr_name] = val
yield cls.from_dict(data)
else:
while attempt < MAX_RETRIES:
try:
for item in cls.get_table().query(hash_key=hash_key,
range_key_condition=range_key_condition,
request_limit=request_limit,
consistent_read=consistent_read,
scan_index_forward=scan_index_forward, item_class=cls):
yield item
return
except DynamoDBResponseError, e:
log.exception('Dynamo Response Error: %s' % e)
cls._table = None
attempt += 1
last_error = e
time.sleep(attempt ** 2)
except BotoServerError, e:
log.error('Boto Server Error: %s' % e)
cls._table = None
attempt += 1
last_error = e
time.sleep(attempt ** 2)
