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add dynamodb pagination

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This commit is contained in:
Brian Cavagnolo 2016-03-01 11:30:35 -08:00
commit 6bab725b36
4 changed files with 122 additions and 43 deletions
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51
moto/dynamodb2/models.py
View file

@ -308,9 +308,9 @@ class Table(object):
except KeyError:
return None
def query(self, hash_key, range_comparison, range_objs, index_name=None):
def query(self, hash_key, range_comparison, range_objs, limit,
exclusive_start_key, scan_index_forward, index_name=None):
results = []
last_page = True # Once pagination is implemented, change this
if index_name:
all_indexes = (self.global_indexes or []) + (self.indexes or [])
@ -365,7 +365,11 @@ class Table(object):
if item.attrs.get(index_range_key['AttributeName']) else None)
else:
results.sort(key=lambda item: item.range_key)
return results, last_page
if scan_index_forward is False:
results.reverse()
return self._trim_results(results, limit, exclusive_start_key)
def all_items(self):
for hash_set in self.items.values():
@ -375,10 +379,9 @@ class Table(object):
else:
yield hash_set
def scan(self, filters):
def scan(self, filters, limit, exclusive_start_key):
results = []
scanned_count = 0
last_page = True # Once pagination is implemented, change this
for result in self.all_items():
scanned_count += 1
@ -401,7 +404,33 @@ class Table(object):
if passes_all_conditions:
results.append(result)
return results, scanned_count, last_page
results, last_evaluated_key = self._trim_results(results, limit,
exclusive_start_key)
return results, scanned_count, last_evaluated_key
def _trim_results(self, results, limit, exclusive_start_key):
if exclusive_start_key is not None:
hash_key = DynamoType(exclusive_start_key.get(self.hash_key_attr))
range_key = exclusive_start_key.get(self.range_key_attr)
if range_key is not None:
range_key = DynamoType(range_key)
for i in range(len(results)):
if results[i].hash_key == hash_key and results[i].range_key == range_key:
results = results[i + 1:]
break
last_evaluated_key = None
if limit and len(results) > limit:
results = results[:limit]
last_evaluated_key = {
self.hash_key_attr: results[-1].hash_key
}
if results[-1].range_key is not None:
last_evaluated_key[self.range_key_attr] = results[-1].range_key
return results, last_evaluated_key
def lookup(self, *args, **kwargs):
if not self.schema:
@ -507,7 +536,8 @@ class DynamoDBBackend(BaseBackend):
hash_key, range_key = self.get_keys_value(table, keys)
return table.get_item(hash_key, range_key)
def query(self, table_name, hash_key_dict, range_comparison, range_value_dicts, index_name=None):
def query(self, table_name, hash_key_dict, range_comparison, range_value_dicts,
limit, exclusive_start_key, scan_index_forward, index_name=None):
table = self.tables.get(table_name)
if not table:
return None, None
@ -515,9 +545,10 @@ class DynamoDBBackend(BaseBackend):
hash_key = DynamoType(hash_key_dict)
range_values = [DynamoType(range_value) for range_value in range_value_dicts]
return table.query(hash_key, range_comparison, range_values, index_name)
return table.query(hash_key, range_comparison, range_values, limit,
exclusive_start_key, scan_index_forward, index_name)
def scan(self, table_name, filters):
def scan(self, table_name, filters, limit, exclusive_start_key):
table = self.tables.get(table_name)
if not table:
return None, None, None
@ -527,7 +558,7 @@ class DynamoDBBackend(BaseBackend):
dynamo_types = [DynamoType(value) for value in comparison_values]
scan_filters[key] = (comparison_operator, dynamo_types)
return table.scan(scan_filters)
return table.scan(scan_filters, limit, exclusive_start_key)
def update_item(self, table_name, key, update_expression, attribute_updates):
table = self.get_table(table_name)

45
moto/dynamodb2/responses.py
View file

@ -238,7 +238,6 @@ class DynamoHandler(BaseResponse):
def query(self):
name = self.body['TableName']
# {u'KeyConditionExpression': u'#n0 = :v0', u'ExpressionAttributeValues': {u':v0': {u'S': u'johndoe'}}, u'ExpressionAttributeNames': {u'#n0': u'username'}}
key_condition_expression = self.body.get('KeyConditionExpression')
if key_condition_expression:
@ -317,19 +316,16 @@ class DynamoHandler(BaseResponse):
range_values = []
index_name = self.body.get('IndexName')
items, last_page = dynamodb_backend2.query(name, hash_key, range_comparison, range_values, index_name=index_name)
exclusive_start_key = self.body.get('ExclusiveStartKey')
limit = self.body.get("Limit")
scan_index_forward = self.body.get("ScanIndexForward")
items, last_evaluated_key = dynamodb_backend2.query(
name, hash_key, range_comparison, range_values, limit,
exclusive_start_key, scan_index_forward, index_name=index_name)
if items is None:
er = 'com.amazonaws.dynamodb.v20111205#ResourceNotFoundException'
return self.error(er)
reversed = self.body.get("ScanIndexForward")
if reversed is False:
items.reverse()
limit = self.body.get("Limit")
if limit:
items = items[:limit]
result = {
"Count": len(items),
"ConsumedCapacityUnits": 1,
@ -337,12 +333,9 @@ class DynamoHandler(BaseResponse):
if self.body.get('Select', '').upper() != 'COUNT':
result["Items"] = [item.attrs for item in items]
# Implement this when we do pagination
# if not last_page:
# result["LastEvaluatedKey"] = {
# "HashKeyElement": items[-1].hash_key,
# "RangeKeyElement": items[-1].range_key,
# }
if last_evaluated_key is not None:
result["LastEvaluatedKey"] = last_evaluated_key
return dynamo_json_dump(result)
def scan(self):
@ -356,29 +349,25 @@ class DynamoHandler(BaseResponse):
comparison_values = scan_filter.get("AttributeValueList", [])
filters[attribute_name] = (comparison_operator, comparison_values)
items, scanned_count, last_page = dynamodb_backend2.scan(name, filters)
exclusive_start_key = self.body.get('ExclusiveStartKey')
limit = self.body.get("Limit")
items, scanned_count, last_evaluated_key = dynamodb_backend2.scan(name, filters,
limit,
exclusive_start_key)
if items is None:
er = 'com.amazonaws.dynamodb.v20111205#ResourceNotFoundException'
return self.error(er)
limit = self.body.get("Limit")
if limit:
items = items[:limit]
result = {
"Count": len(items),
"Items": [item.attrs for item in items],
"ConsumedCapacityUnits": 1,
"ScannedCount": scanned_count
}
# Implement this when we do pagination
# if not last_page:
# result["LastEvaluatedKey"] = {
# "HashKeyElement": items[-1].hash_key,
# "RangeKeyElement": items[-1].range_key,
# }
if last_evaluated_key is not None:
result["LastEvaluatedKey"] = last_evaluated_key
return dynamo_json_dump(result)
def delete_item(self):