Cleaned up code

This commit is contained in:
Terry Cain 2017-10-08 04:18:25 +01:00
parent a5895db4f8
commit 77fcafca18
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3 changed files with 255 additions and 71 deletions

View File

@ -69,7 +69,8 @@ def get_filter_expression(expr, names, values):
# Remove all spaces, tbf we could just skip them in the next step.
# The number of known options is really small so we can do a fair bit of cheating
expr = list(re.sub('\s', '', expr)) # 'Id>5ANDattribute_exists(test)ORNOTlength<6'
#expr = list(re.sub('\s', '', expr)) # 'Id>5ANDattribute_exists(test)ORNOTlength<6'
expr = list(expr)
# DodgyTokenisation stage 1
def is_value(val):
@ -90,7 +91,11 @@ def get_filter_expression(expr, names, values):
while len(expr) > 0:
current_char = expr.pop(0)
if current_char == ',': # Split params ,
if current_char == ' ':
if len(stack) > 0:
tokens.append(stack)
stack = ''
elif current_char == ',': # Split params ,
if len(stack) > 0:
tokens.append(stack)
stack = ''
@ -113,6 +118,9 @@ def get_filter_expression(expr, names, values):
if len(stack) > 0:
tokens.append(stack)
def is_op(val):
return val in ('<', '>', '=', '>=', '<=', '<>', 'BETWEEN', 'IN', 'AND', 'OR', 'NOT')
# DodgyTokenisation stage 2, it groups together some elements to make RPN'ing it later easier.
tokens2 = []
token_iterator = iter(tokens)
@ -122,17 +130,30 @@ def get_filter_expression(expr, names, values):
next_token = six.next(token_iterator)
while next_token != ')':
try:
next_token = int(next_token)
except ValueError:
try:
next_token = float(next_token)
except ValueError:
pass
tuple_list.append(next_token)
next_token = six.next(token_iterator)
tokens2.append(tuple(tuple_list))
# Sigh, we only want to group a tuple if it doesnt contain operators
if any([is_op(item) for item in tuple_list]):
tokens2.append('(')
tokens2.extend(tuple_list)
tokens2.append(')')
else:
tokens2.append(tuple(tuple_list))
elif token == 'BETWEEN':
op1 = six.next(token_iterator)
field = tokens2.pop()
op1 = int(six.next(token_iterator))
and_op = six.next(token_iterator)
assert and_op == 'AND'
op2 = six.next(token_iterator)
tokens2.append('BETWEEN')
tokens2.append((op1, op2))
op2 = int(six.next(token_iterator))
tokens2.append(['between', field, op1, op2])
elif is_function(token):
function_list = [token]
@ -161,39 +182,38 @@ def get_filter_expression(expr, names, values):
def is_number(val):
return val not in ('<', '>', '=', '>=', '<=', '<>', 'BETWEEN', 'IN', 'AND', 'OR', 'NOT')
def is_op(val):
return val in ('<', '>', '=', '>=', '<=', '<>', 'BETWEEN', 'IN', 'AND', 'OR', 'NOT')
OPS = {'<': 5, '>': 5, '=': 5, '>=': 5, '<=': 5, '<>': 5, 'IN': 8, 'AND': 11, 'OR': 12, 'NOT': 10, 'BETWEEN': 9, '(': 100, ')': 100}
OPS = {'<': 5, '>': 5, '=': 5, '>=': 5, '<=': 5, '<>': 5, 'IN': 8, 'AND': 11, 'OR': 12, 'NOT': 10, 'BETWEEN': 9, '(': 1, ')': 1}
def shunting_yard(token_list):
output = []
op_stack = []
output = []
op_stack = []
# Basically takes in an infix notation calculation, converts it to a reverse polish notation where there is no
# ambiguaty on which order operators are applied.
while len(tokens2) > 0:
token = tokens2.pop(0)
# Basically takes in an infix notation calculation, converts it to a reverse polish notation where there is no
# ambiguaty on which order operators are applied.
while len(token_list) > 0:
token = token_list.pop(0)
if token == '(':
op_stack.append(token)
elif token == ')':
while len(op_stack) > 0 and op_stack[-1] != '(':
output.append(op_stack.pop())
if len(op_stack) == 0:
# No left paren on the stack, error
raise Exception('Missing left paren')
if token == '(':
op_stack.append(token)
elif token == ')':
while len(op_stack) > 0 and op_stack[-1] != '(':
output.append(op_stack.pop())
lbracket = op_stack.pop()
assert lbracket == '('
# Pop off the left paren
op_stack.pop()
elif is_number(token):
output.append(token)
else:
# Must be operator kw
while len(op_stack) > 0 and OPS[op_stack[-1]] <= OPS[token]:
output.append(op_stack.pop())
op_stack.append(token)
while len(op_stack) > 0:
output.append(op_stack.pop())
elif is_number(token):
output.append(token)
else:
# Must be operator kw
while len(op_stack) > 0 and OPS[op_stack[-1]] <= OPS[token]:
output.append(op_stack.pop())
op_stack.append(token)
while len(op_stack) > 0:
output.append(op_stack.pop())
return output
output = shunting_yard(tokens2)
# Hacky funcition to convert dynamo functions (which are represented as lists) to their Class equivelent
def to_func(val):
@ -217,7 +237,11 @@ def get_filter_expression(expr, names, values):
else:
stack.append(to_func(token))
return stack[0]
result = stack.pop(0)
if len(stack) > 0:
raise ValueError('Malformed filter expression')
return result
class Op(object):
@ -249,7 +273,7 @@ class Op(object):
rhs = self.rhs
if isinstance(self.rhs, (Op, Func)):
rhs = self.rhs.expr(item)
elif isinstance(self.lhs, six.string_types):
elif isinstance(self.rhs, six.string_types):
try:
rhs = item.attrs[self.rhs].cast_value
except Exception:
@ -357,15 +381,6 @@ class OpIn(Op):
return lhs in rhs
class OpBetween(Op):
OP = 'BETWEEN'
def expr(self, item):
lhs = self._lhs(item)
rhs = self._rhs(item)
return rhs[0] <= lhs <= rhs[1]
class FuncAttrExists(Func):
FUNC = 'attribute_exists'
@ -432,18 +447,32 @@ class FuncSize(Func):
def expr(self, item):
if self.attr not in item.attrs:
raise ValueError('Invalid option')
raise ValueError('Invalid attribute name {0}'.format(self.attr))
if item.attrs[self.attr].type in ('S', 'SS', 'NS', 'B', 'BS', 'L', 'M'):
return len(item.attrs[self.attr].value)
raise ValueError('Invalid option')
raise ValueError('Invalid filter expression')
class FuncBetween(Func):
FUNC = 'between'
def __init__(self, attribute, start, end):
self.attr = attribute
self.start = start
self.end = end
def expr(self, item):
if self.attr not in item.attrs:
raise ValueError('Invalid attribute name {0}'.format(self.attr))
return self.start <= item.attrs[self.attr].cast_value <= self.end
OP_CLASS = {
'AND': OpAnd,
'OR': OpOr,
'IN': OpIn,
'BETWEEN': OpBetween,
'<': OpLessThan,
'>': OpGreaterThan,
'<=': OpLessThanOrEqual,
@ -458,5 +487,6 @@ FUNC_CLASS = {
'attribute_type': FuncAttrType,
'begins_with': FuncBeginsWith,
'contains': FuncContains,
'size': FuncSize
'size': FuncSize,
'between': FuncBetween
}

View File

@ -439,13 +439,22 @@ class DynamoHandler(BaseResponse):
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,
filter_expression,
expression_attribute_names,
expression_attribute_values)
try:
items, scanned_count, last_evaluated_key = dynamodb_backend2.scan(name, filters,
limit,
exclusive_start_key,
filter_expression,
expression_attribute_names,
expression_attribute_values)
except ValueError as err:
er = 'com.amazonaws.dynamodb.v20111205#ValidationError'
return self.error(er, 'Bad Filter Expression: {0}'.format(err))
except Exception as err:
er = 'com.amazonaws.dynamodb.v20111205#InternalFailure'
return self.error(er, 'Internal error. {0}'.format(err))
# Items should be a list, at least an empty one. Is None if table does not exist.
# Should really check this at the beginning
if items is None:
er = 'com.amazonaws.dynamodb.v20111205#ResourceNotFoundException'
return self.error(er, 'Requested resource not found')

View File

@ -576,29 +576,51 @@ def test_get_item_returns_consumed_capacity():
def test_filter_expression():
# TODO NOT not yet supported
row1 = moto.dynamodb2.models.Item(None, None, None, None, {'Id': {'N': '8'}, 'Subs': {'N': '5'}, 'Desc': {'S': 'Some description'}, 'KV': {'SS': ['test1', 'test2']}})
row2 = moto.dynamodb2.models.Item(None, None, None, None, {'Id': {'N': '8'}, 'Subs': {'N': '10'}, 'Desc': {'S': 'A description'}, 'KV': {'SS': ['test3', 'test4']}})
filter1 = moto.dynamodb2.comparisons.get_filter_expression('Id > 5 AND Subs < 7', {}, {})
filter1.expr(row1).should.be(True)
filter1.expr(row2).should.be(False)
# AND test
filter_expr = moto.dynamodb2.comparisons.get_filter_expression('Id > 5 AND Subs < 7', {}, {})
filter_expr.expr(row1).should.be(True)
filter_expr.expr(row2).should.be(False)
filter2 = moto.dynamodb2.comparisons.get_filter_expression('attribute_exists(Id) AND attribute_not_exists(User)', {}, {})
filter2.expr(row1).should.be(True)
# OR test
filter_expr = moto.dynamodb2.comparisons.get_filter_expression('Id = 5 OR Id=8', {}, {})
filter_expr.expr(row1).should.be(True)
filter3 = moto.dynamodb2.comparisons.get_filter_expression('attribute_type(Id, N)', {}, {})
filter3.expr(row1).should.be(True)
# BETWEEN test
filter_expr = moto.dynamodb2.comparisons.get_filter_expression('Id BETWEEN 5 AND 10', {}, {})
filter_expr.expr(row1).should.be(True)
filter4 = moto.dynamodb2.comparisons.get_filter_expression('begins_with(Desc, Some)', {}, {})
filter4.expr(row1).should.be(True)
filter4.expr(row2).should.be(False)
# PAREN test
filter_expr = moto.dynamodb2.comparisons.get_filter_expression('Id = 8 AND (Subs = 8 OR Subs = 5)', {}, {})
filter_expr.expr(row1).should.be(True)
filter5 = moto.dynamodb2.comparisons.get_filter_expression('contains(KV, test1)', {}, {})
filter5.expr(row1).should.be(True)
filter5.expr(row2).should.be(False)
# IN test
filter_expr = moto.dynamodb2.comparisons.get_filter_expression('Id IN (7,8, 9)', {}, {})
filter_expr.expr(row1).should.be(True)
filter6 = moto.dynamodb2.comparisons.get_filter_expression('size(Desc) > size(KV)', {}, {})
filter6.expr(row1).should.be(True)
# attribute function tests
filter_expr = moto.dynamodb2.comparisons.get_filter_expression('attribute_exists(Id) AND attribute_not_exists(User)', {}, {})
filter_expr.expr(row1).should.be(True)
filter_expr = moto.dynamodb2.comparisons.get_filter_expression('attribute_type(Id, N)', {}, {})
filter_expr.expr(row1).should.be(True)
# beginswith function test
filter_expr = moto.dynamodb2.comparisons.get_filter_expression('begins_with(Desc, Some)', {}, {})
filter_expr.expr(row1).should.be(True)
filter_expr.expr(row2).should.be(False)
# contains function test
filter_expr = moto.dynamodb2.comparisons.get_filter_expression('contains(KV, test1)', {}, {})
filter_expr.expr(row1).should.be(True)
filter_expr.expr(row2).should.be(False)
# size function test
filter_expr = moto.dynamodb2.comparisons.get_filter_expression('size(Desc) > size(KV)', {}, {})
filter_expr.expr(row1).should.be(True)
@mock_dynamodb2
@ -631,3 +653,126 @@ def test_scan_filter():
FilterExpression=Attr('app').eq('app1')
)
assert response['Count'] == 1
@mock_dynamodb2
def test_bad_scan_filter():
client = boto3.client('dynamodb', region_name='us-east-1')
dynamodb = boto3.resource('dynamodb', region_name='us-east-1')
# Create the DynamoDB table.
client.create_table(
TableName='test1',
AttributeDefinitions=[{'AttributeName': 'client', 'AttributeType': 'S'}, {'AttributeName': 'app', 'AttributeType': 'S'}],
KeySchema=[{'AttributeName': 'client', 'KeyType': 'HASH'}, {'AttributeName': 'app', 'KeyType': 'RANGE'}],
ProvisionedThroughput={'ReadCapacityUnits': 123, 'WriteCapacityUnits': 123}
)
table = dynamodb.Table('test1')
# Bad expression
try:
table.scan(
FilterExpression='client test'
)
except ClientError as err:
err.response['Error']['Code'].should.equal('ValidationError')
else:
raise RuntimeError('Should of raised ResourceInUseException')
@mock_dynamodb2
def test_duplicate_create():
client = boto3.client('dynamodb', region_name='us-east-1')
# Create the DynamoDB table.
client.create_table(
TableName='test1',
AttributeDefinitions=[{'AttributeName': 'client', 'AttributeType': 'S'}, {'AttributeName': 'app', 'AttributeType': 'S'}],
KeySchema=[{'AttributeName': 'client', 'KeyType': 'HASH'}, {'AttributeName': 'app', 'KeyType': 'RANGE'}],
ProvisionedThroughput={'ReadCapacityUnits': 123, 'WriteCapacityUnits': 123}
)
try:
client.create_table(
TableName='test1',
AttributeDefinitions=[{'AttributeName': 'client', 'AttributeType': 'S'}, {'AttributeName': 'app', 'AttributeType': 'S'}],
KeySchema=[{'AttributeName': 'client', 'KeyType': 'HASH'}, {'AttributeName': 'app', 'KeyType': 'RANGE'}],
ProvisionedThroughput={'ReadCapacityUnits': 123, 'WriteCapacityUnits': 123}
)
except ClientError as err:
err.response['Error']['Code'].should.equal('ResourceInUseException')
else:
raise RuntimeError('Should of raised ResourceInUseException')
@mock_dynamodb2
def test_delete_table():
client = boto3.client('dynamodb', region_name='us-east-1')
# Create the DynamoDB table.
client.create_table(
TableName='test1',
AttributeDefinitions=[{'AttributeName': 'client', 'AttributeType': 'S'}, {'AttributeName': 'app', 'AttributeType': 'S'}],
KeySchema=[{'AttributeName': 'client', 'KeyType': 'HASH'}, {'AttributeName': 'app', 'KeyType': 'RANGE'}],
ProvisionedThroughput={'ReadCapacityUnits': 123, 'WriteCapacityUnits': 123}
)
client.delete_table(TableName='test1')
resp = client.list_tables()
len(resp['TableNames']).should.equal(0)
try:
client.delete_table(TableName='test1')
except ClientError as err:
err.response['Error']['Code'].should.equal('ResourceNotFoundException')
else:
raise RuntimeError('Should of raised ResourceNotFoundException')
@mock_dynamodb2
def test_delete_item():
client = boto3.client('dynamodb', region_name='us-east-1')
dynamodb = boto3.resource('dynamodb', region_name='us-east-1')
# Create the DynamoDB table.
client.create_table(
TableName='test1',
AttributeDefinitions=[{'AttributeName': 'client', 'AttributeType': 'S'}, {'AttributeName': 'app', 'AttributeType': 'S'}],
KeySchema=[{'AttributeName': 'client', 'KeyType': 'HASH'}, {'AttributeName': 'app', 'KeyType': 'RANGE'}],
ProvisionedThroughput={'ReadCapacityUnits': 123, 'WriteCapacityUnits': 123}
)
client.put_item(
TableName='test1',
Item={
'client': {'S': 'client1'},
'app': {'S': 'app1'}
}
)
client.put_item(
TableName='test1',
Item={
'client': {'S': 'client1'},
'app': {'S': 'app2'}
}
)
table = dynamodb.Table('test1')
response = table.scan()
assert response['Count'] == 2
# Test deletion and returning old value
response = table.delete_item(Key={'client': 'client1', 'app': 'app1'}, ReturnValues='ALL_OLD')
response['Attributes'].should.contain('client')
response['Attributes'].should.contain('app')
response = table.scan()
assert response['Count'] == 1
# Test deletion returning nothing
response = table.delete_item(Key={'client': 'client1', 'app': 'app2'})
len(response['Attributes']).should.equal(0)
response = table.scan()
assert response['Count'] == 0