Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/azure/core/paging.py: 40%

1# -------------------------------------------------------------------------- 

2# 

3# Copyright (c) Microsoft Corporation. All rights reserved. 

4# 

5# The MIT License (MIT) 

6# 

7# Permission is hereby granted, free of charge, to any person obtaining a copy 

8# of this software and associated documentation files (the ""Software""), to 

9# deal in the Software without restriction, including without limitation the 

10# rights to use, copy, modify, merge, publish, distribute, sublicense, and/or 

11# sell copies of the Software, and to permit persons to whom the Software is 

12# furnished to do so, subject to the following conditions: 

13# 

14# The above copyright notice and this permission notice shall be included in 

15# all copies or substantial portions of the Software. 

16# 

17# THE SOFTWARE IS PROVIDED *AS IS*, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 

18# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 

19# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 

20# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 

21# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 

22# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 

23# IN THE SOFTWARE. 

24# 

25# -------------------------------------------------------------------------- 

26import itertools 

27from typing import ( # pylint: disable=unused-import 

28 Callable, 

29 Optional, 

30 TypeVar, 

31 Iterator, 

32 Iterable, 

33 Tuple, 

34 Any, 

35) 

36import logging 

37 

38from .exceptions import AzureError 

39 

40 

41_LOGGER = logging.getLogger(__name__) 

42 

43ReturnType = TypeVar("ReturnType") 

44ResponseType = TypeVar("ResponseType") 

45 

46 

47class PageIterator(Iterator[Iterator[ReturnType]]): 

48 def __init__( 

49 self, 

50 get_next: Callable[[Optional[str]], ResponseType], 

51 extract_data: Callable[[ResponseType], Tuple[str, Iterable[ReturnType]]], 

52 continuation_token: Optional[str] = None, 

53 ): 

54 """Return an iterator of pages. 

55 

56 :param get_next: Callable that take the continuation token and return a HTTP response 

57 :param extract_data: Callable that take an HTTP response and return a tuple continuation token, 

58 list of ReturnType 

59 :param str continuation_token: The continuation token needed by get_next 

60 """ 

61 self._get_next = get_next 

62 self._extract_data = extract_data 

63 self.continuation_token = continuation_token 

64 self._did_a_call_already = False 

65 self._response: Optional[ResponseType] = None 

66 self._current_page: Optional[Iterable[ReturnType]] = None 

67 

68 def __iter__(self) -> Iterator[Iterator[ReturnType]]: 

69 return self 

70 

71 def __next__(self) -> Iterator[ReturnType]: 

72 if self.continuation_token is None and self._did_a_call_already: 

73 raise StopIteration("End of paging") 

74 try: 

75 self._response = self._get_next(self.continuation_token) 

76 except AzureError as error: 

77 if not error.continuation_token: 

78 error.continuation_token = self.continuation_token 

79 raise 

80 

81 self._did_a_call_already = True 

82 

83 self.continuation_token, self._current_page = self._extract_data(self._response) 

84 

85 return iter(self._current_page) 

86 

87 next = __next__ # Python 2 compatibility. Can't be removed as some people are using ".next()" even in Py3 

88 

89 

90class ItemPaged(Iterator[ReturnType]): 

91 def __init__(self, *args: Any, **kwargs: Any) -> None: 

92 """Return an iterator of items. 

93 

94 args and kwargs will be passed to the PageIterator constructor directly, 

95 except page_iterator_class 

96 """ 

97 self._args = args 

98 self._kwargs = kwargs 

99 self._page_iterator: Optional[Iterator[ReturnType]] = None 

100 self._page_iterator_class = self._kwargs.pop("page_iterator_class", PageIterator) 

101 

102 def by_page(self, continuation_token: Optional[str] = None) -> Iterator[Iterator[ReturnType]]: 

103 """Get an iterator of pages of objects, instead of an iterator of objects. 

104 

105 :param str continuation_token: 

106 An opaque continuation token. This value can be retrieved from the 

107 continuation_token field of a previous generator object. If specified, 

108 this generator will begin returning results from this point. 

109 :returns: An iterator of pages (themselves iterator of objects) 

110 :rtype: iterator[iterator[ReturnType]] 

111 """ 

112 return self._page_iterator_class(continuation_token=continuation_token, *self._args, **self._kwargs) 

113 

114 def __repr__(self) -> str: 

115 return "<iterator object azure.core.paging.ItemPaged at {}>".format(hex(id(self))) 

116 

117 def __iter__(self) -> Iterator[ReturnType]: 

118 return self 

119 

120 def __next__(self) -> ReturnType: 

121 if self._page_iterator is None: 

122 self._page_iterator = itertools.chain.from_iterable(self.by_page()) 

123 return next(self._page_iterator) 

124 

125 next = __next__ # Python 2 compatibility. Can't be removed as some people are using ".next()" even in Py3