Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/google/api_core/gapic_v1/routing_header.py: 62%

1# Copyright 2017 Google LLC 

2# 

3# Licensed under the Apache License, Version 2.0 (the "License"); 

4# you may not use this file except in compliance with the License. 

5# You may obtain a copy of the License at 

6# 

7# http://www.apache.org/licenses/LICENSE-2.0 

8# 

9# Unless required by applicable law or agreed to in writing, software 

10# distributed under the License is distributed on an "AS IS" BASIS, 

11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 

12# See the License for the specific language governing permissions and 

13# limitations under the License. 

14 

15"""Helpers for constructing routing headers. 

16 

17These headers are used by Google infrastructure to determine how to route 

18requests, especially for services that are regional. 

19 

20Generally, these headers are specified as gRPC metadata. 

21""" 

22 

23import functools 

24from enum import Enum 

25from urllib.parse import urlencode 

26 

27ROUTING_METADATA_KEY = "x-goog-request-params" 

28# This is the value for the `maxsize` argument of @functools.lru_cache 

29# https://docs.python.org/3/library/functools.html#functools.lru_cache 

30# This represents the number of recent function calls to store. 

31ROUTING_PARAM_CACHE_SIZE = 32 

32 

33 

34def to_routing_header(params, qualified_enums=True): 

35 """Returns a routing header string for the given request parameters. 

36 

37 Args: 

38 params (Mapping[str, str | bytes | Enum]): A dictionary containing the request 

39 parameters used for routing. 

40 qualified_enums (bool): Whether to represent enum values 

41 as their type-qualified symbol names instead of as their 

42 unqualified symbol names. 

43 

44 Returns: 

45 str: The routing header string. 

46 """ 

47 tuples = params.items() if isinstance(params, dict) else params 

48 if not qualified_enums: 

49 tuples = [(x[0], x[1].name) if isinstance(x[1], Enum) else x for x in tuples] 

50 return "&".join([_urlencode_param(*t) for t in tuples]) 

51 

52 

53def to_grpc_metadata(params, qualified_enums=True): 

54 """Returns the gRPC metadata containing the routing headers for the given 

55 request parameters. 

56 

57 Args: 

58 params (Mapping[str, str | bytes | Enum]): A dictionary containing the request 

59 parameters used for routing. 

60 qualified_enums (bool): Whether to represent enum values 

61 as their type-qualified symbol names instead of as their 

62 unqualified symbol names. 

63 

64 Returns: 

65 Tuple(str, str): The gRPC metadata containing the routing header key 

66 and value. 

67 """ 

68 return (ROUTING_METADATA_KEY, to_routing_header(params, qualified_enums)) 

69 

70 

71# use caching to avoid repeated computation 

72@functools.lru_cache(maxsize=ROUTING_PARAM_CACHE_SIZE) 

73def _urlencode_param(key, value): 

74 """Cacheable wrapper over urlencode 

75 

76 Args: 

77 key (str): The key of the parameter to encode. 

78 value (str | bytes | Enum): The value of the parameter to encode. 

79 

80 Returns: 

81 str: The encoded parameter. 

82 """ 

83 return urlencode( 

84 {key: value}, 

85 # Per Google API policy (go/api-url-encoding), / is not encoded. 

86 safe="/", 

87 )