Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/redis/commands/parser.py: 10%

1from redis.exceptions import RedisError, ResponseError 

2from redis.utils import str_if_bytes 

3 

4 

5class CommandsParser: 

6 """ 

7 Parses Redis commands to get command keys. 

8 COMMAND output is used to determine key locations. 

9 Commands that do not have a predefined key location are flagged with 

10 'movablekeys', and these commands' keys are determined by the command 

11 'COMMAND GETKEYS'. 

12 """ 

13 

14 def __init__(self, redis_connection): 

15 self.commands = {} 

16 self.initialize(redis_connection) 

17 

18 def initialize(self, r): 

19 commands = r.execute_command("COMMAND") 

20 uppercase_commands = [] 

21 for cmd in commands: 

22 if any(x.isupper() for x in cmd): 

23 uppercase_commands.append(cmd) 

24 for cmd in uppercase_commands: 

25 commands[cmd.lower()] = commands.pop(cmd) 

26 self.commands = commands 

27 

28 def parse_subcommand(self, command, **options): 

29 cmd_dict = {} 

30 cmd_name = str_if_bytes(command[0]) 

31 cmd_dict["name"] = cmd_name 

32 cmd_dict["arity"] = int(command[1]) 

33 cmd_dict["flags"] = [str_if_bytes(flag) for flag in command[2]] 

34 cmd_dict["first_key_pos"] = command[3] 

35 cmd_dict["last_key_pos"] = command[4] 

36 cmd_dict["step_count"] = command[5] 

37 if len(command) > 7: 

38 cmd_dict["tips"] = command[7] 

39 cmd_dict["key_specifications"] = command[8] 

40 cmd_dict["subcommands"] = command[9] 

41 return cmd_dict 

42 

43 # As soon as this PR is merged into Redis, we should reimplement 

44 # our logic to use COMMAND INFO changes to determine the key positions 

45 # https://github.com/redis/redis/pull/8324 

46 def get_keys(self, redis_conn, *args): 

47 """ 

48 Get the keys from the passed command. 

49 

50 NOTE: Due to a bug in redis<7.0, this function does not work properly 

51 for EVAL or EVALSHA when the `numkeys` arg is 0. 

52 - issue: https://github.com/redis/redis/issues/9493 

53 - fix: https://github.com/redis/redis/pull/9733 

54 

55 So, don't use this function with EVAL or EVALSHA. 

56 """ 

57 if len(args) < 2: 

58 # The command has no keys in it 

59 return None 

60 

61 cmd_name = args[0].lower() 

62 if cmd_name not in self.commands: 

63 # try to split the command name and to take only the main command, 

64 # e.g. 'memory' for 'memory usage' 

65 cmd_name_split = cmd_name.split() 

66 cmd_name = cmd_name_split[0] 

67 if cmd_name in self.commands: 

68 # save the splitted command to args 

69 args = cmd_name_split + list(args[1:]) 

70 else: 

71 # We'll try to reinitialize the commands cache, if the engine 

72 # version has changed, the commands may not be current 

73 self.initialize(redis_conn) 

74 if cmd_name not in self.commands: 

75 raise RedisError( 

76 f"{cmd_name.upper()} command doesn't exist in Redis commands" 

77 ) 

78 

79 command = self.commands.get(cmd_name) 

80 if "movablekeys" in command["flags"]: 

81 keys = self._get_moveable_keys(redis_conn, *args) 

82 elif "pubsub" in command["flags"] or command["name"] == "pubsub": 

83 keys = self._get_pubsub_keys(*args) 

84 else: 

85 if ( 

86 command["step_count"] == 0 

87 and command["first_key_pos"] == 0 

88 and command["last_key_pos"] == 0 

89 ): 

90 is_subcmd = False 

91 if "subcommands" in command: 

92 subcmd_name = f"{cmd_name}|{args[1].lower()}" 

93 for subcmd in command["subcommands"]: 

94 if str_if_bytes(subcmd[0]) == subcmd_name: 

95 command = self.parse_subcommand(subcmd) 

96 is_subcmd = True 

97 

98 # The command doesn't have keys in it 

99 if not is_subcmd: 

100 return None 

101 last_key_pos = command["last_key_pos"] 

102 if last_key_pos < 0: 

103 last_key_pos = len(args) - abs(last_key_pos) 

104 keys_pos = list( 

105 range(command["first_key_pos"], last_key_pos + 1, command["step_count"]) 

106 ) 

107 keys = [args[pos] for pos in keys_pos] 

108 

109 return keys 

110 

111 def _get_moveable_keys(self, redis_conn, *args): 

112 """ 

113 NOTE: Due to a bug in redis<7.0, this function does not work properly 

114 for EVAL or EVALSHA when the `numkeys` arg is 0. 

115 - issue: https://github.com/redis/redis/issues/9493 

116 - fix: https://github.com/redis/redis/pull/9733 

117 

118 So, don't use this function with EVAL or EVALSHA. 

119 """ 

120 pieces = [] 

121 cmd_name = args[0] 

122 # The command name should be splitted into separate arguments, 

123 # e.g. 'MEMORY USAGE' will be splitted into ['MEMORY', 'USAGE'] 

124 pieces = pieces + cmd_name.split() 

125 pieces = pieces + list(args[1:]) 

126 try: 

127 keys = redis_conn.execute_command("COMMAND GETKEYS", *pieces) 

128 except ResponseError as e: 

129 message = e.__str__() 

130 if ( 

131 "Invalid arguments" in message 

132 or "The command has no key arguments" in message 

133 ): 

134 return None 

135 else: 

136 raise e 

137 return keys 

138 

139 def _get_pubsub_keys(self, *args): 

140 """ 

141 Get the keys from pubsub command. 

142 Although PubSub commands have predetermined key locations, they are not 

143 supported in the 'COMMAND's output, so the key positions are hardcoded 

144 in this method 

145 """ 

146 if len(args) < 2: 

147 # The command has no keys in it 

148 return None 

149 args = [str_if_bytes(arg) for arg in args] 

150 command = args[0].upper() 

151 keys = None 

152 if command == "PUBSUB": 

153 # the second argument is a part of the command name, e.g. 

154 # ['PUBSUB', 'NUMSUB', 'foo']. 

155 pubsub_type = args[1].upper() 

156 if pubsub_type in ["CHANNELS", "NUMSUB"]: 

157 keys = args[2:] 

158 elif command in ["SUBSCRIBE", "PSUBSCRIBE", "UNSUBSCRIBE", "PUNSUBSCRIBE"]: 

159 # format example: 

160 # SUBSCRIBE channel [channel ...] 

161 keys = list(args[1:]) 

162 elif command == "PUBLISH": 

163 # format example: 

164 # PUBLISH channel message 

165 keys = [args[1]] 

166 return keys