Conditions | 6 |
Total Lines | 52 |
Code Lines | 18 |
Lines | 0 |
Ratio | 0 % |
Changes | 0 |
Small methods make your code easier to understand, in particular if combined with a good name. Besides, if your method is small, finding a good name is usually much easier.
For example, if you find yourself adding comments to a method's body, this is usually a good sign to extract the commented part to a new method, and use the comment as a starting point when coming up with a good name for this new method.
Commonly applied refactorings include:
If many parameters/temporary variables are present:
1 | #!/usr/bin/env python3 |
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101 | @contextmanager |
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102 | def redis_lock(lock_id, blocking=False, expire=True): |
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103 | """ |
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104 | This function get a lock relying on a lock name and other status. You |
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105 | can describe more process using the same lock name and give exclusive |
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106 | access to one of them. |
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107 | |||
108 | Args: |
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109 | lock_id (str): the name of the lock to take |
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110 | blocking (bool): if True, we wait until we have the block, if False |
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111 | we returns immediately False |
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112 | expire (bool): if True, lock will expire after LOCK_EXPIRE timeout, |
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113 | if False, it will persist until lock is released |
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114 | |||
115 | Returns: |
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116 | bool: True if lock acquired, False otherwise |
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117 | """ |
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118 | |||
119 | # read parameters from settings |
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120 | REDIS_CLIENT = redis.StrictRedis( |
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121 | host=settings.REDIS_HOST, |
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122 | port=settings.REDIS_PORT, |
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123 | db=settings.REDIS_DB) |
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124 | |||
125 | # this will be the redis lock |
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126 | lock = None |
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127 | |||
128 | # timeout for the lock (if expire condition) |
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129 | timeout_at = monotonic() + LOCK_EXPIRE - 3 |
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130 | |||
131 | if expire: |
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132 | lock = REDIS_CLIENT.lock(lock_id, timeout=LOCK_EXPIRE) |
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133 | |||
134 | else: |
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135 | lock = REDIS_CLIENT.lock(lock_id, timeout=None) |
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136 | |||
137 | status = lock.acquire(blocking=blocking) |
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138 | |||
139 | try: |
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140 | logger.debug("lock %s acquired is: %s" % (lock_id, status)) |
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141 | yield status |
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142 | |||
143 | finally: |
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144 | # we take advantage of using add() for atomic locking |
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145 | # don't release the lock if we didn't acquire it |
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146 | if status and ((monotonic() < timeout_at and expire) or not expire): |
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147 | logger.debug("Releasing lock %s" % lock_id) |
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148 | # don't release the lock if we exceeded the timeout |
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149 | # to lessen the chance of releasing an expired lock |
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150 | # owned by someone else |
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151 | # if no timeout and lock is taken, release it |
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152 | lock.release() |
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153 |