utils.py 2.5 KB

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  1. import json
  2. import redis
  3. import uuid
  4. class RedisLock:
  5. def __init__(self, redis_url, lock_name, timeout_secs):
  6. self.lock_name = lock_name
  7. self.lock_id = str(uuid.uuid4())
  8. self.timeout_secs = timeout_secs
  9. self.lock_obtained = False
  10. self.redis = redis.Redis.from_url(redis_url, decode_responses=True)
  11. def aquire_lock(self):
  12. # nx=True will only set this key if it _hasn't_ already been set
  13. self.lock_obtained = self.redis.set(
  14. self.lock_name, self.lock_id, nx=True, ex=self.timeout_secs
  15. )
  16. return self.lock_obtained
  17. def renew_lock(self):
  18. # xx=True will only set this key if it _has_ already been set
  19. return self.redis.set(
  20. self.lock_name, self.lock_id, xx=True, ex=self.timeout_secs
  21. )
  22. def release_lock(self):
  23. lock_value = self.redis.get(self.lock_name)
  24. if lock_value and lock_value == self.lock_id:
  25. self.redis.delete(self.lock_name)
  26. class RedisDict:
  27. def __init__(self, name, redis_url):
  28. self.name = name
  29. self.redis = redis.Redis.from_url(redis_url, decode_responses=True)
  30. def __setitem__(self, key, value):
  31. serialized_value = json.dumps(value)
  32. self.redis.hset(self.name, key, serialized_value)
  33. def __getitem__(self, key):
  34. value = self.redis.hget(self.name, key)
  35. if value is None:
  36. raise KeyError(key)
  37. return json.loads(value)
  38. def __delitem__(self, key):
  39. result = self.redis.hdel(self.name, key)
  40. if result == 0:
  41. raise KeyError(key)
  42. def __contains__(self, key):
  43. return self.redis.hexists(self.name, key)
  44. def __len__(self):
  45. return self.redis.hlen(self.name)
  46. def keys(self):
  47. return self.redis.hkeys(self.name)
  48. def values(self):
  49. return [json.loads(v) for v in self.redis.hvals(self.name)]
  50. def items(self):
  51. return [(k, json.loads(v)) for k, v in self.redis.hgetall(self.name).items()]
  52. def get(self, key, default=None):
  53. try:
  54. return self[key]
  55. except KeyError:
  56. return default
  57. def clear(self):
  58. self.redis.delete(self.name)
  59. def update(self, other=None, **kwargs):
  60. if other is not None:
  61. for k, v in other.items() if hasattr(other, "items") else other:
  62. self[k] = v
  63. for k, v in kwargs.items():
  64. self[k] = v
  65. def setdefault(self, key, default=None):
  66. if key not in self:
  67. self[key] = default
  68. return self[key]