import os, uuid from typing import Any, Dict, List, Optional, Set, Tuple from redis.client import Redis from .._Backend import _Backend from ..Tools import key_to_str from .Mutex import Mutex DEFAULT_SERVICE_HOST = '127.0.0.1' DEFAULT_SERVICE_PORT = 6379 DEFAULT_DATABASE_ID = 0 def get_setting(settings : Dict[str, Any], name : str, default : Any) -> Any: value = settings.get(name, os.environ.get(name)) return default if value is None else value class RedisBackend(_Backend): def __init__(self, **settings) -> None: # pylint: disable=super-init-not-called host = get_setting(settings, 'REDIS_SERVICE_HOST', DEFAULT_SERVICE_HOST) port = get_setting(settings, 'REDIS_SERVICE_PORT', DEFAULT_SERVICE_PORT) dbid = get_setting(settings, 'REDIS_DATABASE_ID', DEFAULT_DATABASE_ID ) self._client = Redis.from_url('redis://{host}:{port}/{dbid}'.format(host=host, port=port, dbid=dbid)) self._mutex = Mutex(self._client) def lock(self, keys : List[List[str]], owner_key : Optional[str] = None) -> Tuple[bool, str]: str_keys = {key_to_str(key) for key in keys} owner_key = str(uuid.uuid4()) if owner_key is None else owner_key return self._mutex.acquire(str_keys, owner_key=owner_key, blocking=True) def unlock(self, keys : List[List[str]], owner_key : str) -> bool: str_keys = {key_to_str(key) for key in keys} return self._mutex.release(str_keys, owner_key) def keys(self) -> list: return [k.decode('UTF-8') for k in self._client.keys()] def exists(self, key : List[str]) -> bool: str_key = key_to_str(key) return self._client.exists(str_key) == 1 def delete(self, key : List[str]) -> bool: str_key = key_to_str(key) return self._client.delete(str_key) == 1 def dict_get(self, key : List[str], fields : List[str] = []) -> Dict[str, str]: str_key = key_to_str(key) if len(fields) == 0: keys_values = self._client.hgetall(str_key).items() else: fields = list(fields) keys_values = zip(fields, self._client.hmget(str_key, fields)) attributes = {} for key,value in keys_values: str_key = key.decode('UTF-8') if isinstance(key, bytes) else key attributes[str_key] = value.decode('UTF-8') if isinstance(value, bytes) else value return attributes def dict_update(self, key : List[str], fields : Dict[str, str] = {}) -> None: str_key = key_to_str(key) if len(fields) > 0: self._client.hset(str_key, mapping=fields) def dict_delete(self, key : List[str], fields : List[str] = []) -> None: str_key = key_to_str(key) if len(fields) == 0: self._client.delete(str_key) else: self._client.hdel(str_key, set(fields)) def list_get_all(self, key : List[str]) -> List[str]: str_key = key_to_str(key) return list(map(lambda m: m.decode('UTF-8'), self._client.lrange(str_key, 0, -1))) def list_push_last(self, key : List[str], item : str) -> None: str_key = key_to_str(key) self._client.rpush(str_key, item) def list_remove_first_occurrence(self, key : List[str], item: str) -> None: str_key = key_to_str(key) self._client.lrem(str_key, 1, item) def set_add(self, key : List[str], item : str) -> None: str_key = key_to_str(key) self._client.sadd(str_key, item) def set_has(self, key : List[str], item : str) -> bool: str_key = key_to_str(key) return self._client.sismember(str_key, item) == 1 def set_get_all(self, key : List[str]) -> Set[str]: str_key = key_to_str(key) return set(map(lambda m: m.decode('UTF-8'), self._client.smembers(str_key))) def set_remove(self, key : List[str], item : str) -> None: str_key = key_to_str(key) self._client.srem(str_key, item) def dump(self) -> List[Tuple[str, str, Any]]: entries = [] for str_key in self._client.keys(): str_key = str_key.decode('UTF-8') key_type = self._client.type(str_key) if key_type is not None: key_type = key_type.decode('UTF-8') key_type = { 'hash' : 'dict', 'list' : 'list', 'set' : 'set', 'string': 'str', }.get(key_type) key_content = { 'dict': lambda key: {k.decode('UTF-8'):v.decode('UTF-8') for k,v in self._client.hgetall(key).items()}, 'list': lambda key: [m.decode('UTF-8') for m in self._client.lrange(key, 0, -1)], 'set' : lambda key: {m.decode('UTF-8') for m in self._client.smembers(key)}, 'str' : lambda key: self._client.get(key).decode('UTF-8'), }.get(key_type, lambda key: 'UNSUPPORTED_TYPE') entries.append((str_key, key_type, key_content(str_key))) return entries