redis_cache.py

import redis
import fakeredis
import ujson
from contextlib import suppress


class RedisClient:
    def __init__(self, host=None, port=6379, db=0, prefix='libtorrent'):
        self.prefix = prefix
        self.host = host

        if self.host is None:
            self.r = fakeredis.FakeStrictRedis(decode_responses=True)
        else:
            self.r = redis.Redis(host=host, port=port,
                                 db=db, decode_responses=True)

    def eval(self, value):
        with suppress(Exception):
            return eval(value)
        return value

    def set(self, key, value, overwrite=False):
        key = str(key).strip()

        if overwrite:
            self.delete(key)

        if isinstance(value, dict):
            for (k, v) in value.items():
                self.r.set(f"{self.prefix}.{key}.{k}", str(v))
        else:
            self.r.set(f"{self.prefix}.{key}", str(value))

    def get(self, key):
        key = str(key).strip()
        value = self.r.get(f"{self.prefix}.{key}")
        if value is not None:
            return self.eval(value)

        keys = list(self.r.scan_iter(f"{self.prefix}.{key}.*"))
        if keys:
            data = {}
            for k in keys:
                orig_key = k.lstrip(self.prefix)[1:].lstrip(key)[1:]
                data[orig_key] = self.eval(self.r.get(k))
            return data

    def all_keys(self):
        return list(self.r.scan_iter(f"{self.prefix}.*"))
    
    def parent_keys(self):
        return set([x.lstrip(f"{self.prefix}.").split(".")[0]
            for x in list(self.r.scan_iter(f"{self.prefix}.*"))])

    def delete(self, key):
        keys = list(self.r.scan_iter(f"{self.prefix}.{key}*"))
        if keys:
            [self.r.delete(k) for k in keys]
    
    def purge(self):
        self.delete("*")