package orestes.bloomfilter.redis.helper;
import orestes.bloomfilter.FilterBuilder;
import orestes.bloomfilter.HashProvider.HashMethod;
import redis.clients.jedis.Transaction;
import java.util.HashMap;
import java.util.Map;
/**
* Encapsulates the Redis keys for the Redis Bloom Filters
*/
public class RedisKeys {
//Redis key constants
public static final String N_KEY = "n";
public static final String M_KEY = "m";
public static final String K_KEY = "k";
public static final String C_KEY = "c";
public static final String P_KEY = "p";
public static final String HASH_METHOD_KEY = "hashmethod";
public final String BITS_KEY;
public final String COUNTS_KEY;
public RedisKeys(String instanceName) {
this.BITS_KEY = instanceName + ":bits";
this.COUNTS_KEY = instanceName + ":counts";
}
public FilterBuilder persistConfig(RedisPool pool, FilterBuilder builder) {
return pool.safelyReturn(jedis -> {
FilterBuilder newConfig = null;
//Retry on concurrent changes
while (newConfig == null) {
if (!builder.overwriteIfExists() && jedis.exists(builder.name())) {
newConfig = this.parseConfigHash(jedis.hgetAll(builder.name()), builder.name());
} else {
Map<String, String> hash = this.buildConfigHash(builder);
jedis.watch(builder.name());
Transaction t = jedis.multi();
hash.forEach((k, v) -> t.hset(builder.name(), k, v));
if (t.exec() != null) {
newConfig = builder;
}
}
}
return newConfig;
});
}
public Map<String, String> buildConfigHash(FilterBuilder config) {
Map<String, String> map = new HashMap<>();
map.put(P_KEY, String.valueOf(config.falsePositiveProbability()));
map.put(M_KEY, String.valueOf(config.size()));
map.put(K_KEY, String.valueOf(config.hashes()));
map.put(N_KEY, String.valueOf(config.expectedElements()));
map.put(C_KEY, String.valueOf(config.countingBits()));
map.put(HASH_METHOD_KEY, config.hashMethod().name());
return map;
}
public FilterBuilder parseConfigHash(Map<String, String> map, String name) {
FilterBuilder config = new FilterBuilder();
config.name(name);
config.redisBacked(true);
config.falsePositiveProbability(Double.valueOf(map.get(P_KEY)));
config.size(Integer.valueOf(map.get(M_KEY)));
config.hashes(Integer.valueOf(map.get(K_KEY)));
config.expectedElements(Integer.valueOf(map.get(N_KEY)));
config.countingBits(Integer.valueOf(map.get(C_KEY)));
config.hashFunction(HashMethod.valueOf(map.get(HASH_METHOD_KEY)));
config.complete();
return config;
}
}