org.springframework.data.redis.connection.ValueEncoding Maven / Gradle / Ivy
/*
* Copyright 2018 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.data.redis.connection;
import java.util.Optional;
import org.springframework.lang.Nullable;
import org.springframework.util.ObjectUtils;
/**
* {@link ValueEncoding} is used for the Redis internal data representation used in order to store the value associated
* with a key.
*
* - Strings
* - {@link RedisValueEncoding#RAW} or {@link RedisValueEncoding#INT}
* - Lists
* - {@link RedisValueEncoding#ZIPLIST} or {@link RedisValueEncoding#LINKEDLIST}
* - Sets
* - {@link RedisValueEncoding#INTSET} or {@link RedisValueEncoding#HASHTABLE}
* - Hashes
* - {@link RedisValueEncoding#ZIPLIST} or {@link RedisValueEncoding#HASHTABLE}
* - Sorted Sets
* - {@link RedisValueEncoding#ZIPLIST} or {@link RedisValueEncoding#SKIPLIST}
* - Absent keys
* - {@link RedisValueEncoding#VACANT}
*
*
* @author Christoph Strobl
* @since 2.1
*/
public interface ValueEncoding {
@Nullable
String raw();
/**
* Get the {@link ValueEncoding} for given {@code encoding}.
*
* @param encoding can be {@literal null}.
* @return never {@literal null}.
*/
static ValueEncoding of(@Nullable String encoding) {
return RedisValueEncoding.lookup(encoding).orElse(() -> encoding);
}
/**
* Default {@link ValueEncoding} implementation of encodings used in Redis.
*
* @author Christoph Strobl
* @since 2.1
*/
enum RedisValueEncoding implements ValueEncoding {
/**
* Normal string encoding.
*/
RAW("raw"), //
/**
* 64 bit signed interval String representing an integer.
*/
INT("int"), //
/**
* Space saving representation for small lists, hashes and sorted sets.
*/
ZIPLIST("ziplist"), //
/**
* Encoding for large lists.
*/
LINKEDLIST("linkedlist"), //
/**
* Space saving representation for small sets that contain only integers.ø
*/
INTSET("intset"), //
/**
* Encoding for large hashes.
*/
HASHTABLE("hashtable"), //
/**
* Encoding for sorted sets of any size.
*/
SKIPLIST("skiplist"), //
/**
* No encoding present due to non existing key.
*/
VACANT(null);
private final @Nullable String raw;
RedisValueEncoding(@Nullable String raw) {
this.raw = raw;
}
@Override
public String raw() {
return raw;
}
@Nullable
static Optional lookup(@Nullable String encoding) {
for (ValueEncoding valueEncoding : values()) {
if (ObjectUtils.nullSafeEquals(valueEncoding.raw(), encoding)) {
return Optional.of(valueEncoding);
}
}
return Optional.empty();
}
}
}