Add TtlFunction to RedisCacheConfiguration for dynamic Time to Live.

We now support a TtlFunction to compute the time to live for cache entries.

Closes spring-projects#1433
Original pull request: spring-projects#2587

Author: Koooooo-7

src/main/java/org/springframework/data/redis/cache/RedisCache.java

@@ -185,7 +185,7 @@ public void put(Object key, @Nullable Object value) {
 		}
 
 		getCacheWriter().put(getName(), createAndConvertCacheKey(key), serializeCacheValue(cacheValue),
-			getCacheConfiguration().getTtl());
+			getCacheConfiguration().getTtl(key, value));
 	}
 
 	@Override
@@ -198,7 +198,7 @@ public ValueWrapper putIfAbsent(Object key, @Nullable Object value) {
 		}
 
 		byte[] result = getCacheWriter().putIfAbsent(getName(), createAndConvertCacheKey(key),
-			serializeCacheValue(cacheValue), getCacheConfiguration().getTtl());
+			serializeCacheValue(cacheValue), getCacheConfiguration().getTtl(key, value));
 
 		return result != null ? new SimpleValueWrapper(fromStoreValue(deserializeCacheValue(result))) : null;
 	}

src/main/java/org/springframework/data/redis/cache/RedisCacheConfiguration.java

@@ -17,6 +17,7 @@
 
 import java.nio.charset.StandardCharsets;
 import java.time.Duration;
+import java.util.function.BiFunction;
 import java.util.function.Consumer;
 
 import org.springframework.cache.Cache;
@@ -40,6 +41,7 @@
  * @author Christoph Strobl
  * @author Mark Paluch
  * @author John Blum
+ * @author Koy Zhuang
  * @since 2.0
  */
 public class RedisCacheConfiguration {
@@ -106,7 +108,7 @@ public static RedisCacheConfiguration defaultCacheConfig(@Nullable ClassLoader c
 
 		registerDefaultConverters(conversionService);
 
-		return new RedisCacheConfiguration(Duration.ZERO, DEFAULT_CACHE_NULL_VALUES, DEFAULT_USE_PREFIX,
+		return new RedisCacheConfiguration((k, v) -> Duration.ZERO, DEFAULT_CACHE_NULL_VALUES, DEFAULT_USE_PREFIX,
 				CacheKeyPrefix.simple(),
 				SerializationPair.fromSerializer(RedisSerializer.string()),
 				SerializationPair.fromSerializer(RedisSerializer.java(classLoader)), conversionService);
@@ -119,17 +121,17 @@ public static RedisCacheConfiguration defaultCacheConfig(@Nullable ClassLoader c
 
 	private final ConversionService conversionService;
 
-	private final Duration ttl;
+	private final BiFunction<Object, Object, Duration> ttlProvider;
 
 	private final SerializationPair<String> keySerializationPair;
 	private final SerializationPair<Object> valueSerializationPair;
 
 	@SuppressWarnings("unchecked")
-	private RedisCacheConfiguration(Duration ttl, Boolean cacheNullValues, Boolean usePrefix, CacheKeyPrefix keyPrefix,
+	private RedisCacheConfiguration(BiFunction<Object, Object, Duration> ttlProvider, Boolean cacheNullValues, Boolean usePrefix, CacheKeyPrefix keyPrefix,
 			SerializationPair<String> keySerializationPair, SerializationPair<?> valueSerializationPair,
 			ConversionService conversionService) {
 
-		this.ttl = ttl;
+		this.ttlProvider = ttlProvider;
 		this.cacheNullValues = cacheNullValues;
 		this.usePrefix = usePrefix;
 		this.keyPrefix = keyPrefix;
@@ -165,7 +167,7 @@ public RedisCacheConfiguration computePrefixWith(CacheKeyPrefix cacheKeyPrefix)
 
 		Assert.notNull(cacheKeyPrefix, "Function for computing prefix must not be null");
 
-		return new RedisCacheConfiguration(ttl, cacheNullValues, DEFAULT_USE_PREFIX, cacheKeyPrefix,
+		return new RedisCacheConfiguration(ttlProvider, cacheNullValues, DEFAULT_USE_PREFIX, cacheKeyPrefix,
 				keySerializationPair, valueSerializationPair, conversionService);
 	}
 
@@ -178,7 +180,7 @@ public RedisCacheConfiguration computePrefixWith(CacheKeyPrefix cacheKeyPrefix)
 	 * @return new {@link RedisCacheConfiguration}.
 	 */
 	public RedisCacheConfiguration disableCachingNullValues() {
-		return new RedisCacheConfiguration(ttl, DO_NOT_CACHE_NULL_VALUES, usePrefix, keyPrefix, keySerializationPair,
+		return new RedisCacheConfiguration(ttlProvider, DO_NOT_CACHE_NULL_VALUES, usePrefix, keyPrefix, keySerializationPair,
 				valueSerializationPair, conversionService);
 	}
 
@@ -191,12 +193,12 @@ public RedisCacheConfiguration disableCachingNullValues() {
 	 */
 	public RedisCacheConfiguration disableKeyPrefix() {
 
-		return new RedisCacheConfiguration(ttl, cacheNullValues, DO_NOT_USE_PREFIX, keyPrefix, keySerializationPair,
+		return new RedisCacheConfiguration(ttlProvider, cacheNullValues, DO_NOT_USE_PREFIX, keyPrefix, keySerializationPair,
 				valueSerializationPair, conversionService);
 	}
 
 	/**
-	 * Set the ttl to apply for cache entries. Use {@link Duration#ZERO} to declare an eternal cache.
+	 * Set the constant ttl to apply for cache entries. Use {@link Duration#ZERO} to declare an eternal cache.
 	 *
 	 * @param ttl must not be {@literal null}.
 	 * @return new {@link RedisCacheConfiguration}.
@@ -205,10 +207,25 @@ public RedisCacheConfiguration entryTtl(Duration ttl) {
 
 		Assert.notNull(ttl, "TTL duration must not be null");
 
-		return new RedisCacheConfiguration(ttl, cacheNullValues, usePrefix, keyPrefix, keySerializationPair,
+		return new RedisCacheConfiguration((k, v) -> ttl, cacheNullValues, usePrefix, keyPrefix, keySerializationPair,
 			valueSerializationPair, conversionService);
 	}
 
+	/**
+	 * Set the ttl Provider, which can dynamic provide ttl to apply for cache entries.
+	 * @param ttlProvider {@link BiFunction} calculate ttl with the actual original cache key and value,
+	 * which must not be {@literal null}, and the ttl must not be {@literal null} either.
+	 *
+	 * @return new {@link RedisCacheConfiguration}.
+	 */
+	public RedisCacheConfiguration entryTtlProvider(BiFunction<Object, Object, Duration> ttlProvider) {
+
+		Assert.notNull(ttlProvider, "ttlProvider must not be null");
+
+		return new RedisCacheConfiguration(ttlProvider, cacheNullValues, usePrefix, keyPrefix, keySerializationPair,
+				valueSerializationPair, conversionService);
+	}
+
 	/**
 	 * Define the {@link SerializationPair} used for de-/serializing cache keys.
 	 *
@@ -219,7 +236,7 @@ public RedisCacheConfiguration serializeKeysWith(SerializationPair<String> keySe
 
 		Assert.notNull(keySerializationPair, "KeySerializationPair must not be null");
 
-		return new RedisCacheConfiguration(ttl, cacheNullValues, usePrefix, keyPrefix, keySerializationPair,
+		return new RedisCacheConfiguration(ttlProvider, cacheNullValues, usePrefix, keyPrefix, keySerializationPair,
 				valueSerializationPair, conversionService);
 	}
 
@@ -233,7 +250,7 @@ public RedisCacheConfiguration serializeValuesWith(SerializationPair<?> valueSer
 
 		Assert.notNull(valueSerializationPair, "ValueSerializationPair must not be null");
 
-		return new RedisCacheConfiguration(ttl, cacheNullValues, usePrefix, keyPrefix, keySerializationPair,
+		return new RedisCacheConfiguration(ttlProvider, cacheNullValues, usePrefix, keyPrefix, keySerializationPair,
 				valueSerializationPair, conversionService);
 	}
 
@@ -247,7 +264,7 @@ public RedisCacheConfiguration withConversionService(ConversionService conversio
 
 		Assert.notNull(conversionService, "ConversionService must not be null");
 
-		return new RedisCacheConfiguration(ttl, cacheNullValues, usePrefix, keyPrefix, keySerializationPair,
+		return new RedisCacheConfiguration(ttlProvider, cacheNullValues, usePrefix, keyPrefix, keySerializationPair,
 			valueSerializationPair, conversionService);
 	}
 
@@ -301,9 +318,21 @@ public SerializationPair<Object> getValueSerializationPair() {
 	}
 
 	/**
-	 * @return The expiration time (ttl) for cache entries. Never {@literal null}.
+	 * @return The constant expiration time (ttl) for cache entries. Never {@literal null}.
 	 */
 	public Duration getTtl() {
+		Duration ttl = ttlProvider.apply(Object.class, Object.class);
+		Assert.notNull(ttl, "TTL duration must not be null");
+		return ttl;
+	}
+
+	/**
+	 * @return The expiration time (ttl) for cache entries with original key and value. Never {@literal null}.
+	 */
+	public Duration getTtl(Object key, Object val) {
+		Duration ttl = ttlProvider.apply(key, val);
+		Assert.notNull(ttl, "TTL duration must not be null");
+
 		return ttl;
 	}
 

src/test/java/org/springframework/data/redis/cache/RedisCacheConfigurationUnitTests.java

@@ -24,6 +24,9 @@
 import org.springframework.instrument.classloading.ShadowingClassLoader;
 import org.springframework.lang.Nullable;
 
+import java.time.Duration;
+import java.util.function.BiFunction;
+
 /**
  * Unit tests for {@link RedisCacheConfiguration}.
  *
@@ -56,6 +59,21 @@ void shouldAllowConverterRegistration() {
 		assertThat(config.getConversionService().canConvert(DomainType.class, String.class)).isTrue();
 	}
 
+
+	@Test
+	void shouldGetDynamicTtlGivenTtlProvider() {
+
+		BiFunction<Object, Object, Duration> ttlProvider = (key, val) ->
+				Duration.ofSeconds(Integer.parseInt(key + String.valueOf(val)));
+
+		RedisCacheConfiguration defaultCacheConfiguration = RedisCacheConfiguration.defaultCacheConfig()
+				.entryTtlProvider(ttlProvider);
+
+		assertThat(defaultCacheConfiguration.getTtl(1, 12)).isEqualTo(Duration.ofSeconds(112));
+		assertThat(defaultCacheConfiguration.getTtl(15, 22)).isEqualTo(Duration.ofSeconds(1522));
+		assertThat(defaultCacheConfiguration.getTtl(77, 0)).isEqualTo(Duration.ofSeconds(770));
+	}
+
 	private static class DomainType {
 
 	}