Cache

Module for creating caches based on Caffeine or Redis using both declarative-style annotations and using their imperative style.

Caffeine

Library-based implementation of Caffeine for in-memory caches within the application.

Dependency

Java Kotlin

Dependency build.gradle:

implementation "ru.tinkoff.kora:cache-caffeine"

Module:

@KoraApp
public interface Application extends CaffeineCacheModule { }

Dependency build.gradle.kts:

implementation("ru.tinkoff.kora:cache-caffeine")

Module: `kotlin @KoraApp interface Application : CaffeineCacheModule

Configuration

Example of complete configuration for mycache.config cache, parameters are described in the CaffeineCacheConfig class (default or example values are specified):

Hocon YAML

mycache {
    config {
        expireAfterWrite = "10s" //(1)!
        expireAfterAccess = "10s" //(2)!
        initialSize = 10 //(3)!
        maximumSize = 10 //(4)!
    }
}

1. Time after which the value for the key will be deleted is reported after the value is added (optional)
2. Time after which the value for the key will be deleted, counted after a read operation (optional)
3. Initial cache size (helps to avoid cache expansion in case of active swelling) (optional)
4. Maximum cache size (When the boundary is reached or slightly earlier will exclude the least relevant values from the cache) (default is 100000)

mycache:
  config:
    expireAfterWrite: "10s" #(1)!
    expireAfterAccess: "10s" #(2)!
    initialSize: 10 #(3)!
    maximumSize: 10 #(4)!

1. Time after which the value for the key will be expired is reported after the value is added (optional)
2. Time after which the value for the key will be deleted is counted after a read operation (optional)
3. Initial cache size (helps to avoid cache expansion in case of active swelling) (optional)
4. Maximum cache size (When the boundary is reached or slightly earlier will exclude the least relevant values from the cache) (default is 100000)

Redis

Implementation based on in-memory database Redis and connection driver Lettuce.

Dependency

Java Kotlin

Dependency build.gradle:

implementation "ru.tinkoff.kora:cache-redis"

Module:

@KoraApp
public interface Application extends RedisCacheModule { }

Dependency build.gradle.kts:

implementation("ru.tinkoff.kora:cache-redis")

Module: `kotlin @KoraApp interface Application : RedisCacheModule

Configuration

It is required to separately configure the Lettuce driver to connect to Redis. A single connection is used for all caches.

Example of a complete configuration for lettuce driver, parameters are described in the LettuceConfig class (default or example values are specified):

Hocon YAML

lettuce {
    uri = "redis://locahost:6379" //(1)!
    user = "admin" //(2)!
    password = "12345" //(3)!
    database = 1 //(4)!
    protocol = "REP3" //(5)!
    socketTimeout = "15s" //(6)!
    commandTimeout = "15s" //(7)!
}

1. URI to connect to Redis (required)
2. Username for connection (optional)
3. Password for connection (optional)
4. Database number for connection (optional)
5. Protocol for connection
6. Connection timeout
7. Command execution timeout

lettuce:
  uri: "redis://locahost:6379" #(1)!
  user: "admin" #(2)!
  password: "12345" #(3)!
  database: 1 #(4)!
  protocol: "REP3" #(5)!
  socketTimeout: "15s" #(6)!
  commandTimeout: "15s" #(7)!

1. URI to connect to Redis (required)
2. Username for connection (optional)
3. Password for connection (optional)
4. Database number for connection (optional)
5. Protocol for connection
6. Connection timeout
7. Command execution timeout

Redis cache configurations configure the behavior of a particular cache.

Example of a complete configuration for mycache.config cache, parameters are described in the RedisCacheConfig class (example values are specified):

Hocon `YAML

mycache {
    config {    
        expireAfterWrite = "10s" //(1)!
        expireAfterAccess = "10s" //(2)!
        keyPrefix = "mykey" //(3)!
    }
}

1. When writing, sets the expiration time (optional)
2. When reading, sets the time expiration (optional)
3. Prefix a key in a particular cache to avoid key collisions within a Redis database, can be an empty string then keys will be without prefixes (required)

mycache:
  config:
    expireAfterWrite: "10s" #(1)!
    expireAfterAccess: "10s" #(2)!
    keyPrefix: "mykey" //(3)!

1. Sets the expiration time when writing (optional)
2. When reading, sets the time expiration (optional)
3. Prefix a key in a specific cache to avoid key collisions within a Redis database, can be an empty string then keys will be without prefixes (required)

Usage

Creating a cache will require registering a typed @Cache contract. The contract interface should only be inherited from Kora's provided implementations: CaffeineCache / RedisCache. For such @Cache an implementation will be created and added to the graph, it can be used to enforce dependencies.

To register @Cache and specify the config, it is required to annotate with the @Cache annotation where the value argument means the full path to the config.

Java Kotlin

@Cache("mycache.config")
public interface MyCache extends CaffeineCache<String, String> { }

`kotlin @Cache("mycache.config") interface MyCache : CaffeineCache<String, String>

Imperative

Caches are available for injection as dependencies on the interface and can be used in conjunction with declarative operations.

The CaffeineCache implementation provides basic Cache interface contracts for synchronous operations, and RedisCache provides both Cache and AsyncCache for asynchronous operations with CompletionStage signatures.

The interfaces provide get, delete, update, batch, etc. operations. Cache implementations can also provide self-specific contracts.

Declarative

All aspect use cases will assume the cache implementation above.

Get

To cache and retrieve a value from the cache for the get() method, annotate it with the @Cacheable annotation.

The key for the cache is compiled from the method arguments, the order of the arguments matters, in this case it will be compiled from the value arg1.

Java Kotlin

@Component
public class SomeService {

    @Cacheable(MyCache.class)
    public String get(String arg1) {
        // do something
    }
}

@Component
class SomeService {

    @Cacheable(MyCache::class)
    fun get(arg1: String): String {
        // do something
    }
}

Put

To add values to the cache via the put() method, annotate it with the @CachePut annotation. The method annotated with @CachePut will be called and its value put into the cache defined in value.

The key for the cache is compiled from the method arguments, the order of the arguments matters, in this case it will be compiled from the value arg1.

Java Kotlin

@Component
public class SomeService {

    @CachePut(MyCache.class)
    public String put(String arg1) {
        // do something
    }
}

@Component
class SomeService {

    @CachePut(MyCache::class)
    fun put(arg1: String): String {
        // do something
    }
}

Invalidate

To remove a keyed value from the cache via the evict() method, annotate it with the @CacheInvalidate annotation. The method annotated with @CacheInvalidate will be called and then the keyed values for the cache defined in value will be deleted by key.

The key for the cache is compiled from the method arguments, the order of the arguments matters, in this case it will be compiled from the value arg1.

Java Kotlin

@Component
public class SomeService {

    @CacheInvalidate(MyCache.class)
    public void evict(String arg1) {
        // do something
    }
}

@Component
class SomeService {

    @CacheInvalidate(MyCache::class)
    fun evict(arg1: String) {
        // do something
    }
}

Invalidate all

To remove all values from the cache via the evictAll() method, annotate it with the @CacheInvalidate annotation and specify the invalidateAll = true parameter.

The method annotated with @CacheInvalidate will be called and then all of the cache values defined in value will be removed.

Java Kotlin

@Component
public class SomeService {

    @CacheInvalidate(value = MyCache.class, invalidateAll = true)
    public void evictAll(String arg1) {
        // do something
    }
}

@Component
class SomeService {

    @CacheInvalidate(value = MyCache::class, invalidateAll = true)
    fun evict(arg1: String) {
        // do something
    }
}

Composite cache

In case you have multiple caches, you need to connect both modules and specify the appropriate number of annotations over the method.

Java Kotlin

@KoraApp
public interface Application extends RedisCacheModule, CaffeineCacheModule {

    @Cache("mycache.caffeine.config")
    public interface MyCaffeineCache extends CaffeineCache<String, String> { }

    @Cache("mycache.redis.config")
    public interface MyRedisCache extends RedisCache<String, String> { }
}

@KoraApp
interface Application : RedisCacheModule, CaffeineCacheModule { 

    @Cache("mycache.caffeine.config")
    interface MyCaffeineCache : CaffeineCache<String, String> { }

    @Cache("mycache.redis.config")
    interface MyRedisCache : RedisCache<String, String> { }
}

And the annotated class itself is like this:

Java Kotlin

@Component
public class SomeService {

    @Cacheable(MyCaffeineCache.class)
    @Cacheable(MyRedisCache.class)
    public String get(String arg1) {
        // do something
    }
}

@Component
class SomeService {

    @Cacheable(MyCaffeineCache::class)
    @Cacheable(MyRedisCache::class)
    fun get(arg1: String): String {
        // do something
    }
}

The order of aspect calls corresponds to the order of annotations above the method, top to bottom.

Key

In case the cache key represents 1 argument, it is required to register Cache with a signature corresponding to the key and value types.

Java Kotlin

@Cache("mycache.config")
public interface MyCache extends CaffeineCache<String, String> { }

@Cache("mycache.config")
interface MyCache : CaffeineCache<String, String>

Conversion

In case an argument cannot be converted to a cache key, the cache implementation will require an appropriate converter with the CacheKeyMapper interface, in case there are 2 arguments for the key then CacheKeyMapper2 will be required, and so on.

Such a converter can also be provided manually using the @Mapping annotation, example of converting a complex object into a simple cache key:

Java Kotlin

@Component
public class SomeService {

    public record UserContext(String userId, String traceId) { }

    public static final class UserContextMapping implements CacheKeyMapper<String, UserContext> {

        @Nonnull
        @Override
        public String map(UserContext arg) {
            return arg.userId();
        }
    }

    @Mapping(UserContextMapping.class)
    @Cacheable(MyCache.class)
    public String get(UserContext context) {
        // do something
    }
}

@Component
class SomeService {

    @Cacheable(MyCache::class)
    fun get(arg1: String, arg2: BigDecimal): String {
        // do something
    }
}

Composite key

In case the cache key represents N arguments, it is required to register Cache using an class to describe such a key.

Example for Cache where the composite key consists of 2 elements:

Java Kotlin

It is supposed to create its own record class that would describe the composite key.

@Cache("mycache.config")
public interface MyCache extends CaffeineCache<MyCache.Key, String> {

    record Key(String k1, Long k2) { }
}

It is supposed to create its own data class that would describe the composite key.

@Cache("mycache.config")
interface MyCache : CaffeineCache<MyCache.Key, String> {

    data class Key(val k1: String, val k2: Long)
}

If RedisCache is used, it is assumed that all composite key arguments will default to non null, or a custom key resolver will need to be used.

Argument ordering

If the method accepts arguments that you want to exclude from the composite key, or the order of the arguments does not match the order of the arguments of the composite key constructor, you should use the parameters annotation attribute and define which method arguments to use and in what order.

Java Kotlin

@Component
public class SomeService {

    @Cacheable(value = MyCache.class, parameters = {"arg1", "arg2"})
    public String get(Long arg2, String arg3, String arg1) {
        // do something
    }
}

@Component
class SomeService {

    @Cacheable(value = MyCache::class, parameters = ["arg1", "arg2"])
    fun get(arg2: Long, arg3: String, arg1: String): String {
        // do something
    }
}

Loadable Cache

The library provides a component for building an entity that combines GET and PUT operations without using aspects - LoadableCache

Java Kotlin

@Cache("mycache.config")
public interface MyCache extends CaffeineCache<String, String> { }

@KoraApp
public interface Application : CaffeineCacheModule {

    default LoadableCache<String, String> loadableCache(MyCache cache, SomeService someService) {
        return cache.asLoadable(someService::loadEntity);
    }
}

@Cache("mycache.config")
interface MyCache : CaffeineCache<String, String>

@KoraApp
interface Application : CaffeineCacheModule {

    fun loadableCache(
        cache: MyCache,
        someService: SomeService,
    ): LoadableCache<String, String> {
        return cache.asLoadable(someService::loadEntity)
    }
}

Signatures

Available signatures for repository methods out of the box:

Java Kotlin

Class must be non final in order for aspects to work.

The T refers to the type of the return value.

• T myMethod()
• @Nullable T myMethod()
• Optional<T> myMethod()
• Mono<T> myMethod() Project Reactor (require dependency)

Class must be open in order for aspects to work.

By T we mean the type of the return value, either T?, or Unit.

• myMethod(): T
• suspend myMethod(): T Kotlin Coroutine (require dependency as implementation)