Kotlin Utility Library

A library of tools and extensions for Java and Kotlin designed to simplify working with various third-party libraries. Currently, it includes two tools for interacting with Memcached.

Features

• MemCache: An interface that defines a simple in-memory, synchronous cache designed for single-instance applications.
• MemCachedImpl: An implementation of the MemCached interface that uses a ConcurrentHashMap, making it thread-safe and well-suited for concurrent environments.
• MemCacheAsync: An interface that defines an asynchronous cache designed for use with the Ratpack framework. It returns a ratpack.Promise, enabling seamless integration with Ratpack’s asynchronous programming model.
• MemCacheRedis: An implementation of the MemCacheAsync interface that utilizes Redis as the underlying storage through the Lettuce package. This implementation is ideal for multi-instance applications, as it leverages Redis to provide distributed caching.

The primary goal of both MemCached and MemCacheAsync is to atomically check for the presence of a key and save data only if the key is unique, ensuring consistent and reliable caching behavior.

Installation

Add the library to your project by including it in your build.gradle or build.gradle.kts:

dependencies {
    implementation("io.github.xmm:jvmcraft:<VERSION>")
}

Usage Examples

Using MemCache

val memCache: MemCached<String, String> = MemCachedImpl(Duration.ofMinutes(5))
val isSaved = memCache.putIfNotExist("key", "value", ttl = 300)
assertTrue(isSaved)

val retrieved: String? = memCache.get("key")
assertEqual("value", retrieved)

Using MemCacheAsync

val redisClient = RedisClient.create("redis://localhost")
val mapper: ObjectMapper = jacksonObjectMapper()
val memCacheAsync: MemCachedAsync<String, String> = MemCachedRedis(redisClient, mapper, Duration.ofMinutes(5))
ExecHarness.runSingle { exec ->
    memCacheAsync.putIfNotExist("newKey", "value").then { wasSet ->
        assertTrue(wasSet)
        memCacheAsync.get("newKey").then { result ->
            assertEquals("value", result)
        }
    }
}

License

This project is licensed under the MIT License. See the LICENSE file for details.