🌐 KtorCache#

Ktor's HttpClient has an excellent built-in HttpCache plugin, but by default, it relies on simple memory structures.

We provide a KtorCache adapter, allowing you to plug either InMemoryCache or FileCache directly into Ktor's networking layer.

🚀 Installation#

Ensure you have the Ktor Client dependencies installed alongside KtorCache:

[libraries]
kommons-cache-ktor = { group = "dev.datlag.kommons", name = "cache-ktor", version.ref = "cache" }
ktor-client = { group = "io.ktor", name = "ktor-client-core", version = "..." }

Add the dependency to your module:

dependencies {
    implementation(libs.kommons.cache.ktor)
    implementation(libs.ktor.client)
}

🛠️ Usage#

The KtorCache adapter includes factory operators that completely simplify integration.

In-Memory HTTP Caching#

When you initialize a KtorCache with an InMemoryCache backing it, it automatically applies a smart SizeCalculator. This means the 50 megabyte limit applies to the actual downloaded byte payloads of the HTTP responses, rather than arbitrarily counting 50 HTTP entries!

val client = HttpClient {
    install(HttpCache) {
        // Keeps HTTP responses in RAM, dropping oldest responses once 50 MB is reached.
        publicStorage(
            KtorCache(maxSize = 50.mb) {
                evictionPolicy = EvictionPolicy.LRU
            }
        )
    }
}

Persistent Disk HTTP Caching#

Want to persist your web responses to disk so your app loads data instantly even after a reboot?

Simply use the Path based factory. The adapter will automatically inject the highly-optimized binary CachedResponseDataCodec to serialize your Ktor responses safely to the disk.

val persistentClient = HttpClient {
    install(HttpCache) {
        // Caches up to 250 MB of HTTP Responses to the local file system.
        publicStorage(
            KtorCache(
                directory = Path("my_ktor_cache"),
                maxSize = 250.mb
            ) {
                evictionPolicy = EvictionPolicy.LFU
            }
        )
    }
}