Reference: Storage

Installation

dependencies {
    
    implementation(platform("org.http4k:http4k-bom:6.36.0.0"))

    implementation("org.http4k:http4k-connect-storage-core")
}

http4k-connect contains a simple lightweight pluggable Key-Value storage abstraction in the http4k-connect-storage-core module, which can be used to serialise objects to an underlying store.

Standard Operations are:

  • Set
  • Get
  • Remove
  • Get all keys with a particular prefix
  • Remove all keys with a particular prefix

In-Memory Storage

All data is held in process memory.

Kotlin in_memory.kt
package content.ecosystem.connect.reference.storage.core

import org.http4k.connect.storage.InMemory
import org.http4k.connect.storage.Storage

data class AnEntity(val name: String)

val storage = Storage.InMemory<AnEntity>()
val store = run {
    storage["myKey"] = AnEntity("hello")
    println(storage["myKey"])
    storage.removeAll("myKey")
}

On-Disk Storage

All data is serialised to disk by passing it though an http4k AutoMarshalling adapter (see the http4k-format-XXX modules). In the example below we use a JSON adapter backed by Moshi (which is the default).

Kotlin on_disk.kt
package content.ecosystem.connect.reference.storage.core

import org.http4k.connect.storage.Disk
import org.http4k.connect.storage.Storage
import org.http4k.format.Moshi
import java.io.File

val diskStorage = Storage.Disk<AnEntity>(File("."), Moshi)
val diskStore = run {
    diskStorage["myKey"] = AnEntity("hello")
    println(diskStorage["myKey"])
    diskStorage.removeAll("myKey")
}
scarf