KStorage is a lightweight Kotlin Multiplatform library that provides a unified and type-safe interface for key-value storage across different platforms. It simplifies the process of storing and retrieving data by abstracting the underlying storage mechanisms.
- Multiplatform Support: Works across Android, iOS, Jvm and other Kotlin-supported platforms.
- Type-Safe API: Ensures compile-time type checking for stored values.
- Lightweight: Minimal overhead with a focus on simplicity and performance.
- Extensible: Easily integrate with various storage backends.
[versions]
klibs-kstorage = "<latest-version>"
[libraries]
klibs-kstorage = { module = "ru.astrainteractive.klibs:kstorage", version.ref = "klibs-kstorage" }implementation("ru.astrainteractive.klibs:kstorage:<version>")
// or version catalogs
implementation(libs.klibs.kstorage)class SettingsApi(private val intSettingsMap: MutableMap<String, Int>) {
/**
* The intSettingsMap["INT_KEY"] may return null
* But since we have factory = { 0 }, the krate will be non-null!
*/
val mutableKrate: MutableKrate<Int> = DefaultMutableKrate(
factory = { 0 },
loader = { intSettingsMap["INT_KEY"] },
saver = { value -> intSettingsMap["INT_KEY"] = value }
)
// Want to cache your value?
val cachedMutableKrate: CachedKrate<Int> = mutableKrate.asCachedMutableKrate()
// Want even more and make it StateFlow?
val stateFlowKrate: StateFlowMutableKrate<Int> = mutableKrate.asStateFlowMutableKrate()
// Have a nullable krate somewhere, but also somewhere need it non-null?
val nonNullableMutableKrate: MutableKrate<Int> = DefaultMutableKrate(
factory = { null },
loader = { intSettingsMap["INT_KEY"] },
saver = { value ->
if (value == null) intSettingsMap.remove("INT_KEY")
else intSettingsMap["INT_KEY"] = value
}
).withDefault { 102 }
// Don't want to call krate.cachedValue every time? Use delegates!
val cachedKrateValue by cachedMutableKrate
val cachedStateFlowKrateValue by stateFlowKrate
}Want suspend-style api? It's almost the same!
class SuspendSettingsApi(private val intSettingsMap: MutableMap<String, Int>) {
val suspendMutableKrate: SuspendMutableKrate<Int> = DefaultSuspendMutableKrate(
factory = { 0 },
loader = { intSettingsMap["INT_KEY"] },
saver = { value -> intSettingsMap["INT_KEY"] = value }
)
val stateFlowSuspendMutableKrate: StateFlowSuspendMutableKrate<Int> = DefaultStateFlowSuspendMutableKrate(
factory = { 0 },
loader = { intSettingsMap["INT_KEY"] },
saver = { value -> intSettingsMap["INT_KEY"] = value }
)
val nonNullableStateFlowSuspendMutableKrate = DefaultStateFlowSuspendMutableKrate(
factory = { null },
loader = { intSettingsMap["INT_KEY"] },
saver = { value ->
if (value == null) intSettingsMap.remove("INT_KEY")
else intSettingsMap["INT_KEY"] = value
}
).withDefault { 102 }
val nullableSuspendMutableKrate: SuspendMutableKrate<Int?> = DefaultSuspendMutableKrate(
factory = { null },
loader = { intSettingsMap["INT_KEY"] },
saver = { value ->
if (value != null) intSettingsMap["INT_KEY"] = value
else intSettingsMap.remove("INT_KEY")
}
)
val nullableStateFlowSuspendMutableKrate = nullableSuspendMutableKrate.asStateFlowMutableKrate()
val nullableStateFlowSuspendMutableKrate = nullableSuspendMutableKrate.asStateFlowMutableKrate { 10 }
}Want to use Jetpack DataStore? There's Flow API for your needs!
You can even integrate it with ROOM or on-disk files if you want!
class FlowApi {
private val key = intPreferencesKey("KEY_2")
// Create Jetpack DataStore instance
private val dataStore: DataStore<Preferences> = PreferenceDataStoreFactory.createWithPath {
val path = FileSystem.SYSTEM_TEMPORARY_DIRECTORY / "$key.preferences_pb"
val file = path.toFile()
if (file.exists()) file.delete()
path
}
// Create your krate
val flowKrate = DefaultFlowMutableKrate(
factory = { 10 },
loader = { dataStore.data.map { it[key] } },
saver = { value ->
dataStore.edit { preferences ->
preferences[key] = value
}
}
)
// Make it StateFlow if you need
val stateFlowValue = flowKrate.stateFlow(GlobalScope)
}class IntKrate(
key: String,
settingsMap: MutableMap<String, Int>
) : MutableKrate<Int?> by DefaultMutableKrate(
factory = { null },
loader = { settingsMap[key] },
saver = { value -> settingsMap[key] = value }
)data class CustomClass(val number: Int)
class CustomClassKrate(
key: String,
settingsMap: MutableMap<String, Int>
) : MutableKrate<CustomClass> by DefaultMutableKrate(
factory = { CustomClass(0) },
loader = {
val intValue = settingsMap[key]
if (intValue != null) CustomClass(intValue)
else null
},
saver = { value -> settings[key] = value.number }
)fun krateForUser(userId: String): MutableKrate<Int> {
return DefaultMutableKrate(
factory = { 0 },
loader = { settings[userId] ?: 0 },
saver = { value -> settings[key] = value }
)
}