Store/README.md
Matt 4689ca59c7
[Store5] Target Android, iOS, JVM, JS (#493)
* [Temp] Remove all modules

* Remove references to Store 4

* Update CHANGELOG

* Update README

* Add Store 5 foundation

Signed-off-by: mramotar <mramotar@dropbox.com>

* Dump API

Signed-off-by: mramotar <mramotar@dropbox.com>

* Delete scratch API

Signed-off-by: mramotar <mramotar@dropbox.com>

* Fix workflow

Signed-off-by: mramotar <mramotar@dropbox.com>

* Rename clear to delete

Signed-off-by: mramotar <mramotar@dropbox.com>

* Flatten sealed classes

Signed-off-by: mramotar <mramotar@dropbox.com>

* Make ShareableLruCache threadsafe

Signed-off-by: mramotar <mramotar@dropbox.com>

* First stab

Signed-off-by: mramotar <mramotar@dropbox.com>

* Remove scope

Signed-off-by: mramotar <mramotar@dropbox.com>

* Remove scope

Signed-off-by: mramotar <mramotar@dropbox.com>

* Cherry pick

Signed-off-by: mramotar <mramotar@dropbox.com>

* Remove scope

Signed-off-by: mramotar <mramotar@dropbox.com>

* Fix multithreading LRU cache test

Signed-off-by: mramotar <mramotar@dropbox.com>

* Remove logs

Signed-off-by: mramotar <mramotar@dropbox.com>

* Cover multithreaded market write

Signed-off-by: mramotar <mramotar@dropbox.com>

* Remove redundant advance

Signed-off-by: mramotar <mramotar@dropbox.com>

* Remove Stately !!

Signed-off-by: mramotar <mramotar@dropbox.com>

* Use mutex

Signed-off-by: mramotar <mramotar@dropbox.com>

* Refactor Store to interface with factory

Signed-off-by: mramotar <mramotar@dropbox.com>

* Rename to MemoryLruCache

Signed-off-by: mramotar <mramotar@dropbox.com>

* Rename to RealMarket

Signed-off-by: mramotar <mramotar@dropbox.com>

* Rename to delete all

Signed-off-by: mramotar <mramotar@dropbox.com>

* Rename tests

Signed-off-by: mramotar <mramotar@dropbox.com>

* Clean up Android LRU cache tests

Signed-off-by: mramotar <mramotar@dropbox.com>

* Fix market factory

Signed-off-by: mramotar <mramotar@dropbox.com>

* Rename ConflictResolver to Bookkeeper

Signed-off-by: mramotar <mramotar@dropbox.com>

* From desktop

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Fix tests

Signed-off-by: mramotar <mramotar@dropbox.com>

* Document Lightswitch

Signed-off-by: mramotar <mramotar@dropbox.com>

* Guard against multiple releases

Signed-off-by: mramotar <mramotar@dropbox.com>

* Rename to StoreSafety

Signed-off-by: mramotar <mramotar@dropbox.com>

* Use withLock

Signed-off-by: mramotar <mramotar@dropbox.com>

* Document load

Signed-off-by: mramotar <mramotar@dropbox.com>

* Make delete and deleteAll optional

Signed-off-by: mramotar <mramotar@dropbox.com>

* Add foundation for sample app

Signed-off-by: mramotar <mramotar@dropbox.com>

* Remove Kotlin serialization

Signed-off-by: mramotar <mramotar@dropbox.com>

* Rename masterLock to mainLock

Signed-off-by: mramotar <mramotar@dropbox.com>

* Rename Bookkeeper methods

Signed-off-by: mramotar <mramotar@dropbox.com>

* Rename using Market/Network prefix

Signed-off-by: mramotar <mramotar@dropbox.com>

* Make NetworkFetcher an interface

Signed-off-by: mramotar <mramotar@dropbox.com>

* Make NetworkUpdater an interface

Signed-off-by: mramotar <mramotar@dropbox.com>

* Make MarketReader an interface

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Make MarketWriter an interface

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Add app and main activity

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Add scoping

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Remove unused mipmap

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Add Dagger components

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Remove icon

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Draft README.md

Signed-off-by: mramotar <mramotar@dropbox.com>

* Wire account tab

Signed-off-by: mramotar <mramotar@dropbox.com>

* Remove campaigns sample

Signed-off-by: mramotar <mramotar@dropbox.com>

* Add Market wiring

Signed-off-by: mramotar <mramotar@dropbox.com>

* Remove unused resources

Signed-off-by: mramotar <mramotar@dropbox.com>

* Fix Gradle plugins

Signed-off-by: mramotar <mramotar@dropbox.com>

* Fix rebase issue

Signed-off-by: mramotar <mramotar@dropbox.com>

* Fix wiring

Signed-off-by: mramotar <mramotar@dropbox.com>

* Introduce GoodValidator

Signed-off-by: mramotar <mramotar@dropbox.com>

* Add unit tests

Signed-off-by: mramotar <mramotar@dropbox.com>

* Only load if read not in progress

Signed-off-by: mramotar <mramotar@dropbox.com>

* Update CI and autogenerate Swift Package (#469)

* Update CI and autogenerate Swift Package

Signed-off-by: mramotar <mramotar@dropbox.com>

* Update CI and autogenerate Swift Package

Signed-off-by: mramotar <mramotar@dropbox.com>

* Run on MacOS

Signed-off-by: mramotar <mramotar@dropbox.com>

* Only run on push

Signed-off-by: mramotar <mramotar@dropbox.com>

Signed-off-by: mramotar <mramotar@dropbox.com>

* Use KMM Bridge (#470)

* Clean up deps

Signed-off-by: mramotar <mramotar@dropbox.com>

* Use KMM Bridge

Signed-off-by: mramotar <mramotar@dropbox.com>

* Fix version prefix

Signed-off-by: mramotar <mramotar@dropbox.com>

Signed-off-by: mramotar <mramotar@dropbox.com>

* Fix Maven publish plugin (#471)

Signed-off-by: mramotar <mramotar@dropbox.com>

Signed-off-by: mramotar <mramotar@dropbox.com>

* Refactor fetcher and updater to 1:1 with market

Signed-off-by: mramotar <mramotar@dropbox.com>

* Reset Fake API

Signed-off-by: mramotar <mramotar@dropbox.com>

* Remove unused imports

Signed-off-by: mramotar <mramotar@dropbox.com>

* Run check on store

Signed-off-by: mramotar <mramotar@dropbox.com>

* Format

Signed-off-by: mramotar <mramotar@dropbox.com>

* Api Dump + Format

Signed-off-by: mramotar <mramotar@dropbox.com>

* Add default config

Signed-off-by: mramotar <mramotar@dropbox.com>

* Check all

Signed-off-by: mramotar <mramotar@dropbox.com>

* Add ItemValidator

Signed-off-by: mramotar <mramotar@dropbox.com>

* README.md

Signed-off-by: mramotar <mramotar@dropbox.com>

* With ViewModel

Signed-off-by: mramotar <mramotar@dropbox.com>

* Format

Signed-off-by: mramotar <mramotar@dropbox.com>

* Implement fetcher and updater

Signed-off-by: mramotar <mramotar@dropbox.com>

* Cleanup Readme/Remove Persister (#474)

* cleanup readme and rename a few concepts

* fix tests

* readme cleanup

* readme cleanup

* readme cleanup

* readme cleanup

* lint

Co-authored-by: Mike Nakhimovich <mnakhimovich@Mikes-MBP.localdomain>

* Regenerate gradle-wrapper.jar

Signed-off-by: mramotar <mramotar@dropbox.com>

* Prepare for release 5.0.0-alpha1

Signed-off-by: mramotar <mramotar@dropbox.com>

* Prepare for next development version

Signed-off-by: mramotar <mramotar@dropbox.com>

* Target browser and Node!

Signed-off-by: mramotar <mramotar@dropbox.com>

* Only generate Swift Package on release

Signed-off-by: mramotar <mramotar@dropbox.com>

* Fix iOS targets

Signed-off-by: mramotar <mramotar@dropbox.com>

* Fix workflow

Signed-off-by: mramotar <mramotar@dropbox.com>

* Fix workflow

Signed-off-by: mramotar <mramotar@dropbox.com>

* Run manually only

Signed-off-by: mramotar <mramotar@dropbox.com>

* Update RELEASING.md

Signed-off-by: mramotar <mramotar@dropbox.com>

* Update README.md

Signed-off-by: matt-ramotar <mramotar@dropbox.com>

* Run on macos

Signed-off-by: mramotar <mramotar@dropbox.com>

* Remove Dropbox references

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Prepare for release 5.0.0-alpha02

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Prepare next development version

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Update CHANGELOG.md

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Add tests for complex markets

Signed-off-by: mramotar <mramotar@dropbox.com>

* Fix import

Signed-off-by: mramotar <mramotar@dropbox.com>

* Fix tests

Signed-off-by: mramotar <mramotar@dropbox.com>

* Format

Signed-off-by: mramotar <mramotar@dropbox.com>

* Distinguish network, store, and common representations

Signed-off-by: mramotar <mramotar@dropbox.com>

* Update NetworkFetcher

Signed-off-by: mramotar <mramotar@dropbox.com>

* Refactor inputs + outputs

Signed-off-by: mramotar <mramotar@dropbox.com>

* Update sample + fix tests

Signed-off-by: mramotar <mramotar@dropbox.com>

* Update comment

Signed-off-by: mramotar <mramotar@dropbox.com>

* Port Cache

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Update README.md

Signed-off-by: Matt <mramotar@dropbox.com>

* Move README.md

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Update README.md

Signed-off-by: Matt <mramotar@dropbox.com>

* Update README.md

Signed-off-by: Matt <mramotar@dropbox.com>

* Merge multicast from github.com/MobileNativeFoundation/Store/tree/Kmp

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Fix build errors

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Format

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Format

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Move to market package

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Add Fetcher + FetcherResult

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Api dump + format

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Port Store

Signed-off-by: mramotar <mramotar@dropbox.com>

* Add unit test

Signed-off-by: mramotar <mramotar@dropbox.com>

* Format

Signed-off-by: mramotar <mramotar@dropbox.com>

* Fix tests

Signed-off-by: mramotar <mramotar@dropbox.com>

* Update .gitignore

Signed-off-by: mramotar <mramotar@dropbox.com>

* Api Dump

Signed-off-by: mramotar <mramotar@dropbox.com>

* Cover stream and fresh

Signed-off-by: mramotar <mramotar@dropbox.com>

* Fix tests

Signed-off-by: mramotar <mramotar@dropbox.com>

* Run on MacOS

Signed-off-by: mramotar <mramotar@dropbox.com>

* Use Java 11

Signed-off-by: mramotar <mramotar@dropbox.com>

* Add HotFlowStoreTest

Signed-off-by: mramotar <mramotar@dropbox.com>

* Add gradle plugin repository

Signed-off-by: mramotar <mramotar@dropbox.com>

* Update check.yml

Signed-off-by: Matt <mramotar@dropbox.com>

* Update check.yml

Signed-off-by: Matt <mramotar@dropbox.com>

* Add ClearAllStoreTests

Signed-off-by: mramotar <mramotar@dropbox.com>

* Use Java 11

Signed-off-by: mramotar <mramotar@dropbox.com>

* Format

Signed-off-by: mramotar <mramotar@dropbox.com>

* Fix tests

Signed-off-by: mramotar <mramotar@dropbox.com>

* Remove binary-compatibility-validator

Signed-off-by: mramotar <mramotar@dropbox.com>

* Ignore Store podspec

Signed-off-by: mramotar <mramotar@dropbox.com>

* Update check.yml

Signed-off-by: mramotar <mramotar@dropbox.com>

* Use Java 11

Signed-off-by: mramotar <mramotar@dropbox.com>

* Use channel flow

Signed-off-by: mramotar <mramotar@dropbox.com>

* Format

Signed-off-by: mramotar <mramotar@dropbox.com>

* Fix tests

Signed-off-by: mramotar <mramotar@dropbox.com>

* Revert workflow

Signed-off-by: mramotar <mramotar@dropbox.com>

* Disable transformation

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Disable transformation

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Disable transformation

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Add ClearStoreByKeyTests

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Add FetcherResponseTests

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Add KeyTrackerTests

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Add StoreWithInMemoryCacheTests

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Add StreamWithoutSourceOfTruthTests

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* ValueFetcherTests

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Add MapIndexedTests

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Add FetcherControllerTests

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Add StoreResponseTests

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Add SourceOfTruthErrorsTests

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Add SourceOfTruthWithBarrierTests

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Remove Market and update README

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Remove Market sample

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Update README

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

* Update CHANGELOG

Signed-off-by: Matt Ramotar <mramotar@dropbox.com>

Signed-off-by: mramotar <mramotar@dropbox.com>
Signed-off-by: Matt Ramotar <mramotar@dropbox.com>
Signed-off-by: matt-ramotar <mramotar@dropbox.com>
Signed-off-by: Matt <mramotar@dropbox.com>
Co-authored-by: Mike Nakhimovich <digitalbuddha@users.noreply.github.com>
Co-authored-by: Mike Nakhimovich <mnakhimovich@Mikes-MBP.localdomain>
2022-12-18 10:53:21 -05:00

14 KiB
Raw Blame History

Store 5

Why We Made Store

  • Modern software needs data representations to be fluid and always available.
  • Users expect their UI experience to never be compromised (blocked) by new data loads. Whether an application is social, news or business-to-business, users expect a seamless experience both online and offline.
  • International users expect minimal data downloads as many megabytes of downloaded data can quickly result in astronomical phone bills.

Store is a Kotlin library for loading data from remote and local sources.

Overview

A Store is responsible for managing a particular data request. When you create an implementation of a Store, you provide it with a Fetcher, a function that defines how data will be fetched over network. You can also define how your Store will cache data in-memory and on-disk. Since Store returns your data as a Flow, threading is a breeze! Once a Store is built, it handles the logic around data flow, allowing your views to use the best data source and ensuring that the newest data is always available for later offline use.

Store leverages multiple request throttling to prevent excessive calls to the network and disk cache. By utilizing Store, you eliminate the possibility of flooding your network with the same request while adding two layers of caching (memory and disk) as well as ability to add disk as a source of truth where you can modify the disk directly without going through Store (works best with databases that can provide observables sources like Jetpack Room , SQLDelight or Realm)

How to include in your project

Artifacts are hosted on Maven Central.

STORE_VERSION = "5.0.0-alpha03"

Android

implementation "org.mobilenativefoundation.store:store5:$STORE_VERSION"

Multiplatform (Common, JVM, Native, JS)

commonMain {
  dependencies {
    implementation("org.mobilenativefoundation.store:store5:$STORE_VERSION")
  }
}

Fully Configured Store

Let's start by looking at what a fully configured Store looks like. We will then walk through simpler examples showing each piece:

StoreBuilder
  .from(
    fetcher = Fetcher.of { api.fetchSubreddit(it, "10").data.children.map(::toPosts) },
    sourceOfTruth = SourceOfTruth.of(
      reader = db.postDao()::loadPosts,
      writer = db.postDao()::insertPosts,
      delete = db.postDao()::clearFeed,
      deleteAll = db.postDao()::clearAllFeeds
    )
  ).build()

With the above setup you have:

  • In-memory caching for rotation
  • Disk caching for when users are offline
  • Throttling of API calls when parallel requests are made for the same resource
  • Rich API to ask for data whether you want cached, new or a stream of future data updates.

And now for the details:

Creating a Store

You create a Store using a builder. The only requirement is to include a Fetcher which is just a typealias to a function that returns a Flow<FetcherResult<ReturnType>>.

val store = StoreBuilder
  .from(Fetcher.ofFlow { articleId -> api.getArticle(articleId) }) // api returns Flow<Article>
  .build()

Store uses generic keys as identifiers for data. A key can be any value object that properly implements toString(), equals() and hashCode(). When your Fetcher function is called, it will be passed a particular Key value. Similarly, the key will be used as a primary identifier within caches (Make sure to have a proper hashCode()!!).

Note: We highly recommend using built-in types that implement equals and hashcode or Kotlin data classes for complex keys.

Public Interface - Stream

The primary function provided by a Store instance is the stream function which has the following signature:

fun stream(request: StoreRequest<Key>): Flow<StoreResponse<Output>>

Each stream call receives a StoreRequest object, which defines which key to fetch and which data sources to utilize. The response is a Flow of StoreResponse. StoreResponse is a Kotlin sealed class that can be either a Loading, Data or Error instance. Each StoreResponse includes an origin field which specifies where the event is coming from.

  • The Loading class only has an origin field. This can provide you information like "network is fetching data", which can be a good signal to activate the loading spinner in your UI.
  • The Data class has a value field which includes an instance of the type returned by Store.
  • The Error class includes an error field that contains the exception thrown by the given origin.

When an error happens, Store does not throw an exception, instead, it wraps it in a StoreResponse.Error type which allows Flow to continue so that it can still receive updates that might be triggered by either changes in your data source or subsequent fetch operations.

viewModelScope.launch {
  store.stream(StoreRequest.cached(key = key, refresh = true)).collect { response ->
    when (response) {
      is StoreResponse.Loading -> showLoadingSpinner()
      is StoreResponse.Data -> {
        if (response.origin == ResponseOrigin.Fetcher) hideLoadingSpinner()
        updateUI(response.value)
      }
      is StoreResponse.Error -> {
        if (response.origin == ResponseOrigin.Fetcher) hideLoadingSpinner()
        showError(response.error)
      }
    }
  }
}

For convenience, there are Store.get(key) and Store.fresh(key) extension functions.

  • suspend fun Store.get(key: Key): Value: This method returns a single value for the given key. If available, it will be returned from the in memory cache or the sourceOfTruth. An error will be thrown if no value is available in either the cache or sourceOfTruth, and the fetcher fails to load the data from the network.
  • suspend fun Store.fresh(key: Key): Value: This method returns a single value for the given key that is obtained by querying the fetcher. An error will be thrown if the fetcher fails to load the data from the network, regardless of whether any value is available in the cache or sourceOfTruth.
lifecycleScope.launchWhenStarted {
  val article = store.get(key)
  updateUI(article)
}

The first time you call to suspend store.get(key), the response will be stored in an in-memory cache and in the sourceOfTruth, if provided. All subsequent calls to store.get(key) with the same Key will retrieve the cached version of the data, minimizing unnecessary data calls. This prevents your app from fetching fresh data over the network (or from another external data source) in situations when doing so would unnecessarily waste bandwidth and battery. A great use case is any time your views are recreated after a rotation, they will be able to request the cached data from your Store. Having this data available can help you avoid the need to retain this in the view layer.

By default, 100 items will be cached in memory for 24 hours. You may pass in your own memory policy to override the default policy.

Skipping Memory/Disk

Alternatively, you can call store.fresh(key) to get a suspended result that skips the memory ( and optional disk cache).

A good use case is overnight background updates use fresh() to make sure that calls to store.get() will not have to hit the network during normal usage. Another good use case for fresh() is when a user wants to pull to refresh.

Calls to both fresh() and get() emit one value or throw an error.

Stream

For real-time updates, you may also call store.stream() which returns a Flow<T> that emits each time a new item is returned from your store. You can think of stream as a way to create reactive streams that update when you db or memory cache updates

example calls:

lifecycleScope.launchWhenStarted {
  store.stream(
    StoreRequest.cached(
      3,
      refresh = false
    )
  ) //will get cached value followed by any fresh values, refresh will also trigger network call if set to `true` even if the data is available in cache or disk.
    .collect {}
  store.stream(StoreRequest.fresh(3)) //skip cache, go directly to fetcher
    .collect {}
}

Inflight Debouncer

To prevent duplicate requests for the same data, Store offers an inflight debouncer. If the same request is made as a previous identical request that has not completed, the same response will be returned. This is useful for situations when your app needs to make many async calls for the same data at startup or when users are obsessively pulling to refresh. As an example, The New York Times news app asynchronously calls ConfigStore.get() from 12 different places on startup. The first call blocks while all others wait for the data to arrive. We have seen a dramatic decrease in the app's data usage after implementing this inflight logic.

Disk as Cache

Stores can enable disk caching by passing a SourceOfTruth into the builder. Whenever a new network request is made, the Store will first write to the disk cache and then read from the disk cache.

Disk as Single Source of Truth

Providing sourceOfTruth whose reader function can return a Flow<Value?> allows you to make Store treat your disk as source of truth. Any changes made on disk, even if it is not made by Store, will update the active Store streams.

This feature, combined with persistence libraries that provide observable queries (Jetpack Room , SQLDelight or Realm) allows you to create offline first applications that can be used without an active network connection while still providing a great user experience.

StoreBuilder
  .from(
    fetcher = Fetcher.of { api.fetchSubreddit(it, "10").data.children.map(::toPosts) },
    sourceOfTruth = SourceOfTruth.of(
      reader = db.postDao()::loadPosts,
      writer = db.postDao()::insertPosts,
      delete = db.postDao()::clearFeed,
      deleteAll = db.postDao()::clearAllFeeds
    )
  ).build()

Stores dont care how youre storing or retrieving your data from disk. As a result, you can use Stores with object storage or any database (Realm, SQLite, CouchDB, Firebase etc). Technically, there is nothing stopping you from implementing an in-memory cache for the "sourceOfTruth" implementation and instead have two levels of in-memory caching--one with inflated and one with deflated models, allowing for sharing of the “sourceOfTruth” cache data between stores.

If using SQLite we recommend working with Room which returns a Flow from a query

The above builder is how we recommend working with data on Android. With the above setup you have:

  • Memory caching with TTL & Size policies
  • Disk caching with simple integration with Room
  • In-flight request management
  • Ability to get cached data or bust through your caches (get() vs. fresh())
  • Ability to listen for any new emissions from network (stream)
  • Structured Concurrency through APIs build on Coroutines and Kotlin Flow

Configuring in-memory Cache

You can configure in-memory cache with the MemoryPolicy:

StoreBuilder
  .from(
    fetcher = Fetcher.of { api.fetchSubreddit(it, "10").data.children.map(::toPosts) },
    sourceOfTruth = SourceOfTruth.of(
      reader = db.postDao()::loadPosts,
      writer = db.postDao()::insertPosts,
      delete = db.postDao()::clearFeed,
      deleteAll = db.postDao()::clearAllFeeds
    )
  ).cachePolicy(
    MemoryPolicy.builder<Any, Any>()
      .setMaxSize(10)
      .setExpireAfterAccess(10.minutes) // or setExpireAfterWrite(10.minutes)
      .build()
  ).build()
  • setMaxSize(maxSize: Long) sets the maximum number of entries to be kept in the cache before starting to evict the least recently used items.
  • setExpireAfterAccess(expireAfterAccess: Duration) sets the maximum time an entry can live in the cache since the last access, where "access" means reading the cache, adding a new cache entry, and replacing an existing entry with a new one. This duration is also known as time-to-idle (TTI).
  • setExpireAfterWrite(expireAfterWrite: Duration) sets the maximum time an entry can live in the cache since the last write, where "write" means adding a new cache entry and replacing an existing entry with a new one. This duration is also known as time-to-live (TTL).

Note that setExpireAfterAccess and setExpireAfterWrite cannot both be set at the same time.

Clearing store entries

You can delete a specific entry by key from a store, or clear all entries in a store.

Store with no sourceOfTruth

val store = StoreBuilder
  .from(
    fetcher = Fetcher.of { key: String ->
      api.fetchData(key)
    }).build()

The following will clear the entry associated with the key from the in-memory cache:

store.clear("10")

The following will clear all entries from the in-memory cache:

store.clearAll()

Store with sourceOfTruth

When store has a sourceOfTruth, you'll need to provide the delete and deleteAll functions for clear(key) and clearAll() to work:

StoreBuilder
  .from(
    fetcher = Fetcher.of { api.fetchData(key) },
    sourceOfTruth = SourceOfTruth.of(
      reader = dao::loadData,
      writer = dao::writeData,
      delete = dao::clearDataByKey,
      deleteAll = dao::clearAllData
    )
  ).build()

The following will clear the entry associated with the key from both the in-memory cache and the sourceOfTruth:

store.clear("myKey")

The following will clear all entries from both the in-memory cache and the sourceOfTruth:

store.clearAll()

License

Copyright (c) 2022 Mobile Native Foundation.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.