Add a CacheStore module.

libraries/cachestore/api/build.gradle.kts

@@ -0,0 +1,13 @@
+/*
+ * Copyright (c) 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+plugins {
+    id("io.element.android-library")
+}
+
+android {
+    namespace = "io.element.android.libraries.cachestore.api"
+}

libraries/cachestore/api/src/main/kotlin/io/element/android/libraries/cachestore/api/CacheData.kt

@@ -0,0 +1,13 @@
+/*
+ * Copyright (c) 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.libraries.cachestore.api
+
+data class CacheData(
+    val value: String,
+    val updatedAt: Long,
+)

libraries/cachestore/api/src/main/kotlin/io/element/android/libraries/cachestore/api/CacheStore.kt

@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.libraries.cachestore.api
+
+interface CacheStore {
+    suspend fun storeData(key: String, data: CacheData)
+    suspend fun getData(key: String): CacheData?
+    suspend fun deleteData(key: String)
+}

libraries/cachestore/impl/build.gradle.kts

@@ -0,0 +1,48 @@
+import extension.setupDependencyInjection
+import extension.testCommonDependencies
+
+/*
+ * Copyright (c) 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+plugins {
+    id("io.element.android-library")
+    alias(libs.plugins.sqldelight)
+}
+
+android {
+    namespace = "io.element.android.libraries.cachestore.impl"
+}
+
+setupDependencyInjection()
+
+dependencies {
+    implementation(projects.libraries.androidutils)
+    implementation(projects.libraries.core)
+    implementation(projects.libraries.encryptedDb)
+    api(projects.libraries.cachestore.api)
+    implementation(libs.sqldelight.driver.android)
+    implementation(libs.sqlcipher)
+    implementation(libs.sqlite)
+    implementation(projects.libraries.di)
+    implementation(libs.sqldelight.coroutines)
+
+    testCommonDependencies(libs)
+    testImplementation(libs.sqldelight.driver.jvm)
+}
+
+sqldelight {
+    databases {
+        create("CacheDatabase") {
+            // https://sqldelight.github.io/sqldelight/2.1.0/android_sqlite/migrations/
+            // To generate a .db file from your latest schema, run this task
+            // ./gradlew generateDebugCacheDatabaseSchema
+            // Test migration by running
+            // ./gradlew verifySqlDelightMigration
+            schemaOutputDirectory = File("src/main/sqldelight/databases")
+            verifyMigrations = true
+        }
+    }
+}

libraries/cachestore/impl/src/main/kotlin/io/element/android/libraries/cachestore/impl/CacheDataMapper.kt

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.libraries.cachestore.impl
+
+import io.element.android.libraries.cachestore.api.CacheData
+import java.util.Date
+import io.element.android.libraries.cachestore.CacheData as DbCacheData
+
+internal fun CacheData.toDbModel(key: String): DbCacheData {
+    return DbCacheData(
+        key = key,
+        value_ = value,
+        updatedAt = updatedAt.time,
+    )
+}
+
+internal fun DbCacheData.toApiModel(): CacheData {
+    return CacheData(
+        value = value_,
+        updatedAt = Date(updatedAt),
+    )
+}

libraries/cachestore/impl/src/main/kotlin/io/element/android/libraries/cachestore/impl/DatabaseCacheStore.kt

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.libraries.cachestore.impl
+
+import dev.zacsweers.metro.AppScope
+import dev.zacsweers.metro.ContributesBinding
+import dev.zacsweers.metro.SingleIn
+import io.element.android.libraries.cachestore.api.CacheData
+import io.element.android.libraries.cachestore.api.CacheStore
+
+@SingleIn(AppScope::class)
+@ContributesBinding(AppScope::class)
+class DatabaseCacheStore(
+    private val database: CacheDatabase,
+) : CacheStore {
+    override suspend fun getData(key: String): CacheData? {
+        return database.cacheDataQueries.selectData(key)
+            .executeAsOneOrNull()
+            ?.toApiModel()
+    }
+
+    override suspend fun storeData(key: String, data: CacheData) {
+        database.cacheDataQueries.insertData(
+            data.toDbModel(key)
+        )
+    }
+
+    override suspend fun deleteData(key: String) {
+        database.cacheDataQueries.deleteData(key)
+    }
+}

libraries/cachestore/impl/src/main/kotlin/io/element/android/libraries/cachestore/impl/di/CacheStoreModule.kt

@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.libraries.cachestore.impl.di
+
+import android.content.Context
+import dev.zacsweers.metro.AppScope
+import dev.zacsweers.metro.BindingContainer
+import dev.zacsweers.metro.ContributesTo
+import dev.zacsweers.metro.Provides
+import dev.zacsweers.metro.SingleIn
+import io.element.android.libraries.cachestore.impl.CacheDatabase
+import io.element.android.libraries.di.annotations.ApplicationContext
+import io.element.encrypteddb.SqlCipherDriverFactory
+import io.element.encrypteddb.passphrase.RandomSecretPassphraseProvider
+
+@BindingContainer
+@ContributesTo(AppScope::class)
+object CacheStoreModule {
+    @Provides
+    @SingleIn(AppScope::class)
+    fun provideCacheDatabase(
+        @ApplicationContext context: Context,
+    ): CacheDatabase {
+        val name = "cache_database"
+        val secretFile = context.getDatabasePath("$name.key")
+
+        // Make sure the parent directory of the key file exists, otherwise it will crash in older Android versions
+        val parentDir = secretFile.parentFile
+        if (parentDir != null && !parentDir.exists()) {
+            parentDir.mkdirs()
+        }
+
+        val passphraseProvider = RandomSecretPassphraseProvider(context, secretFile)
+        val driver = SqlCipherDriverFactory(passphraseProvider)
+            .create(CacheDatabase.Schema, "$name.db", context)
+        return CacheDatabase(driver)
+    }
+}

libraries/cachestore/impl/src/main/sqldelight/io/element/android/libraries/cachestore/CacheData.sq

@@ -0,0 +1,26 @@
+--------------------------------------------------------------------
+-- Current version of the DB is the highest value of filename
+-- in the folder `sqldelight/databases`.
+--
+-- When upgrading the schema, you have to create a file .sqm in the
+-- `sqldelight/databases` folder and run the following task to
+-- generate a .db file using the latest schema
+-- > ./gradlew generateDebugCacheDatabaseSchema
+--------------------------------------------------------------------
+
+CREATE TABLE CacheData (
+    key TEXT NOT NULL PRIMARY KEY,
+    value TEXT NOT NULL,
+    updatedAt INTEGER NOT NULL
+);
+
+
+selectData:
+SELECT * FROM CacheData WHERE key = ?;
+
+-- insert or update data by key
+insertData:
+INSERT INTO CacheData VALUES ? ON CONFLICT(key) DO UPDATE SET value = excluded.value, updatedAt = excluded.updatedAt;
+
+deleteData:
+DELETE FROM CacheData WHERE key = ?;

libraries/cachestore/impl/src/test/kotlin/io/element/android/libraries/sessionstorage/impl/DatabaseCacheStoreTest.kt

@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.libraries.sessionstorage.impl
+
+import app.cash.sqldelight.driver.jdbc.sqlite.JdbcSqliteDriver
+import com.google.common.truth.Truth.assertThat
+import io.element.android.libraries.cachestore.api.CacheData
+import io.element.android.libraries.cachestore.impl.CacheDatabase
+import io.element.android.libraries.cachestore.impl.DatabaseCacheStore
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.runTest
+import org.junit.Before
+import org.junit.Test
+import io.element.android.libraries.cachestore.CacheData as DbCacheData
+
+private const val A_KEY = "aKey"
+private const val A_DATA_1 = "aData1"
+private const val A_DATA_2 = "aData2"
+
+class DatabaseCacheStoreTest {
+    private lateinit var database: CacheDatabase
+    private lateinit var databaseCacheStore: DatabaseCacheStore
+
+    @OptIn(ExperimentalCoroutinesApi::class)
+    @Before
+    fun setup() {
+        // Initialise in memory SQLite driver
+        val driver = JdbcSqliteDriver(JdbcSqliteDriver.IN_MEMORY)
+        CacheDatabase.Schema.create(driver)
+
+        database = CacheDatabase(driver)
+        databaseCacheStore = DatabaseCacheStore(
+            database = database,
+        )
+    }
+
+    @Test
+    fun `storeData persists the CacheData into the DB, deleteData deletes it`() = runTest {
+        // Assert that no data is stored for the key
+        assertThat(database.cacheDataQueries.selectData(A_KEY).executeAsOneOrNull()).isNull()
+        // Store data
+        databaseCacheStore.storeData(A_KEY, CacheData(A_DATA_1, 1))
+        assertThat(database.cacheDataQueries.selectData(A_KEY).executeAsOneOrNull()).isEqualTo(
+            DbCacheData(
+                key = A_KEY,
+                value_ = A_DATA_1,
+                updatedAt = 1,
+            )
+        )
+        // Update data
+        databaseCacheStore.storeData(A_KEY, CacheData(A_DATA_2, 2))
+        assertThat(database.cacheDataQueries.selectData(A_KEY).executeAsOneOrNull()).isEqualTo(
+            DbCacheData(
+                key = A_KEY,
+                value_ = A_DATA_2,
+                updatedAt = 2,
+            )
+        )
+        // Delete data
+        databaseCacheStore.deleteData(A_KEY)
+        assertThat(database.cacheDataQueries.selectData(A_KEY).executeAsOneOrNull()).isNull()
+    }
+}

libraries/cachestore/impl/src/test/kotlin/io/element/android/libraries/sessionstorage/impl/Fixtures.kt

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.libraries.sessionstorage.impl
+
+import io.element.android.libraries.cachestore.CacheData
+import java.util.Date
+
+internal fun aCacheData(
+    key: String = "aKey",
+    value: String = "aValue",
+    updatedAt: Date = Date(),
+) = CacheData(
+    key = key,
+    value_ = value,
+    updatedAt = updatedAt.time,
+)

libraries/cachestore/test/build.gradle.kts

@@ -0,0 +1,17 @@
+/*
+ * Copyright (c) 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+plugins {
+    id("io.element.android-library")
+}
+
+android {
+    namespace = "io.element.android.libraries.cachestore.test"
+}
+
+dependencies {
+    implementation(projects.libraries.cachestore.api)
+}

libraries/cachestore/test/src/main/kotlin/io/element/android/libraries/sessionstorage/test/CacheData.kt

@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.libraries.sessionstorage.test
+
+import io.element.android.libraries.cachestore.api.CacheData
+
+fun aCacheData(
+    value: String = "aValue",
+    updatedAt: Long = 0,
+) = CacheData(
+    value = value,
+    updatedAt = updatedAt,
+)

libraries/cachestore/test/src/main/kotlin/io/element/android/libraries/sessionstorage/test/InMemoryCacheStore.kt

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.libraries.sessionstorage.test
+
+import io.element.android.libraries.cachestore.api.CacheData
+import io.element.android.libraries.cachestore.api.CacheStore
+
+class InMemoryCacheStore(
+    initialData: Map<String, CacheData> = emptyMap(),
+) : CacheStore {
+    val dataMap = initialData.toMutableMap()
+
+    override suspend fun storeData(key: String, data: CacheData) {
+        dataMap[key] = data
+    }
+
+    override suspend fun getData(key: String): CacheData? {
+        return dataMap[key]
+    }
+
+    override suspend fun deleteData(key: String) {
+        dataMap.remove(key)
+    }
+}

plugins/src/main/kotlin/extension/DependencyHandleScope.kt

@@ -104,6 +104,7 @@ fun DependencyHandlerScope.allLibrariesImpl() {
     implementation(project(":libraries:architecture"))
     implementation(project(":libraries:dateformatter:impl"))
     implementation(project(":libraries:di"))
+    implementation(project(":libraries:cachestore:impl"))
     implementation(project(":libraries:session-storage:impl"))
     implementation(project(":libraries:mediapickers:impl"))
     implementation(project(":libraries:mediaupload:impl"))