Delete media caches on startup (#1807)

Clear media caches on app startup

features/cachecleaner/api/build.gradle.kts

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+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+plugins {
+    id("io.element.android-library")
+    alias(libs.plugins.anvil)
+}
+
+android {
+    namespace = "io.element.android.features.cachecleaner.api"
+}
+
+dependencies {
+    implementation(projects.libraries.architecture)
+    implementation(libs.androidx.startup)
+}

features/cachecleaner/api/src/main/kotlin/io/element/android/features/cachecleaner/api/CacheCleaner.kt

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+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.element.android.features.cachecleaner.api
+
+interface CacheCleaner {
+    /**
+     * Clear the cache subdirs holding temporarily decrypted content (such as media and voice messages).
+     *
+     * Will fail silently in case of errors while deleting the files.
+     */
+    fun clearCache()
+}

features/cachecleaner/api/src/main/kotlin/io/element/android/features/cachecleaner/api/CacheCleanerBindings.kt

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+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.element.android.features.cachecleaner.api
+
+import com.squareup.anvil.annotations.ContributesTo
+import io.element.android.libraries.di.AppScope
+
+@ContributesTo(AppScope::class)
+interface CacheCleanerBindings {
+    fun cacheCleaner(): CacheCleaner
+}

features/cachecleaner/api/src/main/kotlin/io/element/android/features/cachecleaner/api/CacheCleanerInitializer.kt

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+/*
+ * Copyright (c) 2022 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.element.android.features.cachecleaner.api
+
+import android.content.Context
+import androidx.startup.Initializer
+import io.element.android.libraries.architecture.bindings
+
+class CacheCleanerInitializer : Initializer<Unit> {
+    override fun create(context: Context) {
+        context.bindings<CacheCleanerBindings>().cacheCleaner().clearCache()
+    }
+
+    override fun dependencies(): List<Class<out Initializer<*>>> = emptyList()
+}

features/cachecleaner/impl/build.gradle.kts

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+plugins {
+    id("io.element.android-compose-library")
+    alias(libs.plugins.anvil)
+}
+
+android {
+    namespace = "io.element.android.features.cachecleaner.impl"
+}
+
+anvil {
+    generateDaggerFactories.set(true)
+}
+
+dependencies {
+    implementation(projects.anvilannotations)
+    anvil(projects.anvilcodegen)
+    api(projects.features.cachecleaner.api)
+    implementation(projects.libraries.core)
+    implementation(projects.libraries.architecture)
+
+    testImplementation(libs.test.junit)
+    testImplementation(libs.coroutines.test)
+    testImplementation(libs.test.truth)
+    testImplementation(projects.tests.testutils)
+}

features/cachecleaner/impl/src/main/kotlin/io/element/android/features/cachecleaner/impl/DefaultCacheCleaner.kt

@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.element.android.features.cachecleaner.impl
+
+import com.squareup.anvil.annotations.ContributesBinding
+import io.element.android.features.cachecleaner.api.CacheCleaner
+import io.element.android.libraries.core.coroutine.CoroutineDispatchers
+import io.element.android.libraries.di.AppScope
+import io.element.android.libraries.di.CacheDirectory
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.launch
+import timber.log.Timber
+import java.io.File
+import javax.inject.Inject
+
+/**
+ * Default implementation of [CacheCleaner].
+ */
+@ContributesBinding(AppScope::class)
+class DefaultCacheCleaner @Inject constructor(
+    private val scope: CoroutineScope,
+    private val dispatchers: CoroutineDispatchers,
+    @CacheDirectory private val cacheDir: File,
+) : CacheCleaner {
+    companion object {
+        val SUBDIRS_TO_CLEANUP = listOf("temp/media", "temp/voice")
+    }
+
+    override fun clearCache() {
+        scope.launch(dispatchers.io) {
+            runCatching {
+                SUBDIRS_TO_CLEANUP.forEach {
+                    File(cacheDir.path, it).apply {
+                        if (exists()) {
+                            if (!deleteRecursively()) error("Failed to delete recursively cache directory $this")
+                        }
+                        if (!mkdirs()) error("Failed to create cache directory $this")
+                    }
+                }
+            }.onFailure {
+                Timber.e(it, "Failed to clear cache")
+            }
+        }
+    }
+}

features/cachecleaner/impl/src/test/kotlin/io/element/android/features/cachecleaner/impl/DefaultCacheCleanerTest.kt

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+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.element.android.features.cachecleaner.impl
+
+import com.google.common.truth.Truth
+import io.element.android.tests.testutils.testCoroutineDispatchers
+import kotlinx.coroutines.test.TestScope
+import kotlinx.coroutines.test.runTest
+import org.junit.Rule
+import org.junit.Test
+import org.junit.rules.TemporaryFolder
+import java.io.File
+
+class DefaultCacheCleanerTest {
+    @get:Rule
+    val temporaryFolder = TemporaryFolder()
+
+    @Test
+    fun `calling clearCache actually removes file in the SUBDIRS_TO_CLEANUP list`() = runTest {
+        // Create temp subdirs and fill with 2 files each
+        DefaultCacheCleaner.SUBDIRS_TO_CLEANUP.forEach {
+            File(temporaryFolder.root, it).apply {
+                mkdirs()
+                File(this, "temp1").createNewFile()
+                File(this, "temp2").createNewFile()
+            }
+        }
+
+        // Clear cache
+        aCacheCleaner().clearCache()
+
+        // Check the files are gone but the sub dirs are not.
+        DefaultCacheCleaner.SUBDIRS_TO_CLEANUP.forEach {
+            File(temporaryFolder.root, it).apply {
+                Truth.assertThat(exists()).isTrue()
+                Truth.assertThat(isDirectory).isTrue()
+                Truth.assertThat(listFiles()).isEmpty()
+            }
+        }
+    }
+
+    @Test
+    fun `clear cache fails silently`() = runTest {
+        // Set cache dir as unreadable, unwritable and unexecutable so that the deletion fails.
+        check(temporaryFolder.root.setReadable(false))
+        check(temporaryFolder.root.setWritable(false))
+        check(temporaryFolder.root.setExecutable(false))
+
+        aCacheCleaner().clearCache()
+    }
+
+    private fun TestScope.aCacheCleaner() = DefaultCacheCleaner(
+        scope = this,
+        dispatchers = this.testCoroutineDispatchers(true),
+        cacheDir = temporaryFolder.root,
+    )
+}