Issue mozilla-mobile#7021: Integrate the ThumbnailDiskCache with Brow…

…serThumbnails

components/browser/thumbnails/build.gradle

@@ -35,6 +35,7 @@ tasks.withType(org.jetbrains.kotlin.gradle.tasks.KotlinCompile).all {
 dependencies {
     implementation project(':browser-state')
     implementation project(':concept-engine')
+    implementation project(':support-images')
     implementation project(':support-ktx')
 
     implementation Dependencies.androidx_annotation

components/browser/thumbnails/src/main/java/mozilla/components/browser/thumbnails/ThumbnailsMiddleware.kt

@@ -0,0 +1,36 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package mozilla.components.browser.thumbnails
+
+import mozilla.components.browser.state.action.BrowserAction
+import mozilla.components.browser.state.action.ContentAction
+import mozilla.components.browser.state.state.BrowserState
+import mozilla.components.browser.thumbnails.storage.ThumbnailStorage
+import mozilla.components.lib.state.Middleware
+import mozilla.components.lib.state.MiddlewareStore
+
+/**
+ * [Middleware] implementation for handling [ContentAction.UpdateThumbnailAction] and storing
+ * the thumbnail to the disk cache.
+ */
+class ThumbnailsMiddleware(
+    private val thumbnailStorage: ThumbnailStorage
+) : Middleware<BrowserState, BrowserAction> {
+    override fun invoke(
+        store: MiddlewareStore<BrowserState, BrowserAction>,
+        next: (BrowserAction) -> Unit,
+        action: BrowserAction
+    ) {
+        when (action) {
+            is ContentAction.UpdateThumbnailAction -> {
+                // Store the captured tab screenshot from the EngineView when the session's
+                // thumbnail is updated.
+                thumbnailStorage.saveThumbnail(action.sessionId, action.thumbnail)
+            }
+        }
+
+        next(action)
+    }
+}

components/browser/thumbnails/src/main/java/mozilla/components/browser/thumbnails/ThumbnailsUseCases.kt

@@ -0,0 +1,45 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package mozilla.components.browser.thumbnails
+
+import android.graphics.Bitmap
+import mozilla.components.browser.state.selector.findTab
+import mozilla.components.browser.state.store.BrowserStore
+import mozilla.components.browser.thumbnails.storage.ThumbnailStorage
+import mozilla.components.support.base.log.logger.Logger
+
+/**
+ * Contains use cases related to the thumbnails feature.
+ */
+class ThumbnailsUseCases(
+    store: BrowserStore,
+    thumbnailStorage: ThumbnailStorage
+) {
+    /**
+     * Load thumbnail use case.
+     */
+    class LoadThumbnailUseCase internal constructor(
+        private val store: BrowserStore,
+        private val thumbnailStorage: ThumbnailStorage
+    ) {
+        private val logger = Logger("ThumbnailsUseCases")
+
+        /**
+         * Loads the thumbnail for a tab from its in-memory [ContentState] or from the disk cache
+         * of [ThumbnailStorage].
+         */
+        suspend operator fun invoke(sessionIdOrUrl: String): Bitmap? {
+            val tab = store.state.findTab(sessionIdOrUrl)
+            tab?.content?.thumbnail?.let {
+                logger.debug("Loaded thumbnail from memory (sessionIdOrUrl = $sessionIdOrUrl)")
+                return@invoke it
+            }
+
+            return thumbnailStorage.loadThumbnail(sessionIdOrUrl).await()
+        }
+    }
+
+    val loadThumbnail: LoadThumbnailUseCase by lazy { LoadThumbnailUseCase(store, thumbnailStorage) }
+}

components/browser/thumbnails/src/main/java/mozilla/components/browser/thumbnails/storage/ThumbnailStorage.kt

@@ -0,0 +1,79 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package mozilla.components.browser.thumbnails.storage
+
+import android.content.Context
+import android.graphics.Bitmap
+import androidx.annotation.WorkerThread
+import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Deferred
+import kotlinx.coroutines.asCoroutineDispatcher
+import kotlinx.coroutines.async
+import mozilla.components.browser.thumbnails.R
+import mozilla.components.browser.thumbnails.utils.ThumbnailDiskCache
+import mozilla.components.support.base.log.logger.Logger
+import mozilla.components.support.images.DesiredSize
+import mozilla.components.support.images.decoder.AndroidImageDecoder
+import java.util.concurrent.Executors
+
+private const val MAXIMUM_SCALE_FACTOR = 2.0f
+
+// Number of worker threads we are using internally.
+private const val THREADS = 3
+
+internal val sharedDiskCache = ThumbnailDiskCache()
+
+/**
+ * Thumbnail storage layer which handles saving and loading the thumbnail from the disk cache.
+ */
+class ThumbnailStorage(
+    private val context: Context,
+    jobDispatcher: CoroutineDispatcher = Executors.newFixedThreadPool(THREADS).asCoroutineDispatcher()
+) {
+    private val decoders = AndroidImageDecoder()
+    private val logger = Logger("ThumbnailStorage")
+    private val maximumSize = context.resources.getDimensionPixelSize(R.dimen.mozac_browser_thumbnails_maximum_size)
+    private val scope = CoroutineScope(jobDispatcher)
+
+    /**
+     * Asynchronously loads a thumbnail [Bitmap] for the given session ID or url.
+     */
+    fun loadThumbnail(sessionIdOrUrl: String): Deferred<Bitmap?> = scope.async {
+        loadThumbnailInternal(sessionIdOrUrl).also { loadedThumbnail ->
+            if (loadedThumbnail != null) {
+                logger.debug("Loaded thumbnail from disk (sessionIdOrUrl = $sessionIdOrUrl)")
+            } else {
+                logger.debug("No thumbnail loaded (sessionIdOrUrl = $sessionIdOrUrl)")
+            }
+        }
+    }
+
+    @WorkerThread
+    private fun loadThumbnailInternal(sessionIdOrUrl: String): Bitmap? {
+        val desiredSize = DesiredSize(
+            targetSize = context.resources.getDimensionPixelSize(R.dimen.mozac_browser_thumbnails_size_default),
+            maxSize = maximumSize,
+            maxScaleFactor = MAXIMUM_SCALE_FACTOR
+        )
+
+        val data = sharedDiskCache.getThumbnailData(context, sessionIdOrUrl)
+
+        if (data != null) {
+            return decoders.decode(data, desiredSize)
+        }
+
+        return null
+    }
+
+    /**
+     * Stores the given thumbnail [Bitmap] into the disk cache with the provided session ID or url
+     * as its key.
+     */
+    fun saveThumbnail(sessionIdOrUrl: String, bitmap: Bitmap) {
+        logger.debug("Saved thumbnail to disk (sessionIdOrUrl = $sessionIdOrUrl)")
+        sharedDiskCache.putThumbnailBitmap(context, sessionIdOrUrl, bitmap)
+    }
+}

components/browser/thumbnails/src/main/java/mozilla/components/browser/thumbnails/utils/ThumbnailDiskCache.kt

@@ -6,6 +6,7 @@ package mozilla.components.browser.thumbnails.utils
 
 import android.content.Context
 import android.graphics.Bitmap
+import androidx.annotation.VisibleForTesting
 import com.jakewharton.disklrucache.DiskLruCache
 import mozilla.components.support.base.log.logger.Logger
 import java.io.File
@@ -23,6 +24,12 @@ class ThumbnailDiskCache {
     private var thumbnailCache: DiskLruCache? = null
     private val thumbnailCacheWriteLock = Any()
 
+    @VisibleForTesting(otherwise = VisibleForTesting.NONE)
+    internal fun clear(context: Context) {
+        getThumbnailCache(context).delete()
+        thumbnailCache = null
+    }
+
     /**
      * Retrieves the thumbnail data from the disk cache for the given session ID or URL.
      *

components/browser/thumbnails/src/main/res/values/dimens.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<resources xmlns:tools="http://schemas.android.com/tools">
+    <dimen name="mozac_browser_thumbnails_size_default">102dp</dimen>
+
+    <dimen name="mozac_browser_thumbnails_maximum_size" tools:ignore="PxUsage">2153px</dimen>
+</resources>

components/browser/thumbnails/src/test/java/mozilla/components/browser/thumbnails/ThumbnailsMiddlewareTest.kt

@@ -0,0 +1,37 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package mozilla.components.browser.thumbnails
+
+import android.graphics.Bitmap
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import mozilla.components.browser.state.action.ContentAction
+import mozilla.components.browser.state.state.BrowserState
+import mozilla.components.browser.state.state.createTab
+import mozilla.components.browser.state.store.BrowserStore
+import mozilla.components.browser.thumbnails.storage.ThumbnailStorage
+import mozilla.components.support.test.ext.joinBlocking
+import mozilla.components.support.test.mock
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.Mockito.verify
+
+@RunWith(AndroidJUnit4::class)
+class ThumbnailsMiddlewareTest {
+
+    @Test
+    fun `thumbnail storage stores the provided thumbnail on update thumbnail action`() {
+        val sessionIdOrUrl = "test-tab1"
+        val tab = createTab("https://www.mozilla.org", id = "test-tab1")
+        val thumbnailStorage: ThumbnailStorage = mock()
+        val store = BrowserStore(
+            initialState = BrowserState(tabs = listOf(tab)),
+            middleware = listOf(ThumbnailsMiddleware(thumbnailStorage))
+        )
+
+        val bitmap: Bitmap = mock()
+        store.dispatch(ContentAction.UpdateThumbnailAction(sessionIdOrUrl, bitmap)).joinBlocking()
+        verify(thumbnailStorage).saveThumbnail(sessionIdOrUrl, bitmap)
+    }
+}

components/browser/thumbnails/src/test/java/mozilla/components/browser/thumbnails/ThumbnailsUseCasesTest.kt

@@ -0,0 +1,60 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package mozilla.components.browser.thumbnails
+
+import android.graphics.Bitmap
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import kotlinx.coroutines.CompletableDeferred
+import kotlinx.coroutines.runBlocking
+import mozilla.components.browser.state.state.BrowserState
+import mozilla.components.browser.state.state.createTab
+import mozilla.components.browser.state.store.BrowserStore
+import mozilla.components.browser.thumbnails.storage.ThumbnailStorage
+import mozilla.components.support.test.any
+import mozilla.components.support.test.mock
+import org.junit.Assert.assertEquals
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.Mockito.`when`
+import org.mockito.Mockito.verify
+
+@RunWith(AndroidJUnit4::class)
+class ThumbnailsUseCasesTest {
+
+    @Test
+    fun `LoadThumbnailUseCase - loads the thumbnail from the in-memory ContentState if available`() = runBlocking {
+        val sessionIdOrUrl = "test-tab1"
+        val bitmap: Bitmap = mock()
+        val tab = createTab("https://www.mozilla.org", id = "test-tab1", thumbnail = bitmap)
+        val thumbnailStorage: ThumbnailStorage = mock()
+        val store = BrowserStore(
+            initialState = BrowserState(tabs = listOf(tab)),
+            middleware = listOf(ThumbnailsMiddleware(thumbnailStorage))
+        )
+        val useCases = ThumbnailsUseCases(store, thumbnailStorage)
+
+        val thumbnail = useCases.loadThumbnail(sessionIdOrUrl)
+        assertEquals(bitmap, thumbnail)
+    }
+
+    @Test
+    fun `LoadThumbnailUseCase - loads the thumbnail from the disk cache if in-memory thumbnail is unavailable`() = runBlocking {
+        val sessionIdOrUrl = "test-tab1"
+        val bitmap: Bitmap = mock()
+        val tab = createTab("https://www.mozilla.org", id = "test-tab1")
+        val thumbnailStorage: ThumbnailStorage = mock()
+        val store = BrowserStore(
+            initialState = BrowserState(tabs = listOf(tab)),
+            middleware = listOf(ThumbnailsMiddleware(thumbnailStorage))
+        )
+        val useCases = ThumbnailsUseCases(store, thumbnailStorage)
+
+        `when`(thumbnailStorage.loadThumbnail(any())).thenReturn(CompletableDeferred(bitmap))
+
+        val thumbnail = useCases.loadThumbnail(sessionIdOrUrl)
+        verify(thumbnailStorage).loadThumbnail(sessionIdOrUrl)
+        assertEquals(bitmap, thumbnail)
+    }
+}

components/browser/thumbnails/src/test/java/mozilla/components/browser/thumbnails/storage/ThumbnailStorageTest.kt

@@ -0,0 +1,58 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package mozilla.components.browser.thumbnails.storage
+
+import android.graphics.Bitmap
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import kotlinx.coroutines.CompletableDeferred
+import kotlinx.coroutines.runBlocking
+import mozilla.components.support.test.mock
+import mozilla.components.support.test.robolectric.testContext
+import org.junit.After
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNotNull
+import org.junit.Assert.assertNull
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.Mockito.`when`
+import org.mockito.Mockito.spy
+
+@RunWith(AndroidJUnit4::class)
+class ThumbnailStorageTest {
+
+    @Before
+    @After
+    fun cleanUp() {
+        sharedDiskCache.clear(testContext)
+    }
+
+    @Test
+    fun `saveThumbnail`() = runBlocking {
+        val sessionIdOrUrl = "test-tab1"
+        val bitmap: Bitmap = mock()
+        val thumbnailStorage = spy(ThumbnailStorage(testContext))
+        var thumbnail = thumbnailStorage.loadThumbnail(sessionIdOrUrl).await()
+
+        assertNull(thumbnail)
+
+        thumbnailStorage.saveThumbnail(sessionIdOrUrl, bitmap)
+        thumbnail = thumbnailStorage.loadThumbnail(sessionIdOrUrl).await()
+        assertNotNull(thumbnail)
+    }
+
+    @Test
+    fun `loadThumbnail`() = runBlocking {
+        val sessionIdOrUrl = "test-tab1"
+        val bitmap: Bitmap = mock()
+        val thumbnailStorage = spy(ThumbnailStorage(testContext))
+
+        thumbnailStorage.saveThumbnail(sessionIdOrUrl, bitmap)
+        `when`(thumbnailStorage.loadThumbnail(sessionIdOrUrl)).thenReturn(CompletableDeferred(bitmap))
+
+        val thumbnail = thumbnailStorage.loadThumbnail(sessionIdOrUrl).await()
+        assertEquals(bitmap, thumbnail)
+    }
+}

components/feature/tabs/build.gradle

@@ -31,6 +31,7 @@ tasks.withType(org.jetbrains.kotlin.gradle.tasks.KotlinCompile).all {
 
 dependencies {
     implementation project(':browser-session')
+    implementation project(':browser-thumbnails')
     api project(':feature-session')
     implementation project(':concept-engine')
     implementation project(':concept-tabstray')

components/feature/tabs/src/main/java/mozilla/components/feature/tabs/tabstray/TabsFeature.kt

@@ -7,6 +7,7 @@ package mozilla.components.feature.tabs.tabstray
 import androidx.annotation.VisibleForTesting
 import mozilla.components.browser.state.state.TabSessionState
 import mozilla.components.browser.state.store.BrowserStore
+import mozilla.components.browser.thumbnails.ThumbnailsUseCases
 import mozilla.components.concept.tabstray.TabsTray
 import mozilla.components.feature.tabs.TabsUseCases
 import mozilla.components.feature.tabs.ext.toTabs
@@ -18,17 +19,20 @@ import mozilla.components.support.base.feature.LifecycleAwareFeature
  * @param defaultTabsFilter A tab filter that is used for the initial presenting of tabs that will be used by
  * [TabsFeature.filterTabs] by default as well.
  */
+@Suppress("LongParameterList")
 class TabsFeature(
     tabsTray: TabsTray,
     private val store: BrowserStore,
     tabsUseCases: TabsUseCases,
+    thumbnailsUseCases: ThumbnailsUseCases,
     private val defaultTabsFilter: (TabSessionState) -> Boolean = { true },
     closeTabsTray: () -> Unit
 ) : LifecycleAwareFeature {
     @VisibleForTesting
     internal var presenter = TabsTrayPresenter(
         tabsTray,
         store,
+        thumbnailsUseCases,
         defaultTabsFilter,
         closeTabsTray
     )