Removed overcomplicated updates loading

The mechanism was replaced by loading updated directly by id to the initial list. There are two factors why yesterday-me was dumb:

1) By asynchronously loading update state, you have no control over it - hence no search
2) It's incredibly wasteful; running that hardcore search on every query? Not cool
...and from UX stand-point having updates inlined right under installed modules is by far better than nitpicking it from the list or in the search

app/src/main/java/com/topjohnwu/magisk/data/database/Repo.kt

@@ -11,6 +11,9 @@ interface RepoBase {
     fun getRepos(offset: Int, limit: Int = LIMIT): List<Repo>
     fun searchRepos(query: String, offset: Int, limit: Int = LIMIT): List<Repo>
 
+    @Query("SELECT * FROM repos WHERE id = :id AND versionCode > :versionCode LIMIT 1")
+    fun getUpdatableRepoById(id: String, versionCode: Int): Repo?
+
     companion object {
         const val LIMIT = 10
     }

app/src/main/java/com/topjohnwu/magisk/model/entity/recycler/ModuleRvItem.kt

@@ -95,20 +95,24 @@ class SectionTitle(
 ) : ObservableItem<SectionTitle>() {
     override val layoutRes = R.layout.item_section_md2
 
-    @Bindable
     var button = _button
+        @Bindable get
         set(value) {
             field = value
             notifyChange(BR.button)
         }
-    @Bindable
     var icon = _icon
+        @Bindable get
         set(value) {
             field = value
             notifyChange(BR.icon)
         }
-
-    val hasButton = KObservableField(button != 0 || icon != 0)
+    var hasButton = button != 0 || icon != 0
+        @Bindable get
+        set(value) {
+            field = value
+            notifyChange(BR.hasButton)
+        }
 
     override fun onBindingBound(binding: ViewDataBinding) {
         super.onBindingBound(binding)
@@ -120,14 +124,27 @@ class SectionTitle(
     override fun contentSameAs(other: SectionTitle): Boolean = this === other
 }
 
-class RepoItem(val item: Repo) : ComparableRvItem<RepoItem>() {
+sealed class RepoItem(val item: Repo) : ObservableItem<RepoItem>() {
     override val layoutRes: Int = R.layout.item_repo_md2
 
     val progress = KObservableField(0)
-    val isUpdate = KObservableField(false)
+    var isUpdate = false
+        @Bindable get
+        protected set(value) {
+            field = value
+            notifyChange(BR.update)
+        }
 
     override fun contentSameAs(other: RepoItem): Boolean = item == other.item
     override fun itemSameAs(other: RepoItem): Boolean = item.id == other.item.id
+
+    class Update(item: Repo) : RepoItem(item) {
+        init {
+            isUpdate = true
+        }
+    }
+
+    class Remote(item: Repo) : RepoItem(item)
 }
 
 class ModuleItem(val item: Module) : ObservableItem<ModuleItem>(), Observable {
@@ -158,7 +175,7 @@ class ModuleItem(val item: Module) : ObservableItem<ModuleItem>(), Observable {
 
     fun delete(viewModel: ModuleViewModel) {
         isRemoved = !isRemoved
-        viewModel.moveToState()
+        viewModel.updateActiveState()
     }
 
     override fun contentSameAs(other: ModuleItem): Boolean = item.version == other.item.version

app/src/main/java/com/topjohnwu/magisk/redesign/module/ModuleViewModel.kt

@@ -33,7 +33,6 @@ import io.reactivex.Single
 import io.reactivex.android.schedulers.AndroidSchedulers
 import io.reactivex.disposables.Disposable
 import me.tatarka.bindingcollectionadapter2.BindingRecyclerViewAdapter
-import org.jetbrains.annotations.NotNull
 import timber.log.Timber
 import kotlin.math.roundToInt
 
@@ -70,13 +69,23 @@ class ModuleViewModel(
     }
 
     companion object {
-        private val sectionRemote =
-            SectionTitle(R.string.module_section_remote, R.string.sorting_order)
+        private val sectionRemote = SectionTitle(
+            R.string.module_section_remote,
+            R.string.sorting_order
+        )
+
+        private val sectionUpdate = SectionTitle(
+            R.string.module_section_pending,
+            R.string.module_section_pending_action,
+            R.drawable.ic_update_md2
+            // enable with implementation of https://github.com/topjohnwu/Magisk/issues/2036
+        ).also { it.hasButton = false }
+
         private val sectionActive = SectionTitle(
             R.string.module_section_installed,
             R.string.reboot,
             R.drawable.ic_restart
-        ).also { it.hasButton.value = false }
+        ).also { it.hasButton = false }
 
         init {
             updateOrderIcon()
@@ -94,11 +103,13 @@ class ModuleViewModel(
     // ---
 
     private val itemsInstalled
-        @WorkerThread get() = items.asSequence()
-            .filterIsInstance<ModuleItem>()
-            .toList()
+        @WorkerThread get() = items.filterIsInstance<ModuleItem>()
+
+    private val itemsUpdatable: List<RepoItem>
+        @WorkerThread get() = items.filterIsInstance<RepoItem.Update>()
+
     private val itemsRemote
-        @WorkerThread get() = items.filterIsInstance<RepoItem>()
+        @WorkerThread get() = items.filterIsInstance<RepoItem.Remote>()
 
     private var remoteJob: Disposable? = null
     private val dao
@@ -126,19 +137,15 @@ class ModuleViewModel(
     override fun refresh() = Single.fromCallable { Module.loadModules() }
         .map { it.map { ModuleItem(it) } }
         .map { it.order() }
-        .map { build(active = it) }
+        .map { build(active = it, updatable = loadUpdates(it)) }
         .map { it to items.calculateDiff(it) }
         .applyViewModel(this)
         .subscribeK {
             items.update(it.first, it.second)
             if (!items.contains(sectionRemote)) {
                 loadRemote()
-            } else {
-                Single.fromCallable { itemsRemote }
-                    .subscribeK { it.ensureUpdateState() }
-                    .add()
             }
-            moveToState()
+            updateActiveState()
         }
 
     fun loadRemoteImplicit() = let { items.clear(); itemsSearch.clear() }
@@ -181,8 +188,7 @@ class ModuleViewModel(
                 .subscribeOn(AndroidSchedulers.mainThread())
         }
         return Single.fromCallable { dao.searchRepos(query, offset) }
-            .map { it.map { RepoItem(it) } }
-            .doOnSuccess { it.ensureUpdateState() }
+            .map { it.map { RepoItem.Remote(it) } }
     }
 
     private fun query(query: String = this.query, offset: Int = 0) {
@@ -207,7 +213,7 @@ class ModuleViewModel(
         offset: Int = 0,
         downloadRepos: Boolean = offset == 0
     ): Single<List<RepoItem>> = Single.fromCallable { dao.getRepos(offset) }
-        .map { it.map { RepoItem(it) } }
+        .map { it.map { RepoItem.Remote(it) } }
         .flatMap {
             when {
                 // in case we find result empty and offset is initial we need to refresh the repos.
@@ -216,7 +222,6 @@ class ModuleViewModel(
                 else -> Single.just(it)
             }
         }
-        .doOnSuccess { it.ensureUpdateState() }
 
     private fun downloadRepos() = Single.just(Unit)
         .flatMap { repoUpdater() }
@@ -237,56 +242,15 @@ class ModuleViewModel(
 
     // ---
 
-    /**
-     * Dynamically allocated list of [itemsInstalled]. It might be invalidated any time on any
-     * thread hence it needs to be volatile.
-     *
-     * There might be a state where this field gets assigned `null` whilst being used by another
-     * instance of any job, so the list will be immediately reinstated back.
-     *
-     * ### Note:
-     *
-     * It is caller's responsibility to invalidate this variable at the end of every job to save
-     * memory.
-     * */
-    @Volatile
-    private var cachedItemsInstalled: List<ModuleItem>? = null
-        @WorkerThread @NotNull get() = field ?: itemsInstalled.also { field = it }
-
-    private val Repo.isUpdatable: Boolean
-        @WorkerThread get() {
-            val installed = cachedItemsInstalled!!
-                .firstOrNull { it.item.id == id }
-                ?: return false
-            return installed.item.versionCode < versionCode
-        }
-
-    /**
-     * Asynchronously updates state of all repo items so the loading speed is not impaired by this
-     * seemingly unnecessary operation. Because of the nature of this operation, the "update" status
-     * is not guaranteed for all items and can change any time.
-     *
-     * It is permitted running this function in parallel; it will also attempt to run in parallel
-     * by itself to finish the job as quickly as possible.
-     *
-     * No list manipulations should be done in this method whatsoever! By being heavily parallelized
-     * is will inevitably throw exceptions by simultaneously accessing the same list.
-     *
-     * In order to save time it uses helper [cachedItemsInstalled].
-     * */
-    private fun List<RepoItem>.ensureUpdateState() = Single.just(this)
-        .flattenAsFlowable { it }
-        .parallel()
-        .map { it to it.item.isUpdatable }
-        .sequential()
-        .doOnComplete { cachedItemsInstalled = null }
-        .subscribeK { it.first.isUpdate.value = it.second }
-        .add()
+    @WorkerThread
+    private fun loadUpdates(installed: List<ModuleItem>) = installed
+        .mapNotNull { dao.getUpdatableRepoById(it.item.id, it.item.versionCode) }
+        .map { RepoItem.Update(it) }
 
     // ---
 
-    fun moveToState() = Single.fromCallable { itemsInstalled.any { it.isModified } }
-        .subscribeK { sectionActive.hasButton.value = it }
+    fun updateActiveState() = Single.fromCallable { itemsInstalled.any { it.isModified } }
+        .subscribeK { sectionActive.hasButton = it }
         .add()
 
     fun sectionPressed(item: SectionTitle) = when (item) {
@@ -318,8 +282,10 @@ class ModuleViewModel(
     @WorkerThread
     private fun build(
         active: List<ModuleItem> = itemsInstalled,
+        updatable: List<RepoItem> = itemsUpdatable,
         remote: List<RepoItem> = itemsRemote
     ) = (active + InstallModule).prependIfNotEmpty { sectionActive } +
+            updatable.prependIfNotEmpty { sectionUpdate } +
             remote.prependIfNotEmpty { sectionRemote }
 
     private fun <T> List<T>.prependIfNotEmpty(item: () -> T) =

app/src/main/res/layout/item_repo_md2.xml

@@ -110,7 +110,7 @@
                 android:paddingStart="@dimen/l_50"
                 isEnabled="@{!(item.progress == -100 || (item.progress > 0 && item.progress < 100))}"
                 android:contentDescription="@string/download"
-                srcCompat="@{item.isUpdate() ? R.drawable.ic_update_md2 : R.drawable.ic_download_md2}"
+                srcCompat="@{item.isUpdate ? R.drawable.ic_update_md2 : R.drawable.ic_download_md2}"
                 app:layout_constraintBottom_toBottomOf="parent"
                 app:layout_constraintEnd_toEndOf="parent"
                 app:layout_constraintTop_toBottomOf="@+id/module_divider"

app/src/main/res/values/strings_md2.xml

@@ -75,7 +75,8 @@
 
     <string name="module_safe_mode_message">You\'re in safe mode. None of user modules will work.\nThis message will disappear once safe mode is disabled.</string>
     <string name="module_version_author">%1$s by %2$s</string>
-    <string name="module_section_pending">Pending changes</string>
+    <string name="module_section_pending">Updates</string>
+    <string name="module_section_pending_action">Update all</string>
     <string name="module_section_installed">Installed</string>
     <string name="module_section_remote">Remote</string>
     <string name="module_state_remove">Remove</string>

build.gradle

@@ -7,7 +7,7 @@ if (configPath.exists())
     configPath.withInputStream { is -> props.load(is) }
 
 buildscript {
-    ext.vKotlin = '1.3.50'
+    ext.vKotlin = '1.3.60'
 
     repositories {
         google()