Refactored our code to properly show the downloading online library progress.

* Added a head request to get the library length and showing the progress on behalf of that length.
* Improved the library loading process: previously, fetching the online library involved making two requests, which not only took more time to get a response from the server but also used twice the bandwidth. To address this, we have refactored our code to ensure that only one request is made at a time.
* Upgraded the retrofit, and interceptor dependencies to latest version.

app/detekt_baseline.xml

@@ -5,7 +5,7 @@
     <ID>EmptyFunctionBlock:None.kt$None${ }</ID>
     <ID>EmptyFunctionBlock:SimplePageChangeListener.kt$SimplePageChangeListener${ }</ID>
     <ID>LongParameterList:ZimManageViewModel.kt$ZimManageViewModel$( booksOnFileSystem: List&lt;BookOnDisk>, activeDownloads: List&lt;DownloadModel>, allLanguages: List&lt;Language>, libraryNetworkEntity: LibraryNetworkEntity, filter: String, fileSystemState: FileSystemState )</ID>
-    <ID>LongParameterList:ZimManageViewModel.kt$ZimManageViewModel$( private val downloadDao: DownloadRoomDao, private val bookDao: NewBookDao, private val languageDao: NewLanguagesDao, private val storageObserver: StorageObserver, private var kiwixService: KiwixService, private val context: Application, private val connectivityBroadcastReceiver: ConnectivityBroadcastReceiver, private val bookUtils: BookUtils, private val fat32Checker: Fat32Checker, private val defaultLanguageProvider: DefaultLanguageProvider, private val dataSource: DataSource, private val connectivityManager: ConnectivityManager, private val sharedPreferenceUtil: SharedPreferenceUtil )</ID>
+    <ID>LongParameterList:ZimManageViewModel.kt$ZimManageViewModel$( private val downloadDao: DownloadRoomDao, private val bookDao: NewBookDao, private val languageDao: NewLanguagesDao, private val storageObserver: StorageObserver, private var kiwixService: KiwixService, val context: Application, private val connectivityBroadcastReceiver: ConnectivityBroadcastReceiver, private val bookUtils: BookUtils, private val fat32Checker: Fat32Checker, private val defaultLanguageProvider: DefaultLanguageProvider, private val dataSource: DataSource, private val connectivityManager: ConnectivityManager, private val sharedPreferenceUtil: SharedPreferenceUtil )</ID>
     <ID>MagicNumber:LibraryListItem.kt$LibraryListItem.LibraryDownloadItem$1000L</ID>
     <ID>MagicNumber:PeerGroupHandshake.kt$PeerGroupHandshake$15000</ID>
     <ID>MagicNumber:ShareFiles.kt$ShareFiles$24</ID>

app/src/main/java/org/kiwix/kiwixmobile/nav/destination/library/OnlineLibraryFragment.kt

@@ -87,7 +87,6 @@ import org.kiwix.kiwixmobile.core.utils.dialog.KiwixDialog
 import org.kiwix.kiwixmobile.core.utils.dialog.KiwixDialog.YesNoDialog.WifiOnly
 import org.kiwix.kiwixmobile.databinding.FragmentDestinationDownloadBinding
 import org.kiwix.kiwixmobile.zimManager.NetworkState
-import org.kiwix.kiwixmobile.zimManager.OnlineLibraryStatus
 import org.kiwix.kiwixmobile.zimManager.ZimManageViewModel
 import org.kiwix.kiwixmobile.zimManager.libraryView.AvailableSpaceCalculator
 import org.kiwix.kiwixmobile.zimManager.libraryView.adapter.LibraryAdapter
@@ -106,7 +105,7 @@ class OnlineLibraryFragment : BaseFragment(), FragmentActivityExtensions {
   @Inject lateinit var availableSpaceCalculator: AvailableSpaceCalculator
   @Inject lateinit var alertDialogShower: AlertDialogShower
   private var fragmentDestinationDownloadBinding: FragmentDestinationDownloadBinding? = null
-
+  private val lock = Any()
   private var downloadBookItem: LibraryListItem.BookItem? = null
   private val zimManageViewModel by lazy {
     requireActivity().viewModel<ZimManageViewModel>(viewModelFactory)
@@ -302,10 +301,11 @@ class OnlineLibraryFragment : BaseFragment(), FragmentActivityExtensions {
     }
   }
 
-  private fun onLibraryStatusChanged(onlineLibraryStatus: OnlineLibraryStatus) {
+  private fun onLibraryStatusChanged(libraryStatus: String) {
-    fragmentDestinationDownloadBinding?.apply {
+    synchronized(lock) {
-      onlineLibraryProgressBar.progress = onlineLibraryStatus.progress
+      fragmentDestinationDownloadBinding?.apply {
-      onlineLibraryProgressStatusText.text = onlineLibraryStatus.status
+        onlineLibraryProgressStatusText.text = libraryStatus
+      }
     }
   }
 

app/src/main/java/org/kiwix/kiwixmobile/zimManager/AppProgressListenerProvider.kt

@@ -18,18 +18,27 @@
 
 package org.kiwix.kiwixmobile.zimManager
 
+import org.kiwix.kiwixmobile.core.R
 import org.kiwix.kiwixmobile.core.data.remote.OnlineLibraryProgressListener
+import org.kiwix.kiwixmobile.core.downloader.downloadManager.DEFAULT_INT_VALUE
+import org.kiwix.kiwixmobile.core.downloader.downloadManager.HUNDERED
+import org.kiwix.kiwixmobile.core.downloader.downloadManager.ZERO
 
 class AppProgressListenerProvider(
   private val zimManageViewModel: ZimManageViewModel
 ) : OnlineLibraryProgressListener {
   @Suppress("MagicNumber")
-  override fun onProgress(bytesRead: Long, contentLength: Long, done: Boolean) {
+  override fun onProgress(bytesRead: Long, contentLength: Long) {
-    val progress = if (contentLength == -1L) 0 else (bytesRead * 100 / contentLength).toInt()
+    val progress =
+      if (contentLength == DEFAULT_INT_VALUE.toLong()) {
+        ZERO
+      } else {
+        (bytesRead * HUNDERED / contentLength).toInt() * 3
+      }
     zimManageViewModel.downloadProgress.postValue(
-      OnlineLibraryStatus(
+      zimManageViewModel.context.getString(
-        progress,
+        R.string.downloading_library,
-        "Downloading online content"
+        zimManageViewModel.context.getString(R.string.percentage, progress)
       )
     )
   }

app/src/main/java/org/kiwix/kiwixmobile/zimManager/OnlineLibraryStatus.kt

@@ -1,21 +0,0 @@
-/*
- * Kiwix Android
- * Copyright (c) 2024 Kiwix <android.kiwix.org>
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- *
- */
-
-package org.kiwix.kiwixmobile.zimManager
-
-data class OnlineLibraryStatus(val progress: Int, val status: String)

app/src/main/java/org/kiwix/kiwixmobile/zimManager/ZimManageViewModel.kt

@@ -34,6 +34,7 @@ import io.reactivex.processors.BehaviorProcessor
 import io.reactivex.processors.PublishProcessor
 import io.reactivex.schedulers.Schedulers
 import okhttp3.OkHttpClient
+import okhttp3.Request
 import okhttp3.logging.HttpLoggingInterceptor
 import okhttp3.logging.HttpLoggingInterceptor.Level.BASIC
 import okhttp3.logging.HttpLoggingInterceptor.Level.NONE
@@ -47,6 +48,7 @@ import org.kiwix.kiwixmobile.core.dao.NewBookDao
 import org.kiwix.kiwixmobile.core.dao.NewLanguagesDao
 import org.kiwix.kiwixmobile.core.data.DataSource
 import org.kiwix.kiwixmobile.core.data.remote.KiwixService
+import org.kiwix.kiwixmobile.core.data.remote.KiwixService.Companion.LIBRARY_NETWORK_PATH
 import org.kiwix.kiwixmobile.core.data.remote.ProgressResponseBody
 import org.kiwix.kiwixmobile.core.data.remote.UserAgentInterceptor
 import org.kiwix.kiwixmobile.core.di.modules.CALL_TIMEOUT
@@ -106,7 +108,7 @@ class ZimManageViewModel @Inject constructor(
   private val languageDao: NewLanguagesDao,
   private val storageObserver: StorageObserver,
   private var kiwixService: KiwixService,
-  private val context: Application,
+  val context: Application,
   private val connectivityBroadcastReceiver: ConnectivityBroadcastReceiver,
   private val bookUtils: BookUtils,
   private val fat32Checker: Fat32Checker,
@@ -140,7 +142,7 @@ class ZimManageViewModel @Inject constructor(
   val requestFiltering = BehaviorProcessor.createDefault("")
 
   private var compositeDisposable: CompositeDisposable? = CompositeDisposable()
-  val downloadProgress = MutableLiveData<OnlineLibraryStatus>()
+  val downloadProgress = MutableLiveData<String>()
 
   init {
     // add listener to retrofit to get updates of downloading online library
@@ -150,6 +152,7 @@ class ZimManageViewModel @Inject constructor(
   }
 
   private fun createKiwixServiceWithProgressListener(): KiwixService {
+    val contentLength = getContentLengthOfLibraryXmlFile()
     val customOkHttpClient = OkHttpClient().newBuilder()
       .followRedirects(true)
       .followSslRedirects(true)
@@ -168,7 +171,8 @@ class ZimManageViewModel @Inject constructor(
           .body(
             ProgressResponseBody(
               originalResponse.body!!,
-              AppProgressListenerProvider(this)
+              AppProgressListenerProvider(this),
+              contentLength
             )
           )
           .build()
@@ -177,6 +181,29 @@ class ZimManageViewModel @Inject constructor(
     return KiwixService.ServiceCreator.newHackListService(customOkHttpClient, KIWIX_DOWNLOAD_URL)
   }
 
+  private fun getContentLengthOfLibraryXmlFile(): Long {
+    val headRequest = Request.Builder()
+      .url("$KIWIX_DOWNLOAD_URL$LIBRARY_NETWORK_PATH")
+      .head()
+      .header("Accept-Encoding", "identity")
+      .build()
+    val client = OkHttpClient().newBuilder()
+      .followRedirects(true)
+      .followSslRedirects(true)
+      .connectTimeout(CONNECTION_TIMEOUT, SECONDS)
+      .readTimeout(READ_TIMEOUT, SECONDS)
+      .callTimeout(CALL_TIMEOUT, SECONDS)
+      .addNetworkInterceptor(UserAgentInterceptor(USER_AGENT))
+      .build()
+    client.newCall(headRequest).execute().use { response ->
+      if (response.isSuccessful) {
+        return@getContentLengthOfLibraryXmlFile response.header("content-length")?.toLongOrNull()
+          ?: -1L
+      }
+    }
+    return -1L
+  }
+
   @VisibleForTesting
   fun onClearedExposed() {
     onCleared()
@@ -300,37 +327,22 @@ class ZimManageViewModel @Inject constructor(
       }
       .subscribeOn(Schedulers.io())
       .observeOn(Schedulers.io())
-      .flatMap {
+      .concatMap {
         kiwixService.library
           .toFlowable()
           .retry(5)
           .doOnSubscribe {
-            downloadProgress.postValue(OnlineLibraryStatus(0, "Downloading library 0%"))
+            downloadProgress.postValue(context.getString(R.string.start_server_label))
           }
           .map { response ->
-            downloadProgress.postValue(
+            downloadProgress.postValue(context.getString(R.string.parsing_remote_library))
-              OnlineLibraryStatus(
-                0,
-                "Downloading library... parsing response"
-              )
-            )
             response
           }
           .doFinally {
-            downloadProgress.postValue(
+            downloadProgress.postValue(context.getString(R.string.parsing_remote_library))
-              OnlineLibraryStatus(
-                0,
-                "Remote library downloaded, parsing data"
-              )
-            )
           }
           .onErrorReturn {
             it.printStackTrace()
-            downloadProgress.postValue(
-              OnlineLibraryStatus(
-                0, "Failed to download the library"
-              )
-            )
             LibraryNetworkEntity().apply { book = LinkedList() }
           }
       }

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

@@ -67,12 +67,12 @@
     tools:ignore="RequiredSize" />
 
   <androidx.cardview.widget.CardView
-    android:id="@+id/progressCardView"
+    android:id="@+id/onlineLibraryProgressLayout"
-    android:layout_width="wrap_content"
+    android:layout_width="140dp"
-    android:layout_height="wrap_content"
+    android:layout_height="100dp"
     android:layout_margin="16dp"
-    android:visibility="visible"
+    android:visibility="gone"
-    app:cardCornerRadius="4dp"
+    app:cardCornerRadius="8dp"
     app:cardElevation="4dp"
     app:layout_constraintBottom_toBottomOf="parent"
     app:layout_constraintEnd_toEndOf="parent"
@@ -80,30 +80,28 @@
     app:layout_constraintTop_toTopOf="parent">
 
     <LinearLayout
-      android:id="@+id/onlineLibraryProgressLayout"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
+      android:layout_gravity="center"
       android:gravity="center"
       android:orientation="vertical"
-      android:padding="@dimen/activity_horizontal_margin"
+      android:padding="@dimen/find_in_page_button_padding">
-      android:visibility="gone">
 
       <ProgressBar
         android:id="@+id/onlineLibraryProgressBar"
-        android:layout_width="wrap_content"
+        android:layout_width="40dp"
-        android:layout_height="wrap_content"
+        android:layout_height="40dp" />
-        android:layout_marginTop="@dimen/activity_horizontal_margin" />
 
       <TextView
         android:id="@+id/onlineLibraryProgressStatusText"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_marginTop="8dp"
-        android:layout_marginBottom="@dimen/activity_horizontal_margin"
         android:gravity="center"
         android:text="@string/reaching_remote_library"
         android:textColor="@color/mine_shaft_gray900"
-        android:textSize="12sp" />
+        android:textSize="10sp"
+        tools:ignore="SmallSp" />
     </LinearLayout>
   </androidx.cardview.widget.CardView>
 </androidx.constraintlayout.widget.ConstraintLayout>

buildSrc/src/main/kotlin/Versions.kt

@@ -20,9 +20,9 @@ object Versions {
 
   const val tracing: String = "1.1.0"
 
-  const val com_squareup_retrofit2: String = "2.9.0"
+  const val com_squareup_retrofit2: String = "2.11.0"
 
-  const val com_squareup_okhttp3: String = "4.10.0"
+  const val com_squareup_okhttp3: String = "4.12.0"
 
   const val org_jetbrains_kotlin: String = "1.9.20"
 

core/src/main/java/org/kiwix/kiwixmobile/core/data/remote/OnlineLibraryProgressListener.kt

@@ -19,5 +19,5 @@
 package org.kiwix.kiwixmobile.core.data.remote
 
 interface OnlineLibraryProgressListener {
-  fun onProgress(bytesRead: Long, contentLength: Long, done: Boolean)
+  fun onProgress(bytesRead: Long, contentLength: Long)
 }

core/src/main/java/org/kiwix/kiwixmobile/core/data/remote/ProgressResponseBody.kt

@@ -25,11 +25,13 @@ import okio.BufferedSource
 import okio.ForwardingSource
 import okio.Source
 import okio.buffer
-import org.kiwix.kiwixmobile.core.utils.files.Log
+import org.kiwix.kiwixmobile.core.downloader.downloadManager.DEFAULT_INT_VALUE
+import org.kiwix.kiwixmobile.core.downloader.downloadManager.ZERO
 
 class ProgressResponseBody(
   private val responseBody: ResponseBody,
-  private val progressListener: OnlineLibraryProgressListener
+  private val progressListener: OnlineLibraryProgressListener,
+  private val contentLength: Long
 ) : ResponseBody() {
 
   private lateinit var bufferedSource: BufferedSource
@@ -37,7 +39,6 @@ class ProgressResponseBody(
   override fun contentType(): MediaType? = responseBody.contentType()
 
   override fun contentLength(): Long = responseBody.contentLength()
-
   override fun source(): BufferedSource {
     if (!::bufferedSource.isInitialized) {
       bufferedSource = source(responseBody.source()).buffer()
@@ -47,24 +48,11 @@ class ProgressResponseBody(
 
   private fun source(source: Source): Source {
     return object : ForwardingSource(source) {
-      var totalBytesRead = 0L
+      var totalBytesRead = ZERO.toLong()
       override fun read(sink: Buffer, byteCount: Long): Long {
         val bytesRead = super.read(sink, byteCount)
-        totalBytesRead += if (bytesRead != -1L) bytesRead else 0
+        totalBytesRead += if (bytesRead != DEFAULT_INT_VALUE.toLong()) bytesRead else ZERO.toLong()
-        val isDone = bytesRead == -1L
+        progressListener.onProgress(totalBytesRead, contentLength)
-        progressListener.onProgress(
-          totalBytesRead,
-          responseBody.contentLength(),
-          isDone
-        )
-          .also {
-            Log.e(
-              "PROGRESS",
-              "onProgress: ${contentLength()} and byteRead = $totalBytesRead\n" +
-                " sink ${bytesRead == -1L} \n byteRead = $bytesRead " +
-                "\n bufferedSource = ${bufferedSource.isOpen}"
-            )
-          }
         return bytesRead
       }
     }

core/src/main/res/values/strings.xml

@@ -349,6 +349,9 @@
   <string name="allow">Allow</string>
   <string name="swipe_down_for_library">Swipe Down for Library</string>
   <string name="reaching_remote_library">Reaching remote library</string>
+  <string name="parsing_remote_library">Parsing remote library</string>
+  <string name="starting_downloading_remote_library">Starting download of the online library</string>
+  <string name="downloading_library">Downloading library %s</string>
   <string-array name="pref_dark_modes_entries">
     <item>@string/on</item>
     <item>@string/off</item>