Updated service to use extra transformer so the service itself is not plagued by unnecessary code

app/src/main/java/com/topjohnwu/magisk/di/ApplicationModule.kt

@@ -4,6 +4,8 @@ import android.content.Context
 import androidx.preference.PreferenceManager
 import com.skoumal.teanity.rxbus.RxBus
 import com.topjohnwu.magisk.App
+import com.topjohnwu.magisk.model.download.ModuleTransformer
+import com.topjohnwu.magisk.model.entity.internal.DownloadSubject
 import org.koin.dsl.module
 
 
@@ -15,4 +17,6 @@ val applicationModule = module {
     factory(Protected) { get<App>().protectedContext }
     single(SUTimeout) { get<Context>(Protected).getSharedPreferences("su_timeout", 0) }
     single { PreferenceManager.getDefaultSharedPreferences(get<Context>(Protected)) }
+
+    factory { (subject: DownloadSubject) -> ModuleTransformer(get(), subject) }
 }

app/src/main/java/com/topjohnwu/magisk/model/download/ModuleTransformer.kt

@@ -0,0 +1,68 @@
+package com.topjohnwu.magisk.model.download
+
+import android.content.Context
+import com.topjohnwu.magisk.model.entity.internal.DownloadSubject
+import com.topjohnwu.magisk.utils.cachedFile
+import com.topjohnwu.magisk.utils.withStreams
+import java.io.File
+import java.util.zip.ZipEntry
+import java.util.zip.ZipInputStream
+import java.util.zip.ZipOutputStream
+
+class ModuleTransformer(
+    private val context: Context,
+    subject: DownloadSubject
+) {
+
+    private val destination = context.cachedFile(subject.fileName)
+
+    fun inject(file: File, installer: File): File {
+        return injectInternal(move(file), installer)
+    }
+
+    // ---
+
+    private fun injectInternal(file: File, installer: File): File {
+        val input = ZipInputStream(file.inputStream())
+        val output = ZipOutputStream(destination.outputStream())
+
+        withStreams(input, output) { zin, zout ->
+            zout.putNextEntry(ZipEntry("META-INF/"))
+            zout.putNextEntry(ZipEntry("META-INF/com/"))
+            zout.putNextEntry(ZipEntry("META-INF/com/google/"))
+            zout.putNextEntry(ZipEntry("META-INF/com/google/android/"))
+            zout.putNextEntry(ZipEntry("META-INF/com/google/android/update-binary"))
+            installer.inputStream().copyTo(zout).also { zout.flush() }
+
+            zout.putNextEntry(ZipEntry("META-INF/com/google/android/updater-script"))
+            zout.write("#MAGISK\n".toByteArray(charset("UTF-8")))
+
+            var off = -1
+            var entry: ZipEntry? = zin.nextEntry
+            while (entry != null) {
+                if (off < 0) {
+                    off = entry.name.indexOf('/') + 1
+                }
+
+                val path = entry.name.substring(off)
+                if (path.isNotEmpty() && !path.startsWith("META-INF")) {
+                    zout.putNextEntry(ZipEntry(path))
+                    if (!entry.isDirectory) {
+                        zin.copyTo(zout).also { zout.flush() }
+                    }
+                }
+
+                entry = zin.nextEntry
+            }
+        }
+
+        file.delete()
+
+        return destination
+    }
+
+    private fun move(file: File) = context.cachedFile("temp").apply {
+        file.renameTo(this)
+    }
+
+}

app/src/main/java/com/topjohnwu/magisk/model/download/RemoteFileService.kt

@@ -9,20 +9,17 @@ import com.topjohnwu.magisk.R
 import com.topjohnwu.magisk.data.repository.FileRepository
 import com.topjohnwu.magisk.model.entity.internal.DownloadSubject
 import com.topjohnwu.magisk.model.entity.internal.DownloadSubject.*
-import com.topjohnwu.magisk.utils.cachedFile
-import com.topjohnwu.magisk.utils.withStreams
 import com.topjohnwu.magisk.utils.writeToCachedFile
 import com.topjohnwu.magisk.view.Notifications
 import com.topjohnwu.superuser.ShellUtils
 import io.reactivex.Single
 import io.reactivex.android.schedulers.AndroidSchedulers
 import okhttp3.ResponseBody
+import org.koin.android.ext.android.get
 import org.koin.android.ext.android.inject
+import org.koin.core.parameter.parametersOf
 import timber.log.Timber
 import java.io.File
-import java.util.zip.ZipEntry
-import java.util.zip.ZipInputStream
-import java.util.zip.ZipOutputStream
 
 abstract class RemoteFileService : NotificationService() {
 
@@ -40,7 +37,7 @@ abstract class RemoteFileService : NotificationService() {
 
     // ---
 
-    private fun startInternal(subject: DownloadSubject) = search(subject)
+    private fun startInternal(subject: DownloadSubject): Single<File> = search(subject)
         .onErrorResumeNext(download(subject))
         .doOnSubscribe { update(subject.hashCode()) { it.setContentTitle(subject.fileName) } }
         .observeOn(AndroidSchedulers.mainThread())
@@ -76,57 +73,22 @@ abstract class RemoteFileService : NotificationService() {
     }
 
     private fun download(subject: DownloadSubject) = repo.downloadFile(subject.url)
+        .map { it.toFile(subject.hashCode(), subject.fileName) }
         .map {
             when (subject) {
-                is Module -> appendInstaller(it, subject)
+                is Module -> {
-                else -> it.toFile(subject.hashCode(), subject.fileName)
+                    update(subject.hashCode()) {
-            }
+                        it.setContentText(getString(R.string.download_module))
-        }
+                            .setProgress(0, 0, true)
-
-    private fun appendInstaller(body: ResponseBody, subject: DownloadSubject): File {
-        update(subject.hashCode()) {
-            it.setContentText(getString(R.string.download_module))
-        }
-
-        val installer = startInternal(Installer).blockingGet()
-        val target = cachedFile(subject.fileName)
-
-        val input = ZipInputStream(body.byteStream())
-        val output = ZipOutputStream(target.outputStream())
-
-        withStreams(input, output) { zin, zout ->
-            zout.putNextEntry(ZipEntry("META-INF/"))
-            zout.putNextEntry(ZipEntry("META-INF/com/"))
-            zout.putNextEntry(ZipEntry("META-INF/com/google/"))
-            zout.putNextEntry(ZipEntry("META-INF/com/google/android/"))
-            zout.putNextEntry(ZipEntry("META-INF/com/google/android/update-binary"))
-            installer.inputStream().copyTo(zout).also { zout.flush() }
-
-            zout.putNextEntry(ZipEntry("META-INF/com/google/android/updater-script"))
-            zout.write("#MAGISK\n".toByteArray(charset("UTF-8")))
-
-            var off = -1
-            var entry: ZipEntry? = zin.nextEntry
-            while (entry != null) {
-                if (off < 0) {
-                    off = entry.name.indexOf('/') + 1
-                }
-
-                val path = entry.name.substring(off)
-                if (path.isNotEmpty() && !path.startsWith("META-INF")) {
-                    zout.putNextEntry(ZipEntry(path))
-                    if (!entry.isDirectory) {
-                        zin.copyTo(zout).also { zout.flush() }
                     }
-                }
 
-                entry = zin.nextEntry
+                    get<ModuleTransformer> { parametersOf(subject) }
+                        .inject(it, startInternal(Installer).blockingGet())
+                }
+                else -> it
             }
         }
 
-        return target
-    }
-
     // ---
 
     private fun ResponseBody.toFile(id: Int, name: String): File {