From 3bbd1bebed0c15860c18779f9abb56a1d95536f6 Mon Sep 17 00:00:00 2001
From: rushiiMachine <33725716+rushiiMachine@users.noreply.github.com>
Date: Wed, 15 Jan 2025 01:46:35 -0800
Subject: [PATCH] feat: use `extractNativeLibs` to reduce installed app size

While this increases the APK size, it also reduces the installed size due to libs not having to be extracted.
---
 app/src/main/AndroidManifest.xml              |  1 +
 .../patcher/steps/install/AlignmentStep.kt    | 31 ++++++++++++++-----
 .../manager/patcher/util/ManifestPatcher.kt   | 16 +++++++++-
 3 files changed, 40 insertions(+), 8 deletions(-)

diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 7fe1b13..d938db2 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -22,6 +22,7 @@
 
   <application
       android:name=".ManagerApplication"
+      android:extractNativeLibs="false"
       android:icon="@mipmap/ic_launcher"
       android:label="@string/app_name"
       android:largeHeap="true"
diff --git a/app/src/main/kotlin/com/aliucord/manager/patcher/steps/install/AlignmentStep.kt b/app/src/main/kotlin/com/aliucord/manager/patcher/steps/install/AlignmentStep.kt
index f94376d..a2e4395 100644
--- a/app/src/main/kotlin/com/aliucord/manager/patcher/steps/install/AlignmentStep.kt
+++ b/app/src/main/kotlin/com/aliucord/manager/patcher/steps/install/AlignmentStep.kt
@@ -6,14 +6,13 @@ import com.aliucord.manager.manager.PathManager
 import com.aliucord.manager.patcher.StepRunner
 import com.aliucord.manager.patcher.steps.StepGroup
 import com.aliucord.manager.patcher.steps.base.Step
-import com.aliucord.manager.patcher.steps.base.StepState
 import com.aliucord.manager.patcher.steps.download.CopyDependenciesStep
 import com.github.diamondminer88.zip.*
 import org.koin.core.component.KoinComponent
 import org.koin.core.component.inject
 
 /**
- * Align certain files in the APK to the respective boundaries.
+ * Align certain files in the APK to the necessary boundaries.
  */
 class AlignmentStep : Step(), KoinComponent {
     private val paths: PathManager by inject()
@@ -24,12 +23,8 @@ class AlignmentStep : Step(), KoinComponent {
     override suspend fun execute(container: StepRunner) {
         val apk = container.getStep<CopyDependenciesStep>().patchedApk
 
-        if (Build.VERSION.SDK_INT < 29) {
-            state = StepState.Skipped
-            return
-        }
-
         var resourcesArscBytes: ByteArray? = null
+        var nativeLibPaths: List<String>? = null
         var dexCount: Int = -1
 
         // Align resources.arsc due to targeting API 30 for silent install
@@ -54,6 +49,18 @@ class AlignmentStep : Step(), KoinComponent {
             }
         }
 
+        // Align native libs due to using extractNativeLibs
+        nativeLibPaths = ZipReader(apk).use { zip ->
+            val libPaths = zip.entryNames.filter { it.endsWith(".so") }
+            for ((idx, path) in libPaths.withIndex()) {
+                // Index is just used as a placeholder id to cache on disk
+                val bytes = zip.openEntry(path)!!.read()
+                val file = paths.patchingWorkingDir().resolve("$idx.so")
+                file.writeBytes(bytes)
+            }
+            libPaths
+        }
+
         ZipWriter(apk, /* append = */ true).use { zip ->
             // Delete all the unaligned files from APK
             if (resourcesArscBytes != null)
@@ -62,6 +69,9 @@ class AlignmentStep : Step(), KoinComponent {
             for (i in 0..<dexCount)
                 zip.deleteEntry(getDexName(i))
 
+            for (path in nativeLibPaths)
+                zip.deleteEntry(path)
+
             // Write all the files back aligned this time
             if (resourcesArscBytes != null)
                 zip.writeEntry("resources.arsc", resourcesArscBytes, ZipCompression.NONE, 4)
@@ -71,6 +81,13 @@ class AlignmentStep : Step(), KoinComponent {
                 val bytes = file.readBytes()
                 zip.writeEntry(getDexName(idx), bytes, ZipCompression.NONE, 4)
             }
+
+            // Write back native libraries aligned to 16KiB page boundary
+            for ((idx, path) in nativeLibPaths.withIndex()) {
+                val file = paths.patchingWorkingDir().resolve("$idx.so")
+                val bytes = file.readBytes()
+                zip.writeEntry(path, bytes, ZipCompression.NONE, 16384)
+            }
         }
     }
 
diff --git a/app/src/main/kotlin/com/aliucord/manager/patcher/util/ManifestPatcher.kt b/app/src/main/kotlin/com/aliucord/manager/patcher/util/ManifestPatcher.kt
index c2d89dc..45bbfd2 100644
--- a/app/src/main/kotlin/com/aliucord/manager/patcher/util/ManifestPatcher.kt
+++ b/app/src/main/kotlin/com/aliucord/manager/patcher/util/ManifestPatcher.kt
@@ -15,6 +15,7 @@ object ManifestPatcher {
     private const val DEBUGGABLE = "debuggable"
     private const val VM_SAFE_MODE = "vmSafeMode"
     private const val USE_EMBEDDED_DEX = "useEmbeddedDex"
+    private const val EXTRACT_NATIVE_LIBS = "extractNativeLibs"
     private const val REQUEST_LEGACY_EXTERNAL_STORAGE = "requestLegacyExternalStorage"
     private const val NETWORK_SECURITY_CONFIG = "networkSecurityConfig"
     private const val LABEL = "label"
@@ -91,19 +92,24 @@ object ManifestPatcher {
                                 mapOf(
                                     LABEL to appName,
                                     DEBUGGABLE to debuggable,
-                                    REQUEST_LEGACY_EXTERNAL_STORAGE to true
+                                    REQUEST_LEGACY_EXTERNAL_STORAGE to true,
+                                    VM_SAFE_MODE to true,
+                                    USE_EMBEDDED_DEX to true,
+                                    EXTRACT_NATIVE_LIBS to true,
                                 )
                             ) {
                                 private var addDebuggable = debuggable
                                 private var addLegacyStorage = true
                                 private var addVmSafeMode = true
                                 private var addUseEmbeddedDex = true
+                                private var addExtractNativeLibs = true
 
                                 override fun attr(ns: String?, name: String, resourceId: Int, type: Int, value: Any?) {
                                     if (name == NETWORK_SECURITY_CONFIG) return
                                     if (name == REQUEST_LEGACY_EXTERNAL_STORAGE) addLegacyStorage = false
                                     if (name == VM_SAFE_MODE) addVmSafeMode = false
                                     if (name == USE_EMBEDDED_DEX) addUseEmbeddedDex = false
+                                    if (name == EXTRACT_NATIVE_LIBS) addExtractNativeLibs = false
                                     if (name == DEBUGGABLE) addDebuggable = false
                                     super.attr(ns, name, resourceId, type, value)
                                 }
@@ -152,6 +158,14 @@ object ManifestPatcher {
                                         super.attr(ANDROID_NAMESPACE, VM_SAFE_MODE, android.R.attr.vmSafeMode, TYPE_INT_BOOLEAN, 1)
                                     }
 
+                                    if (addExtractNativeLibs) super.attr(
+                                        ANDROID_NAMESPACE,
+                                        EXTRACT_NATIVE_LIBS,
+                                        android.R.attr.extractNativeLibs,
+                                        TYPE_INT_BOOLEAN,
+                                        1
+                                    )
+
                                     super.end()
                                 }
                             }