only cache offsets that require IO

Author: vvb2060

library/src/androidTest/java/org/lsposed/hiddenapibypass/HiddenApiBypassTest.java

@@ -11,7 +11,6 @@
 import android.content.pm.ApplicationInfo;
 import android.graphics.drawable.ClipDrawable;
 import android.os.Build;
-import android.os.Process;
 
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import androidx.test.filters.SdkSuppress;
@@ -165,20 +164,14 @@ class X {
     public void PtestCachedOffset() {
         var context = InstrumentationRegistry.getInstrumentation().getContext();
         var artVersion = Helper.getArtVersion(context);
-        var isOld = artVersion == -1L;
         var isNew = artVersion >= 36_00_00000L;
-        var is64bit = Process.is64Bit();
         var data = new long[10];
         data[0] = 24;
         data[1] = 12;
         data[2] = 24;
         data[3] = 48;
         data[4] = 40;
         data[5] = isNew ? 40 : 56;
-        data[6] = isOld ? is64bit ? 40 : 28 : is64bit ? 32 : 24;
-        data[7] = is64bit ? 8 : 4;
-        data[8] = 16;
-        data[9] = 4;
         assertArrayEquals("art version " + artVersion, data, Helper.getCachedOffsetData());
     }
 

library/src/main/java/org/lsposed/hiddenapibypass/Helper.java

@@ -49,7 +49,7 @@ public static long[] getCachedOffsetData() {
     }
 
     public static void setCachedOffsetData(long[] data) {
-        if (cachedOffsetData != null || data.length != 10) return;
+        if (cachedOffsetData != null || data.length != 6) return;
         cachedOffsetData = data;
 
         if (cacheFile == null) return;
@@ -63,6 +63,7 @@ public static void setCachedOffsetData(long[] data) {
     }
 
     public static void enableOffsetCache(Context context) {
+        if (cacheFile != null) return;
         cacheFile = new File(context.getCacheDir(), "HiddenApiBypass");
         artVersion = getArtVersion(context);
 

library/src/main/java/org/lsposed/hiddenapibypass/HiddenApiBypass.java

@@ -63,7 +63,7 @@ public final class HiddenApiBypass {
             unsafe = (Unsafe) Unsafe.class.getDeclaredMethod("getUnsafe").invoke(null);
             var data = Helper.getCachedOffsetData();
             if (data == null) {
-                data = readOffsetData();
+                data = readOffsetDataIO();
                 Helper.setCachedOffsetData(data);
             } else if (BuildConfig.DEBUG) {
                 Log.d(TAG, "Using cached offset data");
@@ -74,18 +74,19 @@ public final class HiddenApiBypass {
             methodsOffset = data[3];
             iFieldOffset = data[4];
             sFieldOffset = data[5];
-            artMethodSize = data[6];
-            artMethodBias = data[7];
-            artFieldSize = data[8];
-            artFieldBias = data[9];
+            var dataRT = readOffsetDataRT();
+            artMethodSize = dataRT[0];
+            artMethodBias = dataRT[1];
+            artFieldSize = dataRT[2];
+            artFieldBias = dataRT[3];
         } catch (ReflectiveOperationException e) {
             Log.e(TAG, "Initialize error", e);
             throw new ExceptionInInitializerError(e);
         }
 
     }
 
-    private static long[] readOffsetData() throws ReflectiveOperationException {
+    private static long[] readOffsetDataIO() throws ReflectiveOperationException {
         ClassLoader bootClassloader = new CoreOjClassLoader();
         Class<?> executableClass = bootClassloader.loadClass(Executable.class.getName());
         Class<?> methodHandleClass = bootClassloader.loadClass(MethodHandle.class.getName());
@@ -95,16 +96,27 @@ private static long[] readOffsetData() throws ReflectiveOperationException {
         var artOffset = unsafe.objectFieldOffset(methodHandleClass.getDeclaredField("artFieldOrMethod"));
         var methodsOffset = unsafe.objectFieldOffset(classClass.getDeclaredField("methods"));
 
-        long iField;
-        long sField;
+        long iFieldOffset;
+        long sFieldOffset;
         try {
-            iField = unsafe.objectFieldOffset(classClass.getDeclaredField("fields"));
-            sField = iField;
+            iFieldOffset = unsafe.objectFieldOffset(classClass.getDeclaredField("fields"));
+            sFieldOffset = iFieldOffset;
         } catch (NoSuchFieldException e) {
-            iField = unsafe.objectFieldOffset(classClass.getDeclaredField("iFields"));
-            sField = unsafe.objectFieldOffset(classClass.getDeclaredField("sFields"));
+            iFieldOffset = unsafe.objectFieldOffset(classClass.getDeclaredField("iFields"));
+            sFieldOffset = unsafe.objectFieldOffset(classClass.getDeclaredField("sFields"));
         }
 
+        long[] data = new long[6];
+        data[0] = methodOffset;
+        data[1] = classOffset;
+        data[2] = artOffset;
+        data[3] = methodsOffset;
+        data[4] = iFieldOffset;
+        data[5] = sFieldOffset;
+        return data;
+    }
+
+    private static long[] readOffsetDataRT() throws ReflectiveOperationException {
         Method mA = Helper.NeverCall.class.getDeclaredMethod("a");
         Method mB = Helper.NeverCall.class.getDeclaredMethod("b");
         mA.setAccessible(true);
@@ -129,25 +141,19 @@ private static long[] readOffsetData() throws ReflectiveOperationException {
         MethodHandle mhJ = MethodHandles.lookup().unreflectGetter(fJ);
         long iAddr = unsafe.getLong(mhI, artOffset);
         long jAddr = unsafe.getLong(mhJ, artOffset);
-        long iFields = unsafe.getLong(Helper.NeverCall.class, iField);
+        long iFields = unsafe.getLong(Helper.NeverCall.class, iFieldOffset);
         var artFieldSize = jAddr - iAddr;
         if (BuildConfig.DEBUG) Log.v(TAG, artFieldSize + " " +
                 Long.toString(iAddr, 16) + ", " +
                 Long.toString(jAddr, 16) + ", " +
                 Long.toString(iFields, 16));
         var artFieldBias = iAddr - iFields;
 
-        long[] data = new long[10];
-        data[0] = methodOffset;
-        data[1] = classOffset;
-        data[2] = artOffset;
-        data[3] = methodsOffset;
-        data[4] = iField;
-        data[5] = sField;
-        data[6] = artMethodSize;
-        data[7] = artMethodBias;
-        data[8] = artFieldSize;
-        data[9] = artFieldBias;
+        long[] data = new long[4];
+        data[0] = artMethodSize;
+        data[1] = artMethodBias;
+        data[2] = artFieldSize;
+        data[3] = artFieldBias;
         return data;
     }