More deterministic output

Fixes #32
ThexXTURBOXx · Mar 28, 2023 · 34cdd5e · 34cdd5e
1 parent dd5cc4e
commit 34cdd5e
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Showing 2 changed files with 17 additions and 2 deletions.
diff --git a/dex-translator/src/main/java/com/googlecode/d2j/dex/Dex2Asm.java b/dex-translator/src/main/java/com/googlecode/d2j/dex/Dex2Asm.java
@@ -41,7 +41,6 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
-import java.util.Random;
 import java.util.Set;
 import java.util.Stack;
 import org.objectweb.asm.AnnotationVisitor;
@@ -67,7 +66,7 @@ public static class ClzCtx {
         public String buildHexDecodeMethodName(String x) {
             if (hexDecodeMethodNamePrefix == null) {
                 byte[] d = new byte[4];
-                new Random().nextBytes(d);
+                Dex2jar.random.nextBytes(d);
                 hexDecodeMethodNamePrefix = "$d2j$hex$" + IR2JConverter.hexEncode(d);
             }
             return hexDecodeMethodNamePrefix + "$decode_" + x;

diff --git a/dex-translator/src/main/java/com/googlecode/d2j/dex/Dex2jar.java b/dex-translator/src/main/java/com/googlecode/d2j/dex/Dex2jar.java
@@ -20,12 +20,19 @@
 import java.nio.file.spi.FileSystemProvider;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Random;
 import org.objectweb.asm.ClassVisitor;
 import org.objectweb.asm.ClassWriter;
 import org.objectweb.asm.MethodVisitor;
 
 public final class Dex2jar {
 
+    /**
+     * For rather deterministic output, we use a fixed seed for random number generator.
+     * This field is freely writable by any thread. Use carefully.
+     */
+    public static Random random = new Random(0);
+
     private DexExceptionHandler exceptionHandler;
 
     private final BaseDexFileReader reader;
@@ -279,6 +286,15 @@ public Dex2jar skipExceptions(boolean b) {
         return this;
     }
 
+    public Dex2jar setRandom(Random random) {
+        Dex2jar.random = random;
+        return this;
+    }
+
+    public Dex2jar resetRandom() {
+        return setRandom(new Random(0));
+    }
+
     public static Dex2jar from(byte[] in) throws IOException {
         return from(MultiDexFileReader.open(in));
     }