feat: properly manage ClassProxy & add ProxyBackedClassList

Signed-off-by: oSumAtrIX <johan.melkonyan1@web.de>

src/main/kotlin/app/revanced/patcher/Patcher.kt

@@ -3,7 +3,6 @@ package app.revanced.patcher
 import app.revanced.patcher.patch.Patch
 import app.revanced.patcher.patch.PatchMetadata
 import app.revanced.patcher.patch.PatchResultSuccess
-import app.revanced.patcher.proxy.ClassProxy
 import app.revanced.patcher.signature.MethodSignature
 import app.revanced.patcher.signature.resolver.SignatureResolver
 import app.revanced.patcher.util.ListBackedSet
@@ -49,18 +48,18 @@ class Patcher(
         for (file in files) {
             val dexFile = MultiDexIO.readDexFile(true, file, NAMER, null, null)
             for (classDef in dexFile.classes) {
-                val e = patcherData.classes.findIndexed { it.type == classDef.type }
+                val e = patcherData.classes.internalClasses.findIndexed { it.type == classDef.type }
                 if (e != null) {
                     if (throwOnDuplicates) {
                         throw Exception("Class ${classDef.type} has already been added to the patcher.")
                     }
                     val (_, idx) = e
                     if (allowedOverwrites.contains(classDef.type)) {
-                        patcherData.classes[idx] = classDef
+                        patcherData.classes.internalClasses[idx] = classDef
                     }
                     continue
                 }
-                patcherData.classes.add(classDef)
+                patcherData.classes.internalClasses.add(classDef)
             }
         }
     }
@@ -70,28 +69,17 @@ class Patcher(
      */
     fun save(): Map<String, MemoryDataStore> {
         val newDexFile = object : DexFile {
-            private fun MutableList<ClassDef>.replaceWith(proxy: ClassProxy) {
-                this[proxy.originalIndex] = proxy.mutatedClass
-            }
-
             override fun getClasses(): Set<ClassDef> {
-                for (proxy in patcherData.classProxies) {
+                val classes = patcherData.classes
+                val internalClasses = classes.internalClasses
+                for (proxy in classes.proxies) {
                     if (!proxy.proxyUsed) continue
 
-                    patcherData.classes.replaceWith(proxy)
+                    val index = internalClasses.indexOfFirst { it.type == proxy.immutableClass.type }
+                    internalClasses[index] = proxy.mutatedClass
                 }
-                for (patch in patcherData.patches) {
-                    for (signature in patch.signatures) {
-                        val result = signature.result
-                        result ?: continue
 
-                        val proxy = result.definingClassProxy
+                return ListBackedSet(internalClasses)
-                        if (!proxy.proxyUsed) continue
-
-                        patcherData.classes.replaceWith(proxy)
-                    }
-                }
-                return ListBackedSet(patcherData.classes)
             }
 
             override fun getOpcodes(): Opcodes {
@@ -129,7 +117,7 @@ class Patcher(
         if (signatures.isEmpty()) {
             throw IllegalStateException("No signatures found to resolve.")
         }
-        SignatureResolver(patcherData.classes, signatures).resolve()
+        SignatureResolver(patcherData.classes.internalClasses, signatures).resolve(patcherData)
         signaturesResolved = true
         return signatures
     }

src/main/kotlin/app/revanced/patcher/PatcherData.kt

@@ -4,14 +4,15 @@ import app.revanced.patcher.methodWalker.MethodWalker
 import app.revanced.patcher.patch.Patch
 import app.revanced.patcher.proxy.ClassProxy
 import app.revanced.patcher.signature.SignatureResolverResult
+import app.revanced.patcher.util.ProxyBackedClassList
 import org.jf.dexlib2.iface.ClassDef
 import org.jf.dexlib2.iface.Method
 
 class PatcherData(
-    internal val classes: MutableList<ClassDef>,
+    internalClasses: MutableList<ClassDef>,
 ) {
-    internal val classProxies = mutableSetOf<ClassProxy>()
+    val classes = ProxyBackedClassList(internalClasses)
-    internal val patches = mutableSetOf<Patch>()
+    internal val patches = mutableListOf<Patch>()
 
     /**
      * Find a class by a given class name
@@ -30,19 +31,14 @@ class PatcherData(
                 val result = signature.result
                 result ?: continue
 
-                if (predicate(result.definingClassProxy.immutableClass))
+                if (predicate(result.definingClassProxy.immutableClass)) return result.definingClassProxy  // ...then return that proxy
-                    return result.definingClassProxy  // ...then return that proxy
             }
         }
 
-        // else search the original class list
+        // else resolve the class to a proxy and return it, if the predicate is matching a class
-        val (foundClass, index) = classes.findIndexed(predicate) ?: return null
+        return classes.find(predicate)?.let {
-        // create a class proxy with the index of the class in the classes list
+            proxy(it)
-        val classProxy = ClassProxy(foundClass, index)
+        }
-        // add it to the cache and
-        this.classProxies.add(classProxy)
-        // return the proxy class
-        return classProxy
     }
 }
 
@@ -75,3 +71,12 @@ internal inline fun <T> Iterable<T>.findIndexed(predicate: (T) -> Boolean): Pair
     }
     return null
 }
+
+fun PatcherData.proxy(classProxy: ClassDef): ClassProxy {
+    var proxy = this.classes.proxies.find { it.immutableClass.type == classProxy.type }
+    if (proxy == null) {
+        proxy = ClassProxy(classProxy)
+        this.classes.proxies.add(proxy)
+    }
+    return proxy
+}

src/main/kotlin/app/revanced/patcher/proxy/ClassProxy.kt

@@ -9,11 +9,9 @@ import org.jf.dexlib2.iface.ClassDef
  * A class proxy simply holds a reference to the original class
  * and allocates a mutable clone for the original class if needed.
  * @param immutableClass The class to proxy
- * @param originalIndex The original index of the class in the list of classes
  */
 class ClassProxy(
     val immutableClass: ClassDef,
-    val originalIndex: Int,
 ) {
     internal var proxyUsed = false
     internal lateinit var mutatedClass: MutableClass

src/main/kotlin/app/revanced/patcher/signature/resolver/SignatureResolver.kt

@@ -1,5 +1,7 @@
 package app.revanced.patcher.signature.resolver
 
+import app.revanced.patcher.PatcherData
+import app.revanced.patcher.proxy
 import app.revanced.patcher.proxy.ClassProxy
 import app.revanced.patcher.signature.MethodSignature
 import app.revanced.patcher.signature.PatternScanMethod
@@ -13,14 +15,14 @@ internal class SignatureResolver(
     private val classes: List<ClassDef>,
     private val methodSignatures: Iterable<MethodSignature>
 ) {
-    fun resolve() {
+    fun resolve(patcherData: PatcherData) {
-        for ((index, classDef) in classes.withIndex()) {
+        for (classDef in classes) {
             for (signature in methodSignatures) {
                 for (method in classDef.methods) {
                     val patternScanData = compareSignatureToMethod(signature, method) ?: continue
 
                     // create class proxy, in case a patch needs mutability
-                    val classProxy = ClassProxy(classDef, index)
+                    val classProxy = patcherData.proxy(classDef)
                     signature.result = SignatureResolverResult(
                         classProxy,
                         patternScanData,

src/main/kotlin/app/revanced/patcher/util/ProxyBackedClassList.kt

@@ -0,0 +1,28 @@
+package app.revanced.patcher.util
+
+import app.revanced.patcher.proxy.ClassProxy
+import org.jf.dexlib2.iface.ClassDef
+
+class ProxyBackedClassList(internal val internalClasses: MutableList<ClassDef>) : List<ClassDef> {
+    internal val proxies = mutableListOf<ClassProxy>()
+
+    fun add(classDef: ClassDef) {
+        internalClasses.add(classDef)
+    }
+
+    fun add(classProxy: ClassProxy) {
+        proxies.add(classProxy)
+    }
+
+    override val size get() = internalClasses.size
+    override fun contains(element: ClassDef) = internalClasses.contains(element)
+    override fun containsAll(elements: Collection<ClassDef>) = internalClasses.containsAll(elements)
+    override fun get(index: Int) = internalClasses[index]
+    override fun indexOf(element: ClassDef) = internalClasses.indexOf(element)
+    override fun isEmpty() = internalClasses.isEmpty()
+    override fun iterator() = internalClasses.iterator()
+    override fun lastIndexOf(element: ClassDef) = internalClasses.lastIndexOf(element)
+    override fun listIterator() = internalClasses.listIterator()
+    override fun listIterator(index: Int) = internalClasses.listIterator(index)
+    override fun subList(fromIndex: Int, toIndex: Int) = internalClasses.subList(fromIndex, toIndex)
+}

src/test/kotlin/app/revanced/patcher/usage/ExamplePatch.kt

@@ -3,10 +3,7 @@ package app.revanced.patcher.usage
 import app.revanced.patcher.PatcherData
 import app.revanced.patcher.extensions.addInstructions
 import app.revanced.patcher.extensions.or
-import app.revanced.patcher.patch.Patch
+import app.revanced.patcher.patch.*
-import app.revanced.patcher.patch.PatchMetadata
-import app.revanced.patcher.patch.PatchResult
-import app.revanced.patcher.patch.PatchResultSuccess
 import app.revanced.patcher.proxy.mutableTypes.MutableField.Companion.toMutable
 import app.revanced.patcher.proxy.mutableTypes.MutableMethod.Companion.toMutable
 import app.revanced.patcher.signature.MethodMetadata
@@ -31,12 +28,19 @@ import org.jf.dexlib2.immutable.reference.ImmutableStringReference
 import org.jf.dexlib2.immutable.value.ImmutableFieldEncodedValue
 import org.jf.dexlib2.util.Preconditions
 
+val packageMetadata = listOf(
+    PackageMetadata(
+        "com.example.examplePackage",
+        listOf("0.0.1", "0.0.2")
+    )
+)
+
 class ExamplePatch : Patch(
     PatchMetadata(
         "example-patch",
         "ReVanced example patch",
         "A demonstrative patch to feature the core features of the ReVanced patcher",
-        listOf("com.example.examplePackage"),
+        packageMetadata,
         "0.0.1"
     ),
     setOf(
@@ -48,7 +52,7 @@ class ExamplePatch : Patch(
                     "main",
                 ),
                 PatternScanMethod.Fuzzy(1),
-                listOf("com.example.examplePackage"),
+                packageMetadata,
                 "The main method of TestClass",
                 "1.0.0"
             ),