more ASM work...

src/main/java/com/falsepattern/lib/asm/SmartTransformer.java

@@ -0,0 +1,55 @@
+package com.falsepattern.lib.asm;
+
+import com.falsepattern.lib.asm.exceptions.AsmTransformException;
+import com.falsepattern.lib.internal.CoreLoadingPlugin;
+import lombok.val;
+import org.apache.logging.log4j.Logger;
+import org.objectweb.asm.ClassReader;
+import org.objectweb.asm.ClassWriter;
+
+import net.minecraft.launchwrapper.IClassTransformer;
+
+import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.List;
+
+/**
+ * An ASM transformation dispatcher utility, inspired by mixins.
+ */
+public interface SmartTransformer extends IClassTransformer {
+    Logger logger();
+    List<IClassNodeTransformer> transformers();
+    @Override
+    default byte[] transform(String name, String transformedName, byte[] bytes) {
+        if (bytes == null) {
+            return null;
+        }
+        val transformers = new ArrayList<IClassNodeTransformer>();
+        val cn = ASMUtil.parseClass(bytes, ClassReader.EXPAND_FRAMES);
+        for (val transformer: transformers()) {
+            if (transformer.shouldTransform(cn, transformedName, CoreLoadingPlugin.isObfuscated())) {
+                transformers.add(transformer);
+            }
+        }
+        if (transformers.isEmpty()) {
+            return bytes;
+        }
+        transformers.sort(Comparator.comparingInt(IClassNodeTransformer::internalSortingOrder));
+        val log = logger();
+        for (val transformer: transformers) {
+            log.debug("Patching {} with {}...", transformedName, transformer.getName());
+            try {
+                transformer.transform(cn, transformedName, CoreLoadingPlugin.isObfuscated());
+            } catch (RuntimeException | Error t) {
+                log.error("Error transforming {} with {}: {}", transformedName, transformer.getName(), t.getMessage());
+                throw t;
+            } catch (Throwable t) {
+                log.error("Error transforming {} with {}: {}", transformedName, transformer.getName(), t.getMessage());
+                throw new RuntimeException(t);
+            }
+        }
+        val result = ASMUtil.serializeClass(cn, ClassWriter.COMPUTE_FRAMES);
+        log.debug("Patched {} successfully.", transformedName);
+        return result;
+    }
+}