Sadly, those two putBoolean calls are required. Due to API stability across versions, UnsafeInflater is replaced with InflaterHackery, which instead just calls the appropriate methods instead of updating fields

Slight perf loss, which is depressing, but stability is a must.

Author: Col-E

pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>software.coley</groupId>
     <artifactId>lljzip</artifactId>
-    <version>1.6.0</version>
+    <version>1.6.1</version>
 
     <name>LL Java ZIP</name>
     <description>Lower level ZIP support for Java</description>

src/main/java/software/coley/llzip/format/compression/UnsafeDeflateDecompressor.java

@@ -3,7 +3,7 @@
 import software.coley.llzip.format.model.LocalFileHeader;
 import software.coley.llzip.util.ByteData;
 import software.coley.llzip.util.FastWrapOutputStream;
-import software.coley.llzip.util.UnsafeInflater;
+import software.coley.llzip.util.InflaterHackery;
 
 import java.io.IOException;
 import java.util.ArrayDeque;
@@ -43,9 +43,7 @@ public ByteData decompress(LocalFileHeader header, ByteData data) throws IOExcep
 		if (entry == null) {
 			entry = new DeflateEntry();
 		} else {
-			// Normal 'Inflater' reset() is synchronized and bottlenecks us,
-			// but we're using 'UnsafeInflater' which bypasses that.
-			entry.inflater.reset();
+			InflaterHackery.reset(entry.inflater);
 		}
 		try {
 			byte[] output = entry.decompress;
@@ -90,7 +88,7 @@ public ByteData decompress(LocalFileHeader header, ByteData data) throws IOExcep
 	}
 
 	private static final class DeflateEntry {
-		final Inflater inflater = new UnsafeInflater(true);
+		final Inflater inflater = new Inflater(true);
 		final byte[] decompress = new byte[1024];
 		final byte[] buffer = new byte[8192];
 	}

src/main/java/software/coley/llzip/format/compression/ZipCompressions.java

@@ -2,7 +2,6 @@
 
 import software.coley.llzip.format.model.LocalFileHeader;
 import software.coley.llzip.util.ByteData;
-import software.coley.llzip.util.UnsafeInflater;
 
 import java.io.IOException;
 
@@ -210,11 +209,7 @@ static ByteData decompress(LocalFileHeader header) throws IOException {
 				return header.getFileData();
 			case DEFLATED:
 				// Use unsafe decompressor if available since it is faster.
-				if (UnsafeInflater.initFail) {
-					return header.decompress(new DeflateDecompressor());
-				} else {
-					return header.decompress(new UnsafeDeflateDecompressor());
-				}
+				return header.decompress(new UnsafeDeflateDecompressor());
 			default:
 				// TODO: Support other decompressing techniques
 				String methodName = getName(method);

src/main/java/software/coley/llzip/util/InflaterHackery.java

@@ -0,0 +1,56 @@
+package software.coley.llzip.util;
+
+import sun.misc.Unsafe;
+
+import java.lang.invoke.MethodHandle;
+import java.lang.invoke.MethodHandles;
+import java.lang.invoke.MethodType;
+import java.lang.reflect.Field;
+import java.util.zip.Inflater;
+
+/**
+ * Used to more efficiently reset a {@link Inflater} than the default impl of {@link Inflater#reset()}.
+ *
+ * @author xDark
+ */
+public final class InflaterHackery {
+	private static final Unsafe UNSAFE = UnsafeUtil.get();
+	private static final MethodHandle MH_RESET;
+	private static final MethodHandle MH_FINISHED;
+	private static final long zRef_offset;
+	private static final long zRef_address_offset;
+
+	private InflaterHackery() {
+	}
+
+	/**
+	 * @param inflater
+	 * 		Inflater to reset.
+	 */
+	public static void reset(Inflater inflater) {
+		Unsafe u = UNSAFE;
+		long address = u.getLong(u.getObject(inflater, zRef_offset), zRef_address_offset);
+		try {
+			MH_RESET.invokeExact(address);
+			MH_FINISHED.invokeExact(inflater, false);
+		} catch (Throwable t) {
+			throw new RuntimeException(t);
+		}
+	}
+
+	static {
+		try {
+			Unsafe u = UNSAFE;
+			Field f = Inflater.class.getDeclaredField("zsRef");
+			Class<?> zrefClass = f.getType();
+			zRef_offset = u.objectFieldOffset(f);
+			f = zrefClass.getDeclaredField("address");
+			zRef_address_offset = u.objectFieldOffset(f);
+			MethodHandles.Lookup l = UnsafeUtil.lookup();
+			MH_RESET = l.findStatic(Inflater.class, "reset", MethodType.methodType(void.class, long.class));
+			MH_FINISHED = l.findSetter(Inflater.class, "finished", boolean.class);
+		} catch (ReflectiveOperationException ex) {
+			throw new ExceptionInInitializerError(ex);
+		}
+	}
+}