--- /dev/null	2016-12-10 08:16:53.177999985 +0000
+++ new/src/java.base/share/classes/jdk/internal/module/ModuleReferenceImpl.java	2016-12-15 09:19:29.026229563 +0000
@@ -0,0 +1,169 @@
+/*
+ * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.internal.module;
+
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.lang.module.ModuleDescriptor;
+import java.lang.module.ModuleReader;
+import java.lang.module.ModuleReference;
+import java.net.URI;
+import java.util.Objects;
+import java.util.function.Supplier;
+
+/**
+ * A ModuleReference implementation that supports referencing a module that
+ * is patched and/or can be tied to other modules by means of hashes.
+ */
+
+public class ModuleReferenceImpl extends ModuleReference {
+
+    private final Supplier<ModuleReader> readerSupplier;
+
+    // non-null if the module is patched
+    private final ModulePatcher patcher;
+
+    // the hashes of other modules recorded in this module
+    private final ModuleHashes recordedHashes;
+
+    // the function that computes the hash of this module
+    private final ModuleHashes.HashSupplier hasher;
+
+    // ModuleResolution flags
+    private final ModuleResolution moduleResolution;
+
+    // cached hash of this module to avoid needing to compute it many times
+    private byte[] cachedHash;
+
+    /**
+     * Constructs a new instance of this class.
+     */
+    ModuleReferenceImpl(ModuleDescriptor descriptor,
+                        URI location,
+                        Supplier<ModuleReader> readerSupplier,
+                        ModulePatcher patcher,
+                        ModuleHashes recordedHashes,
+                        ModuleHashes.HashSupplier hasher,
+                        ModuleResolution moduleResolution)
+    {
+        super(descriptor, Objects.requireNonNull(location));
+        this.readerSupplier = readerSupplier;
+        this.patcher = patcher;
+        this.recordedHashes = recordedHashes;
+        this.hasher = hasher;
+        this.moduleResolution = moduleResolution;
+    }
+
+    @Override
+    public ModuleReader open() throws IOException {
+        try {
+            return readerSupplier.get();
+        } catch (UncheckedIOException e) {
+            throw e.getCause();
+        }
+    }
+
+    /**
+     * Returns {@code true} if this module has been patched via --patch-module.
+     */
+    public boolean isPatched() {
+        return (patcher != null);
+    }
+
+    /**
+     * Returns the hashes recorded in this module or {@code null} if there
+     * are no hashes recorded.
+     */
+    public ModuleHashes recordedHashes() {
+        return recordedHashes;
+    }
+
+    /**
+     * Returns the supplier that computes the hash of this module.
+     */
+    ModuleHashes.HashSupplier hasher() {
+        return hasher;
+    }
+
+    /**
+     * Returns the ModuleResolution flags.
+     */
+    public ModuleResolution moduleResolution() {
+        return moduleResolution;
+    }
+
+    /**
+     * Computes the hash of this module. Returns {@code null} if the hash
+     * cannot be computed.
+     *
+     * @throws java.io.UncheckedIOException if an I/O error occurs
+     */
+    public byte[] computeHash(String algorithm) {
+        byte[] result = cachedHash;
+        if (result != null)
+            return result;
+        if (hasher == null)
+            return null;
+        cachedHash = result = hasher.generate(algorithm);
+        return result;
+    }
+
+    @Override
+    public int hashCode() {
+        int hc = hash;
+        if (hc == 0) {
+            hc = descriptor().hashCode();
+            hc = 43 * hc + Objects.hashCode(location());
+            hc = 43 * hc + Objects.hashCode(patcher);
+            if (hc == 0)
+                hc = -1;
+            hash = hc;
+        }
+        return hc;
+    }
+
+    private int hash;
+
+    @Override
+    public boolean equals(Object ob) {
+        if (!(ob instanceof ModuleReferenceImpl))
+            return false;
+        ModuleReferenceImpl that = (ModuleReferenceImpl)ob;
+
+        // assume module content, recorded hashes, etc. are the same
+        // when the modules have equal module descriptors, are at the
+        // same location, and are patched by the same patcher.
+        return Objects.equals(this.descriptor(), that.descriptor())
+                && Objects.equals(this.location(), that.location())
+                && Objects.equals(this.patcher, that.patcher);
+    }
+
+    @Override
+    public String toString() {
+        return super.toString();
+    }
+
+}