diff --git a/src/java/org/apache/lucene/search/CachingWrapperFilter.java b/src/java/org/apache/lucene/search/CachingWrapperFilter.java
new file mode 100644
index 00000000000..0d043ed269e
--- /dev/null
+++ b/src/java/org/apache/lucene/search/CachingWrapperFilter.java
@@ -0,0 +1,104 @@
+package org.apache.lucene.search;
+
+/* ====================================================================
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 2001 The Apache Software Foundation.  All rights
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The end-user documentation included with the redistribution,
+ *    if any, must include the following acknowledgment:
+ *       "This product includes software developed by the
+ *        Apache Software Foundation (http://www.apache.org/)."
+ *    Alternately, this acknowledgment may appear in the software itself,
+ *    if and wherever such third-party acknowledgments normally appear.
+ *
+ * 4. The names "Apache" and "Apache Software Foundation" and
+ *    "Apache Lucene" must not be used to endorse or promote products
+ *    derived from this software without prior written permission. For
+ *    written permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache",
+ *    "Apache Lucene", nor may "Apache" appear in their name, without
+ *    prior written permission of the Apache Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ */
+
+import org.apache.lucene.index.IndexReader;
+import java.util.BitSet;
+import java.util.WeakHashMap;
+import java.util.Map;
+import java.io.IOException;
+
+/**
+ * @todo add documentation after this is fully accepted
+ */
+public class CachingWrapperFilter extends Filter {
+  private Filter filter;
+
+  /**
+   * @todo What about serialization in RemoteSearchable?  Caching won't work.
+   *       Should transient be removed?
+   */
+  private transient Map cache;
+
+  /**
+   * @param filter Filter to cache results of
+   * @todo Do we want another constructor to allow user to supply
+   *       a backing caching Map implementation?
+   */
+  public CachingWrapperFilter(Filter filter) {
+    this.filter = filter;
+  }
+
+  public BitSet bits(IndexReader reader) throws IOException {
+    if (cache == null) {
+      cache = new WeakHashMap();
+    }
+
+    synchronized (cache) {  // check cache
+      BitSet cached = (BitSet) cache.get(reader);
+      if (cached != null) {
+        return cached;
+      }
+    }
+
+    final BitSet bits = filter.bits(reader);
+
+    synchronized (cache) {  // update cache
+      cache.put(reader, bits);
+    }
+
+    return bits;
+  }
+}
diff --git a/src/test/org/apache/lucene/search/MockFilter.java b/src/test/org/apache/lucene/search/MockFilter.java
new file mode 100644
index 00000000000..4e5b4b4db9c
--- /dev/null
+++ b/src/test/org/apache/lucene/search/MockFilter.java
@@ -0,0 +1,75 @@
+package org.apache.lucene.search;
+
+/* ====================================================================
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 2001 The Apache Software Foundation.  All rights
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The end-user documentation included with the redistribution,
+ *    if any, must include the following acknowledgment:
+ *       "This product includes software developed by the
+ *        Apache Software Foundation (http://www.apache.org/)."
+ *    Alternately, this acknowledgment may appear in the software itself,
+ *    if and wherever such third-party acknowledgments normally appear.
+ *
+ * 4. The names "Apache" and "Apache Software Foundation" and
+ *    "Apache Lucene" must not be used to endorse or promote products
+ *    derived from this software without prior written permission. For
+ *    written permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache",
+ *    "Apache Lucene", nor may "Apache" appear in their name, without
+ *    prior written permission of the Apache Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ */
+
+import org.apache.lucene.index.IndexReader;
+import java.util.BitSet;
+
+public class MockFilter extends Filter {
+  private boolean wasCalled;
+
+  public BitSet bits(IndexReader reader) {
+    wasCalled = true;
+    return new BitSet();
+  }
+
+  public void clear() {
+    wasCalled = false;
+  }
+
+  public boolean wasCalled() {
+    return wasCalled;
+  }
+}
diff --git a/src/test/org/apache/lucene/search/TestCachingrWrapperFilter.java b/src/test/org/apache/lucene/search/TestCachingrWrapperFilter.java
new file mode 100644
index 00000000000..414594a7815
--- /dev/null
+++ b/src/test/org/apache/lucene/search/TestCachingrWrapperFilter.java
@@ -0,0 +1,86 @@
+package org.apache.lucene.search;
+
+/* ====================================================================
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 2001 The Apache Software Foundation.  All rights
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The end-user documentation included with the redistribution,
+ *    if any, must include the following acknowledgment:
+ *       "This product includes software developed by the
+ *        Apache Software Foundation (http://www.apache.org/)."
+ *    Alternately, this acknowledgment may appear in the software itself,
+ *    if and wherever such third-party acknowledgments normally appear.
+ *
+ * 4. The names "Apache" and "Apache Software Foundation" and
+ *    "Apache Lucene" must not be used to endorse or promote products
+ *    derived from this software without prior written permission. For
+ *    written permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache",
+ *    "Apache Lucene", nor may "Apache" appear in their name, without
+ *    prior written permission of the Apache Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ */
+
+import junit.framework.TestCase;
+import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.RAMDirectory;
+import org.apache.lucene.index.IndexReader;
+import org.apache.lucene.index.IndexWriter;
+import org.apache.lucene.analysis.standard.StandardAnalyzer;
+
+public class TestCachingrWrapperFilter extends TestCase {
+  public void testCachingWorks() throws Exception {
+    Directory dir = new RAMDirectory();
+    IndexWriter writer = new IndexWriter(dir, new StandardAnalyzer(), true);
+    writer.close();
+
+    IndexReader reader = IndexReader.open(dir);
+
+    MockFilter filter = new MockFilter();
+    CachingWrapperFilter cacher = new CachingWrapperFilter(filter);
+
+    // first time, nested filter is called
+    cacher.bits(reader);
+    assertTrue("first time", filter.wasCalled());
+
+    // second time, nested filter should not be called
+    filter.clear();
+    cacher.bits(reader);
+    assertFalse("second time", filter.wasCalled());
+
+    reader.close();
+ }
+}