Fix for JCR-3535 - Davex remoting should support absolute path hrefs

jackrabbit-spi2dav/src/main/java/org/apache/jackrabbit/spi2dav/IdPathCache.java

@@ -0,0 +1,97 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.jackrabbit.spi2dav;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+import org.apache.jackrabbit.spi.ItemId;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * The <code>IdPathCache</code> maintains a bidirectional LRU cache from itemId to its path.
+ */
+class IdPathCache {
+
+    private static Logger log = LoggerFactory.getLogger(IdPathCache.class);
+
+    private LRUCache<ItemId, String> idToPathCache;
+    private LRUCache<String, ItemId> pathToIdCache;
+
+    public IdPathCache(int limit) {
+        idToPathCache = new LRUCache<ItemId, String>(limit);
+        pathToIdCache = new LRUCache<String, ItemId>(limit);
+    }
+
+    public ItemId getItemId(String path) {
+        return pathToIdCache.get(path);
+    }
+
+    public String getPath(ItemId itemId) {
+        return idToPathCache.get(itemId);
+    }
+
+    public boolean containsPath(String path) {
+        return pathToIdCache.containsKey(path);
+    }
+
+    public boolean containsItemId(ItemId itemId) {
+        return idToPathCache.containsKey(itemId);
+    }
+
+    public void add(String path, ItemId itemId) {
+        pathToIdCache.put(path, itemId);
+        idToPathCache.put(itemId, path);
+        log.debug("Added: ItemId = " + itemId + " PATH = {}", path);
+    }
+
+    public void remove(String path) {
+        ItemId itemId = pathToIdCache.remove(path);
+        if (itemId != null) {
+            idToPathCache.remove(itemId);
+        }
+        log.debug("Removed: ItemId = " + itemId + " PATH = {}", path);
+    }
+
+    public void remove(ItemId itemId) {
+        String path = idToPathCache.remove(itemId);
+        if (path != null) {
+            pathToIdCache.remove(path);
+        }
+        log.debug("Removed: ItemId = " + itemId + " PATH = {}", path);
+    }
+
+    public void clear() {
+        idToPathCache.clear();
+        pathToIdCache.clear();
+    }
+
+    private class LRUCache<K, V> extends LinkedHashMap<K, V> {
+
+        private final int limit;
+
+        public LRUCache(int limit) {
+            super(16, 0.75f, true);
+            this.limit = limit;
+        }
+
+        @Override
+        protected boolean removeEldestEntry(Map.Entry<K,V> eldest) {
+            return size() > limit;
+        }
+    }
+}