Merged HEAD (5.1) to 5.1.N (5.1.1)

117474 bhorje: CM-690 virtualization


git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/BRANCHES/DEV/5.1.N/root@117559 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

source/java/org/alfresco/repo/virtual/ref/HierarchicalPathHasher.java

@@ -0,0 +1,135 @@
+/* 
+ * Copyright (C) 2005-2015 Alfresco Software Limited.
+ *
+ * This file is part of Alfresco
+ *
+ * Alfresco is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Alfresco 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Alfresco. If not, see http://www.gnu.org/licenses/.
+ */
+
+package org.alfresco.repo.virtual.ref;
+
+import org.alfresco.util.Pair;
+import org.alfresco.util.ParameterCheck;
+import org.apache.commons.codec.binary.Base64;
+
+/**
+ * Creates and looks up hashes of '/' paths defining strings.<br>
+ * Paths are hashed using {@link HashStore} defined hashes. <br>
+ * Store defined hashes are matched for the longest possible sub-path of a given
+ * path. The remaining path is encoded using a Base64 encoder. The two resulted
+ * strings.
+ */
+public abstract class HierarchicalPathHasher implements PathHasher
+{
+    private static String normalizePath(String classpath)
+    {
+        String normalizedClasspath = classpath.trim();
+        if (!normalizedClasspath.startsWith("/"))
+        {
+            normalizedClasspath = "/" + normalizedClasspath;
+        }
+        if (normalizedClasspath.endsWith("/"))
+        {
+            normalizedClasspath = normalizedClasspath.substring(0,
+                                                                normalizedClasspath.length() - 1);
+        }
+        return normalizedClasspath;
+    }
+
+    protected abstract String hashSubpath(String subpath);
+
+    protected abstract String lookupSubpathHash(String hash);
+
+    @Override
+    public Pair<String, String> hash(String path)
+    {
+        ParameterCheck.mandatoryString("path",
+                                       path);
+
+        String normalClasspath = normalizePath(path);
+        String searchedClasspath = normalClasspath;
+        String notFoundPath = null;
+        String hash = hashSubpath(searchedClasspath);
+
+        while (hash == null)
+        {
+            int lastSeparator = searchedClasspath.lastIndexOf('/');
+            if (lastSeparator < 0)
+            {
+                String code = new String(Base64.encodeBase64(normalClasspath.getBytes(),
+                                                             false));
+                return new Pair<String, String>(null,
+                                                code);
+            }
+
+            if (notFoundPath != null)
+            {
+                notFoundPath = searchedClasspath.substring(lastSeparator + 1) + "/" + notFoundPath;
+
+            }
+            else
+            {
+                notFoundPath = searchedClasspath.substring(lastSeparator + 1);
+
+            }
+
+            searchedClasspath = searchedClasspath.substring(0,
+                                                            lastSeparator);
+            hash = hashSubpath(searchedClasspath);
+
+            if (hash != null)
+            {
+                String notFoundClasspathBase64 = new String(Base64.encodeBase64(notFoundPath.getBytes(),
+                                                                                false));
+
+                return new Pair<String, String>(hash,
+                                                notFoundClasspathBase64);
+            }
+        }
+
+        return new Pair<String, String>(hash,
+                                        null);
+
+    }
+
+    @Override
+    public String lookup(Pair<String, String> hash)
+    {
+        if (hash.getSecond() == null)
+        {
+            return lookupSubpathHash(hash.getFirst());
+        }
+        else if (hash.getFirst() == null)
+        {
+            return lookupSubpathCode(hash.getSecond());
+        }
+        else
+        {
+            String lHash = lookupSubpathHash(hash.getFirst());
+            String lCode = lookupSubpathCode(hash.getSecond());
+            return lHash + "/" + lCode;
+        }
+    }
+
+    private String lookupSubpathCode(String code)
+    {
+        if (code.isEmpty())
+        {
+            return "/";
+        }
+        byte[] decodedBytes = Base64.decodeBase64(code.getBytes());
+        return new String(decodedBytes);
+    }
+
+}