CcmNG: Implementation of the lock method for WebDAV access to theme files

git-svn-id: https://svn.libreccm.org/ccm/ccm_ng@5450 8810af33-2d31-482b-a856-94f89814c4df

ccm-core/src/main/java/org/libreccm/theming/webdav/AlreadyLockedException.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2018 LibreCCM Foundation.
+ *
+ * This library 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 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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 this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301  USA
+ */
+
+package org.libreccm.theming.webdav;
+
+/**
+ *
+ * @author <a href="mailto:jens.pelzetter@googlemail.com">Jens Pelzetter</a>
+ */
+class AlreadyLockedException extends Exception {
+
+    private static final long serialVersionUID = 1L;
+
+    /**
+     * Creates a new instance of <code>AlreadyLockedException</code> without detail message.
+     */
+    public AlreadyLockedException() {
+        super();
+    }
+
+
+    /**
+     * Constructs an instance of <code>AlreadyLockedException</code> with the specified detail message.
+     *
+     * @param msg The detail message.
+     */
+    public AlreadyLockedException(final String msg) {
+        super(msg);
+    }
+
+    /**
+      * Constructs an instance of <code>AlreadyLockedException</code> which wraps the 
+      * specified exception.
+      *
+      * @param exception The exception to wrap.
+      */
+    public AlreadyLockedException(final Exception exception) {
+        super(exception);
+    }
+
+    /**
+      * Constructs an instance of <code>AlreadyLockedException</code> with the specified message which also wraps the 
+      * specified exception.
+      *
+      * @param msg The detail message.
+      * @param exception The exception to wrap.
+      */
+    public AlreadyLockedException(final String msg, final Exception exception) {
+        super(msg, exception);
+    }
+}

ccm-core/src/main/java/org/libreccm/theming/webdav/ThemeFiles.java

@@ -41,16 +41,24 @@ import org.libreccm.theming.ThemeInfo;
 import org.libreccm.theming.ThemeVersion;
 import org.libreccm.theming.Themes;
 import org.libreccm.webdav.ResponseStatus;
+import org.libreccm.webdav.methods.LOCK;
+import org.libreccm.webdav.xml.elements.ActiveLock;
 import org.libreccm.webdav.xml.elements.Collection;
+import org.libreccm.webdav.xml.elements.Depth;
 import org.libreccm.webdav.xml.elements.HRef;
+import org.libreccm.webdav.xml.elements.LockInfo;
+import org.libreccm.webdav.xml.elements.LockRoot;
+import org.libreccm.webdav.xml.elements.LockToken;
 import org.libreccm.webdav.xml.elements.MultiStatus;
 import org.libreccm.webdav.xml.elements.Prop;
 import org.libreccm.webdav.xml.elements.PropStat;
 import org.libreccm.webdav.xml.elements.Status;
+import org.libreccm.webdav.xml.elements.TimeOut;
 import org.libreccm.webdav.xml.elements.WebDavResponse;
 import org.libreccm.webdav.xml.properties.DisplayName;
 import org.libreccm.webdav.xml.properties.GetContentLength;
 import org.libreccm.webdav.xml.properties.GetContentType;
+import org.libreccm.webdav.xml.properties.LockDiscovery;
 
 import java.util.LinkedList;
 import java.util.List;
@@ -72,14 +80,17 @@ import javax.ws.rs.ext.Providers;
 public class ThemeFiles {
 
     @Inject
-    private Themes themes;
+    private HttpServletRequest request;
 
     @Inject
     private ServletContext servletContext;
-    
+
     @Inject
-    private HttpServletRequest request;
+    private Themes themes;
-    
+
+    @Inject
+    private ThemeFilesLockManager lockManager;
+
     @GET
     @Path("/{path}")
     public Response getFile(@PathParam("theme") final String theme,
@@ -117,6 +128,38 @@ public class ThemeFiles {
 
     }
 
+    @LOCK
+    @Path("/{path}")
+    public Prop lock(@PathParam("theme")
+                     final String theme,
+                     @PathParam("path")
+                     final String path,
+                     final LockInfo lockInfo) {
+
+        final String lockedPath = String.format("%s/path",
+                                                theme,
+                                                path);
+        
+        try {
+            final String lockToken = lockManager.lockFile(lockedPath);
+
+            return new Prop(new LockDiscovery(
+                new ActiveLock(lockInfo.getLockScope(),
+                               lockInfo.getLockType(),
+                               Depth.ZERO,
+                               lockInfo.getOwner(),
+                               new TimeOut(3600),
+                               new LockToken(new HRef(String
+                                   .format("opaquelocktoken:%s",
+                                           lockToken))),
+                               new LockRoot(new HRef(lockedPath)))));
+
+        } catch (AlreadyLockedException ex) {
+            throw new WebApplicationException(
+                ResponseStatus.LOCKED.getStatusCode());
+        }
+    }
+
     @OPTIONS
     public Response options() {
 
@@ -209,10 +252,10 @@ public class ThemeFiles {
 
         return response;
     }
-    
+
     private WebDavResponse buildWebDavResponse(final String basePath,
                                                final ThemeFileInfo fileInfo) {
-        
+
         final PropStat propStat;
         if (fileInfo.isDirectory()) {
             propStat = new PropStat(

ccm-core/src/main/java/org/libreccm/theming/webdav/ThemeFilesLockManager.java

@@ -0,0 +1,98 @@
+/*
+ * Copyright (C) 2018 LibreCCM Foundation.
+ *
+ * This library 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 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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 this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301  USA
+ */
+package org.libreccm.theming.webdav;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+import java.util.UUID;
+
+import javax.enterprise.context.ApplicationScoped;
+
+/**
+ * Manages the locks on files for WebDAV.
+ *
+ * @author <a href="mailto:jens.pelzetter@googlemail.com">Jens Pelzetter</a>
+ */
+@ApplicationScoped
+class ThemeFilesLockManager {
+
+    /**
+     * Mapping between file path and lock token
+     */
+    private final Map<String, String> lockedFiles = new HashMap<>();
+
+    /**
+     * Mapping between lock token and file.
+     */
+    private final Map<String, String> locks = new HashMap<>();
+
+    /**
+     * Lock a file
+     *
+     * @param file Path of the file to lock.
+     *
+     * @return The lock token.
+     *
+     * @throws AlreadyLockedException If the file is already locked.
+     */
+    protected String lockFile(final String file) throws AlreadyLockedException {
+
+        if (lockedFiles.containsKey(file)) {
+            throw new AlreadyLockedException(String.format(
+                "File %s is already locked.", file));
+        } else {
+
+            final String lockToken = UUID.randomUUID().toString();
+            lockedFiles.put(file, lockToken);
+            locks.put(lockToken, file);
+
+            return lockToken;
+        }
+    }
+
+    /**
+     * Check if a file is locked.
+     *
+     * @param file The file to check for a lock.
+     *
+     * @return An {@link Optional} with the lock token of the file if the file
+     *         is locked, an empty {@code Optional} otherwise.
+     */
+    protected Optional<String> isLocked(final String file) {
+        if (lockedFiles.containsKey(file)) {
+            return Optional.of(lockedFiles.get(file));
+        } else {
+            return Optional.empty();
+        }
+    }
+
+    /**
+     * Removes the lock from a file.
+     * 
+     * @param lockToken The token of the lock to remove.
+     */
+    protected void unlock(final String lockToken) {
+
+        final String file = locks.get(lockToken);
+        locks.remove(lockToken);
+        lockedFiles.remove(file);
+    }
+
+}