# HG changeset patch
# User Alexander Simon <alexvsimon@netbeans.org>
# Date 1320241788 -10800
# Node ID 144cc23a6dc1dc0c81ea5618f132ff022846ae95
# Parent  951d08566353ee8b5fa3ac80b84a47d16d9a556b
Third iteration Bug #199806 Provide bridge between remote file system and VCS
- renamed ProvidedExtensions2
- delegate proxy operations to remote file system
- remove dependency on masterfs
- implement all methods

diff --git a/fsbridge/build.xml b/fsbridge/build.xml
new file mode 100644
--- /dev/null
+++ b/fsbridge/build.xml
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project basedir="." default="netbeans" name="fsbridge">
+    <description>Builds, tests, and runs the project org.netbeans.modules.fsbridge</description>
+    <import file="../nbbuild/templates/projectized.xml"/>
+</project>
diff --git a/fsbridge/manifest.mf b/fsbridge/manifest.mf
new file mode 100644
--- /dev/null
+++ b/fsbridge/manifest.mf
@@ -0,0 +1,5 @@
+Manifest-Version: 1.0
+OpenIDE-Module: org.netbeans.modules.fsbridge
+OpenIDE-Module-Localizing-Bundle: org/netbeans/modules/fsbridge/Bundle.properties
+OpenIDE-Module-Specification-Version: 1.0
+
diff --git a/fsbridge/nbproject/project.properties b/fsbridge/nbproject/project.properties
new file mode 100644
--- /dev/null
+++ b/fsbridge/nbproject/project.properties
@@ -0,0 +1,2 @@
+javac.source=1.6
+javac.compilerargs=-Xlint -Xlint:-serial
diff --git a/fsbridge/nbproject/project.xml b/fsbridge/nbproject/project.xml
new file mode 100644
--- /dev/null
+++ b/fsbridge/nbproject/project.xml
@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://www.netbeans.org/ns/project/1">
+    <type>org.netbeans.modules.apisupport.project</type>
+    <configuration>
+        <data xmlns="http://www.netbeans.org/ns/nb-module-project/3">
+            <code-name-base>org.netbeans.modules.fsbridge</code-name-base>
+            <module-dependencies>
+                <dependency>
+                    <code-name-base>org.netbeans.modules.dlight.nativeexecution</code-name-base>
+                    <build-prerequisite/>
+                    <compile-dependency/>
+                    <run-dependency>
+                        <specification-version>1.10.3</specification-version>
+                    </run-dependency>
+                </dependency>
+                <dependency>
+                    <code-name-base>org.openide.filesystems</code-name-base>
+                    <build-prerequisite/>
+                    <compile-dependency/>
+                    <run-dependency>
+                        <specification-version>7.47.1</specification-version>
+                    </run-dependency>
+                </dependency>
+            </module-dependencies>
+            <friend-packages>
+                <friend>org.netbeans.modules.dlight.remote.impl</friend>
+                <friend>org.netbeans.modules.versioning</friend>
+                <package>org.netbeans.modules.fsbridge.spi</package>
+            </friend-packages>
+        </data>
+    </configuration>
+</project>
diff --git a/fsbridge/src/org/netbeans/modules/fsbridge/Bundle.properties b/fsbridge/src/org/netbeans/modules/fsbridge/Bundle.properties
new file mode 100644
--- /dev/null
+++ b/fsbridge/src/org/netbeans/modules/fsbridge/Bundle.properties
@@ -0,0 +1,5 @@
+OpenIDE-Module-Display-Category=Infrastructure
+OpenIDE-Module-Long-Description=\
+    Remote File System Bridge
+OpenIDE-Module-Name=Remote File System Bridge
+OpenIDE-Module-Short-Description=Remote File System Bridge
diff --git a/fsbridge/src/org/netbeans/modules/fsbridge/spi/Bridge.java b/fsbridge/src/org/netbeans/modules/fsbridge/spi/Bridge.java
new file mode 100644
--- /dev/null
+++ b/fsbridge/src/org/netbeans/modules/fsbridge/spi/Bridge.java
@@ -0,0 +1,106 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
+ *
+ * Copyright 2011 Oracle and/or its affiliates. All rights reserved.
+ *
+ * Oracle and Java are registered trademarks of Oracle and/or its affiliates.
+ * Other names may be trademarks of their respective owners.
+ *
+ * The contents of this file are subject to the terms of either the GNU
+ * General Public License Version 2 only ("GPL") or the Common
+ * Development and Distribution License("CDDL") (collectively, the
+ * "License"). You may not use this file except in compliance with the
+ * License. You can obtain a copy of the License at
+ * http://www.netbeans.org/cddl-gplv2.html
+ * or nbbuild/licenses/CDDL-GPL-2-CP. See the License for the
+ * specific language governing permissions and limitations under the
+ * License.  When distributing the software, include this License Header
+ * Notice in each file and include the License file at
+ * nbbuild/licenses/CDDL-GPL-2-CP.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the GPL Version 2 section of the License file that
+ * accompanied this code. If applicable, add the following below the
+ * License Header, with the fields enclosed by brackets [] replaced by
+ * your own identifying information:
+ * "Portions Copyrighted [year] [name of copyright owner]"
+ *
+ * If you wish your version of this file to be governed by only the CDDL
+ * or only the GPL Version 2, indicate your decision by adding
+ * "[Contributor] elects to include this software in this distribution
+ * under the [CDDL or GPL Version 2] license." If you do not indicate a
+ * single choice of license, a recipient has the option to distribute
+ * your version of this file under either the CDDL, the GPL Version 2 or
+ * to extend the choice of license to its licensees as provided above.
+ * However, if you add GPL Version 2 code and therefore, elected the GPL
+ * Version 2 license, then the option applies only if the new code is
+ * made subject to such option by the copyright holder.
+ *
+ * Contributor(s):
+ *
+ * Portions Copyrighted 2011 Sun Microsystems, Inc.
+ */
+package org.netbeans.modules.fsbridge.spi;
+
+import java.io.File;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import org.netbeans.modules.nativeexecution.api.ExecutionEnvironment;
+import org.openide.filesystems.FileObject;
+import org.openide.filesystems.FileStateInvalidException;
+import org.openide.filesystems.FileSystem;
+
+/**
+ *
+ * @author Alexander Simon
+ */
+public final class Bridge {
+    private Bridge() {
+    }
+
+    public static FileProxy createLocalFileProxy(final File file) {
+        return new FileProxy(file.getAbsolutePath(), null);
+    }
+
+    public static FileProxy createFileProxy(final FileObject file) {
+        try {
+            FileProxyOperations fileProxyOperations = getFileProxyOperations(file.getFileSystem());
+            if (fileProxyOperations == null) {
+                return new FileProxy(file.getPath(), null);
+            } else {
+                return new FileProxy(file.getPath(), fileProxyOperations);
+            }
+        } catch (FileStateInvalidException ex) {
+            Logger.getLogger(Bridge.class.getName()).log(Level.SEVERE, null, ex);
+        }
+        return new FileProxy(file.getPath(), null);
+    }
+
+    public static FileProxy createFileProxy(FileSystem fs, String path) {
+        FileProxyOperations fileProxyOperations = getFileProxyOperations(fs);
+        if (fileProxyOperations == null) {
+            return new FileProxy(path, null);
+        } else {
+            return new FileProxy(path, fileProxyOperations);
+        }
+    }
+
+    public static FileObject toFileObject(final FileProxy path) {
+        return path.toFileObject();
+    }
+    
+    public static FileProxy normalizeFile(final FileProxy file) {
+        return file.normalizeFile();
+    }
+    
+    public static ExecutionEnvironment getExecutionEnvironment(FileProxy file) {
+        return file.getExecutionEnvironment();
+    }
+
+    private static FileProxyOperations getFileProxyOperations(FileSystem fs) {
+        return (FileProxyOperations) getAttribute(fs, FileProxyOperations.ATTRIBUTE);
+    }
+
+    private static Object getAttribute(FileSystem fileSystem, String attrName) {
+        return fileSystem.getRoot().getAttribute(attrName);
+    }
+}
diff --git a/fsbridge/src/org/netbeans/modules/fsbridge/spi/FileProxy.java b/fsbridge/src/org/netbeans/modules/fsbridge/spi/FileProxy.java
new file mode 100644
--- /dev/null
+++ b/fsbridge/src/org/netbeans/modules/fsbridge/spi/FileProxy.java
@@ -0,0 +1,170 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
+ *
+ * Copyright 2011 Oracle and/or its affiliates. All rights reserved.
+ *
+ * Oracle and Java are registered trademarks of Oracle and/or its affiliates.
+ * Other names may be trademarks of their respective owners.
+ *
+ * The contents of this file are subject to the terms of either the GNU
+ * General Public License Version 2 only ("GPL") or the Common
+ * Development and Distribution License("CDDL") (collectively, the
+ * "License"). You may not use this file except in compliance with the
+ * License. You can obtain a copy of the License at
+ * http://www.netbeans.org/cddl-gplv2.html
+ * or nbbuild/licenses/CDDL-GPL-2-CP. See the License for the
+ * specific language governing permissions and limitations under the
+ * License.  When distributing the software, include this License Header
+ * Notice in each file and include the License file at
+ * nbbuild/licenses/CDDL-GPL-2-CP.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the GPL Version 2 section of the License file that
+ * accompanied this code. If applicable, add the following below the
+ * License Header, with the fields enclosed by brackets [] replaced by
+ * your own identifying information:
+ * "Portions Copyrighted [year] [name of copyright owner]"
+ *
+ * If you wish your version of this file to be governed by only the CDDL
+ * or only the GPL Version 2, indicate your decision by adding
+ * "[Contributor] elects to include this software in this distribution
+ * under the [CDDL or GPL Version 2] license." If you do not indicate a
+ * single choice of license, a recipient has the option to distribute
+ * your version of this file under either the CDDL, the GPL Version 2 or
+ * to extend the choice of license to its licensees as provided above.
+ * However, if you add GPL Version 2 code and therefore, elected the GPL
+ * Version 2 license, then the option applies only if the new code is
+ * made subject to such option by the copyright holder.
+ *
+ * Contributor(s):
+ *
+ * Portions Copyrighted 2011 Sun Microsystems, Inc.
+ */
+package org.netbeans.modules.fsbridge.spi;
+
+import java.io.File;
+import org.netbeans.modules.nativeexecution.api.ExecutionEnvironment;
+import org.netbeans.modules.nativeexecution.api.ExecutionEnvironmentFactory;
+import org.openide.filesystems.FileObject;
+import org.openide.filesystems.FileUtil;
+
+/**
+ * Represents file on remote or local file system.
+ *
+ * @author Alexander Simon
+ */
+public final class FileProxy {
+
+    private final String path;
+    private final FileProxyOperations proxy;
+
+    FileProxy(String path, FileProxyOperations proxy) {
+        this.path = path;
+        this.proxy = proxy;
+    }
+
+    public String getAbsolutePath() {
+        return path;
+    }
+    
+    public String getName() {
+        if (proxy == null) {
+            return new File(path).getName();
+        } else {
+            return proxy.getName(this);
+        }
+    }
+    
+    public boolean isDirectory() {
+        if (proxy == null) {
+            return new File(path).isDirectory();
+        } else {
+            return proxy.isDirectory(this);
+        }
+    }
+    
+    public boolean isFile() {
+        if (proxy == null) {
+            return new File(path).isFile();
+        } else {
+            return proxy.isFile(this);
+        }
+    }
+    
+    public boolean canWrite() {
+        if (proxy == null) {
+            return new File(path).canWrite();
+        } else {
+            return proxy.canWrite(this);
+        }
+    }
+    
+    public FileProxy getParentFile() {
+        if (proxy == null) {
+            return Bridge.createLocalFileProxy(new File(path).getParentFile());
+        } else {
+            return proxy.getParentFile(this);
+        }
+    }
+    public boolean exists() {
+        if (proxy == null) {
+            return new File(path).exists();
+        } else {
+            return proxy.exists(this);
+        }
+    }
+    
+    @Override
+    public String toString() {
+        return path;
+    }
+
+    @Override
+    public int hashCode() {
+        int hash = 5;
+        hash = 61 * hash + (this.path != null ? this.path.hashCode() : 0);
+        hash = 61 * hash + (this.proxy != null ? this.proxy.hashCode() : 0);
+        return hash;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj == null) {
+            return false;
+        }
+        if (getClass() != obj.getClass()) {
+            return false;
+        }
+        final FileProxy other = (FileProxy) obj;
+        if ((this.path == null) ? (other.path != null) : !this.path.equals(other.path)) {
+            return false;
+        }
+        if (this.proxy != other.proxy && (this.proxy == null || !this.proxy.equals(other.proxy))) {
+            return false;
+        }
+        return true;
+    }
+
+    ExecutionEnvironment getExecutionEnvironment() {
+        if (proxy == null) {
+            return ExecutionEnvironmentFactory.getLocal();
+        } else {
+            return proxy.getExecutionEnvironment();
+        }
+    }
+
+    FileObject toFileObject() {
+        if (proxy == null) {
+            return FileUtil.toFileObject(new File(FileUtil.normalizePath(path)));
+        } else {
+            return proxy.toFileObject(this);
+        }
+    }
+
+    FileProxy normalizeFile() {
+        if (proxy == null) {
+            return new FileProxy(FileUtil.normalizePath(path), null);
+        } else {
+            return proxy.normalize(this);
+        }
+    }
+}
diff --git a/fsbridge/src/org/netbeans/modules/fsbridge/spi/FileProxyOperations.java b/fsbridge/src/org/netbeans/modules/fsbridge/spi/FileProxyOperations.java
new file mode 100644
--- /dev/null
+++ b/fsbridge/src/org/netbeans/modules/fsbridge/spi/FileProxyOperations.java
@@ -0,0 +1,73 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
+ *
+ * Copyright 2011 Oracle and/or its affiliates. All rights reserved.
+ *
+ * Oracle and Java are registered trademarks of Oracle and/or its affiliates.
+ * Other names may be trademarks of their respective owners.
+ *
+ * The contents of this file are subject to the terms of either the GNU
+ * General Public License Version 2 only ("GPL") or the Common
+ * Development and Distribution License("CDDL") (collectively, the
+ * "License"). You may not use this file except in compliance with the
+ * License. You can obtain a copy of the License at
+ * http://www.netbeans.org/cddl-gplv2.html
+ * or nbbuild/licenses/CDDL-GPL-2-CP. See the License for the
+ * specific language governing permissions and limitations under the
+ * License.  When distributing the software, include this License Header
+ * Notice in each file and include the License file at
+ * nbbuild/licenses/CDDL-GPL-2-CP.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the GPL Version 2 section of the License file that
+ * accompanied this code. If applicable, add the following below the
+ * License Header, with the fields enclosed by brackets [] replaced by
+ * your own identifying information:
+ * "Portions Copyrighted [year] [name of copyright owner]"
+ *
+ * If you wish your version of this file to be governed by only the CDDL
+ * or only the GPL Version 2, indicate your decision by adding
+ * "[Contributor] elects to include this software in this distribution
+ * under the [CDDL or GPL Version 2] license." If you do not indicate a
+ * single choice of license, a recipient has the option to distribute
+ * your version of this file under either the CDDL, the GPL Version 2 or
+ * to extend the choice of license to its licensees as provided above.
+ * However, if you add GPL Version 2 code and therefore, elected the GPL
+ * Version 2 license, then the option applies only if the new code is
+ * made subject to such option by the copyright holder.
+ *
+ * Contributor(s):
+ *
+ * Portions Copyrighted 2011 Sun Microsystems, Inc.
+ */
+package org.netbeans.modules.fsbridge.spi;
+
+import org.netbeans.modules.nativeexecution.api.ExecutionEnvironment;
+import org.openide.filesystems.FileObject;
+
+/**
+ *
+ * @author Vladimir Voskresensky
+ */
+public interface FileProxyOperations {
+    public static final String ATTRIBUTE = "FileProxyOperations";
+    
+    String getName(FileProxy file);
+    
+    boolean isDirectory(FileProxy file);
+    
+    boolean isFile(FileProxy file);
+    
+    boolean canWrite(FileProxy file);
+    
+    FileProxy getParentFile(FileProxy file);
+
+    String getAbsolutePath(FileProxy file);
+    
+    boolean exists(FileProxy file);
+
+    ExecutionEnvironment getExecutionEnvironment();
+
+    FileProxy normalize(FileProxy file);
+
+    FileObject toFileObject(FileProxy path);
+}
diff --git a/fsbridge/src/org/netbeans/modules/fsbridge/spi/FileProxyOperationsInterceptor.java b/fsbridge/src/org/netbeans/modules/fsbridge/spi/FileProxyOperationsInterceptor.java
new file mode 100644
--- /dev/null
+++ b/fsbridge/src/org/netbeans/modules/fsbridge/spi/FileProxyOperationsInterceptor.java
@@ -0,0 +1,213 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
+ *
+ * Copyright 2011 Oracle and/or its affiliates. All rights reserved.
+ *
+ * Oracle and Java are registered trademarks of Oracle and/or its affiliates.
+ * Other names may be trademarks of their respective owners.
+ *
+ * The contents of this file are subject to the terms of either the GNU
+ * General Public License Version 2 only ("GPL") or the Common
+ * Development and Distribution License("CDDL") (collectively, the
+ * "License"). You may not use this file except in compliance with the
+ * License. You can obtain a copy of the License at
+ * http://www.netbeans.org/cddl-gplv2.html
+ * or nbbuild/licenses/CDDL-GPL-2-CP. See the License for the
+ * specific language governing permissions and limitations under the
+ * License.  When distributing the software, include this License Header
+ * Notice in each file and include the License file at
+ * nbbuild/licenses/CDDL-GPL-2-CP.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the GPL Version 2 section of the License file that
+ * accompanied this code. If applicable, add the following below the
+ * License Header, with the fields enclosed by brackets [] replaced by
+ * your own identifying information:
+ * "Portions Copyrighted [year] [name of copyright owner]"
+ *
+ * If you wish your version of this file to be governed by only the CDDL
+ * or only the GPL Version 2, indicate your decision by adding
+ * "[Contributor] elects to include this software in this distribution
+ * under the [CDDL or GPL Version 2] license." If you do not indicate a
+ * single choice of license, a recipient has the option to distribute
+ * your version of this file under either the CDDL, the GPL Version 2 or
+ * to extend the choice of license to its licensees as provided above.
+ * However, if you add GPL Version 2 code and therefore, elected the GPL
+ * Version 2 license, then the option applies only if the new code is
+ * made subject to such option by the copyright holder.
+ *
+ * Contributor(s):
+ *
+ * Portions Copyrighted 2011 Sun Microsystems, Inc.
+ */
+package org.netbeans.modules.fsbridge.spi;
+
+import java.io.IOException;
+import java.util.List;
+import org.openide.filesystems.FileObject;
+
+/**
+ * Extension of {@link org.netbeans.modules.masterfs.providers.ProvidedExtensions} to process remote file operations.
+ * 
+ * @author Alexander Simon
+ */
+public interface FileProxyOperationsInterceptor {
+    
+    public interface FileProxyIOHandler {
+        /**
+         * @throws java.io.IOException if handled operation isn't successful
+         */
+        void handle() throws IOException;
+    }
+    
+    public interface FileProxyDeleteHandler {
+        /**
+         * Deletes the file or directory denoted by this abstract pathname.  If
+         * this pathname denotes a directory, then the directory must be empty in
+         * order to be deleted.
+         *
+         * @return  <code>true</code> if and only if the file or directory is
+         *          successfully deleted; <code>false</code> otherwise
+         */
+        boolean delete(FileProxy file);
+    }
+    
+
+    /**
+     * Return instance of {@link FileProxyOperationsInterceptor.FileProxyIOHandler}
+     * that is responsible for copying the file or null.
+     *
+     * Just the first non null instance of <code>FileProxyIOHandler</code> is used by
+     *  <code>RemoteFileSystem</code>
+     *
+     * @param from file to be copied
+     * @param to target to copy this file to
+     * @return instance of {@link FileProxyOperationsInterceptor.FileProxyIOHandler}
+     * that is responsible for copying the file or null
+     */
+    FileProxyOperationsInterceptor.FileProxyIOHandler getCopyHandler(FileProxy from, FileProxy to);
+
+    /**
+     * Return instance of {@link FileProxyOperationsInterceptor.FileProxyIOHandler}
+     * that is responsible for moving the file or null.
+     *
+     * Just the first non null instance of <code>FileProxyIOHandler</code> is used by
+     *  <code>RemoteFileSystem</code>
+     *
+     * @param from file to be moved
+     * @param to target to move this file to
+     * @return instance of {@link FileProxyOperationsInterceptor.FileProxyIOHandler} 
+     * that is responsible for moving the file or null
+     */
+    FileProxyOperationsInterceptor.FileProxyIOHandler getMoveHandler(FileProxy from, FileProxy to);
+    
+    /*
+     * Return instance of {@link FileProxyOperationsInterceptor.FileProxyIOHandler}
+     * that is responsible for renaming the file or null.
+     *
+     * Just the first non null instance of <code>FileProxyIOHandler</code> is used by
+     *  <code>RemoteFileSystem</code>
+     *
+     * @param from file to be renamed
+     * @param newName new name of file
+     * @return instance of {@link FileProxyOperationsInterceptor.FileProxyIOHandler} 
+     * that is responsible for renaming the file or null
+     */
+    FileProxyOperationsInterceptor.FileProxyIOHandler getRenameHandler(FileProxy from, String newName);
+
+    /*
+     * Return instance of {@link FileProxyOperationsInterceptor.FileProxyDeleteHandler}
+     * that is responsible for deleting the file or null.
+     *
+     * Just the first non null instance of <code>FileProxyDeleteHandler</code> is used by
+     *  <code>RemoteFileSystem</code>
+     *
+     * @param f file or folder to be deleted
+     * @return instance of {@link FileProxyOperationsInterceptor.FileProxyDeleteHandler} 
+     * that is responsible for deleting the file or null
+     */    
+    FileProxyOperationsInterceptor.FileProxyDeleteHandler getDeleteHandler(FileProxy f);
+    
+    /**
+     * Called by <code>RemoteFileSystem</code> before <code>FileObject</code>
+     * is copied
+     * @param from FileObject to be moved
+     * @param to FileProxy target to move this file to
+     */
+    void beforeCopy(FileObject from, FileProxy to);
+
+    /**
+     * Called by <code>RemoteFileSystem</code> after <code>FileObject</code>
+     * was successfully copied
+     * @param from FileObject to be moved
+     * @param to FileProxy target to move this file to
+     */
+    void copySuccess(FileObject from, FileProxy to);
+
+    /**
+     * Called by <code>RemoteFileSystem</code> after a <code>FileObject</code>
+     * copy failed
+     * @param from FileObject to be moved
+     * @param to FileProxy target to move this file to
+     */
+    void copyFailure(FileObject from, FileProxy to);
+
+    /**
+     * Called by <code>RemoteFileSystem</code> before <code>FileObject</code>
+     * is moved
+     * @param from FileObject to be moved
+     * @param to FileProxy target to move this file to
+     */
+    void beforeMove(FileObject from, FileProxy to);
+
+    /**
+     * Called by <code>RemoteFileSystem</code> after <code>FileObject</code>
+     * was successfully
+     * @param from FileObject to be moved
+     * @param to FileProxy target to move this file to
+     */
+    void moveSuccess(FileObject from, FileProxy to);
+
+    /**
+     * Called by <code>RemoteFileSystem</code> after a <code>FileObject</code>
+     * move failed
+     * @param from FileObject to be moved
+     * @param to FileProxy target to move this file to
+     */
+    void moveFailure(FileObject from, FileProxy to);
+
+    /**
+     * Called by <code>RemoteFileSystem</code> when <code>FileObject</code> is queried for writability with the
+     * canWrite() method.
+     * 
+     * @param f a FileProxy to query
+     * @return true if the file can be written to, deleted or moved, false otherwise
+     */
+    boolean canWrite(FileProxy f);
+
+    /**
+     * Called by {@code RemoteFileSystem} when {@code FileObject} is
+     * queried for attribute and attribute's name starts with {@code ProvidedExtensions}
+     * prefix.
+     * @param attrName name of attribute
+     * @return value of attribute
+     */
+    Object getAttribute(FileProxy file, String attrName);
+
+    /** Allows versioning system to exclude some children from recursive
+     * listening check. Also notifies the versioning whenever a refresh
+     * is required and allows the versiniong to provide special timestamp
+     * for a directory.
+     * <p>
+     * Default implementation of this method returns -1.
+     *
+     * @param dir the directory to check timestamp for
+     * @param lastTimeStamp the previously known timestamp or -1
+     * @param children add subfiles that shall be iterated into this array
+     * @return the timestamp that shall represent this directory, it will
+     *   be compared with timestamps of all children and the newest
+     *   one will be kept and next time passed as lastTimeStamp. Return
+     *   0 if the directory does not have any special timestamp. Return
+     *   -1 if you are not providing any special implementation
+     */
+    long refreshRecursively(FileProxy dir, long lastTimeStamp, List<? super FileProxy> children);
+}