# Directory Leasing Feature - Detailed Design Document

## 1. Overview

Directory leasing extends the SMB3 lease concept to directories, enabling client-side caching of directory metadata and change notifications. This significantly improves performance for applications that frequently enumerate directories or monitor directory changes.

## 2. Protocol Specification Reference

- **MS-SMB2 Section 2.2.13.2.12**: SMB2_CREATE_REQUEST_LEASE_V2 for directories

import jcifs.internal.smb2.lease.Smb2LeaseState;

/**
 * Extension methods for SmbFile to support directory leasing functionality.
 *
 * This utility class provides static methods that enhance SmbFile operations with
 * directory leasing capabilities for improved performance through caching when
 * SMB3 directory leasing is available and enabled.
 */
public class SmbFileDirectoryLeasingExtension {

    /**

     */
    public static final int SMB2_DIALECT_ANY = 0x02FF;

    /**
     * Server supports DFS
     */
    public static final int SMB2_GLOBAL_CAP_DFS = 0x1;

    /**
     * Server supports leasing
     */
    public static final int SMB2_GLOBAL_CAP_LEASING = 0x2;

    /**
     * Server supports multi-credit operations
     */
    public static final int SMB2_GLOBAL_CAP_LARGE_MTU = 0x4;

    /**

- Update `SmbSession` for multi-channel awareness
- Enhance `SmbTransport` for channel management

---

### Phase 4: Directory Leasing
**Priority: MEDIUM** | **Estimated Effort: 2-3 weeks**

Directory leasing extends the lease concept to directories for improved metadata caching.

#### 4.1 Core Directory Lease Infrastructure
```
Package: jcifs.internal.smb2.lease

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
package jcifs.internal.smb2.lease;

/**
 * Defines the scope of directory caching for SMB3 directory leasing
 */
public enum DirectoryCacheScope {
    /**
     * Cache only direct children of the directory
     */
    IMMEDIATE_CHILDREN,

    /**
     * Cache entire subtree recursively (if supported by server)

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
package jcifs.internal.smb2.lease;

/**
 * Defines directory lease state constants for SMB2/SMB3 directory leasing.
 *
 * This class provides constants and utility methods for managing directory lease states
 * in SMB2/SMB3 protocol implementations. Directory leases enable clients to cache

                }
            } catch (NumberFormatException e) {
                // Invalid values ignored
            }
        }

        // Directory leasing configuration
        value = props.getProperty("jcifs.smb.client.useDirectoryLeasing");
        if (value != null) {
            this.useDirectoryLeasing = Boolean.parseBoolean(value);
        }

import org.mockito.Mock;
import org.mockito.MockitoAnnotations;

import jcifs.CIFSContext;
import jcifs.Configuration;
import jcifs.smb.SmbFile;

/**
 * Integration tests for directory leasing functionality
 */
public class DirectoryLeasingIntegrationTest {

    @Mock
    private CIFSContext context;

    @Mock
    private Configuration config;

    @Mock
    private SmbFile mockFile1;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import jcifs.internal.util.SMBUtil;
import jcifs.smb.SmbFile;

/**
 * Handles directory change notifications for SMB3 directory leasing
 */
public class DirectoryChangeNotifier {

    private static final Logger log = LoggerFactory.getLogger(DirectoryChangeNotifier.class);

    // Backoff and timing constants (in ms)

        // Prepare test data with realistic SMB3 values
        byte[] buffer = new byte[50];
        int bufferIndex = 0;

        // SMB3 capabilities
        int testCapabilities = 0x0000002F; // DFS, LEASING, LARGE_MTU, MULTI_CHANNEL, PERSISTENT_HANDLES, DIRECTORY_LEASING

        // Random but realistic GUID