# 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;

    /**

            assertEquals(0x1, Smb2Constants.SMB2_GLOBAL_CAP_DFS, "DFS capability must be 0x1");
        }

        @Test
        @DisplayName("Leasing capability should be 0x2")
        void testGlobalCapLeasing() {
            assertEquals(0x2, Smb2Constants.SMB2_GLOBAL_CAP_LEASING, "Leasing capability must be 0x2");
        }

        @Test
        @DisplayName("Large MTU capability should be 0x4")

     * @return lease key
     */
    public Smb2LeaseKey requestDirectoryLease(String directoryPath, int requestedState, DirectoryCacheScope scope) {
        // Directory leasing requires SMB 3.0 or higher
        // MS-SMB2: Level 2 leasing (which includes directory leasing) is only supported in SMB 3.0+
        // We'll validate this when we actually need to use the session

        // Request base lease

- 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);
        }

    protected int handleReconnectRetries = 3;
    /** Directory to store persistent handle state */
    protected String handleStateDirectory;

    // Directory leasing configuration fields
    /**
     * Whether to use directory leasing for cached directory listings
     */
    protected boolean useDirectoryLeasing = true;
    /**