assertNotNull(buffer, "Buffer should not be null even when cache is full");
            assertEquals(SmbComTransaction.TRANSACTION_BUF_SIZE, buffer.length, "Buffer should have correct size");
            buffers.add(buffer);
        }

        // When - Release all buffers back
        for (byte[] buffer : buffers) {
            BufferCache.releaseBuffer(buffer);
        }

        byte[] buffer2 = testCache.getBuffer();

        // Then
        assertNotNull(buffer1, "First buffer should not be null");
        assertNotNull(buffer2, "Second buffer should not be null");
        assertEquals(1024, buffer1.length, "Buffer should have expected size");
        assertEquals(1024, buffer2.length, "Buffer should have expected size");

        assertSame(testResponseBuffer, negotiationWithNullResponse.getResponseRaw());
    }

    @Test
    @DisplayName("Constructor with null buffers should work")
    void testConstructorWithNullBuffers() {
        // Test that null buffers are handled properly
        SmbNegotiation negotiationWithNullBuffers = new SmbNegotiation(mockRequest, mockResponse, null, null);

        assertThrows(Exception.class, () -> new Pac(pacData, keys));
    }

    @Test
    void testZeroBufferCount() throws IOException {
        // Test PAC with zero buffers (missing required buffers)
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        writeLittleEndianInt(baos, 0); // bufferCount = 0
        writeLittleEndianInt(baos, PacConstants.PAC_VERSION); // valid version

            byte[][] buffers = new byte[][] { new byte[8], new byte[8] };

            when(src.toString()).thenReturn("smb://src");
            when(dest.toString()).thenReturn("smb://dest");

            // Act + Assert
            SmbException ex =
                    assertThrows(SmbException.class, () -> SmbCopyUtil.copyFile(src, dest, buffers, 8, new WriterThread(), sh, dh));

     *
     * @param buffer buffer to release
     */
    public void releaseBuffer(ByteBuffer buffer) {
        // For direct buffers, we rely on GC
        // Could implement a more sophisticated buffer pool here
    }

    /**
     * Clean up all pooled regions
     *
     * This method should be called when shutting down to
     * release all resources.
     */

     */
    public BufferCacheImpl(final Configuration cfg) {
        this(cfg.getBufferCacheSize(), cfg.getMaximumBufferSize());
    }

    /**
     * Constructs a buffer cache with specified parameters.
     *
     * @param maxBuffers the maximum number of buffers to cache
     * @param maxSize the size of each buffer in bytes
     *
     */
    public BufferCacheImpl(final int maxBuffers, final int maxSize) {

 */

package jcifs.smb1.smb1;

import jcifs.smb1.Config;

/**
 * Buffer cache implementation for SMB1 protocol operations.
 * Manages a pool of byte buffers to reduce garbage collection overhead.
 *
 * Performance optimizations:
 * - Uses ConcurrentLinkedQueue for O(1) operations
 * - Lock-free operations for better concurrency
 * - Proper buffer validation and limits
 */
public class BufferCache {

    /**

        assertTrue(e.getMessage().contains("PAC"));
    }

    // Test exception for missing buffers
    @Test
    void testConstructorMissingBuffers() throws IOException {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        DataOutputStream dos = new DataOutputStream(baos);

        // Write header with no buffers
        dos.writeInt(Integer.reverseBytes(0));

        // Given
        byte[] buffer1 = new byte[256];
        byte[] buffer2 = new byte[256];

        // Prepare both buffers with valid structure
        SMBUtil.writeInt2(4, buffer1, 0);
        SMBUtil.writeInt2(0, buffer1, 2);
        SMBUtil.writeInt2(4, buffer2, 10);
        SMBUtil.writeInt2(0, buffer2, 12);

        // When