# Using the Request Directly { #using-the-request-directly }

Up to now, you have been declaring the parts of the request that you need with their types.

Taking data from:

* The path as parameters.
* Headers.
* Cookies.
* etc.

And by doing so, **FastAPI** is validating that data, converting it and generating documentation for your API automatically.

But there are situations where you might need to access the `Request` object directly.

2. By using a `with` block, we make sure that the file-like object is closed after the generator function is done. So, after it finishes sending the response.
3. This `yield from` tells the function to iterate over that thing named `file_like`. And then, for each part iterated, yield that part as coming from this generator function (`iterfile`).

    So, it is a generator function that transfers the "generating" work to something else internally.

import jakarta.annotation.PreDestroy;

/**
 * Helper class for managing crawler statistics and performance metrics.
 * This class provides functionality to track, record, and report statistics
 * about crawler operations including timing data, performance metrics, and
 * operational events. It uses an internal cache to maintain statistics
 * objects and provides methods to begin tracking, record events, and
 * finalize statistics collection.
 *
 */

 *   <li>Thread pool management for crawler execution</li>
 *   <li>Session-based crawling with cleanup operations</li>
 *   <li>Old document deletion after successful crawling</li>
 *   <li>Crawling execution monitoring and timing</li>
 * </ul>
 */
public class DataIndexHelper {

    /** Logger instance for this class */
    private static final Logger logger = LogManager.getLogger(DataIndexHelper.class);

    // The task thread waits for the latch, so we expect a timeout here.
    try {
      future.get(20, MILLISECONDS);
      fail("Should have timed out trying to get the value.");
    } catch (TimeoutException expected) {
    } finally {
      latch.countDown();
    }
  }

  /**
   * Tests that a canceled future throws a cancellation exception.
   *

   *
   * <p><b>Warning:</b> If the input future does not already implement {@code ListenableFuture}, the
   * returned future will emulate {@link ListenableFuture#addListener} by taking a thread from an
   * internal, unbounded pool at the first call to {@code addListener} and holding it until the
   * future is {@linkplain Future#isDone() done}.
   *

            assertFalse(isValid, "Different session keys should fail verification");
        }
    }

    @Nested
    @DisplayName("Secure Key Wiping Tests")
    class SecureKeyWipingTests {

        @Test
        @DisplayName("Should securely wipe signing key")
        void testSecureWipeKey() throws GeneralSecurityException {

   * deterministic iteration behavior.
   *
   * <p><b>Note:</b> this method is now unnecessary and should be treated as deprecated. Instead,
   * use the {@code HashSet} constructor directly, taking advantage of <a
   * href="https://docs.oracle.com/javase/tutorial/java/generics/genTypeInference.html#type-inference-instantiation">"diamond"
   * syntax</a>.
   */

     */
    public void resetStatistics() {
        for (AtomicLong counter : eventCounters.values()) {
            counter.set(0);
        }
        for (AtomicLong timing : eventTimings.values()) {
            timing.set(0);
        }
    }

    /**
     * Enable or disable JSON logging
     *
     * @param enable true to enable JSON logging
     */

            final byte[] cmp = new byte[SIGNATURE_LENGTH];
            System.arraycopy(mac.doFinal(), 0, cmp, 0, SIGNATURE_LENGTH);

            // Use constant-time comparison to prevent timing attacks
            if (!MessageDigest.isEqual(sig, cmp)) {
                return false; // Signature verification failed
            }
            return true; // Signature verification succeeded
        } finally {