Caching
=======

OkHttp implements an optional, off by default, Cache. OkHttp aims for RFC correct and
pragmatic caching behaviour, following common real-world browser like Firefox/Chrome and 
server behaviour when ambiguous.

# Basic Usage

```kotlin
  private val client: OkHttpClient = OkHttpClient.Builder()
      .cache(Cache(
          directory = File(application.cacheDir, "http_cache"),
          // $0.05 worth of phone storage in 2020

  - pymdownx.tabbed:
      alternate_style: true
  - tables

plugins:
  - search
  - redirects:
      redirect_maps:
        # Redirect all feature pages to features/*
        'caching.md': 'features/caching.md'
        'calls.md': 'features/calls.md'
        'connections.md': 'features/connections.md'
        'events.md': 'features/events.md'
        'https.md': 'features/events.md'

import static com.google.common.base.Preconditions.checkNotNull;

import java.util.Map;
import org.jspecify.annotations.Nullable;

/**
 * A {@link MapIteratorCache} that adds additional caching. In addition to the caching provided by
 * {@link MapIteratorCache}, this structure caches values for the two most recently retrieved keys.
 *
 * @author James Sexton
 */
final class MapRetrievalCache<K, V> extends MapIteratorCache<K, V> {

- Support for query parameters, headers, body (String or stream), compression, SSL configuration, proxies, and timeouts
- Automatic in-memory or on-disk caching of request/response bodies
- Synchronous and asynchronous (callback) execution
- Minimal dependencies (only Apache Commons IO)

## Installation

### Maven

import jakarta.annotation.PostConstruct;

/**
 * Helper class for managing popular words and suggestions.
 * Provides functionality to retrieve popular words based on search parameters
 * and manages caching for improved performance.
 */
public class PopularWordHelper {
    /** Logger instance for this class */
    private static final Logger logger = LogManager.getLogger(PopularWordHelper.class);

        // No matching host header
        String key = virtualHostHelper.getVirtualHostKey();
        assertEquals("", key);

        // Matching host header
        request.addHeader("Host", "example.com");
        key = virtualHostHelper.getVirtualHostKey();
        assertEquals("", key); // Still empty due to caching

        // Test caching by calling again - should return cached value

/**
 * A builder of {@link LoadingCache} and {@link Cache} instances.
 *
 * <h2>Prefer <a href="https://github.com/ben-manes/caffeine/wiki">Caffeine</a> over Guava's caching
 * API</h2>
 *
 * <p>The successor to Guava's caching API is <a
 * href="https://github.com/ben-manes/caffeine/wiki">Caffeine</a>. Its API is designed to make it a

org.gradle.caching=true
org.gradle.parallel=true

android.useAndroidX=true
kotlin.mpp.applyDefaultHierarchyTemplate=false

androidBuild=false
graalBuild=false
loomBuild=false
containerTests=false

 * It implements the Closeable interface to ensure that resources are properly released.
 *
 * <p>This class supports two types of content caching:
 * <ul>
 *   <li>In-memory caching using a byte array</li>
 *   <li>File-based caching using a File object</li>
 * </ul>
 *
 * <p>When an instance of ContentCache is created with a byte array, the content is cached in memory.

 * @author Nick Kralevich
 */
@GwtCompatible
@SuppressWarnings("serial") // uses writeReplace(), not default serialization
final class SingletonImmutableSet<E> extends ImmutableSet<E> {
  // We deliberately avoid caching the asList and hashCode here, to ensure that with
  // compressed oops, a SingletonImmutableSet packs all the way down to the optimal 16 bytes.

  final transient E element;

  SingletonImmutableSet(E element) {