* default, OkHttp will perform lazy initialization upon the first usage of the cache.
   */
  @Throws(IOException::class)
  fun initialize() {
    cache.initialize()
  }

  /**
   * Closes the cache and deletes all of its stored values. This will delete all files in the cache
   * directory including files that weren't created by the cache.
   */

## Version 4.1.1

_2019-09-05_

 *  Fix: Don't drop repeated headers when validating cached responses. In our Kotlin upgrade we
    introduced a regression where we iterated the number of unique header names rather than then
    number of unique headers. If you're using OkHttp's response cache this may impact you.


## Version 4.1.0

_2019-08-12_

 [brotli]: https://github.com/google/brotli

import okhttp3.OkHttpClient
import okhttp3.Request
import okhttp3.Response
import okhttp3.internal.assertHeld
import okhttp3.internal.assertNotHeld
import okhttp3.internal.assertThreadDoesntHoldLock
import okhttp3.internal.cache.CacheInterceptor
import okhttp3.internal.closeQuietly
import okhttp3.internal.connection.Locks.withLock
import okhttp3.internal.http.BridgeInterceptor
import okhttp3.internal.http.CallServerInterceptor

  // 1. successful fresh cached GET response
  // 2. unsuccessful (404, 500) fresh cached GET response
  // 3. successful network response
  // 4. successful stale cached GET response
  // 5. unsuccessful response
  @Test
  fun usesCache() {
    val cache = Cache(cacheFs, "cache".toPath(), (100 * 1024).toLong())
    val cachedClient = bootstrapClient.newBuilder().cache(cache).build()

  }

  companion object {
    /**
     * Cache control request directives that require network validation of responses. Note that such
     * requests may be assisted by the cache via conditional GET requests.
     */
    @JvmField
    val FORCE_NETWORK = commonForceNetwork()

    /**
     * Cache control request directives that uses the cache only, even if the cached response is

import okio.Source
import okio.Timeout
import okio.buffer

/** Serves requests from the cache and writes responses to the cache. */
class CacheInterceptor(internal val cache: Cache?) : Interceptor {
  @Throws(IOException::class)
  override fun intercept(chain: Interceptor.Chain): Response {
    val call = chain.call()
    val cacheCandidate = cache?.get(chain.request().requestForCache())

    val now = System.currentTimeMillis()

    when {
      name.equals("Cache-Control", ignoreCase = true) -> {
        if (headerValue != null) {
          // Multiple cache-control headers means we can't use the raw value.
          canUseHeaderValue = false
        } else {
          headerValue = value
        }
      }
      name.equals("Pragma", ignoreCase = true) -> {
        // Might specify additional cache-control params. We invalidate just in case.

  private lateinit var client: OkHttpClient

  @Before
  fun setUp() {
    context = ApplicationProvider.getApplicationContext<Application>()
    client =
      OkHttpClient.Builder()
        .cache(Cache(FakeFileSystem(), "/cache".toPath(), 10_000_000))
        .build()
  }

  @Test
  fun testRequestExternal() {
    assumeNetwork()

    val request = Request("https://www.google.com/robots.txt".toHttpUrl())

    taskFaker.runNextTask()

    // The rebuild is retried on cache hits and on cache edits.
    val snapshot = cache["b"]!!
    snapshot.close()
    assertThat(cache.edit("d")).isNull()
    assertThat(taskFaker.isIdle()).isFalse()

    // On cache misses, no retry job is queued.
    assertThat(cache["c"]).isNull()
    assertThat(taskFaker.isIdle()).isFalse()

    executeSynchronously("/", "Cache-Control", "only-if-cached")
      .assertCode(504)
      .assertBody("")
      .assertNoNetworkResponse()
      .assertNoCacheResponse()
  }

  @Test
  fun networkDropsOnConditionalGet() {
    client =
      client.newBuilder()
        .cache(cache)
        .build()

    // Seed the cache.
    server.enqueue(
      MockResponse(