var complete = (upstream == null)

  /** The most recently read bytes from [upstream]. This is a suffix of [file]. Guarded by this. */
  val buffer = Buffer()

  /**
   * Reference count of the number of active sources reading this stream. When decremented to 0
   * resources are released and all following calls to [.newSource] return null. Guarded by this.
   */
  var sourceCount = 0

  val isClosed: Boolean
    get() = file == null

   * TODO description.
   *
   * No further calls to this listener will be made.
   */
  open fun onClosed(eventSource: EventSource) {
  }

  /**
   * Invoked when an event source has been closed due to an error reading from or writing to the
   * network. Incoming events may have been lost. No further calls to this listener will be made.
   */
  open fun onFailure(
    eventSource: EventSource,
    t: Throwable?,

    "--connect-timeout",
    help = "Maximum time allowed for connection (seconds)",
  ).int().default(DEFAULT_TIMEOUT)

  val readTimeout: Int by option("--read-timeout", help = "Maximum time allowed for reading data (seconds)").int().default(DEFAULT_TIMEOUT)

  val callTimeout: Int by option(
    "--call-timeout",
    help = "Maximum time allowed for the entire call (seconds)",
  ).int().default(DEFAULT_TIMEOUT)

# Controllers

Istio has a variety of [controllers](https://kubernetes.io/docs/concepts/architecture/controller/), which basically watch some inputs and do something.
This can be reading from Kubernetes and writing other objects back, writing to proxies over XDS, etc.

Unfortunately, writing controllers is very error prone, even for seemingly simple cases.
To work around this, Istio has a variety of abstractions meant to make writing controllers easier.

## Clients

import okio.ByteString.Companion.encodeUtf8

object Http2 {
  @JvmField
  val CONNECTION_PREFACE = "PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n".encodeUtf8()

  /** The initial max frame size, applied independently writing to, or reading from the peer. */
  const val INITIAL_MAX_FRAME_SIZE = 0x4000 // 16384

  const val TYPE_DATA = 0x0
  const val TYPE_HEADERS = 0x1
  const val TYPE_PRIORITY = 0x2
  const val TYPE_RST_STREAM = 0x3

        if (isClient) {
          "Server-sent frames must not be masked."
        } else {
          "Client-sent frames must be masked."
        },
      )
    }

    // Get frame length, optionally reading from follow-up bytes if indicated by special values.
    frameLength = (b1 and B1_MASK_LENGTH).toLong()
    if (frameLength == PAYLOAD_SHORT.toLong()) {

```

### 3. Configuring Prometheus

#### 3.1 Authenticated Prometheus config

> If MinIO is configured to expose metrics without authentication, you don't need to use `mc` to generate prometheus config. You can skip reading further and move to 3.2 section.

  val fileSystem: FileSystem = FileSystem.RESOURCES,
) {
  /** True after we've attempted to read the list for the first time. */
  private val listRead = AtomicBoolean(false)

  /** Used for concurrent threads reading the list for the first time. */
  private val readCompleteLatch = CountDownLatch(1)

  // The lists are held as a large array of UTF-8 bytes. This is to avoid allocating lots of strings

      return null // Another edit is in progress.
    }

    if (entry != null && entry.lockingSourceCount != 0) {
      return null // We can't write this file because a reader is still reading it.
    }

    if (mostRecentTrimFailed || mostRecentRebuildFailed) {
      // The OS has become our enemy! If the trim job failed, it means we are storing more data than

And you want to have a way for the frontend to authenticate with the backend, using a **username** and **password**.

We can use **OAuth2** to build that with **FastAPI**.

But let's save you the time of reading the full long specification just to find those little pieces of information you need.

Let's use the tools provided by **FastAPI** to handle security.

## How it looks