val inflater = MessageInflater(false)

    val goldenValue = "".encodeUtf8()

    val deflated = deflater.deflate(goldenValue)
    assertThat(deflated).isEqualTo("00".decodeHex())
    val inflated = inflater.inflate(deflated)

    assertThat(inflated).isEqualTo(goldenValue)
  }

  @Test fun `inflate deflate with context takeover`() {
    val deflater = MessageDeflater(false)

  private val deflatedBytes = Buffer()

  private val deflater =
    Deflater(
      Deflater.DEFAULT_COMPRESSION,
      // nowrap (omits zlib header):
      true,
    )

  private val deflaterSink = DeflaterSink(deflatedBytes, deflater)

  /** Deflates [buffer] in place as described in RFC 7692 section 7.2.1. */
  @Throws(IOException::class)
  fun deflate(buffer: Buffer) {
    require(deflatedBytes.size == 0L)

 * Sec-WebSocket-Extensions: permessage-deflate; client_no_context_takeover
 * Sec-WebSocket-Extensions: permessage-deflate; server_max_window_bits="15"
 * Sec-WebSocket-Extensions: permessage-deflate; server_max_window_bits=15
 * Sec-WebSocket-Extensions: permessage-deflate; server_no_context_takeover
 * Sec-WebSocket-Extensions: permessage-deflate; server_no_context_takeover;
 *     client_no_context_takeover

    of unacknowledged data per stream and no per-connection limit.

 *  Fix: Don't close a `Deflater` while we're still using it to compress a web socket message. We
    had a severe bug where web sockets were closed on the wrong thread, which caused
    `NullPointerException` crashes in `Deflater`.

 *  Fix: Don't crash after a web socket fails its connection upgrade. We incorrectly released

    compresses messages of size 1 KiB and larger. (Inbound messages are compressed or not based on
    the web socket server's configuration.)
 *  New: Defer constructing `Inflater` and `Deflater` instances until they are needed. This saves
    memory if web socket compression is negotiated but not used.


## Version 4.5.0-RC1

_2020-03-17_

import java.io.Closeable
import java.io.IOException
import java.util.zip.Inflater
import okio.Buffer
import okio.InflaterSource

private const val OCTETS_TO_ADD_BEFORE_INFLATION = 0x0000ffff

class MessageInflater(
  private val noContextTakeover: Boolean,
) : Closeable {
  private val deflatedBytes = Buffer()

  private val inflater =
    Inflater(
      // nowrap (omits zlib header):
      true,
    )

  }

  @Test
  fun emptyParameters() {
    assertThat(parse("permessage-deflate;"))
      .isEqualTo(WebSocketExtensions(perMessageDeflate = true))
  }

  @Test
  fun repeatedPerMessageDeflate() {
    assertThat(parse("permessage-deflate, permessage-deflate; server_no_context_takeover"))
      .isEqualTo(
        WebSocketExtensions(
          perMessageDeflate = true,
          serverNoContextTakeover = true,

		Method: Deflate,
		Mode:   0644,
	},
	{
		Name:   "setuid",
		Data:   []byte("setuid file"),
		Method: Deflate,
		Mode:   0755 | fs.ModeSetuid,
	},
	{
		Name:   "setgid",
		Data:   []byte("setgid file"),
		Method: Deflate,
		Mode:   0755 | fs.ModeSetgid,
	},
	{
		Name:   "symlink",
		Data:   []byte("../link/target"),
		Method: Deflate,
		Mode:   0755 | fs.ModeSymlink,
	},

}

func ExampleWriter_RegisterCompressor() {
	// Override the default Deflate compressor with a higher compression level.

	// Create a buffer to write our archive to.
	buf := new(bytes.Buffer)

	// Create a new zip archive.
	w := zip.NewWriter(buf)

	// Register a custom Deflate compressor.
	w.RegisterCompressor(zip.Deflate, func(out io.Writer) (io.WriteCloser, error) {

	compressors.Store(Deflate, Compressor(func(w io.Writer) (io.WriteCloser, error) { return newFlateWriter(w), nil }))

	decompressors.Store(Store, Decompressor(io.NopCloser))
	decompressors.Store(Deflate, Decompressor(newFlateReader))
}

// RegisterDecompressor allows custom decompressors for a specified method ID.
// The common methods [Store] and [Deflate] are built in.