fun connectionPreface() {
    withLock {
      if (closed) throw IOException("closed")
      if (!client) return // Nothing to write; servers don't send connection headers!
      if (logger.isLoggable(FINE)) {
        logger.fine(format(">> CONNECTION ${CONNECTION_PREFACE.hex()}"))
      }
      sink.write(CONNECTION_PREFACE)
      sink.flush()
    }
  }

  /** Applies `peerSettings` and then sends a settings ACK. */

      if (increment == 0L) throw IOException("windowSizeIncrement was 0")
    } catch (e: Exception) {
      logger.fine(frameLog(true, streamId, length, TYPE_WINDOW_UPDATE, flags))
      throw e
    }
    if (logger.isLoggable(FINE)) {
      logger.fine(
        frameLogWindowUpdate(
          inbound = true,
          streamId = streamId,
          length = length,

    @Override
    public boolean isDebugEnabled() {
        return logger.isLoggable(Level.FINE);
    }

    @Override
    public void debug(final String message) {
        logger.logp(Level.FINE, sourceClass, null, message);
    }

    @Override
    public void debug(final String message, final Throwable t) {
        logger.logp(Level.FINE, sourceClass, null, message, t);
    }

    when {
      logger.isLoggable(Level.FINE) -> Throwable(closer) // These are expensive to allocate.
      else -> null
    }

  open fun logCloseableLeak(
    message: String,
    stackTrace: Any?,
  ) {
    var logMessage = message
    if (stackTrace == null) {
      logMessage += " To see where this was allocated, set the OkHttpClient logger level to " +

          getLogger("org.conscrypt").level = Level.INFO
        } else {
          if (showHttp2Frames) {
            val activeLogger = getLogger(Http2::class.java.name)
            activeLogger.level = Level.FINE
            handler.level = Level.FINE
            handler.formatter = MessageFormatter
            activeLogger.addHandler(handler)
          }

          if (sslDebug) {
            val activeLogger = getLogger("javax.net.ssl")

            try {
                logger.fine(() -> ">>> " + method + " " + url);
                final URL u = new URL(url);
                connection = open(u);
                connection.setRequestMethod(method.toString());
                if (headerList != null) {
                    for (final String[] values : headerList) {
                        logger.fine(() -> ">>> " + values[0] + "=" + values[1]);

import java.util.List;
import org.jspecify.annotations.NullUnmarked;

/**
 * Quick and dirty benchmark of {@link Throwables#lazyStackTrace(Throwable)}. We benchmark a "caller
 * finder" implementation that might be used in a logging framework.
 */
@NullUnmarked
public class LazyStackTraceBenchmark {
  @Param({"20", "200", "2000"})
  int stackDepth;

  @Param({"-1", "3", "15"})
  int breakAt;

import java.util.List;
import org.jspecify.annotations.NullUnmarked;

/**
 * Quick and dirty benchmark of {@link Throwables#lazyStackTrace(Throwable)}. We benchmark a "caller
 * finder" implementation that might be used in a logging framework.
 */
@NullUnmarked
public class LazyStackTraceBenchmark {
  @Param({"20", "200", "2000"})
  int stackDepth;

  @Param({"-1", "3", "15"})
  int breakAt;

        .testEquals();
  }

  public void testRequireBracketsForIPv6() {
    // Bracketed IPv6 works fine.
    assertEquals("::1", HostAndPort.fromString("[::1]").requireBracketsForIPv6().getHost());
    assertEquals("::1", HostAndPort.fromString("[::1]:80").requireBracketsForIPv6().getHost());
    // Non-bracketed non-IPv6 works fine.
    assertEquals("x", HostAndPort.fromString("x").requireBracketsForIPv6().getHost());

        .testEquals();
  }

  public void testRequireBracketsForIPv6() {
    // Bracketed IPv6 works fine.
    assertEquals("::1", HostAndPort.fromString("[::1]").requireBracketsForIPv6().getHost());
    assertEquals("::1", HostAndPort.fromString("[::1]:80").requireBracketsForIPv6().getHost());
    // Non-bracketed non-IPv6 works fine.
    assertEquals("x", HostAndPort.fromString("x").requireBracketsForIPv6().getHost());