// executes at least one write operation if it is closed.
//
// This can be useful within the context of HTTP. At least
// one write operation must happen to send the HTTP headers
// to the peer.
type WriteOnCloser struct {
	io.Writer
	hasWritten bool
}

func (w *WriteOnCloser) Write(p []byte) (int, error) {
	w.hasWritten = true
	return w.Writer.Write(p)
}

    // array slot is read and written exactly once. However, it can have very poor memory locality:
    // benchmarking shows it can take 7 times longer than the other two in some cases. The other two
    // do n swaps, minus a delta (0 or 2 for Reversal, gcd(d, n) for Successive), so that's about
    // twice as many reads and writes. But benchmarking shows that they usually perform better than

  }

internal fun Socket.peerName(): String {
  val address = remoteSocketAddress
  return if (address is InetSocketAddress) address.hostName else address.toString()
}

/**
 * Returns true if new reads and writes should be attempted on this.
 *
 * Unfortunately Java's networking APIs don't offer a good health check, so we go on our own by
 * attempting to read with a short timeout. If the fails immediately we know the socket is

      val body = part.body

      sink!!.write(DASHDASH)
      sink.write(boundaryByteString)
      sink.write(CRLF)

      if (headers != null) {
        for (h in 0 until headers.size) {
          sink.writeUtf8(headers.name(h))
            .write(COLONSPACE)
            .writeUtf8(headers.value(h))
            .write(CRLF)
        }
      }

		var b Buffer
		b.Write(buf[0:1])
		for i := 0; i < 5<<10; i++ {
			b.Write(buf)
			b.Read(buf)
		}
	}
}

// Check that we don't compact too often. From Issue 5154.
func BenchmarkBufferFullSmallReads(b *testing.B) {
	buf := make([]byte, 1024)
	for i := 0; i < b.N; i++ {
		var b Buffer
		b.Write(buf)
		for b.Len()+20 < b.Cap() {
			b.Write(buf[:10])
		}

		return formatSTAR
	case magic == magicUSTAR:
		return FormatUSTAR | FormatPAX
	case magic == magicGNU && version == versionGNU:
		return FormatGNU
	default:
		return formatV7
	}
}

// setFormat writes the magic values necessary for specified format
// and then updates the checksum accordingly.
func (b *block) setFormat(format Format) {
	// Set the magic values.
	switch {
	case format.has(formatV7):

	}
	return n, err
}

// writeTo writes the content of the current file to w.
// The bytes written matches the number of remaining bytes in the current file.
//
// If the current file is sparse and w is an io.WriteSeeker,
// then writeTo uses Seek to skip past holes defined in Header.SparseHoles,
// assuming that skipped regions are filled with NULs.
// This always writes the last byte to ensure w is the right size.
//

	creatorFAT    = 0
	creatorUnix   = 3
	creatorNTFS   = 11
	creatorVFAT   = 14
	creatorMacOSX = 19

	// Version numbers.
	zipVersion20 = 20 // 2.0
	zipVersion45 = 45 // 4.5 (reads and writes zip64 archives)

	// Limits for non zip64 files.
	uint16max = (1 << 16) - 1
	uint32max = (1 << 32) - 1

	// Extra header IDs.
	//
	// IDs 0..31 are reserved for official use by PKWARE.

	architecture.Init(ctxt)
	lexer := lex.NewLexer(input)
	parser := NewParser(ctxt, architecture, lexer)
	pList := new(obj.Plist)
	var ok bool
	testOut = new(strings.Builder) // The assembler writes test output to this buffer.
	ctxt.Bso = bufio.NewWriter(os.Stdout)
	ctxt.IsAsm = true
	defer ctxt.Bso.Flush()
	failed := false
	ctxt.DiagFunc = func(format string, args ...interface{}) {
		failed = true

		if errors.Is(err, errNoHealRequired) {
			countNoHeal++
		}
		r.DiskCount += result.DiskCount
		r.SetCount += result.SetCount
		r.Before.Drives = append(r.Before.Drives, result.Before.Drives...)
		r.After.Drives = append(r.After.Drives, result.After.Drives...)
	}

	// No heal returned by all serverPools, return errNoHealRequired
	if countNoHeal == len(z.serverPools) {
		return r, errNoHealRequired
	}