// Copyright 2024 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package windows

// Socket related.
const (
	TCP_KEEPIDLE  = 0x03
	TCP_KEEPCNT   = 0x10
	TCP_KEEPINTVL = 0x11

	mask1b := byte(int8(t) >> 7) // mask1b is 0xFF iff one block is enough

	separator := byte(0x80) // gets reset to 0x00 once used
	for i := byte(0); i < chunk; i++ {
		mask := byte(int8(i-nx) >> 7) // 0x00 after the end of data

		// if we reached the end of the data, replace with 0x80 or 0x00
		d.x[i] = (^mask & separator) | (mask & d.x[i])

		// zero the separator once used
		separator &= mask

	},
	{
		// Zstd default header.
		header: []byte{0x28, 0xb5, 0x2f, 0xfd},
		f:      formatZstd,
	},
	{
		// Zstd skippable frame header.
		header: []byte{0x2a, 0x4d, 0x18},
		f:      formatZstd,
	},
	{
		// LZ4
		header: []byte{0x4, 0x22, 0x4d, 0x18},
		f:      formatLZ4,
	},
	{
		// Snappy/S2 stream
		header: []byte{0xff, 0x06, 0x00, 0x00},
		f:      formatS2,
	},
	{

00000100  92 26 8f fa 6f 34 83 aa  ec 8f a3 4d 30 4b 30 0e  |.&..o4.....M0K0.|
00000110  06 03 55 1d 0f 01 01 ff  04 04 03 02 05 a0 30 13  |..U...........0.|
00000120  06 03 55 1d 25 04 0c 30  0a 06 08 2b 06 01 05 05  |..U.%..0...+....|
00000130  07 03 01 30 0c 06 03 55  1d 13 01 01 ff 04 02 30  |...0...U.......0|
00000140  00 30 16 06 03 55 1d 11  04 0f 30 0d 82 0b 65 78  |.0...U....0...ex|

	// It is stored here in order for Reset() to be able to put context into
	// initial state.
	initBlock []byte
}

// Consts for configuring initial SHA-3 state
const (
	dsbyteShake  = 0x1f
	dsbyteCShake = 0x04
	rate128      = 168
	rate256      = 136
)

func bytepad(input []byte, w int) []byte {
	// leftEncode always returns max 9 bytes
	buf := make([]byte, 0, 9+len(input)+w)
	buf = append(buf, leftEncode(uint64(w))...)

00000190  81 93 30 81 90 30 0e 06  03 55 1d 0f 01 01 ff 04  |..0..0...U......|
000001a0  04 03 02 05 a0 30 1d 06  03 55 1d 25 04 16 30 14  |.....0...U.%..0.|
000001b0  06 08 2b 06 01 05 05 07  03 01 06 08 2b 06 01 05  |..+.........+...|
000001c0  05 07 03 02 30 0c 06 03  55 1d 13 01 01 ff 04 02  |....0...U.......|
000001d0  30 00 30 19 06 03 55 1d  0e 04 12 04 10 9f 91 16  |0.0...U.........|

					return
				}
				if strings.HasSuffix(errStr, "0x3d") && (strings.Contains(s, "=0=") || strings.Contains(s, "=A=")) {
					return
				}
				if strings.HasSuffix(errStr, "0x0a") || strings.HasSuffix(errStr, "0x0d") {
					// bunch of cases; since whitespace at the end of a line before \n is removed.
					return
				}
			}
			if strings.Contains(errStr, "unexpected EOF") {
				return
			}

00000190  81 93 30 81 90 30 0e 06  03 55 1d 0f 01 01 ff 04  |..0..0...U......|
000001a0  04 03 02 05 a0 30 1d 06  03 55 1d 25 04 16 30 14  |.....0...U.%..0.|
000001b0  06 08 2b 06 01 05 05 07  03 01 06 08 2b 06 01 05  |..+.........+...|
000001c0  05 07 03 02 30 0c 06 03  55 1d 13 01 01 ff 04 02  |....0...U.......|
000001d0  30 00 30 19 06 03 55 1d  0e 04 12 04 10 9f 91 16  |0.0...U.........|

00000190  81 93 30 81 90 30 0e 06  03 55 1d 0f 01 01 ff 04  |..0..0...U......|
000001a0  04 03 02 05 a0 30 1d 06  03 55 1d 25 04 16 30 14  |.....0...U.%..0.|
000001b0  06 08 2b 06 01 05 05 07  03 01 06 08 2b 06 01 05  |..+.........+...|
000001c0  05 07 03 02 30 0c 06 03  55 1d 13 01 01 ff 04 02  |....0...U.......|
000001d0  30 00 30 19 06 03 55 1d  0e 04 12 04 10 9f 91 16  |0.0...U.........|

00000190  81 93 30 81 90 30 0e 06  03 55 1d 0f 01 01 ff 04  |..0..0...U......|
000001a0  04 03 02 05 a0 30 1d 06  03 55 1d 25 04 16 30 14  |.....0...U.%..0.|
000001b0  06 08 2b 06 01 05 05 07  03 01 06 08 2b 06 01 05  |..+.........+...|
000001c0  05 07 03 02 30 0c 06 03  55 1d 13 01 01 ff 04 02  |....0...U.......|
000001d0  30 00 30 19 06 03 55 1d  0e 04 12 04 10 9f 91 16  |0.0...U.........|