Sergey Mashkov | 0b12ffc | 2017-07-26 12:59:16 +0300 | [diff] [blame] | 1 | package kotlinx.coroutines.experimental.io.internal |
| 2 | |
Sergey Mashkov | 6d05993 | 2017-10-06 18:46:23 +0300 | [diff] [blame] | 3 | import kotlinx.io.core.* |
| 4 | import java.nio.* |
| 5 | import java.nio.charset.* |
Sergey Mashkov | 0b12ffc | 2017-07-26 12:59:16 +0300 | [diff] [blame] | 6 | |
| 7 | /** |
| 8 | * Decodes all the bytes to ASCII characters until end of buffer applying every character to [consumer] |
| 9 | * It stops processing if a non-ascii character encountered and returns `false` |
| 10 | * @return `false` if a non-ascii character encountered or `true` if all bytes were processed |
| 11 | */ |
| 12 | internal inline fun ByteBuffer.decodeASCII(consumer: (Char) -> Boolean): Boolean { |
| 13 | while (hasRemaining()) { |
| 14 | val v = get().toInt() and 0xff |
| 15 | if (v and 0x80 != 0 || !consumer(v.toChar())) { |
| 16 | position(position() - 1) |
| 17 | return false |
| 18 | } |
| 19 | } |
| 20 | |
| 21 | return true |
| 22 | } |
| 23 | |
| 24 | /** |
| 25 | * Decodes all the bytes to utf8 applying every character on [consumer] until or consumer return `false`. |
| 26 | * If a consumer returned false then a character will be pushed back (including all surrogates will be pushed back as well) |
| 27 | * and [decodeUTF8] returns 0 |
| 28 | * @return number of bytes required to decode incomplete utf8 character or 0 if all bytes were processed |
Sergey Mashkov | a9a936d | 2017-08-23 14:39:41 +0300 | [diff] [blame] | 29 | * or -1 if consumer rejected loop |
Sergey Mashkov | 0b12ffc | 2017-07-26 12:59:16 +0300 | [diff] [blame] | 30 | */ |
| 31 | internal inline fun ByteBuffer.decodeUTF8(consumer: (Char) -> Boolean): Int { |
| 32 | var byteCount = 0 |
| 33 | var value = 0 |
| 34 | var lastByteCount = 0 |
| 35 | |
| 36 | while (hasRemaining()) { |
| 37 | val v = get().toInt() and 0xff |
| 38 | when { |
| 39 | v and 0x80 == 0 -> { |
| 40 | if (byteCount != 0) throw MalformedInputException(0) |
| 41 | if (!consumer(v.toChar())) { |
| 42 | position(position() - 1) |
| 43 | return -1 |
| 44 | } |
| 45 | } |
| 46 | byteCount == 0 -> { |
| 47 | // first unicode byte |
| 48 | |
| 49 | var mask = 0x80 |
| 50 | value = v |
| 51 | |
| 52 | for (i in 1..6) { // TODO do we support 6 bytes unicode? |
| 53 | if (value and mask != 0) { |
| 54 | value = value and mask.inv() |
| 55 | mask = mask shr 1 |
| 56 | byteCount++ |
| 57 | } else { |
| 58 | break |
| 59 | } |
| 60 | } |
| 61 | |
| 62 | lastByteCount = byteCount |
| 63 | byteCount-- |
| 64 | |
| 65 | if (byteCount > remaining()) { |
| 66 | position(position() - 1) // return one byte back |
| 67 | return lastByteCount |
| 68 | } |
| 69 | } |
| 70 | else -> { |
| 71 | // trailing unicode byte |
| 72 | value = (value shl 6) or (v and 0x7f) |
| 73 | byteCount-- |
| 74 | |
| 75 | if (byteCount == 0) { |
| 76 | if (isBmpCodePoint(value)) { |
| 77 | if (!consumer(value.toChar())) { |
| 78 | position(position() - lastByteCount) |
| 79 | return -1 |
| 80 | } |
| 81 | } else if (!isValidCodePoint(value)) { |
| 82 | throw IllegalArgumentException("Malformed code-point ${Integer.toHexString(value)} found") |
| 83 | } else { |
| 84 | if (!consumer(highSurrogate(value).toChar()) || |
| 85 | !consumer(lowSurrogate(value).toChar())) { |
| 86 | position(position() - lastByteCount) |
| 87 | return -1 |
| 88 | } |
| 89 | } |
| 90 | |
| 91 | value = 0 |
| 92 | } |
| 93 | } |
| 94 | } |
| 95 | } |
| 96 | |
| 97 | return 0 |
| 98 | } |
| 99 | |
Sergey Mashkov | 0b12ffc | 2017-07-26 12:59:16 +0300 | [diff] [blame] | 100 | private const val MaxCodePoint = 0X10ffff |
| 101 | private const val MinLowSurrogate = 0xdc00 |
| 102 | private const val MinHighSurrogate = 0xd800 |
| 103 | private const val MinSupplementary = 0x10000 |
| 104 | private const val HighSurrogateMagic = MinHighSurrogate - (MinSupplementary ushr 10) |
| 105 | |
| 106 | private fun isBmpCodePoint(cp: Int) = cp ushr 16 == 0 |
| 107 | private fun isValidCodePoint(codePoint: Int) = codePoint <= MaxCodePoint |
| 108 | private fun lowSurrogate(cp: Int) = (cp and 0x3ff) + MinLowSurrogate |
| 109 | private fun highSurrogate(cp: Int) = (cp ushr 10) + HighSurrogateMagic |