_ Git - BearSSL/blob - T0/ConstData.cs

   1 /*
   2  * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining
   5  * a copy of this software and associated documentation files (the
   6  * "Software"), to deal in the Software without restriction, including
   7  * without limitation the rights to use, copy, modify, merge, publish,
   8  * distribute, sublicense, and/or sell copies of the Software, and to
   9  * permit persons to whom the Software is furnished to do so, subject to
  10  * the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be
  13  * included in all copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  18  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  19  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  20  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  22  * SOFTWARE.
  23  */
  24
  25 using System;
  26 using System.Collections.Generic;
  27 using System.Text;
  28
  29 class ConstData {
  30
  31         internal long ID { get; private set; }
  32         internal int Address { get; set; }
  33         internal int Length {
  34                 get {
  35                         return len;
  36                 }
  37         }
  38
  39         byte[] buf;
  40         int len;
  41
  42         internal ConstData(T0Comp ctx)
  43         {
  44                 ID = ctx.NextBlobID();
  45                 buf = new byte[4];
  46                 len = 0;
  47         }
  48
  49         void Expand(int elen)
  50         {
  51                 int tlen = len + elen;
  52                 if (tlen > buf.Length) {
  53                         int nlen = Math.Max(buf.Length << 1, tlen);
  54                         byte[] nbuf = new byte[nlen];
  55                         Array.Copy(buf, 0, nbuf, 0, len);
  56                         buf = nbuf;
  57                 }
  58         }
  59
  60         internal void Add8(byte b)
  61         {
  62                 Expand(1);
  63                 buf[len ++] = b;
  64         }
  65
  66         internal void Add16(int x)
  67         {
  68                 Expand(2);
  69                 buf[len ++] = (byte)(x >> 8);
  70                 buf[len ++] = (byte)x;
  71         }
  72
  73         internal void Add24(int x)
  74         {
  75                 Expand(3);
  76                 buf[len ++] = (byte)(x >> 16);
  77                 buf[len ++] = (byte)(x >> 8);
  78                 buf[len ++] = (byte)x;
  79         }
  80
  81         internal void Add32(int x)
  82         {
  83                 Expand(4);
  84                 buf[len ++] = (byte)(x >> 24);
  85                 buf[len ++] = (byte)(x >> 16);
  86                 buf[len ++] = (byte)(x >> 8);
  87                 buf[len ++] = (byte)x;
  88         }
  89
  90         internal void AddString(string s)
  91         {
  92                 byte[] sd = Encoding.UTF8.GetBytes(s);
  93                 Expand(sd.Length + 1);
  94                 Array.Copy(sd, 0, buf, len, sd.Length);
  95                 buf[len + sd.Length] = 0;
  96                 len += sd.Length + 1;
  97         }
  98
  99         void CheckIndex(int off, int dlen)
 100         {
 101                 if (off < 0 || off > (len - dlen)) {
 102                         throw new IndexOutOfRangeException();
 103                 }
 104         }
 105
 106         internal void Set8(int off, byte v)
 107         {
 108                 CheckIndex(off, 1);
 109                 buf[off] = v;
 110         }
 111
 112         internal byte Read8(int off)
 113         {
 114                 CheckIndex(off, 1);
 115                 return buf[off];
 116         }
 117
 118         internal int Read16(int off)
 119         {
 120                 CheckIndex(off, 2);
 121                 return (buf[off] << 8) | buf[off + 1];
 122         }
 123
 124         internal int Read24(int off)
 125         {
 126                 CheckIndex(off, 3);
 127                 return (buf[off] << 16) | (buf[off + 1] << 8) | buf[off + 2];
 128         }
 129
 130         internal int Read32(int off)
 131         {
 132                 CheckIndex(off, 4);
 133                 return (buf[off] << 24) | (buf[off + 1] << 16)
 134                         | (buf[off + 2] << 8) | buf[off + 3];
 135         }
 136
 137         internal string ToString(int off)
 138         {
 139                 StringBuilder sb = new StringBuilder();
 140                 for (;;) {
 141                         int x = DecodeUTF8(ref off);
 142                         if (x == 0) {
 143                                 return sb.ToString();
 144                         }
 145                         if (x < 0x10000) {
 146                                 sb.Append((char)x);
 147                         } else {
 148                                 x -= 0x10000;
 149                                 sb.Append((char)(0xD800 + (x >> 10)));
 150                                 sb.Append((char)(0xDC00 + (x & 0x3FF)));
 151                         }
 152                 }
 153         }
 154
 155         int DecodeUTF8(ref int off)
 156         {
 157                 if (off >= len) {
 158                         throw new IndexOutOfRangeException();
 159                 }
 160                 int x = buf[off ++];
 161                 if (x < 0xC0 || x > 0xF7) {
 162                         return x;
 163                 }
 164                 int elen, acc;
 165                 if (x >= 0xF0) {
 166                         elen = 3;
 167                         acc = x & 0x07;
 168                 } else if (x >= 0xE0) {
 169                         elen = 2;
 170                         acc = x & 0x0F;
 171                 } else {
 172                         elen = 1;
 173                         acc = x & 0x1F;
 174                 }
 175                 if (off + elen > len) {
 176                         return x;
 177                 }
 178                 for (int i = 0; i < elen; i ++) {
 179                         int y = buf[off + i];
 180                         if (y < 0x80 || y >= 0xC0) {
 181                                 return x;
 182                         }
 183                         acc = (acc << 6) + (y & 0x3F);
 184                 }
 185                 if (acc > 0x10FFFF) {
 186                         return x;
 187                 }
 188                 off += elen;
 189                 return acc;
 190         }
 191
 192         internal void Encode(BlobWriter bw)
 193         {
 194                 for (int i = 0; i < len; i ++) {
 195                         bw.Append(buf[i]);
 196                 }
 197         }
 198 }