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.IO; 27 using System.Text; 28 29 /* 30 * A simple class for writing out bytes as hexadecimal constants or 31 * explicit expressions for the initializer of a C array of 'unsigned 32 * char'. It starts every line with a given number of tabs, and aims at 33 * keeping lines below a given threshold (each indentation tab counts as 34 * 8 characters). An explicit newline is inserted before the first 35 * element, and commas are used as separators. 36 */ 37 38 class BlobWriter { 39 40 TextWriter w; 41 int maxLineLen; 42 int indent; 43 int lineLen; 44 45 /* 46 * Create a new instance. 'maxLineLen' is in characters, and 47 * 'indent' is the number of tab characters at the start of 48 * each line. 49 */ 50 internal BlobWriter(TextWriter w, int maxLineLen, int indent) 51 { 52 this.w = w; 53 this.maxLineLen = maxLineLen; 54 this.indent = indent; 55 lineLen = -1; 56 } 57 58 void DoNL() 59 { 60 w.WriteLine(); 61 for (int i = 0; i < indent; i ++) { 62 w.Write('\t'); 63 } 64 lineLen = (indent << 3); 65 } 66 67 /* 68 * Append a new byte value; it will be converted to an hexadecimal 69 * constant in the output. 70 */ 71 internal void Append(byte b) 72 { 73 if (lineLen < 0) { 74 DoNL(); 75 } else { 76 w.Write(','); 77 lineLen ++; 78 if ((lineLen + 5) > maxLineLen) { 79 DoNL(); 80 } else { 81 w.Write(' '); 82 lineLen ++; 83 } 84 } 85 w.Write("0x{0:X2}", b); 86 lineLen += 4; 87 } 88 89 /* 90 * Append a C expression, which will be used as is. The expression 91 * may resolve to several bytes if it uses internal commas. The 92 * writer will try to honour the expected line length, but it 93 * won't insert a newline character inside the expression. 94 */ 95 internal void Append(string expr) 96 { 97 if (lineLen < 0) { 98 DoNL(); 99 } else { 100 w.Write(','); 101 lineLen ++; 102 if ((lineLen + 1 + expr.Length) > maxLineLen) { 103 DoNL(); 104 } else { 105 w.Write(' '); 106 lineLen ++; 107 } 108 } 109 w.Write("{0}", expr); 110 lineLen += expr.Length; 111 } 112 } 113