1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 // 5 // String manipulation functions used in the RLZ library. 6 7 #include "rlz/lib/string_utils.h" 8 9 #include "rlz/lib/assert.h" 10 11 namespace rlz_lib { 12 13 bool IsAscii(unsigned char letter) { 14 return letter < 0x80; 15 } 16 17 bool GetHexValue(char letter, int* value) { 18 if (!value) { 19 ASSERT_STRING("GetHexValue: Invalid output paramter"); 20 return false; 21 } 22 *value = 0; 23 24 if (letter >= '0' && letter <= '9') 25 *value = letter - '0'; 26 else if (letter >= 'a' && letter <= 'f') 27 *value = (letter - 'a') + 0xA; 28 else if (letter >= 'A' && letter <= 'F') 29 *value = (letter - 'A') + 0xA; 30 else 31 return false; 32 33 return true; 34 } 35 36 int HexStringToInteger(const char* text) { 37 if (!text) { 38 ASSERT_STRING("HexStringToInteger: text is NULL."); 39 return 0; 40 } 41 42 int idx = 0; 43 // Ignore leading whitespace. 44 while (text[idx] == '\t' || text[idx] == ' ') 45 idx++; 46 47 if ((text[idx] == '0') && 48 (text[idx + 1] == 'X' || text[idx + 1] == 'x')) 49 idx +=2; // String is of the form 0x... 50 51 int number = 0; 52 int digit = 0; 53 for (; text[idx] != '\0'; idx++) { 54 if (!GetHexValue(text[idx], &digit)) { 55 // Ignore trailing whitespaces, but assert on other trailing characters. 56 bool only_whitespaces = true; 57 while (only_whitespaces && text[idx]) 58 only_whitespaces = (text[idx++] == ' '); 59 if (!only_whitespaces) 60 ASSERT_STRING("HexStringToInteger: text contains non-hex characters."); 61 return number; 62 } 63 number = (number << 4) | digit; 64 } 65 66 return number; 67 } 68 69 bool BytesToString(const unsigned char* data, 70 int data_len, 71 std::string* string) { 72 if (!string) 73 return false; 74 75 string->clear(); 76 if (data_len < 1 || !data) 77 return false; 78 79 static const char kHex[] = "0123456789ABCDEF"; 80 81 // Fix the buffer size to begin with to avoid repeated re-allocation. 82 string->resize(data_len * 2); 83 int index = data_len; 84 while (index--) { 85 string->at(2 * index) = kHex[data[index] >> 4]; // high digit 86 string->at(2 * index + 1) = kHex[data[index] & 0x0F]; // low digit 87 } 88 89 return true; 90 } 91 92 } // namespace rlz_lib 93
