xpcom/glue/nsID.cpp

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* ***** BEGIN LICENSE BLOCK *****
   3  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   4  *
   5  * The contents of this file are subject to the Mozilla Public License Version
   6  * 1.1 (the "License"); you may not use this file except in compliance with
   7  * the License. You may obtain a copy of the License at
   8  * http://www.mozilla.org/MPL/
   9  *
  10  * Software distributed under the License is distributed on an "AS IS" basis,
  11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  12  * for the specific language governing rights and limitations under the
  13  * License.
  14  *
  15  * The Original Code is mozilla.org code.
  16  *
  17  * The Initial Developer of the Original Code is
  18  * Netscape Communications Corporation.
  19  * Portions created by the Initial Developer are Copyright (C) 1998
  20  * the Initial Developer. All Rights Reserved.
  21  *
  22  * Contributor(s):
  23  *   Daniel Bratell <bratell@lysator.liu.se>
  24  *
  25  * Alternatively, the contents of this file may be used under the terms of
  26  * either of the GNU General Public License Version 2 or later (the "GPL"),
  27  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  28  * in which case the provisions of the GPL or the LGPL are applicable instead
  29  * of those above. If you wish to allow use of your version of this file only
  30  * under the terms of either the GPL or the LGPL, and not to allow others to
  31  * use your version of this file under the terms of the MPL, indicate your
  32  * decision by deleting the provisions above and replace them with the notice
  33  * and other provisions required by the GPL or the LGPL. If you do not delete
  34  * the provisions above, a recipient may use your version of this file under
  35  * the terms of any one of the MPL, the GPL or the LGPL.
  36  *
  37  * ***** END LICENSE BLOCK ***** */
  38 #include "nsID.h"
  39 #include "prprf.h"
  40 #include "prmem.h"
  41
  42 static const char gIDFormat[] =
  43   "{%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x}";
  44
  45 static const char gIDFormat2[] =
  46   "%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x";
  47
  48
  49 /**
  50  * Multiplies the_int_var with 16 (0x10) and adds the value of the
  51  * hexadecimal digit the_char. If it fails it returns PR_FALSE from
  52  * the function it's used in.
  53  */
  54
  55 #define ADD_HEX_CHAR_TO_INT_OR_RETURN_FALSE(the_char, the_int_var) \
  56     the_int_var = (the_int_var << 4) + the_char; \
  57     if(the_char >= '0' && the_char <= '9') the_int_var -= '0'; \
  58     else if(the_char >= 'a' && the_char <= 'f') the_int_var -= 'a'-10; \
  59     else if(the_char >= 'A' && the_char <= 'F') the_int_var -= 'A'-10; \
  60     else return PR_FALSE
  61
  62
  63 /**
  64  * Parses number_of_chars characters from the char_pointer pointer and
  65  * puts the number in the dest_variable. The pointer is moved to point
  66  * at the first character after the parsed ones. If it fails it returns
  67  * PR_FALSE from the function the macro is used in.
  68  */
  69
  70 #define PARSE_CHARS_TO_NUM(char_pointer, dest_variable, number_of_chars) \
  71   do { PRInt32 _i=number_of_chars; \
  72   dest_variable = 0; \
  73   while(_i) { \
  74     ADD_HEX_CHAR_TO_INT_OR_RETURN_FALSE(*char_pointer, dest_variable); \
  75     char_pointer++; \
  76     _i--; \
  77   } } while(0)
  78
  79
  80 /**
  81  * Parses a hyphen from the char_pointer string. If there is no hyphen there
  82  * the function returns PR_FALSE from the function it's used in. The
  83  * char_pointer is advanced one step.
  84  */
  85
  86  #define PARSE_HYPHEN(char_pointer)   if(*(char_pointer++) != '-') return PR_FALSE
  87
  88 /*
  89  * Turns a {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx} string into
  90  * an nsID. It can also handle the old format without the { and }.
  91  */
  92
  93 PRBool nsID::Parse(const char *aIDStr)
  94 {
  95   /* Optimized for speed */
  96   if(!aIDStr) {
  97     return PR_FALSE;
  98   }
  99
 100   PRBool expectFormat1 = (aIDStr[0] == '{');
 101   if(expectFormat1) aIDStr++;
 102
 103   PARSE_CHARS_TO_NUM(aIDStr, m0, 8);
 104   PARSE_HYPHEN(aIDStr);
 105   PARSE_CHARS_TO_NUM(aIDStr, m1, 4);
 106   PARSE_HYPHEN(aIDStr);
 107   PARSE_CHARS_TO_NUM(aIDStr, m2, 4);
 108   PARSE_HYPHEN(aIDStr);
 109   int i;
 110   for(i=0; i<2; i++)
 111     PARSE_CHARS_TO_NUM(aIDStr, m3[i], 2);
 112   PARSE_HYPHEN(aIDStr);
 113   while(i < 8) {
 114     PARSE_CHARS_TO_NUM(aIDStr, m3[i], 2);
 115     i++;
 116   }
 117
 118   return expectFormat1 ? *aIDStr == '}' : PR_TRUE;
 119 }
 120
 121 #ifndef XPCOM_GLUE_AVOID_NSPR
 122
 123 /*
 124  * Returns an allocated string in {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}
 125  * format. The string is allocated with PR_Malloc and should be freed by
 126  * the caller.
 127  */
 128
 129 char *nsID::ToString() const
 130 {
 131   char *res = (char*)PR_Malloc(NSID_LENGTH); // use PR_Malloc if this is to be freed with nsCRT::free
 132
 133   if (res != NULL) {
 134     PR_snprintf(res, NSID_LENGTH, gIDFormat,
 135                 m0, (PRUint32) m1, (PRUint32) m2,
 136                 (PRUint32) m3[0], (PRUint32) m3[1], (PRUint32) m3[2],
 137                 (PRUint32) m3[3], (PRUint32) m3[4], (PRUint32) m3[5],
 138                 (PRUint32) m3[6], (PRUint32) m3[7]);
 139   }
 140   return res;
 141 }
 142
 143 void nsID::ToProvidedString(char (&dest)[NSID_LENGTH]) const
 144 {
 145   PR_snprintf(dest, NSID_LENGTH, gIDFormat,
 146               m0, (PRUint32) m1, (PRUint32) m2,
 147               (PRUint32) m3[0], (PRUint32) m3[1], (PRUint32) m3[2],
 148               (PRUint32) m3[3], (PRUint32) m3[4], (PRUint32) m3[5],
 149               (PRUint32) m3[6], (PRUint32) m3[7]);
 150 }
 151
 152 #endif // XPCOM_GLUE_AVOID_NSPR