summaryrefslogtreecommitdiff
path: root/xpcom/glue/nsID.cpp
blob: 0a73bf6c3f2dafc0a2ea17658dce81e19b53a74e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsID.h"
#include "nsMemory.h"
#include "mozilla/Sprintf.h"

void nsID::Clear()
{
  m0 = 0;
  m1 = 0;
  m2 = 0;
  for (int i = 0; i < 8; ++i) {
    m3[i] = 0;
  }
}

/**
 * Multiplies the_int_var with 16 (0x10) and adds the value of the
 * hexadecimal digit the_char. If it fails it returns false from
 * the function it's used in.
 */

#define ADD_HEX_CHAR_TO_INT_OR_RETURN_FALSE(the_char, the_int_var) \
    the_int_var = (the_int_var << 4) + the_char; \
    if(the_char >= '0' && the_char <= '9') the_int_var -= '0'; \
    else if(the_char >= 'a' && the_char <= 'f') the_int_var -= 'a'-10; \
    else if(the_char >= 'A' && the_char <= 'F') the_int_var -= 'A'-10; \
    else return false


/**
 * Parses number_of_chars characters from the char_pointer pointer and
 * puts the number in the dest_variable. The pointer is moved to point
 * at the first character after the parsed ones. If it fails it returns
 * false from the function the macro is used in.
 */

#define PARSE_CHARS_TO_NUM(char_pointer, dest_variable, number_of_chars) \
  do { int32_t _i=number_of_chars; \
  dest_variable = 0; \
  while(_i) { \
    ADD_HEX_CHAR_TO_INT_OR_RETURN_FALSE(*char_pointer, dest_variable); \
    char_pointer++; \
    _i--; \
  } } while(0)


/**
 * Parses a hyphen from the char_pointer string. If there is no hyphen there
 * the function returns false from the function it's used in. The
 * char_pointer is advanced one step.
 */

#define PARSE_HYPHEN(char_pointer) if (*(char_pointer++) != '-') return false

/*
 * Turns a {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx} string into
 * an nsID. It can also handle the old format without the { and }.
 */

bool
nsID::Parse(const char* aIDStr)
{
  /* Optimized for speed */
  if (!aIDStr) {
    return false;
  }

  bool expectFormat1 = (aIDStr[0] == '{');
  if (expectFormat1) {
    ++aIDStr;
  }

  PARSE_CHARS_TO_NUM(aIDStr, m0, 8);
  PARSE_HYPHEN(aIDStr);
  PARSE_CHARS_TO_NUM(aIDStr, m1, 4);
  PARSE_HYPHEN(aIDStr);
  PARSE_CHARS_TO_NUM(aIDStr, m2, 4);
  PARSE_HYPHEN(aIDStr);
  int i;
  for (i = 0; i < 2; ++i) {
    PARSE_CHARS_TO_NUM(aIDStr, m3[i], 2);
  }
  PARSE_HYPHEN(aIDStr);
  while (i < 8) {
    PARSE_CHARS_TO_NUM(aIDStr, m3[i], 2);
    i++;
  }

  return expectFormat1 ? *aIDStr == '}' : true;
}

#ifndef XPCOM_GLUE_AVOID_NSPR

static const char gIDFormat[] =
  "{%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x}";

/*
 * Returns an allocated string in {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}
 * format. The string is allocated with NS_Alloc and should be freed by
 * the caller.
 */

char*
nsID::ToString() const
{
  char* res = (char*)NS_Alloc(NSID_LENGTH);

  if (res) {
    snprintf(res, NSID_LENGTH, gIDFormat,
             m0, (uint32_t)m1, (uint32_t)m2,
             (uint32_t)m3[0], (uint32_t)m3[1], (uint32_t)m3[2],
             (uint32_t)m3[3], (uint32_t)m3[4], (uint32_t)m3[5],
             (uint32_t)m3[6], (uint32_t)m3[7]);
  }
  return res;
}

void
nsID::ToProvidedString(char (&aDest)[NSID_LENGTH]) const
{
  SprintfLiteral(aDest, gIDFormat,
                 m0, (uint32_t)m1, (uint32_t)m2,
                 (uint32_t)m3[0], (uint32_t)m3[1], (uint32_t)m3[2],
                 (uint32_t)m3[3], (uint32_t)m3[4], (uint32_t)m3[5],
                 (uint32_t)m3[6], (uint32_t)m3[7]);
}

#endif // XPCOM_GLUE_AVOID_NSPR