gecko-dev/xpcom/glue/nsID.cpp

124 строки
3.4 KiB
C++

/* -*- 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 "prprf.h"
#include "nsMemory.h"
/**
* 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) {
PR_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
{
PR_snprintf(aDest, 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]);
}
#endif // XPCOM_GLUE_AVOID_NSPR