gecko-dev/xpcom/ds/nsCRT.cpp

188 lines
4.9 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/. */
/**
* MODULE NOTES:
* @update gess7/30/98
*
* Much as I hate to do it, we were using string compares wrong.
* Often, programmers call functions like strcmp(s1,s2), and pass
* one or more null strings. Rather than blow up on these, I've
* added quick checks to ensure that cases like this don't cause
* us to fail.
*
* In general, if you pass a null into any of these string compare
* routines, we simply return 0.
*/
#include "nsCRT.h"
#include "nsIServiceManager.h"
#include "nsCharTraits.h"
#include "nsUTF8Utils.h"
//----------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
// My lovely strtok routine
#define IS_DELIM(m, c) ((m)[(c) >> 3] & (1 << ((c) & 7)))
#define SET_DELIM(m, c) ((m)[(c) >> 3] |= (1 << ((c) & 7)))
#define DELIM_TABLE_SIZE 32
char* nsCRT::strtok(char* string, const char* delims, char* *newStr)
{
NS_ASSERTION(string, "Unlike regular strtok, the first argument cannot be null.");
char delimTable[DELIM_TABLE_SIZE];
uint32_t i;
char* result;
char* str = string;
for (i = 0; i < DELIM_TABLE_SIZE; i++)
delimTable[i] = '\0';
for (i = 0; delims[i]; i++) {
SET_DELIM(delimTable, static_cast<uint8_t>(delims[i]));
}
NS_ASSERTION(delims[i] == '\0', "too many delimiters");
// skip to beginning
while (*str && IS_DELIM(delimTable, static_cast<uint8_t>(*str))) {
str++;
}
result = str;
// fix up the end of the token
while (*str) {
if (IS_DELIM(delimTable, static_cast<uint8_t>(*str))) {
*str++ = '\0';
break;
}
str++;
}
*newStr = str;
return str == result ? NULL : result;
}
////////////////////////////////////////////////////////////////////////////////
/**
* Compare unichar string ptrs, stopping at the 1st null
* NOTE: If both are null, we return 0.
* NOTE: We terminate the search upon encountering a NULL
*
* @update gess 11/10/99
* @param s1 and s2 both point to unichar strings
* @return 0 if they match, -1 if s1<s2; 1 if s1>s2
*/
int32_t nsCRT::strcmp(const PRUnichar* s1, const PRUnichar* s2) {
if(s1 && s2) {
for (;;) {
PRUnichar c1 = *s1++;
PRUnichar c2 = *s2++;
if (c1 != c2) {
if (c1 < c2) return -1;
return 1;
}
if ((0==c1) || (0==c2)) break;
}
}
else {
if (s1) // s2 must have been null
return -1;
if (s2) // s1 must have been null
return 1;
}
return 0;
}
/**
* Compare unichar string ptrs, stopping at the 1st null or nth char.
* NOTE: If either is null, we return 0.
* NOTE: We DO NOT terminate the search upon encountering NULL's before N
*
* @update gess 11/10/99
* @param s1 and s2 both point to unichar strings
* @return 0 if they match, -1 if s1<s2; 1 if s1>s2
*/
int32_t nsCRT::strncmp(const PRUnichar* s1, const PRUnichar* s2, uint32_t n) {
if(s1 && s2) {
if(n != 0) {
do {
PRUnichar c1 = *s1++;
PRUnichar c2 = *s2++;
if (c1 != c2) {
if (c1 < c2) return -1;
return 1;
}
} while (--n != 0);
}
}
return 0;
}
const char* nsCRT::memmem(const char* haystack, uint32_t haystackLen,
const char* needle, uint32_t needleLen)
{
// Sanity checking
if (!(haystack && needle && haystackLen && needleLen &&
needleLen <= haystackLen))
return NULL;
#ifdef HAVE_MEMMEM
return (const char*)::memmem(haystack, haystackLen, needle, needleLen);
#else
// No memmem means we need to roll our own. This isn't really optimized
// for performance ... if that becomes an issue we can take some inspiration
// from the js string compare code in jsstr.cpp
for (int32_t i = 0; i < haystackLen - needleLen; i++) {
if (!memcmp(haystack + i, needle, needleLen))
return haystack + i;
}
#endif
return NULL;
}
PRUnichar* nsCRT::strdup(const PRUnichar* str)
{
uint32_t len = NS_strlen(str);
return strndup(str, len);
}
PRUnichar* nsCRT::strndup(const PRUnichar* str, uint32_t len)
{
nsCppSharedAllocator<PRUnichar> shared_allocator;
PRUnichar* rslt = shared_allocator.allocate(len + 1); // add one for the null
// PRUnichar* rslt = new PRUnichar[len + 1];
if (rslt == NULL) return NULL;
memcpy(rslt, str, len * sizeof(PRUnichar));
rslt[len] = 0;
return rslt;
}
// This should use NSPR but NSPR isn't exporting its PR_strtoll function
// Until then...
int64_t nsCRT::atoll(const char *str)
{
if (!str)
return 0;
int64_t ll = 0;
while (*str && *str >= '0' && *str <= '9') {
ll *= 10;
ll += *str - '0';
str++;
}
return ll;
}