gecko/xpcom/ds/nsCRT.cpp
2011-10-17 10:59:28 -04:00

325 lines
8.6 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/**
* 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 "prbit.h"
#include "nsUTF8Utils.h"
#define ADD_TO_HASHVAL(hashval, c) \
hashval = PR_ROTATE_LEFT32(hashval, 4) ^ (c);
//----------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
// 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];
PRUint32 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<PRUint8>(delims[i]));
}
NS_ASSERTION(delims[i] == '\0', "too many delimiters");
// skip to beginning
while (*str && IS_DELIM(delimTable, static_cast<PRUint8>(*str))) {
str++;
}
result = str;
// fix up the end of the token
while (*str) {
if (IS_DELIM(delimTable, static_cast<PRUint8>(*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
*/
PRInt32 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
*/
PRInt32 nsCRT::strncmp(const PRUnichar* s1, const PRUnichar* s2, PRUint32 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, PRUint32 haystackLen,
const char* needle, PRUint32 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 (PRInt32 i = 0; i < haystackLen - needleLen; i++) {
if (!memcmp(haystack + i, needle, needleLen))
return haystack + i;
}
#endif
return NULL;
}
PRUnichar* nsCRT::strdup(const PRUnichar* str)
{
PRUint32 len = nsCRT::strlen(str);
return strndup(str, len);
}
PRUnichar* nsCRT::strndup(const PRUnichar* str, PRUint32 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;
}
/**
* |nsCRT::HashCode| is identical to |PL_HashString|, which tests
* (http://bugzilla.mozilla.org/showattachment.cgi?attach_id=26596)
* show to be the best hash among several other choices.
*
* We re-implement it here rather than calling it for two reasons:
* (1) in this interface, we also calculate the length of the
* string being hashed; and (2) the narrow and wide and `buffer' versions here
* will hash equivalent strings to the same value, e.g., "Hello" and L"Hello".
*/
PRUint32 nsCRT::HashCode(const char* str, PRUint32* resultingStrLen)
{
PRUint32 h = 0;
const char* s = str;
if (!str) return h;
unsigned char c;
while ( (c = *s++) )
ADD_TO_HASHVAL(h, c);
if ( resultingStrLen )
*resultingStrLen = (s-str)-1;
return h;
}
PRUint32 nsCRT::HashCode(const char* start, PRUint32 length)
{
PRUint32 h = 0;
const char* s = start;
const char* end = start + length;
unsigned char c;
while ( s < end ) {
c = *s++;
ADD_TO_HASHVAL(h, c);
}
return h;
}
PRUint32 nsCRT::HashCode(const PRUnichar* str, PRUint32* resultingStrLen)
{
PRUint32 h = 0;
const PRUnichar* s = str;
if (!str) return h;
PRUnichar c;
while ( (c = *s++) )
ADD_TO_HASHVAL(h, c);
if ( resultingStrLen )
*resultingStrLen = (s-str)-1;
return h;
}
PRUint32 nsCRT::HashCode(const PRUnichar* start, PRUint32 length)
{
PRUint32 h = 0;
const PRUnichar* s = start;
const PRUnichar* end = start + length;
PRUnichar c;
while ( s < end ) {
c = *s++;
ADD_TO_HASHVAL(h, c);
}
return h;
}
PRUint32 nsCRT::HashCodeAsUTF16(const char* start, PRUint32 length,
bool* err)
{
PRUint32 h = 0;
const char* s = start;
const char* end = start + length;
*err = false;
while ( s < end )
{
PRUint32 ucs4 = UTF8CharEnumerator::NextChar(&s, end, err);
if (*err) {
return 0;
}
if (ucs4 < PLANE1_BASE) {
ADD_TO_HASHVAL(h, ucs4);
}
else {
ADD_TO_HASHVAL(h, H_SURROGATE(ucs4));
ADD_TO_HASHVAL(h, L_SURROGATE(ucs4));
}
}
return h;
}
// This should use NSPR but NSPR isn't exporting its PR_strtoll function
// Until then...
PRInt64 nsCRT::atoll(const char *str)
{
if (!str)
return LL_Zero();
PRInt64 ll = LL_Zero(), digitll = LL_Zero();
while (*str && *str >= '0' && *str <= '9') {
LL_MUL(ll, ll, 10);
LL_UI2L(digitll, (*str - '0'));
LL_ADD(ll, ll, digitll);
str++;
}
return ll;
}