gecko-dev/xpcom/glue/nsVersionComparator.cpp

226 lines
4.8 KiB
C++
Executable File

/* ***** 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 XPCOM.
*
* The Initial Developer of the Original Code is
* Benjamin Smedberg <benjamin@smedbergs.us>.
*
* Portions created by the Initial Developer are Copyright (C) 2005
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either 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 ***** */
#include "nsVersionComparator.h"
#include <stdlib.h>
#include <string.h>
struct VersionPart {
PRInt32 numA;
const char *strB; // NOT null-terminated, can be a null pointer
PRUint32 strBlen;
PRInt32 numC;
char *extraD; // null-terminated
};
/**
* Parse a version part into a number and "extra text".
*
* @returns A pointer to the next versionpart, or null if none.
*/
static char*
ParseVP(char *part, VersionPart &result)
{
char *dot;
result.numA = 0;
result.strB = nsnull;
result.strBlen = 0;
result.numC = 0;
result.extraD = nsnull;
if (!part)
return part;
dot = strchr(part, '.');
if (dot)
*dot = '\0';
if (part[0] == '*' && part[1] == '\0') {
result.numA = PR_INT32_MAX;
result.strB = "";
}
else {
result.numA = strtol(part, const_cast<char**>(&result.strB), 10);
}
if (!*result.strB) {
result.strB = nsnull;
result.strBlen = 0;
}
else {
if (result.strB[0] == '+') {
static const char kPre[] = "pre";
++result.numA;
result.strB = kPre;
result.strBlen = sizeof(kPre) - 1;
}
else {
const char *numstart = strpbrk(result.strB, "0123456789+-");
if (!numstart) {
result.strBlen = strlen(result.strB);
}
else {
result.strBlen = numstart - result.strB;
result.numC = strtol(numstart, &result.extraD, 10);
if (!*result.extraD)
result.extraD = nsnull;
}
}
}
if (dot) {
++dot;
if (!*dot)
dot = nsnull;
}
return dot;
}
// compare two null-terminated strings, which may be null pointers
static PRInt32
ns_strcmp(const char *str1, const char *str2)
{
// any string is *before* no string
if (!str1)
return str2 != 0;
if (!str2)
return -1;
return strcmp(str1, str2);
}
// compare two length-specified string, which may be null pointers
static PRInt32
ns_strnncmp(const char *str1, PRUint32 len1, const char *str2, PRUint32 len2)
{
// any string is *before* no string
if (!str1)
return str2 != 0;
if (!str2)
return -1;
for (; len1 && len2; --len1, --len2, ++str1, ++str2) {
if (*str1 < *str2)
return -1;
if (*str1 > *str2)
return 1;
}
if (len1 == 0)
return len2 == 0 ? 0 : -1;
return 1;
}
// compare two PRInt32
static PRInt32
ns_cmp(PRInt32 n1, PRInt32 n2)
{
if (n1 < n2)
return -1;
return n1 != n2;
}
/**
* Compares two VersionParts
*/
static PRInt32
CompareVP(VersionPart &v1, VersionPart &v2)
{
PRInt32 r = ns_cmp(v1.numA, v2.numA);
if (r)
return r;
r = ns_strnncmp(v1.strB, v1.strBlen, v2.strB, v2.strBlen);
if (r)
return r;
r = ns_cmp(v1.numC, v2.numC);
if (r)
return r;
return ns_strcmp(v1.extraD, v2.extraD);
}
PRInt32
NS_CompareVersions(const char *A, const char *B)
{
char *A2 = strdup(A);
if (!A2)
return 1;
char *B2 = strdup(B);
if (!B2) {
free(A2);
return 1;
}
PRInt32 result;
char *a = A2, *b = B2;
do {
VersionPart va, vb;
a = ParseVP(a, va);
b = ParseVP(b, vb);
result = CompareVP(va, vb);
if (result)
break;
} while (a || b);
free(A2);
free(B2);
return result;
}