xml.cpp

Go to the documentation of this file.

/***************************************************************************

    file                 : xml.cpp
    created              : Sat Mar 18 23:50:46 CET 2000
    copyright            : (C) 2000 by Eric Espie
    email                : torcs@free.fr
    version              : $Id$

 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

/*
 *  This set of function is used to store and retrieve
 *  values in parameters files written in XML.
 */

#include <stdlib.h>
#include <stdio.h>
#include <cstring>
#include <sys/stat.h>
#include "xmlparse.h"
#include <xml.h>
#include <portability.h>

#define BUFMAX  256

/*
 * NAME:
 *  NewElt
 *
 * FUNCTION:
 *  Creates a new element
 *
 * PARAMETERS:  
 *  name and attributes
 *
 * RETURNS: 
 *  new element created
 *
 */
static txmlElement *
NewElt(const char *name, const char **atts)
{
    int         nAtts;
    const char      **p;
    const char      *s1, *s2;
    txmlElement     *newElt;
    txmlAttribute   *newAttr;
    
    
    /* Create a new element */
    if ((newElt = (txmlElement*)malloc(sizeof(txmlElement))) == NULL) {
    return (txmlElement*)NULL;
    }
    newElt->name   = strdup(name);
    newElt->pcdata = (char*)NULL;
    newElt->attr   = (txmlAttribute*)NULL;
    newElt->sub    = (txmlElement*)NULL;
    newElt->up     = (txmlElement*)NULL;
    newElt->next   = newElt;
    newElt->level  = 0;

    /* attributes */
    p = atts;
    while (*p)
    ++p;
    nAtts = (p - atts) >> 1;
    if (nAtts > 1) {
    qsort((void *)atts, nAtts, sizeof(char *) * 2, (int (*)(const void *, const void *))strcmp);
    }

    while (*atts) {
    s1 = *atts++;
    s2 = *atts++;
    if ((newAttr = (txmlAttribute*)malloc(sizeof(txmlAttribute))) == NULL) {
        return (txmlElement*)NULL;
    }
    newAttr->name = strdup(s1);
    newAttr->value = strdup(s2);
    /* insert in attributes ring */
    if (newElt->attr == NULL) {
        newElt->attr = newAttr;
        newAttr->next = newAttr;
    } else {
        newAttr->next = newElt->attr->next;
        newElt->attr->next = newAttr;
        newElt->attr = newAttr;
    }
    }

    return newElt;
}


/*
 * NAME:
 *  xmlInsertElt
 *
 * FUNCTION:
 *  Create and Insert a new element in the sub-list of
 *  the element given in parameter
 *
 * PARAMETERS:  
 *  curElt  element
 *  name    name of the new element
 *  atts    attribute list of the new element
 *
 * RETURNS: 
 *  the new element created.
 *
 * NOTE:
 *  Use NULL as current element to create a new tree
 */
txmlElement *
xmlInsertElt(txmlElement *curElt, const char *name, const char **atts)
{
    txmlElement     *newElt;
    
    newElt = NewElt(name, atts);
    
    if (curElt) {
    if (curElt->sub == NULL) {
        curElt->sub = newElt;
        newElt->next = newElt;
    } else {
        newElt->next = curElt->sub->next;
        curElt->sub->next = newElt;
        curElt->sub = newElt;
    }
    newElt->up = curElt;
    newElt->level = curElt->level + 1;
    }
    
    return newElt;
}

/*
 * Function
 *  startElement
 *
 * Description
 *  
 *
 * Parameters
 *  
 *
 * Return
 *  
 */
static void 
startElement(void *userData, const char *name, const char **atts)
{
    txmlElement **curElt = (txmlElement **)userData;
    
    *curElt = xmlInsertElt(*curElt, name, atts);
}

/*
 * Function
 *  endElement
 *
 * Description
 *  
 *
 * Parameters
 *  
 *
 * Return
 *  none
 */
static void 
endElement(void *userData, const char * /* name */)
{
    txmlElement **curElt = (txmlElement **)userData;
    
    if ((*curElt)->up != NULL) {
    *curElt = (*curElt)->up;
    }
}

static void 
CharacterData(void *userData, const char *s, int len)
{
    char *s1,*s2,*s3;
    txmlElement **curElt = (txmlElement **)userData;
    
    if ((s1 = (char*)malloc(len+1)) == NULL) {
    return;
    }
    strncpy(s1, s, len);

    /* remove spaces in front */
    s2 = s1;
    while ((*s2 == ' ') || (*s2 == '\t') || (*s2 == '\n')) {
    s2++;
    }
    
    /* remove spaces at the end */
    s3 = s1+len-1;
    while (((*s3 == ' ') || (*s3 == '\t') || (*s3 == '\n')) && (s3 > s2)) {
    s3--;
    }
    
    if (s3 > s2) {
    *(s3+1) = 0;
    (*curElt)->pcdata = strdup(s2);
    }
    free(s1);
}

/*
 * Function
 *  xmlReadFile
 *
 * Description
 *  Read a config file
 *
 * Parameters
 *  file    name of the config file
 *
 * Return
 *  root of the tree
 *  NULL    error.
 *
 * Remarks
 *  
 */
txmlElement *
xmlReadFile(const char *file)
{
    FILE *in;
    char buf[BUFSIZ];
    XML_Parser parser;
    int done;
    txmlElement *retElt;

    if ((in = fopen(file, "r")) == NULL) {
        fprintf(stderr, "xmlReadFile: file %s has pb (access rights ?)\n", file);
        return (txmlElement*)NULL;
    }

    parser = XML_ParserCreate((XML_Char*)NULL);
    XML_SetUserData(parser, &retElt);
    XML_SetElementHandler(parser, startElement, endElement);
    XML_SetCharacterDataHandler(parser, CharacterData);
    do {
        size_t len = fread(buf, 1, sizeof(buf), in);
        done = len < sizeof(buf);
        if (!XML_Parse(parser, buf, len, done)) {
            fprintf(stderr, "file: %s -> %s at line %d\n", file, XML_ErrorString(XML_GetErrorCode(parser)), XML_GetCurrentLineNumber(parser));

            XML_ParserFree(parser);
            fclose(in);         
            return (txmlElement*)NULL;
        }
    } while (!done);

    XML_ParserFree(parser);
    fclose(in);

    return retElt;
}

static void
wr(int indent, const char *buf, FILE *out)
{
    char blank[BUFMAX];
    int i;
    
    for(i = 0; i < indent*2; i++) blank[i] = ' ';
    blank[i] = 0;
    fprintf(out, "%s%s", blank, buf);
}

static void
wrrec(txmlElement *startElt, FILE *out)
{
    txmlElement     *curElt;
    txmlAttribute   *curAttr;
    char buf[BUFMAX];
    
    curElt = startElt;
    
    if (curElt) {
    wr(0, "\n", out);
    do {
        curElt = curElt->next;
        snprintf(buf, BUFMAX, "<%s", curElt->name);
        wr(curElt->level, buf, out);
        curAttr = curElt->attr;
        if (curAttr) {
        do {
            curAttr = curAttr->next;
            snprintf(buf, BUFMAX, " %s=\"%s\"", curAttr->name, curAttr->value);
            wr(0, buf, out);
        } while (curAttr != curElt->attr);
        }
        snprintf(buf, BUFMAX, ">");
        wr(0, buf, out);
        if (curElt->pcdata) {
        snprintf(buf, BUFMAX, "%s", curElt->pcdata);
        wr(0, buf, out);
        }
        /* recurse the nested elements */
        wrrec(curElt->sub, out);
        snprintf(buf, BUFMAX, "</%s>\n", curElt->name);
        wr(0, buf, out);
    } while (curElt != startElt);
    wr(curElt->level-1, "", out);
    }
}

/*
 * Function
 *  xmlWriteFile
 *
 * Description
 *  Write a parameter file
 *
 * Parameters
 *  file        name of the config file
 *  startElt    root of the tree to write
 *
 * Return
 *  0   ok
 *  -1  failed
 *
 * Remarks
 *  the file is created if necessary
 */
int
xmlWriteFile(const char *file, txmlElement *startElt, char *dtd)
{
    char        buf[BUFMAX];
    FILE        *out;

    if ((out = fopen(file, "w")) == NULL) {
    fprintf(stderr, "xmlWriteFile: file %s has pb (access rights ?)\n", file);
    return -1;
    }

    snprintf(buf, BUFMAX, "<?xml version=\"1.0\" ?>\n");
    wr(0, buf, out);
    snprintf(buf, BUFMAX, "\n<!DOCTYPE params SYSTEM \"%s\">\n\n", dtd);
    wr(0, buf, out);

    wrrec(startElt, out);       
    wr(0, "\n", out);
    
    fclose(out);
    return 0;
}

/*
 * NAME:
 *  xmlGetAttr
 *
 * FUNCTION:
 *  Get the attribute value of an element
 *
 * PARAMETERS:  
 *  curElt      element to consider
 *  attrname    name of the attribute
 *
 * RETURNS: 
 *  the attribute value or NULL if attribute is not present
 *
 */
char *
xmlGetAttr(txmlElement *curElt, char *attrname)
{
    txmlAttribute   *cutAttr;

    cutAttr = curElt->attr;
    if (cutAttr) {
    do {
        cutAttr = cutAttr->next;
        if (strcmp(cutAttr->name, attrname) == 0) {
        return strdup(cutAttr->value);
        }
    } while (cutAttr != curElt->attr);
    }
    return (char*)NULL;
}

/*
 * NAME:
 *  xmlNextElt
 *
 * FUNCTION:
 *  Get the next element (same level)
 *
 * PARAMETERS:  
 *  startElt    element to start with
 *
 * RETURNS: 
 *  the next element or NULL if no more element
 *  at the same level
 *
 */
txmlElement *
xmlNextElt(txmlElement *startElt)
{
    txmlElement *curElt;
    
    curElt = startElt->next;
    if (curElt->up != NULL) {
    if (curElt->up->sub->next == curElt) {
        return (txmlElement*)NULL;
    }
    return curElt;
    }
    return (txmlElement*)NULL;
}


/*
 * NAME:
 *  xmlSubElt   
 *
 * FUNCTION:
 *  Get the first sub-element (nested level)
 *
 * PARAMETERS:  
 *  startElt    element to start with
 *
 * RETURNS: 
 *  the first sub-element or NULL if no sub-element
 *
 */
txmlElement *
xmlSubElt(txmlElement *startElt)
{
    if (startElt->sub != NULL) {
    return startElt->sub->next;
    }
    
    return (txmlElement*)NULL;
}


/*
 * NAME:
 *  xmlWalkElt
 *
 * FUNCTION:
 *  Walk all the tree
 *
 * PARAMETERS:  
 *  startElt    element to start with
 *
 * RETURNS: 
 *  the next element in the tree or NULL if all the tree
 *  has been parsed.
 *
 */
txmlElement *
xmlWalkElt(txmlElement *startElt)
{
    txmlElement *curElt;
    
    curElt = startElt;
    /* in depth first */
    if (curElt->sub != NULL) {
    return curElt->sub->next;
    }

    /* go to the next element */
    if ((curElt->up != NULL) && (curElt != curElt->up->sub)) {
    return curElt->next;
    }
    
    /* end of the ring should go upward */
    while (curElt->up != NULL) {
    curElt = curElt->up;
    if ((curElt->up != NULL) && (curElt != curElt->up->sub)) {
        return curElt->next;
    }
    }

    return (txmlElement*)NULL;
}


/*
 * NAME:
 *  xmlWalkSubElt
 *
 * FUNCTION:
 *  walk a sub-tree
 *
 * PARAMETERS:  
 *  startElt    element to start with
 *  topElt      sub-tree root
 *
 * RETURNS: 
 *  next element in in-depth search or NULL if all sub-tree has been parsed
 *
 */
txmlElement *
xmlWalkSubElt(txmlElement *startElt, txmlElement *topElt)
{
    txmlElement *curElt;
    
    curElt = startElt;
    /* in depth first */
    if (curElt->sub != NULL) {
    return curElt->sub->next;
    }

    /* go to the next element */
    if ((curElt->up != NULL) && (curElt != curElt->up->sub) && (curElt != topElt)) {
    return curElt->next;
    }
    
    /* end of the ring should go upward */
    while ((curElt->up != NULL) && (curElt != topElt)) {
    curElt = curElt->up;
    if ((curElt->up != NULL) && (curElt != curElt->up->sub)) {
        return curElt->next;
    }
    }

    return (txmlElement*)NULL;
}


/*
 * NAME:
 *  xmlFindNextElt
 *
 * FUNCTION:
 *  Find the next element corresponding to name
 *
 * PARAMETERS:  
 *  startElt    element to start with
 *  name        name of the element to find
 *
 * RETURNS: 
 *  pointer on next element corresponding to name
 *  or NULL if no more.
 *
 */
txmlElement *
xmlFindNextElt(txmlElement *startElt, char *name)
{
    txmlElement     *curElt;
    
    curElt = startElt;
    curElt = xmlWalkElt(curElt);
    while (curElt) {
    if (strcmp(curElt->name, name) == 0) {
        return curElt;
    }
    curElt = xmlWalkElt(curElt);
    }
    return (txmlElement*)NULL;
}    


/*
 * NAME:
 *  xmlFindEltAttr
 *
 * FUNCTION:
 *  Find an element with its name an an attribute value
 *
 * PARAMETERS:  
 *  startElt    element to start with
 *  name        name of the element to search
 *  attrname    attribute name
 *  attrvalue   attribute value of the searched element
 *
 * RETURNS: 
 *  the corresponding element or NULL if not found
 *
 */
txmlElement *
xmlFindEltAttr(txmlElement *startElt, char *name, char *attrname, char *attrvalue)
{
    txmlElement     *curElt;
    txmlAttribute   *cutAttr;
    
    curElt = startElt;
    curElt = xmlWalkElt(curElt);
    while (curElt) {
    if (strcmp(curElt->name, name) == 0) {
        cutAttr = curElt->attr;
        if (cutAttr) {
        do {
            cutAttr = cutAttr->next;
            if (strcmp(cutAttr->name, attrname) == 0) {
            if (strcmp(cutAttr->value, attrvalue) == 0) {
                return curElt;
            } else {
                cutAttr = curElt->attr;
            }
            }
        } while (cutAttr != curElt->attr);
        }
    }
    curElt = xmlWalkElt(curElt);
    }
    return (txmlElement*)NULL;
}