Значения Char пусты после итерации в другой функции в C - PullRequest
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Значения Char пусты после итерации в другой функции в C

0 голосов
/ 24 января 2020

Я анализирую xml с использованием библиотеки xerces c ++ и пытаюсь сохранить некоторые теги и значения, которые мне требуются.

У меня есть динамически распределенный массив символов, в котором хранятся фактические значения из проанализированного XML, позже эти значения будут пустыми / отсутствующими?

Примечание: я использую компилятор C ++, я намерен написать как можно больше кода в C.

См. Соответствующие фрагменты основной функции (обратите внимание на важность walk_DOM () & get_data ()). 

      int main(int argc, char *args[])
 {
    //pass in as console argument 
    char *xmlFile = args[1];
    file_observational_area *_file_observational_area = NULL;
    //initialize  file_observational_area
    _file_observational_area = calloc_file_observational_area(_file_observational_area, 1);

    /*xerces irrelevant code was not included in post as xerces is working*/

    parser->parse(xmlFile);

    DOMDocument *dom = parser->getDocument();

    DOMNodeList *dom_node_list = dom->getChildNodes();

    for (unsigned int i = 0; i < dom_node_list->getLength(); i++)
    {
        walk_DOM(dom_node_list->item(i), _file_observational_area);
    }

    get_data(_file_observational_area, xmlFile, 0, 0, 0, _field_data_values_array);

 }

Заголовок для поля field_delilmited: 

#
ifndef FIELD_DELIMITED_H
#define FIELD_DELIMITED_H

# ifdef __cplusplus
extern "C"
{#
    endif

    struct field_delimited
    {
        char *name;
        char *data_type;
        char *unit;
        char *description;

    };

    typedef struct field_delimited field_delimited;

    /*=============================================================================
    Function        correct_column_headers
    Description:    Are all the headers read from data from the same as described 
     *             in the XML?
    References:       
    Inputs:         
    Output:         0 for false &1 for true    
    ==========================================================*/
    int correct_column_headers(field_delimited *_field_delimited, int expected_number_of_columns, char *delimiter, char *read_header);

    #
    ifdef __cplusplus
}#
endif

# endif /*FIELD_DELIMITED_H */

См. Соответствующий фрагмент parse_dom_PDS4 () , это функция, которая устанавливает значения изначально в _file_observational_area- >_table_delimited->_record_delimited->_field_delimited, однако позже значения становятся пустыми при повторении в getData (): 

    file_observational_area* parse_dom_PDS4(DOMNode *dom_node, file_observational_area *_file_observational_area)
{
    /*<Field_Delimited>*/
    if (XMLString::equals(dom_node_name, XMLString::transcode("Field_Delimited")))
    {
        /*<Field_Delimited>
          <name>enc4</name>
          <data_type>ASCII_Real</data_type>
          <unit>rad</unit>
          <description>Joint 4 encoder counts[RA_DOF]</description>
          </Field_Delimited>*/

        /*<Field_Delimited>*/
        XMLCh *tag_Field_Delimited_name = XMLString::transcode("name");
        string tag_Field_Delimited_name_val;
        XMLCh *tag_Field_Delimited_data_type = XMLString::transcode("data_type");
        string tag_Field_Delimited_data_type_val;
        XMLCh *tag_Field_Delimited_unit = XMLString::transcode("unit");
        string tag_Field_Delimited_unit_val;
        XMLCh *tag_Field_Delimited_description = XMLString::transcode("description");
        string tag_Field_Delimited_description_val;
        DOMElement *currentElement = NULL;
        cout << "<Field_Delimited> DETECTED\n";
        int number_of_fields = _file_observational_area->_table_delimited->_record_delimited->fields;

        _file_observational_area->_table_delimited->_record_delimited->_field_delimited = malloc_field_delimited(_file_observational_area->_table_delimited->_record_delimited->_field_delimited, number_of_fields);

        if (dom_node->hasChildNodes())
        {
            //            get Record_Delimited children 
            dom_node_list = dom_node->getChildNodes();

            if (NULL != dom_node_list)
            {
                /*<Field_Delimited> start loop*/
                for (unsigned int Field_Delimited_index = 0; Field_Delimited_index < number_of_fields; Field_Delimited_index++)
                {
                    if (NULL != dom_node_list->item(Field_Delimited_index))
                    {
                        currentElement = dynamic_cast<xercesc::DOMElement*> (dom_node_list->item(Field_Delimited_index));

                        if (NULL != currentElement && NULL != currentElement->getNodeName())
                        {
                            if (XMLString::equals(tag_Field_Delimited_name, currentElement->getNodeName()))
                            {
                                _file_observational_area->_table_delimited->_record_delimited->_field_delimited[Field_Delimited_index].name = XMLString::transcode(currentElement->getTextContent());
                                cout << "Debug: tag_Field_Delimited_name_val:" << _file_observational_area->_table_delimited->_record_delimited->_field_delimited[Field_Delimited_index].name << "\n";
                            }

                            if (XMLString::equals(tag_Field_Delimited_data_type, currentElement->getNodeName()))
                            {
                                _file_observational_area->_table_delimited->_record_delimited->_field_delimited[Field_Delimited_index].data_type = XMLString::transcode(currentElement->getTextContent());
                                cout << "Debug: tag_Field_Delimited_data_type_val:" << _file_observational_area->_table_delimited->_record_delimited->_field_delimited[Field_Delimited_index].data_type << "\n";
                            }

                            if (XMLString::equals(tag_Field_Delimited_unit, currentElement->getNodeName()))
                            {
                                _file_observational_area->_table_delimited->_record_delimited->_field_delimited[Field_Delimited_index].unit = XMLString::transcode(currentElement->getTextContent());
                                cout << "Debug: tag_Field_Delimited_unit_val:" << _file_observational_area->_table_delimited->_record_delimited->_field_delimited[Field_Delimited_index].unit << "\n";
                            }

                            if (XMLString::equals(tag_Field_Delimited_description, currentElement->getNodeName()))
                            {
                                _file_observational_area->_table_delimited->_record_delimited->_field_delimited[Field_Delimited_index].description = XMLString::transcode(currentElement->getTextContent());
                                cout << "Debug: tag_Field_Delimited_description_val:" << _file_observational_area->_table_delimited->_record_delimited->_field_delimited[Field_Delimited_index].description << "\n";
                            }
                        }
                    }   //end item is not  empty 

                } /*<Field_Delimited> end loop */

            }   //end dom node list is not empty 

        }   //end has children 
    }   //end  /*<Field_Delimited>*/
    //other code follows but in irrelevant 
}

Позже я пересекаю _file_observational_area и другие значения там, как и ожидалось, однако значения в _file_observational_area->_table_delimited->_record_delimited->_field_delimited отсутствуют / пустые ??

См. Соответствующий фрагмент ниже, значения теперь пусты 

 void get_data(file_observational_area *_file_observational_area, char *pds4_xml_path, int dimensions, int *start_indices, int *end_indices, field_data_value *field_data_values)
    {
        //number of  fields
        if (_file_observational_area->_table_delimited->_record_delimited->fields > 0)
        {
            //allocate memory for actual data 
            int field_data_value_memory_size = _file_observational_area->_table_delimited->records *_file_observational_area->_table_delimited->_record_delimited->fields;

            field_data_values = (field_data_value*) malloc(field_data_value_memory_size* sizeof(field_data_value));

            // _file_observational_area->_table_delimited->_record_delimited->_field_delimited
            int row_count = 0;
            buffer_size = _file_observational_area->_table_delimited->offset;

            for (int field_record_index = 0; field_record_index < _file_observational_area->_table_delimited->_record_delimited->fields; field_record_index++)
            {
                if (NULL != _file_observational_area->_table_delimited->_record_delimited->_field_delimited)
                {
                    _file_observational_area->_table_delimited->_record_delimited->_field_delimited[field_record_index].name;
                    cout << "name :" << _file_observational_area->_table_delimited->_record_delimited->_field_delimited[field_record_index].name << "\n";

                    //datatype
                    _file_observational_area->_table_delimited->_record_delimited->_field_delimited[field_record_index].data_type;
                    cout << "data_type:" << _file_observational_area->_table_delimited->_record_delimited->_field_delimited[field_record_index].data_type << "\n";
                    //unit
                    _file_observational_area->_table_delimited->_record_delimited->_field_delimited[field_record_index].unit;
                    cout << "unit:" << _file_observational_area->_table_delimited->_record_delimited->_field_delimited[field_record_index].unit << "\n";
                    //unit
                    //description 
                    _file_observational_area->_table_delimited->_record_delimited->_field_delimited[field_record_index].description;
                    cout << "description:" << _file_observational_area->_table_delimited->_record_delimited->_field_delimited[field_record_index].description << "\n";

                    //TODO:  check _file_observational_area->_table_delimited->field_delimiter
                    //TODO:// split character_buffer based on _file_observational_area->_table_delimited->field_delimiter
                    //TODO: output another file for testing, later data structure for querying 

                }
            }

            //other code follows but in irrelevant 

        }

Заголовок для file_observational.h: 

    #include <stdlib.h>
    #include "data_file.h"
    #include "header.h"
    #include "table_delimited.h"
    #include "record_delimited.h"
    #include "field_delimited.h"
    #include <xercesc/dom/DOM.hpp>
    #include <xercesc/dom/DOMNode.hpp>

    #ifndef FILE_OBSERVATIONAL__H
    #define FILE_OBSERVATIONAL__H

        struct file_observational_area 
     {
       data_file * _file; 
       header * _header; 
       table_delimited  * _table_delimited; 

     };

    typedef struct  file_observational_area  file_observational_area; 



    /*=============================================================================
    Function        calloc_file_observational_area
    Description:    Allocates memory for file_observational_area and children
    References:       
    Inputs:         
    Output:            
    ==========================================================*/
    file_observational_area *
    calloc_file_observational_area (file_observational_area * _file_observational_area, int MAX_SIZE);

    /*=============================================================================
    Function        destroy_file_observational_area
    Description:    free allocated memory for file_observational_area and children
    References:       
    Inputs:         
    Output:            
    ==========================================================*/
    void
    destroy_file_observational_area (file_observational_area * _file_observational_area);

    /*=============================================================================
    Function        parse_dom_PDS4
    Description:    parse based on PDS4 tags 
    References:       
    Inputs:         
    Output:            
    ==========================================================*/
    field_delimited * malloc_field_delimited(field_delimited * _field_delimited, int number_of_fields);


    /*=============================================================================
    Function        free_field_delimited
    Description:     free allocated memory for _record_delimited->_field_delimited
     *                  dynamic array 
    References:       
    Inputs:         
    Output:            
    ==========================================================*/
    void
    free_field_delimited(field_delimited * _field_delimited, int number_of_fields);

    //file_observational_area * parse_dom_PDS4(DOMNode * dom_node, 
    //        file_observational_area * _file_observational_area);

    /*=============================================================================
    Function        malloc_field_delimited
    Description:     allocated memory for _record_delimited->_field_delimited
     *                  dynamic array 
    References:       
    Inputs:         
    Output:            
    ==========================================================*/



    #endif /* FILE_OBSERVATIONAL__H */

Соответствующая часть вывода после запуска программы:

DETECTED

, tag_Field_Delimited_name_val: grapple_phase

, tag_Field_Delimited_data_type_val: ASCII_Integer

, tag_Field_Delimited_unit_val: нет

* 1044_объект * получен data () full_file_path: /home/anaim/sample_pds4_files/for_ary/A0087_0008_597249118_597252671_181130002623_eu.csv

_file_observational_area -> заголовок -> текстовый_объект Заголовки столбцов

ТАБЛИЦА

запись с разделителями

имя:

тип_данных:

единица:

описание:

name: grapple_phase

data_type:

unit:

description:

name:

data_type:

единица:

описание:

имя:

тип_данных: ASCII_Integer

единица:

описание:

name:

data_type:

unit:

description:

Как видно, имена выводятся изначально, например, tag_Field_Delimited_name_val:Ft, но позже становятся пустыми при итерации в функции get_data (). Почему текстовые значения исчезли ??

...