db/dbmi_base/index.c

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/*!
   \file lib/db/dbmi_base/index.c
 
   \brief DBMI Library (base) - index management
 
   (C) 1999-2009, 2011 by the GRASS Development Team
 
   This program is free software under the GNU General Public License
   (>=v2). Read the file COPYING that comes with GRASS for details.
 
   \author Joel Jones (CERL/UIUC), Radim Blazek
   \author Doxygenized by Martin Landa <landa.martin gmail.com> (2011)
 */
 
#include <string.h>
#include <stdlib.h>
#include <grass/dbmi.h>
#include <grass/glocale.h>
 
/*!
   \brief Initialize dbIndex
 
   \param index pointer to dbIndex to be initialized
 */
void db_init_index(dbIndex *index)
{
    db_init_string(&index->indexName);
    db_init_string(&index->tableName);
    index->numColumns = 0;
    index->columnNames = NULL;
    index->unique = 0;
}
 
/*!
   \brief Free allocated dbIndex
 
   \param index pointer to dbIndex to be freed
 */
void db_free_index(dbIndex *index)
{
    db_free_string(&index->indexName);
    db_free_string(&index->tableName);
    if (index->numColumns > 0)
        db_free_string_array(index->columnNames, index->numColumns);
    db_init_index(index);
}
 
/*!
   \brief Allocate index columns
 
   \param index pointer to dbIndex
   \param ncols number of columns to be allocated
 
   \return DB_OK
 */
int db_alloc_index_columns(dbIndex *index, int ncols)
{
    index->columnNames = db_alloc_string_array(ncols);
    if (index->columnNames == NULL)
        return db_get_error_code();
    index->numColumns = ncols;
 
    return DB_OK;
}
 
/*!
   \brief Allocate index array
 
   \param count number of items
 
   \return pointer to allocated dbIndex array
 */
dbIndex *db_alloc_index_array(int count)
{
    dbIndex *list;
    int i;
 
    list = (dbIndex *)db_calloc(count, sizeof(dbIndex));
    if (list) {
        for (i = 0; i < count; i++)
            db_init_index(&list[i]);
    }
    return list;
}
 
/*!
   \brief Free index array
 
   \param list dbIndex array
   \param count number of items in the array
 */
void db_free_index_array(dbIndex *list, int count)
{
    int i;
 
    if (list) {
        for (i = 0; i < count; i++)
            db_free_index(&list[i]);
        db_free(list);
    }
}
 
/*!
   \brief Set index name
 
   \param index pointer to dbIndex
   \param name name to be set
 
   \return DB_OK on success
   \return DB_FAILED on error
 */
int db_set_index_name(dbIndex *index, const char *name)
{
    return db_set_string(&index->indexName, name);
}
 
/*!
   \brief Get index name
 
   \param index pointer to dbIndex
 
   \return string buffer with name
 */
const char *db_get_index_name(dbIndex *index)
{
    return db_get_string(&index->indexName);
}
 
/*!
   \brief Set table name
 
   \param index pointer to dbIndex
   \param name name to be set
 
   \return DB_OK on success
   \return DB_FAILED on error
 */
int db_set_index_table_name(dbIndex *index, const char *name)
{
    return db_set_string(&index->tableName, name);
}
 
/*!
   \brief Get table name
 
   \param index pointer to dbIndex
 
   \return string buffer with name
 */
const char *db_get_index_table_name(dbIndex *index)
{
    return db_get_string(&index->tableName);
}
 
/*!
   \brief Get number of columns
 
   \param index pointer to dbIndex
 
   \return number of columns
 */
int db_get_index_number_of_columns(dbIndex *index)
{
    return index->numColumns;
}
 
/*!
   \brief Set column name
 
   \param index pointer to dbIndex
   \param column_num column number
   \param name name to be set
 
   \return DB_OK on success
   \return DB_FAILED on error
 */
int db_set_index_column_name(dbIndex *index, int column_num, const char *name)
{
    if (column_num < 0 || column_num >= index->numColumns) {
        db_error(_("db_set_index_column_name(): invalid column number"));
        return db_get_error_code();
    }
    return db_set_string(&index->columnNames[column_num], name);
}
 
/*!
   \brief Get column number
 
   \param index pointer to dbIndex
   \param column_num column number
 
   \return string buffer with name
 */
const char *db_get_index_column_name(dbIndex *index, int column_num)
{
    if (column_num < 0 || column_num >= index->numColumns) {
        db_error(_("db_get_index_column_name(): invalid column number"));
        return ((const char *)NULL);
    }
    return db_get_string(&index->columnNames[column_num]);
}
 
/*!
   \brief Set index type to unique
 
   \todo return type void?
 
   \param index pointer to dbIndex
 
   \return 0
 */
int db_set_index_type_unique(dbIndex *index)
{
    index->unique = 1;
 
    return 0;
}
 
/*!
   \brief Set index type to non-unique
 
   \todo return type void?
 
   \param index pointer to dbIndex
 
   \return 0
 */
int db_set_index_type_non_unique(dbIndex *index)
{
    index->unique = 0;
 
    return 0;
}
 
/*!
   \brief Test if type is unique
 
   \param index pointer to dbIndex
 
   \return non-zero if True
   \return zero if False
 */
int db_test_index_type_unique(dbIndex *index)
{
    return index->unique != 0;
}
 
/*!
   \brief Report index
 
   \param fd file where to print index info
   \param index pointer to dbIndex
 */
void db_print_index(FILE *fd, dbIndex *index)
{
    int i, nCols;
 
    fprintf(fd, "Name: %s\n", db_get_index_name(index));
    if (db_test_index_type_unique(index))
        fprintf(fd, "Unique: true\n");
    else
        fprintf(fd, "Unique: false\n");
    fprintf(fd, "Table: %s\n", db_get_index_table_name(index));
    nCols = db_get_index_number_of_columns(index);
    fprintf(fd, "Number of columns: %d\nColumns:\n", nCols);
 
    for (i = 0; i < nCols; i++) {
        fprintf(fd, "  %s\n", db_get_index_column_name(index, i));
    }
}