test_osm3.c

test_osm3.c shows how to intentionally abort the parser.Here is a typical usage example, parsing an OSM XML file (.osm):

    ./test_osm3 test.osm 10
    node#1
    node#2
    node#3
    node#4
    node#5
    node#6
    node#7
    node#8
    node#9
    node#10
    PARSING ABORTED

Here is another example, this time parsing a .pbf (Protocol Buffer) OSM file:

    ./test_osm3 test.osm 5
    node#1
    node#2
    node#3
    node#4
    node#5
    PARSING ABORTED

/*
/ test_osm3.c
/
/ libreadosm Sample code
/
/ Author: Sandro Furieri a.furieri@lqt.it
/
/ ------------------------------------------------------------------------------
/
/ 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 the ReadOSM library
/
/ The Initial Developer of the Original Code is Alessandro Furieri
/
/ Portions created by the Initial Developer are Copyright (C) 2012-2017
/ 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.
/
*/
#include <stdio.h>
#include <stdlib.h>
#include "readosm.h"
struct osm_helper
{
/* an user defined struct */
int read_count;
int stop_limit;
};
static int
eval_abort (struct osm_helper *helper)
{
/* testing the stop limit */
if (helper->read_count > helper->stop_limit)
return 1;
return 0;
}
static int
parse_node (const void *user_data, const readosm_node * node)
{
/* parsing a Node (callback function)*/
/* casting the USER_DATA pointer to osm_helper */
struct osm_helper *helper = (struct osm_helper *) user_data;
if (node != NULL)
node = NULL; /* silencing stupid compiler warnings */
helper->read_count++;
if (eval_abort (helper))
return READOSM_ABORT;
printf ("Node#%d\n", helper->read_count);
return READOSM_OK;
}
static int
parse_way (const void *user_data, const readosm_way * way)
{
/* parsing a Way (callback function)*/
/* casting the USER_DATA pointer to osm_helper */
struct osm_helper *helper = (struct osm_helper *) user_data;
if (way != NULL)
way = NULL; /* silencing stupid compiler warnings */
helper->read_count++;
if (eval_abort (helper))
return READOSM_ABORT;
printf ("Way#%d\n", helper->read_count);
return READOSM_OK;
}
static int
parse_relation (const void *user_data, const readosm_relation * relation)
{
/* parsing a Relation stats (callback function)*/
/* casting the USER_DATA pointer to osm_helper */
struct osm_helper *helper = (struct osm_helper *) user_data;
if (relation != NULL)
relation = NULL; /* silencing stupid compiler warnings */
helper->read_count++;
if (eval_abort (helper))
return READOSM_ABORT;
printf ("Relation#%d\n", helper->read_count);
return READOSM_OK;
}
int
main (int argc, char *argv[])
{
const void *osm_handle;
int ret;
struct osm_helper helper;
/* initializing the helper struct */
helper.read_count = 0;
helper.stop_limit = 0;
if (argc != 3)
{
fprintf (stderr, "usage: test_osm3 path-to-OSM limit\n");
return -1;
}
/* setting the stop limit */
helper.stop_limit = atoi (argv[2]);
/*
* STEP #1: opening the OSM file
* this can indifferently be an OSM XML encoded file (.osm)
* or an OSM Protocol Buffer encoded file (.pbf)
* the library will transparently perform any required
* action in both cases.
*/
ret = readosm_open (argv[1], &osm_handle);
if (ret != READOSM_OK)
{
fprintf (stderr, "OPEN error: %d\n", ret);
goto stop;
}
/*
* STEP #2: parsing the OSM file
* this task is unbelievably simple
*
* you are simply required to pass the appropriate
* pointers for callback funtions respectively intended
* to process Node-objects, Way-objects and Relation-objects
*
* the library will then parse the whole input file, calling
* the appropriate callback handling function for each OSM object
* found: please see the callback functions implementing code
* to better understand how it works
*
* important notice: this second example is mainly focused on
* using the USER_DATA pointer. in this example we'll pass the
* address of the osm_statistics struct so to gather some
* general infos.
*/
ret =
readosm_parse (osm_handle, &helper, parse_node, parse_way,
parse_relation);
if (ret != READOSM_OK)
{
fprintf (stderr, "PARSE error: %d\n", ret);
goto stop;
}
stop:
/*
* STEP #3: closing the OSM file
* this will release any internal memory allocation
*/
readosm_close (osm_handle);
return 0;
}
readosm_parse
READOSM_DECLARE int readosm_parse(const void *osm_handle, const void *user_data, readosm_node_callback node_fnct, readosm_way_callback way_fnct, readosm_relation_callback relation_fnct)
Close the .osm or .pbf file and release any allocated resource.
readosm_relation_struct
Definition: readosm.h:219
readosm_node_struct
Definition: readosm.h:132
READOSM_ABORT
#define READOSM_ABORT
user-required parser abort
Definition: readosm.h:101
readosm_open
READOSM_DECLARE int readosm_open(const char *path, const void **osm_handle)
Open the .osm or .pbf file, preparing for future functions.
READOSM_OK
#define READOSM_OK
No error, success.
Definition: readosm.h:88
readosm.h
readosm_way_struct
Definition: readosm.h:165
readosm_close
READOSM_DECLARE int readosm_close(const void *osm_handle)
Close the .osm or .pbf file and release any allocated resource.