/**

 * berkdb.c (C) 2010 Markus Bröker

 *

 */

#include <stdio.h>

#include <stdlib.h>

#include <sys/types.h>

#include <limits.h>

#include <db.h>

#include <fcntl.h>

#include <errno.h>

#include <string.h>

DBT key;

DBT data;

/* initialize the db library and open a db file */

DB *dbinit (DB * db, char *filename)

{

    int ret;

    printf ("Initializing berkley db...\n");

    if ((ret = db_create (&db, NULL, 0)) != 0) {

        perror ("db_create");

        return NULL;

    }

    bzero (&key, sizeof (key));

    bzero (&data, sizeof (data));

    printf ("Opening berkdb.db flat database file...\n");

    if ((ret = db->open (db, NULL, filename, NULL, DB_BTREE, DB_CREATE, 0)) != 0) {

        perror ("db->open");

        return NULL;

    }

    return db;

}

/* insert a key/value pair into the database */

int dbinsert (DB * db, int id, char *description)

{

    key.data = &id;

    key.size = sizeof (int);

    data.data = description;

    data.size = strlen (description) + 1;

    return db->put (db, NULL, &key, &data, DB_NOOVERWRITE);

}

/* get the associated value from the database for the key 'id' */

char *dbget (DB * db, int id)

{

    key.data = &id;

    key.size = sizeof (int);

    if (db->get (db, NULL, &key, &data, 0) == 0)

        return (char *)data.data;

    return NULL;

}

/* iterate over the db and print all values */

void dblist (DB * db)

{

    int ret;

    DBC *dbc;

    if (db->cursor (db, NULL, &dbc, 0) != 0) {

        perror ("db->cursor");

        return;

    }

    bzero (&key, sizeof (key));

    while ((ret = dbc->get (dbc, &key, &data, DB_NEXT)) == 0) {

        printf ("KEY[%02d] => %s\n", *(int *)key.data, (char *)data.data);

    }

    if (dbc != NULL) {

        dbc->close (dbc);

    } else

        perror ("dbc");

}

/* close the db */

int dbclose (DB * db)

{

    if (db != NULL) {

        printf ("Closing berkley db file...\n");

        return db->close (db, 0);

    }

    return EXIT_FAILURE;

}

int main (int argc, char **argv)

{

    char description[80];

    int id;

    DB *db = NULL;

    if ((db = dbinit (db, "berkdb.db")) == NULL)

        return EXIT_FAILURE;

    for (id = 0; id < 100; id++) {

        sprintf (description, "This is value %d", id);

        switch (dbinsert (db, id, description)) {

        case 0:

            printf ("KEY ADDED\n");

            break;

        case DB_KEYEXIST:

            printf ("DUPLICATE KEY %d\n", id);

            break;

        default:

            printf ("Error while storing primary key %d\n", id);

        }

    }

    char *value;

    for (id = 0; id < 10; id++) {

        if ((value = dbget (db, id)) != NULL)

            printf ("DB: %s\n", value);

    }

    dblist (db);

    return dbclose (db);

}