1 /**

     2  * berkdb.c (C) 2010 Markus Bröker

     3  *

     4  */

     5 

     6 #include <stdio.h>

     7 #include <stdlib.h>

     8 

     9 #include <sys/types.h>

    10 #include <limits.h>

    11 #include <db.h>

    12 #include <fcntl.h>

    13 #include <errno.h>

    14 #include <string.h>

    15 

    16 DBT key;

    17 DBT data;

    18 

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

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

    21 {

    22     int ret;

    23 

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

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

    26         perror ("db_create");

    27         return NULL;

    28     }

    29 

    30     bzero (&key, sizeof (key));

    31     bzero (&data, sizeof (data));

    32 

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

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

    35         perror ("db->open");

    36         return NULL;

    37     }

    38 

    39     return db;

    40 }

    41 

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

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

    44 {

    45     key.data = &id;

    46     key.size = sizeof (int);

    47 

    48     data.data = description;

    49     data.size = strlen (description) + 1;

    50 

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

    52 }

    53 

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

    55 char *dbget (DB * db, int id)

    56 {

    57     key.data = &id;

    58     key.size = sizeof (int);

    59 

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

    61         return (char *)data.data;

    62 

    63     return NULL;

    64 }

    65 

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

    67 void dblist (DB * db)

    68 {

    69     int ret;

    70     DBC *dbc;

    71 

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

    73         perror ("db->cursor");

    74         return;

    75     }

    76 

    77     bzero (&key, sizeof (key));

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

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

    80     }

    81 

    82     if (dbc != NULL) {

    83         dbc->close (dbc);

    84     } else

    85         perror ("dbc");

    86 }

    87 

    88 /* close the db */

    89 int dbclose (DB * db)

    90 {

    91     if (db != NULL) {

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

    93         return db->close (db, 0);

    94     }

    95     return EXIT_FAILURE;

    96 }

    97 

    98 int main (int argc, char **argv)

    99 {

   100     char description[80];

   101     int id;

   102 

   103     DB *db = NULL;

   104 

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

   106         return EXIT_FAILURE;

   107 

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

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

   110 

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

   112         case 0:

   113             printf ("KEY ADDED\n");

   114             break;

   115         case DB_KEYEXIST:

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

   117             break;

   118         default:

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

   120         }

   121     }

   122 

   123     char *value;

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

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

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

   127     }

   128 

   129     dblist (db);

   130 

   131     return dbclose (db);

   132 }