m4_ignore([dnl #include #include #include #include #include #include #include #include #define MAXIMUM_RETRY 5 int add_fruit(DB_ENV *, DB *, char *, char *); void db_open(DB_ENV *a, DB **b, char *c, int d) { a = NULL; b = NULL; c = NULL; d = 0; } void usage(){} void env_open(DB_ENV **a) { a = NULL; } void env_dir_create() {} ]) m4_indent([dnl int main(int argc, char *argv[]) { extern int optind; DB *db_cats, *db_color, *db_fruit; DB_ENV *dbenv; int ch; m4_blank while ((ch = getopt(argc, argv, "")) != EOF) switch (ch) { case '?': default: usage(); } argc -= optind; argv += optind; m4_blank env_dir_create(); env_open(&dbenv); m4_blank /* Open database: Key is fruit class; Data is specific type. */ db_open(dbenv, &db_fruit, "fruit", 0); m4_blank /* Open database: Key is a color; Data is an integer. */ db_open(dbenv, &db_color, "color", 0); m4_blank /* * Open database: * Key is a name; Data is: company name, cat breeds. */ db_open(dbenv, &db_cats, "cats", 1); m4_blank m4_cbold([dnl add_fruit(dbenv, db_fruit, "apple", "yellow delicious");]) m4_blank return (0); } m4_blank m4_cbold([dnl int add_fruit(DB_ENV *dbenv, DB *db, char *fruit, char *name) { DBT key, data; DB_TXN *tid; int fail, ret, t_ret; m4_blank /* Initialization. */ memset(&key, 0, sizeof(key)); memset(&data, 0, sizeof(data)); key.data = fruit; key.size = strlen(fruit); data.data = name; data.size = strlen(name); m4_blank for (fail = 0;;) { /* Begin the transaction. */ if ((ret = dbenv-__GT__txn_begin(dbenv, NULL, &tid, 0)) != 0) { dbenv-__GT__err(dbenv, ret, "DB_ENV-__GT__txn_begin"); exit (1); } m4_blank /* Store the value. */ switch (ret = db-__GT__put(db, tid, &key, &data, 0)) { case 0: /* Success: commit the change. */ if ((ret = tid-__GT__commit(tid, 0)) != 0) { dbenv-__GT__err(dbenv, ret, "DB_TXN-__GT__commit"); exit (1); } return (0); case DB_LOCK_DEADLOCK: default: /* Retry the operation. */ if ((t_ret = tid-__GT__abort(tid)) != 0) { dbenv-__GT__err(dbenv, t_ret, "DB_TXN-__GT__abort"); exit (1); } if (fail++ == MAXIMUM_RETRY) return (ret); break; } } }])])