mylmdbtest.c

#include <stdio.h>
#include <stdlib.h>
#include "liblmdb/lmdb.h"

void
check_err(int err)
{
    if (err != 0) {
        fprintf(stderr, "ERROR (%d): %s\n", err, mdb_strerror(err));
        exit(EXIT_FAILURE);
    }
}

int
main(void)
{
    int err = 0;

    MDB_env *env;
    check_err(mdb_env_create(&env));
    check_err(mdb_env_open(env, "./db", 0, 0644));

    MDB_txn *txn_rw;
    MDB_dbi dbi;

    MDB_val key = { .mv_size = 4, .mv_data = "foo" };
    MDB_val val1 = { .mv_size = 4, .mv_data = "bar" };
    check_err(mdb_txn_begin(env, NULL, 0, &txn_rw));
    check_err(mdb_dbi_open(txn_rw, NULL, 0, &dbi));
    check_err(mdb_put(txn_rw, dbi, &key, &val1, 0));
    check_err(mdb_txn_commit(txn_rw));

    MDB_txn *txn_ro;
    MDB_val val2;
    check_err(mdb_txn_begin(env, NULL, MDB_RDONLY, &txn_ro));
    check_err(mdb_get(txn_ro, dbi, &key, &val2));
    mdb_txn_reset(txn_ro);

    printf("%s -> %s\n", (char *) key.mv_data, (char *) val2.mv_data);

    MDB_val val3 = { .mv_size = 12, .mv_data = "hello world" };
    check_err(mdb_txn_begin(env, NULL, 0, &txn_rw));
    check_err(mdb_put(txn_rw, dbi, &key, &val3, 0));
    check_err(mdb_txn_commit(txn_rw));

    MDB_val val4;
    check_err(mdb_txn_renew(txn_ro));
    check_err(mdb_get(txn_ro, dbi, &key, &val4));
    mdb_txn_reset(txn_ro);

    printf("%s -> %s\n", (char *) key.mv_data, (char *) val4.mv_data);

    return 0;
}