lmdb

 

https://blog.csdn.net/weixin_34252090/article/details/92562419

 

https://github.com/LMDB/lmdb

 

#include <stdio.h>
#include "lmdb.h"
 
int main(int argc,char * argv[])
{
  int rc;
  MDB_env *env;
  MDB_dbi dbi;
  MDB_val key, data;
  MDB_txn *txn;
  MDB_cursor *cursor;
  char sval[32];
 
  /* Note: Most error checking omitted for simplicity */
  rc = mdb_env_create(&env);
  rc = mdb_env_open(env, "./testdb", 0, 0664);
  rc = mdb_txn_begin(env, NULL, 0, &txn);
  rc = mdb_dbi_open(txn, NULL, 0, &dbi);
  key.mv_size = sizeof(int);
  key.mv_data = sval;
  data.mv_size = sizeof(sval);
  data.mv_data = sval;
 
  sprintf(sval, "%03x %d foo bar", 32, 3141592);
  rc = mdb_put(txn, dbi, &key, &data, 0);
  rc = mdb_txn_commit(txn);
  if (rc) {
    fprintf(stderr, "mdb_txn_commit: (%d) %s\n", rc, mdb_strerror(rc));
    goto leave;
  }
  rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
  rc = mdb_cursor_open(txn, dbi, &cursor);
  while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
    printf("key: %p %.*s, data: %p %.*s\n",
           key.mv_data,  (int) key.mv_size,  (char *) key.mv_data,
           data.mv_data, (int) data.mv_size, (char *) data.mv_data);
  }
  mdb_cursor_close(cursor);
  mdb_txn_abort(txn);
leave:
  mdb_dbi_close(env, dbi);
  mdb_env_close(env);
  return 0;
}