text: /* mtest.c - memory-mapped database tester/toy */
  /*
   * Copyright 2011-2015 Howard Chu, Symas Corp.
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted only as authorized by the OpenLDAP
   * Public License.
   *
   * A copy of this license is available in the file LICENSE in the
   * top-level directory of the distribution or, alternatively, at
   * <http://www.OpenLDAP.org/license.html>.
   */
  #include <stdio.h>
  #include <stdlib.h>
  #include <time.h>
  #include "lmdb.h"
  
  #define E(expr) CHECK((rc = (expr)) == MDB_SUCCESS, #expr)
  #define RES(err, expr) ((rc = expr) == (err) || (CHECK(!rc, #expr), 0))
  #define CHECK(test, msg) ((test) ? (void)0 : ((void)fprintf(stderr, \
  	"%s:%d: %s: %s\n", __FILE__, __LINE__, msg, mdb_strerror(rc)), abort()))
  
  int main(int argc,char * argv[])
  {
  	int i = 0, j = 0, rc;
  	MDB_env *env;
  	MDB_dbi dbi;
  	MDB_val key, data;
  	MDB_txn *txn;
  	MDB_stat mst;
  	MDB_cursor *cursor, *cur2;
  	MDB_cursor_op op;
  	int count;
  	int *values;
  	char sval[32] = "";
  
  	srand(time(NULL));
  
  	    count = (rand()%384) + 64;
  	    values = (int *)malloc(count*sizeof(int));
  
  	    for(i = 0;i<count;i++) {
  			values[i] = rand()%1024;
  	    }
      
  		E(mdb_env_create(&env));
  		E(mdb_env_set_mapsize(env, 10485760));
  		E(mdb_env_open(env, "./testdb", MDB_FIXEDMAP /*|MDB_NOSYNC*/, 0664));
  		E(mdb_txn_begin(env, NULL, 0, &txn));
  		E(mdb_open(txn, NULL, 0, &dbi));
     
  		key.mv_size = sizeof(int);
  		key.mv_data = sval;
  		data.mv_size = sizeof(sval);
  		data.mv_data = sval;
  
  		printf("Adding %d values\n", count);
  	    for (i=0;i<count;i++) {	
  			sprintf(sval, "%03x %d foo bar", values[i], values[i]);
  			if (RES(MDB_KEYEXIST, mdb_put(txn, dbi, &key, &data, MDB_NOOVERWRITE))) {
  				j++;
  				data.mv_size = sizeof(sval);
  				data.mv_data = sval;
  			}
  	    }
  		if (j) printf("%d duplicates skipped\n", j);
  		E(mdb_txn_commit(txn));
  		E(mdb_env_stat(env, &mst));
  
  		E(mdb_txn_begin(env, NULL, 1, &txn));
  		E(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);
  		}
  		CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
  		mdb_cursor_close(cursor);
  		mdb_txn_abort(txn);
  
  		j=0;
  		key.mv_data = sval;
  	    for (i= count - 1; i > -1; i-= (rand()%5)) {
  			j++;
  			txn=NULL;
  			E(mdb_txn_begin(env, NULL, 0, &txn));
  			sprintf(sval, "%03x ", values[i]);
  			if (RES(MDB_NOTFOUND, mdb_del(txn, dbi, &key, NULL))) {
  				j--;
  				mdb_txn_abort(txn);
  			} else {
  				E(mdb_txn_commit(txn));
  			}
  	    }
  	    free(values);
  		printf("Deleted %d values\n", j);
  
  		E(mdb_env_stat(env, &mst));
  		E(mdb_txn_begin(env, NULL, 1, &txn));
  		E(mdb_cursor_open(txn, dbi, &cursor));
  		printf("Cursor next\n");
  		while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
  			printf("key: %.*s, data: %.*s\n",
  				(int) key.mv_size,  (char *) key.mv_data,
  				(int) data.mv_size, (char *) data.mv_data);
  		}
  		CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
  		printf("Cursor last\n");
  		E(mdb_cursor_get(cursor, &key, &data, MDB_LAST));
  		printf("key: %.*s, data: %.*s\n",
  			(int) key.mv_size,  (char *) key.mv_data,
  			(int) data.mv_size, (char *) data.mv_data);
  		printf("Cursor prev\n");
  		while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_PREV)) == 0) {
  			printf("key: %.*s, data: %.*s\n",
  				(int) key.mv_size,  (char *) key.mv_data,
  				(int) data.mv_size, (char *) data.mv_data);
  		}
  		CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
  		printf("Cursor last/prev\n");
  		E(mdb_cursor_get(cursor, &key, &data, MDB_LAST));
  			printf("key: %.*s, data: %.*s\n",
  				(int) key.mv_size,  (char *) key.mv_data,
  				(int) data.mv_size, (char *) data.mv_data);
  		E(mdb_cursor_get(cursor, &key, &data, MDB_PREV));
  			printf("key: %.*s, data: %.*s\n",
  				(int) key.mv_size,  (char *) key.mv_data,
  				(int) data.mv_size, (char *) data.mv_data);
  
  		mdb_txn_abort(txn);
  
  		printf("Deleting with cursor\n");
  		E(mdb_txn_begin(env, NULL, 0, &txn));
  		E(mdb_cursor_open(txn, dbi, &cur2));
  		for (i=0; i<50; i++) {
  			if (RES(MDB_NOTFOUND, mdb_cursor_get(cur2, &key, &data, MDB_NEXT)))
  				break;
  			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);
  			E(mdb_del(txn, dbi, &key, NULL));
  		}
  
  		printf("Restarting cursor in txn\n");
  		for (op=MDB_FIRST, i=0; i<=32; op=MDB_NEXT, i++) {
  			if (RES(MDB_NOTFOUND, mdb_cursor_get(cur2, &key, &data, op)))
  				break;
  			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(cur2);
  		E(mdb_txn_commit(txn));
  
  		printf("Restarting cursor outside txn\n");
  		E(mdb_txn_begin(env, NULL, 0, &txn));
  		E(mdb_cursor_open(txn, dbi, &cursor));
  		for (op=MDB_FIRST, i=0; i<=32; op=MDB_NEXT, i++) {
  			if (RES(MDB_NOTFOUND, mdb_cursor_get(cursor, &key, &data, op)))
  				break;
  			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_close(env, dbi);
  
  		mdb_txn_abort(txn);
  		mdb_env_close(env);
  
  	return 0;
  }
  