Re: (ITS#7844) LMDB Delete Cursor inconsistencies - openldap-bugs

16 May 2014

      This is a multi-part message in MIME format.
--------------010403060500020806080002
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
armon.dadgar@gmail.com wrote:
...
--5372ac85_8edbdab_1271
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: quoted-printable
Content-Disposition: inline
=46or now, we have application code to retry the delete until no further =
rows are removed.
Still, it would be nice to have this resolved (and tested) in master=21
Unable to reproduce the issue. I've attached my test program based on your 
description.
-- 
   -- Howard Chu
   CTO, Symas Corp.           http://www.symas.com
   Director, Highland Sun     http://highlandsun.com/hyc/
   Chief Architect, OpenLDAP  http://www.openldap.org/project/

--------------010403060500020806080002
Content-Type: text/plain; charset=UTF-8;
 name="7844.c.txt"
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment;
 filename="7844.c.txt"

/* 7844.c - memory-mapped database tester/toy */
/*
 * Copyright 2014 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 <string.h>
#include <uuid/uuid.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()))

#define UUID_LEN	36

typedef char kval[UUID_LEN*2+2];

char sval[100];

int main(int argc,char * argv[])
{
    int i = 0, j = 0, rc;
    MDB_env *env;
    MDB_dbi kdbi, ddbi;
    MDB_val key, ikey, data;
    MDB_txn *txn;
    MDB_stat mst;
    MDB_cursor *cursor, *cur2;
    int count;
    unsigned long lastid = 0;
    kval *keys;
    char prefix[UUID_LEN+1], *ptr;
    uuid_t uuid;

    count = 128;
    keys = (kval *)malloc(count*sizeof(kval));

    E(mdb_env_create(&env));
    E(mdb_env_set_mapsize(env, 128*1024*1024));
    E(mdb_env_set_maxdbs(env, 4));
    E(mdb_env_open(env, "./testdb", MDB_NOSYNC, 0664));
    E(mdb_txn_begin(env, NULL, 0, &txn));
    E(mdb_open(txn, "kvs", MDB_CREATE|MDB_INTEGERKEY, &ddbi));
    E(mdb_open(txn, "kvs_id_idx", MDB_CREATE, &kdbi));

    key.mv_size = UUID_LEN*2+1;
    data.mv_size = sizeof(sval);
    data.mv_data = sval;
    ikey.mv_size = sizeof(lastid);
    ikey.mv_data = &lastid;

    uuid_generate(uuid);
    uuid_unparse(uuid, prefix);
    printf("Adding %d values\n", count);
    for (i=0;i<count;i++) {	
    	uuid_generate(uuid);
    	ptr = (char *)&keys[i];
    	memcpy(ptr, prefix, UUID_LEN);
    	ptr[UUID_LEN] = '/';
    	uuid_unparse(uuid, ptr+UUID_LEN+1);
    	ptr[UUID_LEN*2+1] = '\0';
    	printf("\t%s\n", ptr);
    	key.mv_data = ptr;
    	sprintf(sval, "Some stuff for key %s", ptr);
    	lastid++;
    	if (RES(MDB_KEYEXIST, mdb_put(txn, kdbi, &key, &ikey, MDB_NOOVERWRITE))) {
    		j++;
    		ikey.mv_size = sizeof(lastid);
    		ikey.mv_data = &lastid;
    	}
    	E(mdb_put(txn, ddbi, &ikey, &data, MDB_NOOVERWRITE));
    }
    if (j) printf("%d duplicates skipped\n", j);
    E(mdb_txn_commit(txn));
    E(mdb_env_stat(env, &mst));

    uuid_generate(uuid);
    uuid_unparse(uuid, prefix);
    printf("Adding %d values\n", count);
    E(mdb_txn_begin(env, NULL, 0, &txn));
    for (i=0;i<count;i++) {	
    	uuid_generate(uuid);
    	ptr = (char *)&keys[i];
    	memcpy(ptr, prefix, UUID_LEN);
    	ptr[UUID_LEN] = '/';
    	uuid_unparse(uuid, ptr+UUID_LEN+1);
    	ptr[UUID_LEN*2+1] = '\0';
    	printf("\t%s\n", ptr);
    	key.mv_data = ptr;
    	sprintf(sval, "Some stuff for key %s", ptr);
    	lastid++;
    	if (RES(MDB_KEYEXIST, mdb_put(txn, kdbi, &key, &ikey, MDB_NOOVERWRITE))) {
    		j++;
    		ikey.mv_size = sizeof(lastid);
    		ikey.mv_data = &lastid;
    	}
    	E(mdb_put(txn, ddbi, &ikey, &data, MDB_NOOVERWRITE));
    }
    if (j) printf("%d duplicates skipped\n", j);
    E(mdb_txn_commit(txn));

    E(mdb_txn_begin(env, NULL, 0, &txn));
    E(mdb_cursor_open(txn, kdbi, &cursor));
    E(mdb_cursor_open(txn, ddbi, &cur2));
    key.mv_size = UUID_LEN;
    key.mv_data = prefix;
    j = 0;
    i = count;
    rc = mdb_cursor_get(cursor, &key, &ikey, MDB_SET_RANGE);
    while (rc == 0) {
#if 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);
#endif
    	E(mdb_cursor_get(cur2, &ikey, &data, MDB_SET));
    	E(mdb_cursor_del(cur2, 0));
    	E(mdb_cursor_del(cursor, 0));
    	j++;
    	i--;
    	if (i == 0) break;
    	rc = mdb_cursor_get(cursor, &key, &ikey, MDB_NEXT);
    }
    mdb_cursor_close(cursor);
    mdb_cursor_close(cur2);
    E(mdb_txn_commit(txn));
    printf("Deleted %d values\n", j);

    mdb_env_close(env);

    return 0;
}

--------------010403060500020806080002--