db_berkeley.c

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/*
 * $Id: db_berkeley.c 4518 2008-07-28 15:39:28Z henningw $
 *
 * db_berkeley module, portions of this code were templated using
 * the dbtext and postgres modules.

 * Copyright (C) 2007 Cisco Systems
 *
 * This file is part of Kamailio, a free SIP server.
 *
 * Kamailio is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version
 *
 * Kamailio is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License 
 * along with this program; if not, write to the Free Software 
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 * 
 * History:
 * --------
 * 2007-09-19  genesis (wiquan)
 */

#include <stdio.h>
#include <unistd.h>
#include <sys/stat.h>


#include "../../str.h"
#include "../../ut.h"
#include "../../mem/mem.h"

#include "../../sr_module.h"
#include "../../db/db_res.h"
#include "../../db/db.h"
#include "db_berkeley.h"
#include "bdb_lib.h"
#include "bdb_res.h"
#include "bdb_mi.h"

#ifndef CFG_DIR
#define CFG_DIR "/tmp"
#endif

#define BDB_ID    "berkeley://"
#define BDB_ID_LEN   (sizeof(BDB_ID)-1)
#define BDB_PATH_LEN 256

#define BDB_KEY   1
#define BDB_VALUE 0

MODULE_VERSION

int auto_reload = 0;
int log_enable  = 0;
int journal_roll_interval = 0;

static int mod_init(void);
static void destroy(void);

int bdb_bind_api(db_func_t *dbb);

/*
 * Exported functions
 */
static cmd_export_t cmds[] = {
   {"db_bind_api",    (cmd_function)bdb_bind_api,   0, 0, 0, 0},
   {0, 0, 0, 0, 0, 0}
};


/*
 * Exported parameters
 */
static param_export_t params[] = {
   {"auto_reload",        INT_PARAM, &auto_reload },
   {"log_enable",         INT_PARAM, &log_enable  },
   {"journal_roll_interval", INT_PARAM, &journal_roll_interval  },
   {0, 0, 0}
};

/*
 * Exported MI functions
 */
static mi_export_t mi_cmds[] = {
   { MI_BDB_RELOAD, mi_bdb_reload, 0, 0, 0 },
   { 0, 0, 0, 0, 0}
};

struct module_exports exports = {   
   "db_berkeley",
   DEFAULT_DLFLAGS, /* dlopen flags */
   cmds,     /* Exported functions */
   params,   /* Exported parameters */
   0,        /* exported statistics */
   mi_cmds,  /* exported MI functions */
   0,        /* exported pseudo-variables */
   0,        /* extra processes */
   mod_init, /* module initialization function */
   0,        /* response function*/
   destroy,  /* destroy function */
   0         /* per-child init function */
};


static int mod_init(void)
{
   db_parms_t p;
   
   p.auto_reload = auto_reload;
   p.log_enable = log_enable;
   p.cache_size  = (4 * 1024 * 1024); //4Mb
   p.journal_roll_interval = journal_roll_interval;
   
   if(bdblib_init(&p))
      return -1;

   return 0;
}

static void destroy(void)
{
   bdblib_destroy();
}

int bdb_bind_api(db_func_t *dbb)
{
   if(dbb==NULL)
      return -1;

   memset(dbb, 0, sizeof(db_func_t));

   dbb->use_table   = bdb_use_table;
   dbb->init        = bdb_init;
   dbb->close       = bdb_close;
   dbb->query       = (db_query_f)bdb_query;
   dbb->free_result = bdb_free_query;
   dbb->insert      = (db_insert_f)bdb_insert;
   dbb->delete      = (db_delete_f)bdb_delete; 
   dbb->update      = (db_update_f)bdb_update;

   return 0;
}

int bdb_use_table(db_con_t* _h, const str* _t)
{
   return db_use_table(_h, _t);
}

/*
 * Initialize database connection
 */
db_con_t* bdb_init(const str* _sqlurl)
{
   db_con_t* _res;
   str _s;
   char bdb_path[BDB_PATH_LEN];
   
   if (!_sqlurl || !_sqlurl->s) {
      LM_ERR("invalid parameter value\n");
      return 0;
   }
   
   _s.s = _sqlurl->s;
   _s.len = _sqlurl->len;
   if(_s.len <= BDB_ID_LEN || strncmp(_s.s, BDB_ID, BDB_ID_LEN)!=0)
   {
      LM_ERR("invalid database URL - should be:"
         " <%s[/]path/to/directory>\n", BDB_ID);
      return NULL;
   }
   _s.s   += BDB_ID_LEN;
   _s.len -= BDB_ID_LEN;
   
   if(_s.s[0]!='/')
   {
      if(sizeof(CFG_DIR)+_s.len+2 > BDB_PATH_LEN)
      {
         LM_ERR("path to database is too long\n");
         return NULL;
      }
      strcpy(bdb_path, CFG_DIR);
      bdb_path[sizeof(CFG_DIR)] = '/';
      strncpy(&bdb_path[sizeof(CFG_DIR)+1], _s.s, _s.len);
      _s.len += sizeof(CFG_DIR);
      _s.s = bdb_path;
   }
   
   _res = pkg_malloc(sizeof(db_con_t)+sizeof(bdb_con_t));
   if (!_res)
   {
      LM_ERR("No private memory left\n");
      return NULL;
   }
   memset(_res, 0, sizeof(db_con_t) + sizeof(bdb_con_t));
   _res->tail = (unsigned long)((char*)_res+sizeof(db_con_t));

   LM_INFO("using database at: %.*s", _s.len, _s.s);
   BDB_CON_CONNECTION(_res) = bdblib_get_db(&_s);
   if (!BDB_CON_CONNECTION(_res))
   {
      LM_ERR("cannot get the link to database\n");
      return NULL;
   }

    return _res;
}


/*
 * Close a database connection
 */
void bdb_close(db_con_t* _h)
{
   if(BDB_CON_RESULT(_h))
      db_free_result(BDB_CON_RESULT(_h));
   pkg_free(_h);
}

/* 
 * n can be the dbenv path or a table name
*/
int bdb_reload(char* _n)
{
   int rc = 0;
#ifdef BDB_EXTRA_DEBUG
   LM_DBG("[bdb_reload] Initiate RELOAD in %s\n", _n);
#endif

   if ((rc = bdblib_close(_n)) != 0) 
   {  LM_ERR("[bdb_reload] Error while closing db_berkeley DB.\n");
      return rc;
   }

   if ((rc = bdblib_reopen(_n)) != 0) 
   {  LM_ERR("[bdb_reload] Error while reopening db_berkeley DB.\n");
      return rc;
   }

#ifdef BDB_EXTRA_DEBUG
   LM_DBG("[bdb_reload] RELOAD successful in %s\n", _n);
#endif

   return rc;
}

/*
 * Attempts to reload a Berkeley database; reloads when the inode changes
 */
void bdb_check_reload(db_con_t* _con)
{
   str s;
   char* p;
   int rc, len;
   struct stat st;
   database_p db;
   char n[MAX_ROW_SIZE];
   char t[MAX_TABLENAME_SIZE];
   table_p tp = NULL;
   tbl_cache_p tbc = NULL;
   
   p=n;
   rc = len = 0;
   
   /*get dbenv name*/
   db = BDB_CON_CONNECTION(_con);
   if(!db->dbenv) return;
   s.s = db->name.s;
   s.len = db->name.len;
   len+=s.len;
   
   if(len > MAX_ROW_SIZE)
   {  LM_ERR("dbenv name too long \n");
      return;
   }
   
   strncpy(p, s.s, s.len);
   p+=s.len;
   
   len++;
   if(len > MAX_ROW_SIZE)
   {  LM_ERR("dbenv name too long \n");
      return;
   }
   
   /*append slash */
   *p = '/';
   p++;
   
   /*get table name*/
   s.s = CON_TABLE(_con)->s;
   s.len = CON_TABLE(_con)->len;
   len+=s.len;
   
   if((len>MAX_ROW_SIZE) || (s.len > MAX_TABLENAME_SIZE) )
   {  LM_ERR("table name too long \n");
      return;
   }

   strncpy(t, s.s, s.len);
   t[s.len] = 0;
   
   strncpy(p, s.s, s.len);
   p+=s.len;
   *p=0;
   
   if( (tbc = bdblib_get_table(db, &s)) == NULL)
      return;
   
   if( (tp = tbc->dtp) == NULL)
      return;
   
   LM_DBG("stat file [%.*s]\n", len, n);
   rc = stat(n, &st);
   if(!rc)
   {  if((tp->ino!=0) && (st.st_ino != tp->ino))
         bdb_reload(t); /*file changed on disk*/
      
      tp->ino = st.st_ino;
   }

}


/*
 * Free all memory allocated by get_result
 */
int bdb_free_query(db_con_t* _h, db_res_t* _r)
{
   if(_r)
      db_free_result(_r);
   if(_h)
      BDB_CON_RESULT(_h) = NULL;
   return 0;
}


/*
 * Query table for specified rows
 * _con: structure representing database connection
 * _k: key names
 * _op: operators
 * _v: values of the keys that must match
 * _c: column names to return
 * _n: number of key=values pairs to compare
 * _nc: number of columns to return
 * _o: order by the specified column
 */
int bdb_query(db_con_t* _con, db_key_t* _k, db_op_t* _op, db_val_t* _v, 
         db_key_t* _c, int _n, int _nc, db_key_t _o, db_res_t** _r)
{
   tbl_cache_p _tbc = NULL;
   table_p _tp = NULL;
   char kbuf[MAX_ROW_SIZE];
   char dbuf[MAX_ROW_SIZE];
   u_int32_t i, len, ret; 
   int klen=MAX_ROW_SIZE;
   int *lkey=NULL, *lres=NULL;
   DBT key, data;
   DB *db;
   DBC *dbcp;

   if ((!_con) || (!_r) || !CON_TABLE(_con))
   {
#ifdef BDB_EXTRA_DEBUG
      LM_ERR("Invalid parameter value\n");
#endif
      return -1;
   }
   *_r = NULL;
   
   /*check if underlying DB file has changed inode */
   if(auto_reload)
      bdb_check_reload(_con);

   _tbc = bdblib_get_table(BDB_CON_CONNECTION(_con), (str*)CON_TABLE(_con));
   if(!_tbc)
   {  LM_WARN("table does not exist!\n");
      return -1;
   }

   _tp = _tbc->dtp;
   if(!_tp)
   {  LM_WARN("table not loaded!\n");
      return -1;
   }

#ifdef BDB_EXTRA_DEBUG
   LM_DBG("QUERY in %.*s\n", _tp->name.len, _tp->name.s);

   if (_o)  LM_DBG("DONT-CARE : _o: order by the specified column \n");
   if (_op) LM_DBG("DONT-CARE : _op: operators for refining query \n");
#endif
   
   db = _tp->db;
   if(!db) return -1;
   
   memset(&key, 0, sizeof(DBT));
   memset(kbuf, 0, MAX_ROW_SIZE);
   memset(&data, 0, sizeof(DBT));
   memset(dbuf, 0, MAX_ROW_SIZE);
   
   data.data = dbuf;
   data.ulen = MAX_ROW_SIZE;
   data.flags = DB_DBT_USERMEM;

   /* if _c is NULL and _nc is zero, you will get all table 
      columns in the result
   */
   if (_c)
   {  lres = bdb_get_colmap(_tbc->dtp, _c, _nc);
      if(!lres)
      {  ret = -1;
         goto error;
      }
   }
   
   if(_k)
   {  lkey = bdb_get_colmap(_tbc->dtp, _k, _n);
      if(!lkey) 
      {  ret = -1;
         goto error;
      }
   }
   else
   {
      DB_HASH_STAT st;
      memset(&st, 0, sizeof(DB_HASH_STAT));
      i =0 ;

#ifdef BDB_EXTRA_DEBUG
      LM_DBG("SELECT * FROM %.*s\n", _tp->name.len, _tp->name.s);
#endif

      /* Acquire a cursor for the database. */
      if ((ret = db->cursor(db, NULL, &dbcp, 0)) != 0) 
      {  LM_ERR("Error creating cursor\n");
         goto error;
      }
      
      /*count the number of records*/
      while ((ret = dbcp->c_get(dbcp, &key, &data, DB_NEXT)) == 0)
      {  if(!strncasecmp((char*)key.data,"METADATA",8)) 
            continue;
         i++;
      }
      
      dbcp->c_close(dbcp);
      ret=0;
      
#ifdef BDB_EXTRA_DEBUG
      LM_DBG("%i = SELECT COUNT(*) FROM %.*s\n", i, _tp->name.len, _tp->name.s);
#endif

      *_r = db_new_result();
      if (!*_r) 
      {  LM_ERR("no memory left for result \n");
         ret = -2;
         goto error;
      }
      
      if(i == 0)
      {  
         /*return empty table*/
         RES_ROW_N(*_r) = 0;
         BDB_CON_RESULT(_con) = *_r;
         return 0;
      }
      
      /*allocate N rows in the result*/
      RES_ROW_N(*_r) = i;
      len  = sizeof(db_row_t) * i;
      RES_ROWS(*_r) = (db_row_t*)pkg_malloc( len );
      memset(RES_ROWS(*_r), 0, len);
      
      /*fill in the column part of db_res_t (metadata) */
      if ((ret = bdb_get_columns(_tbc->dtp, *_r, lres, _nc)) < 0) 
      {  LM_ERR("Error while getting column names\n");
         goto error;
      }
      
      /* Acquire a cursor for the database. */
      if ((ret = db->cursor(db, NULL, &dbcp, 0)) != 0) 
      {  LM_ERR("Error creating cursor\n");
         goto error;
      }

      /*convert each record into a row in the result*/
      i =0 ;
      while ((ret = dbcp->c_get(dbcp, &key, &data, DB_NEXT)) == 0)
      {
         if(!strncasecmp((char*)key.data,"METADATA",8)) 
            continue;
         
#ifdef BDB_EXTRA_DEBUG
      LM_DBG("KEY: [%.*s]\nDATA: [%.*s]\n"
         , (int)   key.size
         , (char *)key.data
         , (int)   data.size
         , (char *)data.data);
#endif

         /*fill in the row part of db_res_t */
         if ((ret=bdb_append_row( *_r, dbuf, lres, i)) < 0) 
         {  LM_ERR("Error while converting row\n");
            goto error;
         }
         i++;
      }
      
      dbcp->c_close(dbcp);
      BDB_CON_RESULT(_con) = *_r;
      return 0; 
   }

   if ( (ret = bdblib_valtochar(_tp, lkey, kbuf, &klen, _v, _n, BDB_KEY)) != 0 ) 
   {  LM_ERR("error in query key \n");
      goto error;
   }

   key.data = kbuf;
   key.ulen = MAX_ROW_SIZE;
   key.flags = DB_DBT_USERMEM;
   key.size = klen;

   data.data = dbuf;
   data.ulen = MAX_ROW_SIZE;
   data.flags = DB_DBT_USERMEM;

   /*create an empty db_res_t which gets returned even if no result*/
   *_r = db_new_result();
   if (!*_r) 
   {  LM_ERR("no memory left for result \n");
      ret = -2;
      goto error;
   }
   RES_ROW_N(*_r) = 0;
   BDB_CON_RESULT(_con) = *_r;

#ifdef BDB_EXTRA_DEBUG
      LM_DBG("SELECT  KEY: [%.*s]\n"
         , (int)   key.size
         , (char *)key.data );
#endif

   /*query Berkely DB*/
   if ((ret = db->get(db, NULL, &key, &data, 0)) == 0) 
   {
#ifdef BDB_EXTRA_DEBUG
      LM_DBG("RESULT\nKEY:  [%.*s]\nDATA: [%.*s]\n"
         , (int)   key.size
         , (char *)key.data
         , (int)   data.size
         , (char *)data.data);
#endif

      /*fill in the col part of db_res_t */
      if ((ret = bdb_get_columns(_tbc->dtp, *_r, lres, _nc)) < 0) 
      {  LM_ERR("Error while getting column names\n");
         goto error;
      }
      /*fill in the row part of db_res_t */
      if ((ret=bdb_convert_row( *_r, dbuf, lres)) < 0) 
      {  LM_ERR("Error while converting row\n");
         goto error;
      }
      
   }
   else
   {  
      /*Berkeley DB error handler*/
      switch(ret)
      {
      
      case DB_NOTFOUND:
      
#ifdef BDB_EXTRA_DEBUG
         LM_DBG("NO RESULT for QUERY \n");
#endif
      
         ret=0;
         break;
      /*The following are all critical/fatal */
      case DB_LOCK_DEADLOCK:  
      // The operation was selected to resolve a deadlock. 
      case DB_SECONDARY_BAD:
      // A secondary index references a nonexistent primary key. 
      case DB_RUNRECOVERY:
      default:
         LM_CRIT("DB->get error: %s.\n", db_strerror(ret));
         bdblib_recover(_tp,ret);
         goto error;
      }
   }
   
   if(lkey)
      pkg_free(lkey);
   if(lres)
      pkg_free(lres);
   
   return ret;
   
error:
   if(lkey)
      pkg_free(lkey);
   if(lres)
      pkg_free(lres);
   if(*_r) 
      db_free_result(*_r);
   *_r = NULL;
   
   return ret;
}



/*
 * Raw SQL query
 */
int bdb_raw_query(db_con_t* _h, char* _s, db_res_t** _r)
{
   LM_CRIT("DB RAW QUERY not implemented!\n");
   return -1;
}

/*
 * Insert a row into table
 */
int bdb_insert(db_con_t* _h, db_key_t* _k, db_val_t* _v, int _n)
{
   tbl_cache_p _tbc = NULL;
   table_p _tp = NULL;
   char kbuf[MAX_ROW_SIZE];
   char dbuf[MAX_ROW_SIZE];
   int i, j, ret, klen, dlen;
   int *lkey=NULL;
   DBT key, data;
   DB *db;

   i = j = ret = 0;
   klen=MAX_ROW_SIZE;
   dlen=MAX_ROW_SIZE;

   if ((!_h) || (!_v) || !CON_TABLE(_h))
   {  return -1;
   }

   if (!_k)
   {
#ifdef BDB_EXTRA_DEBUG
   LM_ERR("DB INSERT without KEYs not implemented! \n");
#endif
      return -2;
   }

   _tbc = bdblib_get_table(BDB_CON_CONNECTION(_h), (str*)CON_TABLE(_h));
   if(!_tbc)
   {  LM_WARN("table does not exist!\n");
      return -3;
   }

   _tp = _tbc->dtp;
   if(!_tp)
   {  LM_WARN("table not loaded!\n");
      return -4;
   }

#ifdef BDB_EXTRA_DEBUG
   LM_DBG("INSERT in %.*s\n", _tp->name.len, _tp->name.s );
#endif
   
   db = _tp->db;
   memset(&key, 0, sizeof(DBT));
   memset(kbuf, 0, klen);
   
   if(_tp->ncols<_n) 
   {  LM_WARN("more values than columns!!\n");
      return -5;
   }

   lkey = bdb_get_colmap(_tp, _k, _n);
   if(!lkey)  return -7;

   /* verify col types provided */
   for(i=0; i<_n; i++)
   {  j = (lkey)?lkey[i]:i;
      if(bdb_is_neq_type(_tp->colp[j]->type, _v[i].type))
      {
         LM_WARN("incompatible types v[%d] - c[%d]!\n", i, j);
         ret = -8;
         goto error;
      }
   }
   
   /* make the key */
   if ( (ret = bdblib_valtochar(_tp, lkey, kbuf, &klen, _v, _n, BDB_KEY)) != 0 ) 
   {  LM_ERR("Error in bdblib_valtochar  \n");
      ret = -9;
      goto error;
   }
   
   key.data = kbuf;
   key.ulen = MAX_ROW_SIZE;
   key.flags = DB_DBT_USERMEM;
   key.size = klen;

   //make the value (row)
   memset(&data, 0, sizeof(DBT));
   memset(dbuf, 0, MAX_ROW_SIZE);

   if ( (ret = bdblib_valtochar(_tp, lkey, dbuf, &dlen, _v, _n, BDB_VALUE)) != 0 ) 
   {  LM_ERR("Error in bdblib_valtochar \n");
      ret = -9;
      goto error;
   }

   data.data = dbuf;
   data.ulen = MAX_ROW_SIZE;
   data.flags = DB_DBT_USERMEM;
   data.size = dlen;

   if ((ret = db->put(db, NULL, &key, &data, 0)) == 0) 
   {
      bdblib_log(JLOG_INSERT, _tp, dbuf, dlen);

#ifdef BDB_EXTRA_DEBUG
   LM_DBG("INSERT\nKEY:  [%.*s]\nDATA: [%.*s]\n"
      , (int)   key.size
      , (char *)key.data
      , (int)   data.size
      , (char *)data.data);
#endif
   }
   else
   {  /*Berkeley DB error handler*/
      switch(ret)
      {
      /*The following are all critical/fatal */
      case DB_LOCK_DEADLOCK:  
      /* The operation was selected to resolve a deadlock. */ 
      
      case DB_RUNRECOVERY:
      default:
         LM_CRIT("DB->put error: %s.\n", db_strerror(ret));
         bdblib_recover(_tp, ret);
         goto error;
      }
   }
   
error:
   if(lkey)
      pkg_free(lkey);
   
   return ret;

}

/*
 * Delete a row from table
 *
 * To delete ALL rows:
 *   do Not specify any keys, or values, and _n <=0
 *
 */
int bdb_delete(db_con_t* _h, db_key_t* _k, db_op_t* _op, db_val_t* _v, int _n)
{
   tbl_cache_p _tbc = NULL;
   table_p _tp = NULL;
   char kbuf[MAX_ROW_SIZE];
   int i, j, ret, klen;
   int *lkey=NULL;
   DBT key;
   DB *db;
   DBC *dbcp;

   i = j = ret = 0;
   klen=MAX_ROW_SIZE;

   if (_op)
      return ( _bdb_delete_cursor(_h, _k, _op, _v, _n) );

   if ((!_h) || !CON_TABLE(_h))
      return -1;

   _tbc = bdblib_get_table(BDB_CON_CONNECTION(_h), (str*)CON_TABLE(_h));
   if(!_tbc)
   {  LM_WARN("table does not exist!\n");
      return -3;
   }

   _tp = _tbc->dtp;
   if(!_tp)
   {  LM_WARN("table not loaded!\n");
      return -4;
   }

#ifdef BDB_EXTRA_DEBUG
      LM_DBG("DELETE in %.*s\n", _tp->name.len, _tp->name.s );
#endif

   db = _tp->db;
   memset(&key, 0, sizeof(DBT));
   memset(kbuf, 0, klen);

   if(!_k || !_v || _n<=0)
   {
      /* Acquire a cursor for the database. */
      if ((ret = db->cursor(db, NULL, &dbcp, DB_WRITECURSOR) ) != 0) 
      {  LM_ERR("Error creating cursor\n");
         goto error;
      }
      
      while ((ret = dbcp->c_get(dbcp, &key, NULL, DB_NEXT)) == 0)
      {
         if(!strncasecmp((char*)key.data,"METADATA",8)) 
            continue;
#ifdef BDB_EXTRA_DEBUG
         LM_DBG("KEY: [%.*s]\n"
            , (int)   key.size
            , (char *)key.data);
#endif
         ret = dbcp->c_del(dbcp, 0);
      }
      
      dbcp->c_close(dbcp);
      return 0;
   }

   lkey = bdb_get_colmap(_tp, _k, _n);
   if(!lkey)  return -5;

   /* make the key */
   if ( (ret = bdblib_valtochar(_tp, lkey, kbuf, &klen, _v, _n, BDB_KEY)) != 0 ) 
   {  LM_ERR("Error in bdblib_makekey\n");
      ret = -6;
      goto error;
   }

   key.data = kbuf;
   key.ulen = MAX_ROW_SIZE;
   key.flags = DB_DBT_USERMEM;
   key.size = klen;

   if ((ret = db->del(db, NULL, &key, 0)) == 0)
   {
      bdblib_log(JLOG_DELETE, _tp, kbuf, klen);

#ifdef BDB_EXTRA_DEBUG
      LM_DBG("DELETED ROW \n KEY: %s \n", (char *)key.data);
#endif
   }
   else
   {  /*Berkeley DB error handler*/
      switch(ret){
         
      case DB_NOTFOUND:
         ret = 0;
         break;
         
      /*The following are all critical/fatal */
      case DB_LOCK_DEADLOCK:  
      /* The operation was selected to resolve a deadlock. */ 
      case DB_SECONDARY_BAD:
      /* A secondary index references a nonexistent primary key. */
      case DB_RUNRECOVERY:
      default:
         LM_CRIT("DB->del error: %s.\n"
            , db_strerror(ret));
         bdblib_recover(_tp, ret);
         goto error;
      }
   }

   ret = 0;
   
error:
   if(lkey)
      pkg_free(lkey);
   
   return ret;

}

/*
_bdb_delete_cursor -- called from bdb_delete when the query involves operators 
  other than equal '='. Adds support for queries like this:
   DELETE from SomeTable WHERE _k[0] < _v[0]
  In this case, the keys _k are not the actually schema keys, so we need to 
  iterate via cursor to perform this operation.
*/
int _bdb_delete_cursor(db_con_t* _h, db_key_t* _k, db_op_t* _op, db_val_t* _v, int _n)
{
   tbl_cache_p _tbc = NULL;
   table_p _tp = NULL;
   db_res_t* _r   = NULL;
   char kbuf[MAX_ROW_SIZE];
   char dbuf[MAX_ROW_SIZE];
   int i, ret, klen=MAX_ROW_SIZE;
   DBT key, data;
   DB *db;
   DBC *dbcp;
   int *lkey=NULL;
   
   i = ret = 0;
   
   if ((!_h) || !CON_TABLE(_h))
      return -1;

   _tbc = bdblib_get_table(BDB_CON_CONNECTION(_h), (str*)CON_TABLE(_h));
   if(!_tbc)
   {  LM_WARN("table does not exist!\n");
      return -3;
   }

   _tp = _tbc->dtp;
   if(!_tp)
   {  LM_WARN("table not loaded!\n");
      return -4;
   }
   
#ifdef BDB_EXTRA_DEBUG
   LM_DBG("DELETE by cursor in %.*s\n", _tp->name.len, _tp->name.s );
#endif

   if(_k)
   {  lkey = bdb_get_colmap(_tp, _k, _n);
      if(!lkey) 
      {  ret = -1;
         goto error;
      }
   }
   
   /* create an empty db_res_t which gets returned even if no result */
   _r = db_new_result();
   if (!_r) 
   {  LM_ERR("no memory for result \n");
   }
   
   RES_ROW_N(_r) = 0;
   
   /* fill in the col part of db_res_t */
   if ((ret = bdb_get_columns(_tp, _r, 0, 0)) != 0) 
   {  LM_ERR("Error while getting column names\n");
      goto error;
   }
   
   db = _tp->db;
   memset(&key, 0, sizeof(DBT));
   memset(kbuf, 0, klen);
   memset(&data, 0, sizeof(DBT));
   memset(dbuf, 0, MAX_ROW_SIZE);
   
   data.data = dbuf;
   data.ulen = MAX_ROW_SIZE;
   data.flags = DB_DBT_USERMEM;
   
   /* Acquire a cursor for the database. */
   if ((ret = db->cursor(db, NULL, &dbcp, DB_WRITECURSOR)) != 0) 
   {  LM_ERR("Error creating cursor\n");
   }
   
   while ((ret = dbcp->c_get(dbcp, &key, &data, DB_NEXT)) == 0)
   {
      if(!strncasecmp((char*)key.data,"METADATA",8))
         continue;
      
      /*fill in the row part of db_res_t */
      if ((ret=bdb_convert_row( _r, dbuf, 0)) < 0) 
      {  LM_ERR("Error while converting row\n");
         goto error;
      }
      
      if(bdb_row_match(_k, _op, _v, _n, _r, lkey ))
      {

#ifdef BDB_EXTRA_DEBUG
         LM_DBG("DELETE ROW by KEY:  [%.*s]\n", (int) key.size, 
            (char *)key.data);
#endif

         if((ret = dbcp->c_del(dbcp, 0)) != 0)
         {  
            /* Berkeley DB error handler */
            LM_CRIT("DB->get error: %s.\n", db_strerror(ret));
            bdblib_recover(_tp,ret);
         }
         
      }
      
      memset(dbuf, 0, MAX_ROW_SIZE);
      db_free_rows( _r);
   }
   ret = 0;
   
error:
   if(dbcp)
      dbcp->c_close(dbcp);
   if(_r)
      db_free_result(_r);
   if(lkey)
      pkg_free(lkey);
   
   return ret;
}

/*
 * Updates a row in table
 * Limitation: only knows how to update a single row
 *
 * _con: structure representing database connection
 * _k: key names
 * _op: operators
 * _v: values of the keys that must match
 * _uk: update keys; cols that need to be updated 
 * _uv: update values; col values that need to be commited
 * _un: number of rows to update
 */
int bdb_update(db_con_t* _con, db_key_t* _k, db_op_t* _op, db_val_t* _v,
         db_key_t* _uk, db_val_t* _uv, int _n, int _un)
{
   char *c, *t;
   int ret, i, qcol, len, sum;
   int *lkey=NULL;
   tbl_cache_p _tbc = NULL;
   table_p _tp = NULL;
   char kbuf[MAX_ROW_SIZE];
   char qbuf[MAX_ROW_SIZE];
   char ubuf[MAX_ROW_SIZE];
   DBT key, qdata, udata;
   DB *db;
   
   sum = ret = i = qcol = len = 0;
   
   if (!_con || !CON_TABLE(_con) || !_uk || !_uv || _un <= 0)
      return -1;

   _tbc = bdblib_get_table(BDB_CON_CONNECTION(_con), (str*)CON_TABLE(_con));
   if(!_tbc)
   {  LM_ERR("table does not exist\n");
      return -1;
   }

   _tp = _tbc->dtp;
   if(!_tp)
   {  LM_ERR("table not loaded\n");
      return -1;
   }
   
   db = _tp->db;
   if(!db)
   {  LM_ERR("DB null ptr\n");
      return -1;
   }
   
#ifdef BDB_EXTRA_DEBUG
   LM_DBG("UPDATE in %.*s\n", _tp->name.len, _tp->name.s);
   if (_op) LM_DBG("DONT-CARE : _op: operators for refining query \n");
#endif
   
   memset(&key, 0, sizeof(DBT));
   memset(kbuf, 0, MAX_ROW_SIZE);
   memset(&qdata, 0, sizeof(DBT));
   memset(qbuf, 0, MAX_ROW_SIZE);
   
   qdata.data = qbuf;
   qdata.ulen = MAX_ROW_SIZE;
   qdata.flags = DB_DBT_USERMEM;
   
   if(_k)
   {  lkey = bdb_get_colmap(_tbc->dtp, _k, _n);
      if(!lkey) return -4;
   }
   else
   {
      LM_ERR("Null keys in update _k=0 \n");
      return -1;
   }
   
   len = MAX_ROW_SIZE;
   
   if ( (ret = bdblib_valtochar(_tp, lkey, kbuf, &len, _v, _n, BDB_KEY)) != 0 ) 
   {  LM_ERR("Error in query key \n");
      goto cleanup;
   }
   
   if(lkey) pkg_free(lkey);
   
   key.data = kbuf;
   key.ulen = MAX_ROW_SIZE;
   key.flags = DB_DBT_USERMEM;
   key.size = len;
   
   /*stage 1: QUERY Berkely DB*/
   if ((ret = db->get(db, NULL, &key, &qdata, 0)) == 0) 
   {

#ifdef BDB_EXTRA_DEBUG
      LM_DBG("RESULT\nKEY:  [%.*s]\nDATA: [%.*s]\n"
         , (int)   key.size
         , (char *)key.data
         , (int)   qdata.size
         , (char *)qdata.data);
#endif

   }
   else
   {  goto db_error;
   }
   
   /* stage 2: UPDATE row with new values */
   
   /* map the provided keys to those in our schema */ 
   lkey = bdb_get_colmap(_tbc->dtp, _uk, _un);
   if(!lkey) return -4;
   
   /* build a new row for update data (udata) */
   memset(&udata, 0, sizeof(DBT));
   memset(ubuf, 0, MAX_ROW_SIZE);
   
   /* loop over each column of the qbuf and copy it to our new ubuf unless
      its a field that needs to update
   */
   c = strtok(qbuf, DELIM);
   t = ubuf;
   while( c!=NULL)
   {  char* delim = DELIM;
      int k;
      
      len = strlen(c);
      sum+=len;
      
      if(sum > MAX_ROW_SIZE)
      {  LM_ERR("value too long for string \n");
         ret = -3;
         goto cleanup;
      }
      
      for(i=0;i<_un;i++)
      {
         k = lkey[i];
         if (qcol == k)
         {  /* update this col */
            int j = MAX_ROW_SIZE - sum;
            if( bdb_val2str( &_uv[i], t, &j) )
            {  LM_ERR("value too long for string \n");
               ret = -3;
               goto cleanup;
            }

            goto next;
         }
         
      }
      
      /* copy original column to the new column */
      strncpy(t, c, len);

next:
      t+=len;
      
      /* append DELIM */
      sum += DELIM_LEN;
      if(sum > MAX_ROW_SIZE)
      {  LM_ERR("value too long for string \n");
         ret = -3;
         goto cleanup;
      }
      
      strncpy(t, delim, DELIM_LEN);
      t += DELIM_LEN;
      
      c = strtok(NULL, DELIM);
      qcol++;
   }
   
   ubuf[sum]  = '0';
   udata.data = ubuf;
   udata.ulen  = MAX_ROW_SIZE;
   udata.flags = DB_DBT_USERMEM;
   udata.size  = sum;

#ifdef BDB_EXTRA_DEBUG
   LM_DBG("MODIFIED Data\nKEY:  [%.*s]\nDATA: [%.*s]\n"
      , (int)   key.size
      , (char *)key.data
      , (int)   udata.size
      , (char *)udata.data);
#endif
   /* stage 3: DELETE old row using key*/
   if ((ret = db->del(db, NULL, &key, 0)) == 0)
   {
#ifdef BDB_EXTRA_DEBUG
      LM_DBG("DELETED ROW\nKEY: %s \n", (char *)key.data);
#endif
   }
   else
   {  goto db_error;
   }
   
   /* stage 4: INSERT new row with key*/
   if ((ret = db->put(db, NULL, &key, &udata, 0)) == 0) 
   {
      bdblib_log(JLOG_UPDATE, _tp, ubuf, sum);
#ifdef BDB_EXTRA_DEBUG
   LM_DBG("INSERT \nKEY:  [%.*s]\nDATA: [%.*s]\n"
      , (int)   key.size
      , (char *)key.data
      , (int)   udata.size
      , (char *)udata.data);
#endif
   }
   else
   {  goto db_error;
   }

#ifdef BDB_EXTRA_DEBUG
   LM_DBG("UPDATE COMPLETE \n");
#endif


cleanup:
   if(lkey)
      pkg_free(lkey);
   
   return ret;


db_error:

   /*Berkeley DB error handler*/
   switch(ret)
   {
   
   case DB_NOTFOUND:
   
#ifdef BDB_EXTRA_DEBUG
      LM_DBG("NO RESULT \n");
#endif
      return -1;
   
   /* The following are all critical/fatal */
   case DB_LOCK_DEADLOCK:  
   /* The operation was selected to resolve a deadlock. */
   case DB_SECONDARY_BAD:
   /* A secondary index references a nonexistent primary key.*/ 
   case DB_RUNRECOVERY:
   default:
      LM_CRIT("DB->get error: %s.\n", db_strerror(ret));
      bdblib_recover(_tp,ret);
   }
   
   if(lkey)
      pkg_free(lkey);
   
   return ret;
}