pdns/cdb.hh

   1 /*
   2  * This file is part of PowerDNS or dnsdist.
   3  * Copyright -- PowerDNS.COM B.V. and its contributors
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of version 2 of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * In addition, for the avoidance of any doubt, permission is granted to
  10  * link this program with OpenSSL and to (re)distribute the binaries
  11  * produced as the result of such linking.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21  */
  22 #pragma once
  23 #include <cdb.h>
  24
  25 #include "misc.hh"
  26
  27 // This class is responsible for the reading of a CDB file.
  28 // The constructor opens the CDB file, the destructor closes it, so make sure you call that.
  29 class CDB
  30 {
  31 public:
  32   CDB(const string &cdbfile);
  33   ~CDB();
  34
  35   /* Return negative value on error or non-negative value on success.
  36      Values can be retrieved via readNext() */
  37   int searchKey(const string &key);
  38   bool searchSuffix(const string &key);
  39   void searchAll();
  40   bool readNext(pair<string, string> &value);
  41   vector<string> findall(string &key);
  42   bool keyExists(const string& key);
  43   bool findOne(const string& key, string& value);
  44
  45 private:
  46   bool moveToNext();
  47
  48   int d_fd{-1};
  49   struct cdb d_cdb;
  50   struct cdb_find d_cdbf;
  51   std::string d_key;
  52   unsigned d_seqPtr{0};
  53   enum SearchType { SearchSuffix, SearchKey, SearchAll } d_searchType{SearchKey};
  54 };
  55
  56 class CDBWriter
  57 {
  58 public:
  59   /* we own the fd after this call, don't ever touch it */
  60   CDBWriter(int fd);
  61   ~CDBWriter();
  62
  63   bool addEntry(const std::string& key, const std::string& value);
  64   /* finalize the database and close the fd, the only thing you can do now is to call the destructor */
  65   void close();
  66
  67 private:
  68   struct cdb_make d_cdbm;
  69   int d_fd{-1};
  70 };