xapian-applications/omega/failed.h

   1 /** @file
   2  * @brief Track files we failed to index
   3  */
   4 /* Copyright (C) 2014,2015 Olly Betts
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  19  */
  20
  21 #ifndef OMEGA_INCLUDED_FAILED_H
  22 #define OMEGA_INCLUDED_FAILED_H
  23
  24 #include <cstdlib>
  25 #include <sys/types.h>
  26 #include <string>
  27
  28 #include "str.h"
  29
  30 /** Maintain a "database of failure" in the user metadata.
  31  *
  32  *  This tracks the last-modified timestamp and size for non-indexed files, so
  33  *  we can avoid trying to index them on every pass.
  34  */
  35 class Failed {
  36     Xapian::WritableDatabase db;
  37
  38   public:
  39     Failed() { }
  40
  41     void init(Xapian::WritableDatabase & db_) {
  42         db = db_;
  43     }
  44
  45     /** When we fail on a file, we add or replace its entry. */
  46     void add(const std::string & key, time_t last_mod, off_t size) {
  47         std::string value = str(last_mod);
  48         value += ',';
  49         value += str(size);
  50         db.set_metadata(key, value);
  51     }
  52
  53     bool contains(const std::string & key, time_t& last_mod, off_t& size) {
  54         const std::string value = db.get_metadata(key);
  55         if (value.empty()) return false;
  56         const char * p = value.c_str();
  57         char * end;
  58         long long v = strtoll(p, &end, 10);
  59         if (*end != ',') return false;
  60         // FIXME: check conversions.
  61         last_mod = v;
  62         p = end + 1;
  63         v = strtoll(p, &end, 10);
  64         size = v;
  65         return true;
  66     }
  67
  68     void del(const std::string & key) {
  69         db.set_metadata(key, std::string());
  70     }
  71
  72     void clear() {
  73         for (auto i = db.metadata_keys_begin("U");
  74              i != db.metadata_keys_end("U");
  75              ++i) {
  76             db.set_metadata(*i, std::string());
  77         }
  78     }
  79
  80     bool empty() const {
  81         return db.metadata_keys_begin("U") == db.metadata_keys_end("U");
  82     }
  83 };
  84
  85 #endif // OMEGA_INCLUDED_FAILED_H