xapian-core/examples/xapian-pos.cc

   1 /** @file
   2  * @brief Debug positional data
   3  */
   4 /* Copyright 2018 Olly Betts
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License as
   8  * published by the Free Software Foundation; either version 2 of the
   9  * License, or (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
  19  * USA
  20  */
  21
  22 #include <config.h>
  23
  24 #include <xapian.h>
  25 #include <xapian/iterator.h>
  26
  27 #include <iostream>
  28
  29 #include <algorithm>
  30 #include <cerrno>
  31 #include <cstdlib>
  32 #include <limits>
  33
  34 #include "gnu_getopt.h"
  35 #include "stringutils.h"
  36
  37 using namespace std;
  38
  39 #define PROG_NAME "xapian-pos"
  40 #define PROG_DESC "Debug positional data in a Xapian database"
  41
  42 #define OPT_HELP 1
  43 #define OPT_VERSION 2
  44
  45 static void
  46 show_usage()
  47 {
  48     cout << "Usage: " PROG_NAME " [OPTIONS] DATABASE\n\n"
  49 "Options:\n"
  50 "  -d, --doc=DOCID  Show positions for document DOCID\n"
  51 "  -s, --start=POS  Specifies the first position to show\n"
  52 "  -e, --end=POS    Specifies the last position to show\n"
  53 "  --help           display this help and exit\n"
  54 "  --version        output version information and exit" << endl;
  55 }
  56
  57 class Pos {
  58     Xapian::termpos pos;
  59
  60     Xapian::PositionIterator p;
  61
  62     string term;
  63
  64   public:
  65     Pos(const string& term_, const Xapian::PositionIterator& p_)
  66         : p(p_), term(term_) { pos = *p; }
  67
  68     Xapian::termpos get_pos() const { return pos; }
  69
  70     const string& get_term() const { return term; }
  71
  72     bool next() {
  73         if (!Xapian::iterator_valid(++p)) {
  74             return false;
  75         }
  76         pos = *p;
  77         return true;
  78     }
  79 };
  80
  81 struct PosCmp {
  82     bool operator()(const Pos* a, const Pos* b) {
  83         if (a->get_pos() != b->get_pos()) {
  84             return a->get_pos() > b->get_pos();
  85         }
  86         return a->get_term() > b->get_term();
  87     }
  88 };
  89
  90 template<typename T>
  91 bool to_unsigned_int(const char* s, T& result)
  92 {
  93     errno = 0;
  94     char* e;
  95     auto v = strtoull(s, &e, 0);
  96     if (errno == 0) {
  97         if (*e || e == s) {
  98             // Junk after or empty input.
  99             errno = EINVAL;
 100         } else if (v > numeric_limits<T>::max()) {
 101             // Exceeds the type.
 102             errno = ERANGE;
 103         } else {
 104             result = T(v);
 105             return true;
 106         }
 107     }
 108     return false;
 109 }
 110
 111 int
 112 main(int argc, char **argv)
 113 try {
 114     static const struct option long_opts[] = {
 115         {"doc",         required_argument, 0, 'd'},
 116         {"start",       required_argument, 0, 's'},
 117         {"end",         required_argument, 0, 'e'},
 118         {"help",        no_argument, 0, OPT_HELP},
 119         {"version",     no_argument, 0, OPT_VERSION},
 120         {NULL,          0, 0, 0}
 121     };
 122
 123     Xapian::docid did = 0;
 124     Xapian::termpos startpos = 0;
 125     Xapian::termpos endpos = numeric_limits<Xapian::termpos>::max();
 126     int c;
 127     while ((c = gnu_getopt_long(argc, argv, "d:e:s:", long_opts, 0)) != -1) {
 128         switch (c) {
 129             case 'd':
 130                 if (!to_unsigned_int(optarg, did) || did == 0) {
 131                     if (errno == 0) errno = ERANGE;
 132                     cerr << "Bad docid value '" << optarg << "': "
 133                          << strerror(errno) << endl;
 134                     exit(1);
 135                 }
 136                 break;
 137             case 's':
 138                 if (!to_unsigned_int(optarg, startpos)) {
 139                     cerr << "Bad start position '" << optarg << "': "
 140                          << strerror(errno) << endl;
 141                     exit(1);
 142                 }
 143                 break;
 144             case 'e':
 145                 if (!to_unsigned_int(optarg, endpos)) {
 146                     cerr << "Bad end position '" << optarg << "': "
 147                          << strerror(errno) << endl;
 148                     exit(1);
 149                 }
 150                 break;
 151             case OPT_HELP:
 152                 cout << PROG_NAME " - " PROG_DESC "\n\n";
 153                 show_usage();
 154                 exit(0);
 155             case OPT_VERSION:
 156                 cout << PROG_NAME " - " PACKAGE_STRING << endl;
 157                 exit(0);
 158             default:
 159                 show_usage();
 160                 exit(1);
 161         }
 162     }
 163
 164     // We expect one argument - a database path.
 165     if (argc - optind != 1) {
 166         show_usage();
 167         exit(1);
 168     }
 169
 170     if (did == 0) {
 171         cerr << "--doc=DOCID option required." << endl;
 172         exit(1);
 173     }
 174
 175     vector<Pos*> heap;
 176
 177     Xapian::Database db(argv[optind]);
 178
 179     for (auto term_it = db.termlist_begin(did);
 180          term_it != db.termlist_end(did); ++term_it) {
 181         const string& term = *term_it;
 182         auto pos_it = db.positionlist_begin(did, term);
 183         if (startpos) pos_it.skip_to(startpos);
 184         if (pos_it != db.positionlist_end(did, term)) {
 185             heap.push_back(new Pos(term, pos_it));
 186         }
 187     }
 188
 189     make_heap(heap.begin(), heap.end(), PosCmp());
 190
 191     Xapian::termpos old_pos = startpos - 1;
 192     while (!heap.empty()) {
 193         auto tip = heap.front();
 194         Xapian::termpos pos = tip->get_pos();
 195         if (pos > endpos) break;
 196
 197         switch (pos - old_pos) {
 198             case 0:
 199                 // Another term at the same position.
 200                 cout << ' ';
 201                 break;
 202             case 1:
 203                 cout << '\n' << pos << '\t';
 204                 break;
 205             default:
 206                 cout << "\nGap of " << (pos - old_pos - 1)
 207                      << " unused positions\n" << pos << '\t';
 208                 break;
 209         }
 210         cout << tip->get_term();
 211
 212         old_pos = pos;
 213
 214         if (tip->next()) {
 215             pop_heap(heap.begin(), heap.end(), PosCmp());
 216             push_heap(heap.begin(), heap.end(), PosCmp());
 217         } else {
 218             pop_heap(heap.begin(), heap.end(), PosCmp());
 219             heap.resize(heap.size() - 1);
 220         }
 221     }
 222
 223     cout << endl;
 224 } catch (const Xapian::Error & e) {
 225     cerr << '\n' << argv[0] << ": " << e.get_description() << endl;
 226     exit(1);
 227 }