source: trunk/gsdl/src/library/mgsearch.cpp@ 94

#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>

#ifdef __GNUG__
#  include <iostream.h>
#  include <gdbm.h>

#else
#  ifndef USE_OBJECTSPACE
#    include <iostream>
#  else
#    include <ospace\std\iostream>
#  endif

// gdbm stuff
#  include "autoconf.h"
#  include "systems.h"
#  include "gdbmconst.h"
#  include "gdbm.h"
#endif
  
#include <assert.h>

#include "mgq.h"
#include "mgsearch.h"
#include "locateinfo.h"
#include "gsdlunicode.h"
#include "unitool.h"


/////////////
// globals //
/////////////

static char *quotedquery = NULL;



////////////////////////
// callback functions //
////////////////////////

// This routine is called for each document found in a search
// it assumes that cache_num is set up correctly to point to
// a suitable result cache
int ourquerycallback(char *UDoc, int ULen, int DocNum, 
             float Weight, void *info) {

  
  queryresultsclass *queryresults = (queryresultsclass * )info;

  // check the returned document for the presence of the
  // quoted part of the query, if there was one
 
  if (UDoc != NULL && quotedquery != NULL &&
      quotedquery[0] != '\0' && strstr (UDoc, quotedquery) == NULL) return 0;
  
  // append this entry to the document results
  docresultclass docresult;
  docresult.docnum = DocNum;
  docresult.docweight = Weight;

  queryresults->docs.push_back(docresult);
  
  return 0;
}

// This callback is called once for each term in the query
int termfreqcallback(char *Word, int ULen,  int Freq, 
             float Weight,  void *info) {
  queryresultsclass *queryresults = (queryresultsclass *)info;

  text_t term;
  term.setcarr(Word, ULen);
  termfreqclass termfreq;
  termfreq.termstr = to_uni(term);
  termfreq.termfreq = Freq;
  queryresults->terms.push_back(termfreq);
  
  return 0;
}

// this callback is called once for each variation of each term
int termscallback(char *Word, int ULen, int Freq,
          float Weight, void *info) {

  text_t term;
  term.setcarr(Word, ULen);
  queryresultsclass *queryresults = (queryresultsclass *)info;
  queryresults->termvariants.push_back(to_uni(term));

  return 0;
}

// This callback is for getting document text
int doctextcallback(char *Word, int ULen,  int Freq, 
            float Weight,  void *info) {
  text_t *output = (text_t *)info;
  if (output == NULL) return 0;
  output->clear();

  utf8inconvertclass inconvert;
  convertclass::status_t status;
  inconvert.reset ();
  inconvert.setinput (Word, ULen);
  inconvert.convert (*output, status);
  
  // replace all control-Cs with spaces
  text_t::iterator here = output->begin();
  text_t::iterator end = output->end();
  while (here != end) {
    if (*here == '\x3') *here = ' ';
    here++;
  }
  
  return 0;
}



////////////////////
// mgsearch class //
////////////////////

mgsearchclass::mgsearchclass ()
{
  cache = new querycache (RESULTCACHESIZE);
}

mgsearchclass::~mgsearchclass () 
{
  if (cache != NULL) 
    {
      delete cache;
      cache = NULL;
    }
}


void mgsearchclass::setcollectdir (const text_t &thecollectdir)
{
  collectdir = thecollectdir;
}


bool mgsearchclass::search(const queryparamclass &queryparams, 
               queryresultsclass &queryresults)
{
  bool databaseloaded = true;

  assert (cache != NULL);

  queryresults.clear();

  // first check the cache
  if (cache->find(queryparams, queryresults))
    return true;

  // make sure there is a query to be processed
  text_t::const_iterator queryhere = queryparams.querystring.begin();
  text_t::const_iterator queryend = queryparams.querystring.end();
  while (queryhere != queryend) {
    if (is_unicode_letdig (*queryhere)) break;
    queryhere++;
  }

  // if we reached the end of the query string without finding
  // any alphanumeric characters then return no results (and say
  // the database was loaded)
  if (queryhere == queryend) return true;


  // get the names of the index and text suffixes
  char *idxsuffix = (getindexsuffix (queryparams.collection, 
                     queryparams.search_index)).getcstr();
  assert (idxsuffix != NULL);
  char *txtsuffix = (gettextsuffix (queryparams.collection)).getcstr();
  assert (txtsuffix != NULL);

#ifdef __WIN32__
  char *ccollectdir = (collectdir+"\\").getcstr(); assert (ccollectdir != NULL);
#else
  char *ccollectdir = collectdir.getcstr(); assert (ccollectdir != NULL);
#endif

  if (load_database(ccollectdir, idxsuffix, txtsuffix))
    {
      setsearchmode (queryparams);
      submitquery (queryparams);
      getresults (queryresults);
    }
  else databaseloaded = false;

  // free up the c strings
  delete idxsuffix;
  delete txtsuffix;
  delete ccollectdir;

  return databaseloaded;
}


void mgsearchclass::setsearchmode (const queryparamclass &queryparams)
{
  mgq_ask(".set expert true");
  mgq_ask(".set accumulator_method list");
  mgq_ask(".set max_accumulators 50000");
  mgq_ask(".set verbatim true");
  mgq_ask(".unset skip_dump");
  mgq_ask(".set mode docnums");

  switch (queryparams.search_type) 
    {
    case 0: mgq_ask(".set query boolean");  break;
    case 1:  mgq_ask(".set query ranked"); break;
    }
  switch (queryparams.casefolding) 
    {
    case 1: mgq_ask(".set casefold on");  break;
    case 0: mgq_ask(".set casefold off"); break;
    }
  switch (queryparams.stemming) 
    {
    case 1: mgq_ask(".set stem on");  break;
    case 0: mgq_ask(".set stem off"); break;
    }
  mgq_ask(".set heads_length 150");
  
  char maxdocstr[32];
  sprintf(maxdocstr, ".set maxdocs %i", queryparams.maxdocs);
  mgq_ask(maxdocstr);
}


void mgsearchclass::submitquery (const queryparamclass &queryparams)
{
  // sort out the query string
  text_t ttquerystring = queryparams.querystring;
  text_t ttquotedquery;
  extractquoted (ttquerystring, ttquotedquery);
  filterquery (ttquerystring);
  
  // turn the strings into c strings for mg
  if (quotedquery != NULL) // quotedquery is a global
    {
      delete quotedquery;
      quotedquery = NULL;
    }

  // quotedquery will be deleted on the next call to this function
  quotedquery = to_utf8(ttquotedquery).getcstr ();
  char *querystring = to_utf8(ttquerystring).getcstr();
  
  // submit the query
  mgq_ask(querystring);

  delete querystring;
}


void mgsearchclass::getresults (queryresultsclass &queryresults)
{
  if (quotedquery[0] == '\0') 
    { 
      // don't need the text
      mgq_results(result_docnums, 0, MAXNUMDOCS, 
          ourquerycallback, (void *)(&queryresults));
    }
  else
    {
      // we need the text for this one
      mgq_results(result_docs, 0, MAXNUMDOCS, 
          ourquerycallback, (void *)(&queryresults));
    }
  
  // get the term frequencies
  mgq_results(result_termfreqs, 0, MAXNUMTERMS, 
          termfreqcallback, (void *)(&queryresults));
  mgq_results(result_terms, 0, MAXNUMTERMS,
              termscallback, (void *)(&queryresults));
  queryresults.sortqueryterms();
  queryresults.uniqqueryterms();
}


void mgsearchclass::extractquoted (text_t &ttquerystring, text_t &ttquotedquery)
{
  ttquotedquery.clear();

  text_t::iterator ithere = ttquerystring.begin ();
  text_t::iterator itend = ttquerystring.end ();

  bool inquote = false;

  while (ithere != itend)
    {
      if ((*ithere) == '\"')
    {
      if (!inquote) ttquotedquery.clear ();
      inquote = !inquote;
      *ithere = ' '; // delete the quote
    }
      else if (inquote)
    {
      ttquotedquery.push_back(*ithere);
      *ithere = ' ';
    }
      
      ithere++;
    }
}


void mgsearchclass::filterquery (text_t &ttquerystring) {
  text_t::iterator ithere = ttquerystring.begin ();
  text_t::iterator itend = ttquerystring.end ();
  
  // remove all non alphanumeric characters
  while (ithere != itend) {
    if (!is_unicode_letdig(*ithere)) (*ithere) = ' ';
    ithere++;
  }
}


// the document text for 'docnum' is placed in 'output'
// docTargetDocument returns 'true' if it was able to
// try to get a document
// collection is needed to see if an index from the 
// collection is loaded. If no index has been loaded
// defaultindex is needed to load one
bool mgsearchclass::docTargetDocument(const text_t &defaultindex, 
                      const text_t &collection,
                      int docnum,
                      text_t &output)
{
  bool databaseloaded = true;

  output.clear();


  // make sure index is level 2

  ////// this changed with new naming scheme in new building software
  /////  i.e paragraph level index no longer contain number '3' but begin
  /////  with letter 'p'

  text_t db_loaded = db_loaded_name;

  if (!db_loaded.empty()) {
      text_t::const_iterator here = db_loaded.begin();
      text_t::const_iterator end = db_loaded.end();
  
      
      //while (here != end) {
      //  if (*here == '3')
      //    databaseloaded = false;
      //  here ++;
      //}

      char separator = '/';
      text_t db;
      int found = 0;
#ifdef __WIN32__
      separator = '\\';
#endif;
      // strip away path to db and following collection name
      end --;
      while (end != here) {
          if (*end == separator) {
              if (found) break;
              else {db.clear(); found = 1; end--; continue;}
          }
          db.push_back(*end);
          end --;
      }

      // string will have been reversed above so see if last 
      // character is 'p'
      if (db[db.size()-1] == 'p') databaseloaded = false;
  }

  // find out if the database is already loaded
  // this is needed because a different index (but valid one)
  // might be already loaded.
  // this comparison is needed because 'load_database'
  // is now more oriented towards indexes
  if (databaseloaded == true) {
      text_t::const_iterator here = collection.begin();
      text_t::const_iterator end = collection.end();
      char *dbhere = &db_loaded_name[strlen(db_loaded_name) - collection.size()]; // assumes collection shorter than db_loaded_name
      while (here != end)
      {
          if (*here != *dbhere)
          {
              databaseloaded = false;
              break;
          }
          here++;
          dbhere++;
      }
  }

  // try and load the database
  if (!databaseloaded)
    {
      // get the names of the index and text suffixes
      char *idxsuffix = (getindexsuffix (collection, 
                     defaultindex)).getcstr();
      assert (idxsuffix != NULL);
      char *txtsuffix = (gettextsuffix (collection)).getcstr();
      assert (txtsuffix != NULL);

#ifdef __WIN32__
      char *ccollectdir = (collectdir+"\\").getcstr(); assert (ccollectdir != NULL);
#else
      char *ccollectdir = collectdir.getcstr(); assert (ccollectdir != NULL);
#endif
      
      if (load_database(ccollectdir, idxsuffix, txtsuffix))
    databaseloaded = true;
      else 
    databaseloaded = false;
      
      // free up the c strings
      delete idxsuffix;
      delete txtsuffix;
      delete ccollectdir;
    }
  
  if (databaseloaded)
    {
      // retrieve the document from mg
      char docstr[32];
      sprintf(docstr, "%i", docnum);

      mgq_ask(".set mode text");
      mgq_ask(".set query docnums");
      mgq_ask(docstr);
      mgq_results (result_docs, 0, 1, doctextcallback, (void *)&output);
    }

  return databaseloaded;
}