source: trunk/gsdl/src/colservr/mggdbmsource.cpp@ 249

/**********************************************************************
 *
 * mggdbmsource.cpp -- 
 * Copyright (C) 1999  The New Zealand Digital Library Project
 *
 * PUT COPYRIGHT NOTICE HERE
 *
 * $Id: mggdbmsource.cpp 249 1999-04-30 02:00:48Z sjboddie $
 *
 *********************************************************************/

/*
   $Log$
   Revision 1.7  1999/04/30 02:00:47  sjboddie
   lots of stuff to do with getting documentaction working

   Revision 1.6  1999/04/21 22:40:44  sjboddie
   made another change to the one I just committed. if requested metadata doesn't
   exist it now puts an empty string in the response array so we don't always
   have to test that a value exists before using it.

   Revision 1.5  1999/04/21 05:23:46  sjboddie

   changed the way metadata is returned

   Revision 1.4  1999/04/19 23:56:07  rjmcnab
   Finished the gdbm metadata stuff

   Revision 1.3  1999/04/12 10:30:33  rjmcnab
   Made a little more progress.

   Revision 1.2  1999/04/12 05:21:51  rjmcnab
   Started on a mg and gdbm source.

   Revision 1.1  1999/04/12 03:40:40  rjmcnab
   Initial revision.

 */


#include "mggdbmsource.h"
#include "fileutil.h"
#include "OIDtools.h"


mggdbmsourceclass::mggdbmsourceclass () {
  gdbmptr = NULL;
  mgsearchptr = NULL;
}

mggdbmsourceclass::~mggdbmsourceclass () {
}

void mggdbmsourceclass::configure (const text_t &key, const text_tarray &cfgline) {
  if (cfgline.size() >= 1) {
    const text_t &value = cfgline[0];

    if (key == "collection") collection = value;
    else if (key == "collectdir") collectdir = value;
    else if (key == "gsdlhome") gsdlhome = value;
  }
}

bool mggdbmsourceclass::init (ostream &logout) {
  outconvertclass text_t2ascii;
  
  if (!sourceclass::init (logout)) return false;
  
  // get the collection directory name
  if (collectdir.empty()) {
    collectdir = filename_cat (gsdlhome, "collect", collection);
  }
  
  // get the filename for the database and make sure it exists
  gdbm_filename = filename_cat(collectdir,"index","text",collection);
#ifdef _LITTLE_ENDIAN
  gdbm_filename += ".ldb";
#else
  gdbm_filename += ".bdb";
#endif
  if (!file_exists(gdbm_filename)) {
    logout << text_t2ascii
       << "error: gdbm database \""
       << gdbm_filename << "\" does not exist\n\n";
    return false;
  }
  
  return true;
}

bool mggdbmsourceclass::translate_OID (const text_t &OIDin, text_t &OIDout, 
                       comerror_t &err, ostream &logout) {

  outconvertclass text_t2ascii;

  err = noError;
  if (gdbmptr == NULL) {
    // most likely a configuration problem
    logout << text_t2ascii 
       << "configuration error: mggdbmsource contains a null gdbmclass\n\n";
    err = configurationError;
    return true;
  }

  // open the database
  gdbmptr->setlogout(&logout);
  if (!gdbmptr->opendatabase (gdbm_filename)) {
    // most likely a system problem (we have already checked that the
    // gdbm database exists)
    logout << text_t2ascii
       << "system problem: open on gdbm database \""
       << gdbm_filename << "\" failed\n\n";
    err = systemProblem;
    return true;
  }

  infodbclass info;
  OIDout = gdbmptr->translate_OID (OIDin, info);
  return true;
}

bool mggdbmsourceclass::get_metadata (const text_t &/*requestParams*/, const text_t &/*refParams*/, 
                      const text_tarray &fields, const text_t &OID,
                      MetadataInfo_tarray &metadata, 
                      comerror_t &err, ostream &logout) {
  outconvertclass text_t2ascii;

  metadata.erase(metadata.begin(), metadata.end());

  err = noError;
  if (gdbmptr == NULL) {
    // most likely a configuration problem
    logout << text_t2ascii 
       << "configuration error: mggdbmsource contains a null gdbmclass\n\n";
    err = configurationError;
    return true;
  }

  // open the database
  gdbmptr->setlogout(&logout);
  if (!gdbmptr->opendatabase (gdbm_filename)) {
    // most likely a system problem (we have already checked that the
    // gdbm database exists)
    logout << text_t2ascii
       << "system problem: open on gdbm database \""
       << gdbm_filename << "\" failed\n\n";
    err = systemProblem;
    return true;
  }

  // get the metadata
  infodbclass info;
  if (!gdbmptr->getinfo(OID, info)) return false;

  // adjust the metadata
  text_t &contains = info["contains"];
  if (contains.empty()) info["haschildren"] = 0;
  else info["haschildren"] = 1;
  contains.clear();

  // collect together the metadata
  bool donenextprevtest = false;
  bool hasnext, hasprevious;
  MetadataInfo_t this_metadata;
  text_t *pos_metadata;
  text_tarray::const_iterator fields_here = fields.begin();
  text_tarray::const_iterator fields_end = fields.end();
  while (fields_here != fields_end) {
    this_metadata.clear();
    this_metadata.isRef = false;
    pos_metadata = info.getinfo(*fields_here);
    
    if ((*fields_here == "hasnext" || *fields_here == "hasprevious")) {

      // collect metadata
      if (!donenextprevtest) {
    donenextprevtest = true;

    // cache parent contents array
    text_t thisparent = get_parent (OID);
    if (thisparent != parentOID) {
      parentOID = thisparent;
      parentcontents.erase(parentcontents.begin(), parentcontents.end());
      if (gdbmptr->getinfo(parentOID, parentinfo)) {
        text_t &parentinfocontains = parentinfo["contains"];
      if (!parentinfocontains.empty())
        splitchar (parentinfocontains.begin(), parentinfocontains.end(), ';', parentcontents);
      }
    }

    // do tests
    text_tarray::const_iterator parentcontents_here = parentcontents.begin();
    text_tarray::const_iterator parentcontents_end = parentcontents.end();
    text_t shrunk_OID = OID;
    shrink_parent (shrunk_OID);
    while (parentcontents_here != parentcontents_end) {
      if (*parentcontents_here == shrunk_OID) {
        if (parentcontents_here == parentcontents.begin()) hasprevious = false;
        else hasprevious = true;

        parentcontents_here++;

        if (parentcontents_here == parentcontents.end()) hasnext = false;
        else hasnext = true;

        break;
      }  
        
      parentcontents_here ++;
    }
      }  
    
      // fill in metadata
      if ((*fields_here == "hasnext" && hasnext) ||
      (*fields_here == "hasprevious" && hasprevious))
    this_metadata.values.push_back("1");
      else
    this_metadata.values.push_back("0");

    }
    else if (pos_metadata != NULL && *fields_here != "contains")
      this_metadata.values.push_back(*pos_metadata);
    else 
      this_metadata.values.push_back("");
    metadata.push_back(this_metadata);
    
    fields_here++;
  }

  return true;
}