src/filter_virt_db.cpp

   1 /* This file is part of Metaproxy.
   2    Copyright (C) 2005-2011 Index Data
   3
   4 Metaproxy is free software; you can redistribute it and/or modify it under
   5 the terms of the GNU General Public License as published by the Free
   6 Software Foundation; either version 2, or (at your option) any later
   7 version.
   8
   9 Metaproxy is distributed in the hope that it will be useful, but WITHOUT ANY
  10 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12 for more details.
  13
  14 You should have received a copy of the GNU General Public License
  15 along with this program; if not, write to the Free Software
  16 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17 */
  18
  19 #include "config.hpp"
  20
  21 #include "filter_virt_db.hpp"
  22 #include <metaproxy/package.hpp>
  23
  24 #include <boost/thread/mutex.hpp>
  25 #include <boost/thread/condition.hpp>
  26 #include <boost/shared_ptr.hpp>
  27
  28 #include <metaproxy/util.hpp>
  29
  30 #include <yaz/zgdu.h>
  31 #include <yaz/otherinfo.h>
  32 #include <yaz/diagbib1.h>
  33 #include <yaz/match_glob.h>
  34 #include <yaz/log.h>
  35
  36 #include <map>
  37 #include <iostream>
  38
  39 namespace mp = metaproxy_1;
  40 namespace yf = mp::filter;
  41
  42 namespace metaproxy_1 {
  43     namespace filter {
  44
  45         struct VirtualDB::Set {
  46             Set(BackendPtr b, std::string setname);
  47             Set();
  48             ~Set();
  49
  50             BackendPtr m_backend;
  51             std::string m_setname;
  52         };
  53         struct VirtualDB::Map {
  54             Map(std::string database, std::list<std::string> targets, std::string route);
  55             Map();
  56             bool match(const std::string db) const;
  57             std::string m_dbpattern;
  58             std::list<std::string> m_targets;
  59             std::string m_route;
  60         };
  61         struct VirtualDB::Backend {
  62             mp::Session m_backend_session;
  63             std::list<std::string> m_frontend_databases;
  64             std::list<std::string> m_targets;
  65             std::string m_route;
  66             bool m_named_result_sets;
  67             int m_number_of_sets;
  68         };
  69         struct VirtualDB::Frontend {
  70             Frontend(Rep *rep);
  71             ~Frontend();
  72             mp::Session m_session;
  73             bool m_is_virtual;
  74             bool m_in_use;
  75             yazpp_1::GDU m_init_gdu;
  76             std::list<BackendPtr> m_backend_list;
  77             std::map<std::string,VirtualDB::Set> m_sets;
  78
  79             void search(Package &package, Z_APDU *apdu);
  80             void present(Package &package, Z_APDU *apdu);
  81             void scan(Package &package, Z_APDU *apdu);
  82
  83             void close(Package &package);
  84             typedef std::map<std::string,VirtualDB::Set>::iterator Sets_it;
  85
  86             void fixup_package(Package &p, BackendPtr b);
  87             void fixup_npr_record(ODR odr, Z_NamePlusRecord *npr,
  88                                   BackendPtr b);
  89             void fixup_npr_records(ODR odr, Z_Records *records,
  90                                    BackendPtr b);
  91
  92             BackendPtr lookup_backend_from_databases(
  93                 std::list<std::string> databases);
  94             BackendPtr create_backend_from_databases(
  95                 std::list<std::string> databases,
  96                 int &error_code,
  97                 std::string &failing_database);
  98
  99             BackendPtr init_backend(std::list<std::string> database,
 100                                     Package &package,
 101                                     int &error_code, std::string &addinfo);
 102             Rep *m_p;
 103         };
 104         class VirtualDB::Rep {
 105             friend class VirtualDB;
 106             friend struct Frontend;
 107
 108             FrontendPtr get_frontend(Package &package);
 109             void release_frontend(Package &package);
 110         private:
 111             std::list<VirtualDB::Map>m_maps;
 112             typedef std::map<std::string,VirtualDB::Set>::iterator Sets_it;
 113             boost::mutex m_mutex;
 114             boost::condition m_cond_session_ready;
 115             std::map<mp::Session, FrontendPtr> m_clients;
 116             bool pass_vhosts;
 117         };
 118     }
 119 }
 120
 121 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::lookup_backend_from_databases(
 122     std::list<std::string> databases)
 123 {
 124     std::list<BackendPtr>::const_iterator map_it;
 125     map_it = m_backend_list.begin();
 126     for (; map_it != m_backend_list.end(); map_it++)
 127         if ((*map_it)->m_frontend_databases == databases)
 128             return *map_it;
 129     BackendPtr null;
 130     return null;
 131 }
 132
 133 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::create_backend_from_databases(
 134     std::list<std::string> databases, int &error_code, std::string &addinfo)
 135 {
 136     BackendPtr b(new Backend);
 137     std::list<std::string>::const_iterator db_it = databases.begin();
 138
 139     b->m_number_of_sets = 0;
 140     b->m_frontend_databases = databases;
 141     b->m_named_result_sets = false;
 142
 143     bool first_route = true;
 144
 145     std::map<std::string,bool> targets_dedup;
 146     for (; db_it != databases.end(); db_it++)
 147     {
 148         std::list<VirtualDB::Map>::const_iterator map_it;
 149         map_it = m_p->m_maps.begin();
 150         while (map_it != m_p->m_maps.end())
 151         {
 152             if (map_it->match(*db_it))
 153                 break;
 154             map_it++;
 155         }
 156
 157         if (map_it == m_p->m_maps.end())  // database not found
 158         {
 159             error_code = YAZ_BIB1_DATABASE_DOES_NOT_EXIST;
 160             addinfo = *db_it;
 161             BackendPtr ptr;
 162             return ptr;
 163         }
 164         std::list<std::string>::const_iterator t_it =
 165             map_it->m_targets.begin();
 166         for (; t_it != map_it->m_targets.end(); t_it++) {
 167             if (!targets_dedup[*t_it])
 168             {
 169                 targets_dedup[*t_it] = true;
 170                 b->m_targets.push_back(*t_it);
 171             }
 172         }
 173
 174         // see if we have a route conflict.
 175         if (!first_route && b->m_route != map_it->m_route)
 176         {
 177             // we have a conflict..
 178             error_code =  YAZ_BIB1_COMBI_OF_SPECIFIED_DATABASES_UNSUPP;
 179             BackendPtr ptr;
 180             return ptr;
 181         }
 182         b->m_route = map_it->m_route;
 183         first_route = false;
 184     }
 185     return b;
 186 }
 187
 188 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::init_backend(
 189     std::list<std::string> databases, mp::Package &package,
 190     int &error_code, std::string &addinfo)
 191 {
 192     BackendPtr b = create_backend_from_databases(databases, error_code,
 193                                                  addinfo);
 194     if (!b)
 195         return b;
 196     Package init_package(b->m_backend_session, package.origin());
 197     init_package.copy_filter(package);
 198
 199     mp::odr odr;
 200
 201     Z_APDU *init_apdu = zget_APDU(odr, Z_APDU_initRequest);
 202
 203     mp::util::set_vhost_otherinfo(&init_apdu->u.initRequest->otherInfo, odr,
 204                                    b->m_targets);
 205     Z_InitRequest *req = init_apdu->u.initRequest;
 206
 207     // copy stuff from Frontend Init Request
 208     Z_GDU *org_gdu = m_init_gdu.get();
 209     Z_InitRequest *org_init = org_gdu->u.z3950->u.initRequest;
 210
 211     req->idAuthentication = org_init->idAuthentication;
 212     req->implementationId = org_init->implementationId;
 213     req->implementationName = org_init->implementationName;
 214     req->implementationVersion = org_init->implementationVersion;
 215     *req->preferredMessageSize = *org_init->preferredMessageSize;
 216     *req->maximumRecordSize = *org_init->maximumRecordSize;
 217
 218     ODR_MASK_SET(req->options, Z_Options_search);
 219     ODR_MASK_SET(req->options, Z_Options_present);
 220     ODR_MASK_SET(req->options, Z_Options_namedResultSets);
 221     ODR_MASK_SET(req->options, Z_Options_scan);
 222
 223     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_1);
 224     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_2);
 225     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_3);
 226
 227     init_package.request() = init_apdu;
 228
 229     init_package.move(b->m_route);  // sending init
 230
 231     Z_GDU *gdu = init_package.response().get();
 232     // we hope to get an init response
 233     error_code = YAZ_BIB1_DATABASE_UNAVAILABLE;
 234     if (gdu && gdu->which == Z_GDU_Z3950
 235         && gdu->u.z3950->which == Z_APDU_initResponse
 236         && *gdu->u.z3950->u.initResponse->result)
 237     {
 238         Z_InitResponse *res = gdu->u.z3950->u.initResponse;
 239         if (ODR_MASK_GET(res->options, Z_Options_namedResultSets))
 240         {
 241             b->m_named_result_sets = true;
 242         }
 243         if (*res->result && !init_package.session().is_closed())
 244         {
 245             m_backend_list.push_back(b);
 246             return b;
 247         }
 248         mp::util::get_init_diagnostics(res, error_code, addinfo);
 249     }
 250     if (!init_package.session().is_closed())
 251     {
 252         Package close_package(b->m_backend_session, package.origin());
 253         close_package.copy_filter(package);
 254         close_package.session().close();
 255         close_package.move(b->m_route);  // closing it
 256     }
 257     BackendPtr null;
 258     return null;
 259 }
 260
 261 void yf::VirtualDB::Frontend::search(mp::Package &package, Z_APDU *apdu_req)
 262 {
 263     Z_SearchRequest *req = apdu_req->u.searchRequest;
 264     std::string vhost;
 265     std::string resultSetId = req->resultSetName;
 266     mp::odr odr;
 267
 268     std::list<std::string> databases;
 269     int i;
 270     for (i = 0; i<req->num_databaseNames; i++)
 271         databases.push_back(req->databaseNames[i]);
 272
 273     Sets_it sets_it = m_sets.find(req->resultSetName);
 274     if (sets_it != m_sets.end())
 275     {
 276         // result set already exist
 277         // if replace indicator is off: we return diagnostic if
 278         // result set already exist.
 279         if (*req->replaceIndicator == 0)
 280         {
 281             Z_APDU *apdu =
 282                 odr.create_searchResponse(
 283                     apdu_req,
 284                     YAZ_BIB1_RESULT_SET_EXISTS_AND_REPLACE_INDICATOR_OFF,
 285                     0);
 286             package.response() = apdu;
 287
 288             return;
 289         }
 290         sets_it->second.m_backend->m_number_of_sets--;
 291     }
 292     // pick up any existing database with named result sets ..
 293     // or one which has no result sets.. yet.
 294     BackendPtr b; // null for now
 295     std::list<BackendPtr>::const_iterator map_it;
 296     map_it = m_backend_list.begin();
 297     for (; map_it != m_backend_list.end(); map_it++)
 298     {
 299         BackendPtr tmp = *map_it;
 300         if (tmp->m_frontend_databases == databases &&
 301             (tmp->m_named_result_sets ||
 302              tmp->m_number_of_sets == 0))
 303         {
 304             b = *map_it;
 305             break;
 306         }
 307     }
 308     if (!b)  // no backend yet. Must create a new one
 309     {
 310         int error_code;
 311         std::string addinfo;
 312         b = init_backend(databases, package, error_code, addinfo);
 313         if (!b)
 314         {
 315             // did not get a backend (unavailable somehow?)
 316
 317             Z_APDU *apdu =
 318                 odr.create_searchResponse(
 319                     apdu_req, error_code, addinfo.c_str());
 320             package.response() = apdu;
 321             return;
 322         }
 323     }
 324     m_sets.erase(req->resultSetName);
 325     // sending search to backend
 326     Package search_package(b->m_backend_session, package.origin());
 327
 328     search_package.copy_filter(package);
 329
 330     std::string backend_setname;
 331     if (b->m_named_result_sets)
 332     {
 333         backend_setname = std::string(req->resultSetName);
 334     }
 335     else
 336     {
 337         backend_setname = "default";
 338         req->resultSetName = odr_strdup(odr, backend_setname.c_str());
 339     }
 340
 341     // pick first targets spec and move the databases from it ..
 342     std::list<std::string>::const_iterator t_it = b->m_targets.begin();
 343     if (t_it != b->m_targets.end())
 344     {
 345         mp::util::set_databases_from_zurl(odr, *t_it,
 346                                                 &req->num_databaseNames,
 347                                                 &req->databaseNames);
 348     }
 349
 350     *req->replaceIndicator = 1;
 351
 352     search_package.request() = yazpp_1::GDU(apdu_req);
 353
 354     search_package.move(b->m_route);
 355
 356     if (search_package.session().is_closed())
 357     {
 358         package.response() = search_package.response();
 359         package.session().close();
 360         return;
 361     }
 362     b->m_number_of_sets++;
 363
 364     m_sets[resultSetId] = VirtualDB::Set(b, backend_setname);
 365     fixup_package(search_package, b);
 366     package.response() = search_package.response();
 367 }
 368
 369 yf::VirtualDB::Frontend::Frontend(Rep *rep)
 370 {
 371     m_p = rep;
 372     m_is_virtual = false;
 373 }
 374
 375 void yf::VirtualDB::Frontend::close(mp::Package &package)
 376 {
 377     std::list<BackendPtr>::const_iterator b_it;
 378
 379     for (b_it = m_backend_list.begin(); b_it != m_backend_list.end(); b_it++)
 380     {
 381         (*b_it)->m_backend_session.close();
 382         Package close_package((*b_it)->m_backend_session, package.origin());
 383         close_package.copy_filter(package);
 384         close_package.move((*b_it)->m_route);
 385     }
 386     m_backend_list.clear();
 387 }
 388
 389 yf::VirtualDB::Frontend::~Frontend()
 390 {
 391 }
 392
 393 yf::VirtualDB::FrontendPtr yf::VirtualDB::Rep::get_frontend(mp::Package &package)
 394 {
 395     boost::mutex::scoped_lock lock(m_mutex);
 396
 397     std::map<mp::Session,yf::VirtualDB::FrontendPtr>::iterator it;
 398
 399     while(true)
 400     {
 401         it = m_clients.find(package.session());
 402         if (it == m_clients.end())
 403             break;
 404
 405         if (!it->second->m_in_use)
 406         {
 407             it->second->m_in_use = true;
 408             return it->second;
 409         }
 410         m_cond_session_ready.wait(lock);
 411     }
 412     FrontendPtr f(new Frontend(this));
 413     m_clients[package.session()] = f;
 414     f->m_in_use = true;
 415     return f;
 416 }
 417
 418 void yf::VirtualDB::Rep::release_frontend(mp::Package &package)
 419 {
 420     boost::mutex::scoped_lock lock(m_mutex);
 421     std::map<mp::Session,yf::VirtualDB::FrontendPtr>::iterator it;
 422
 423     it = m_clients.find(package.session());
 424     if (it != m_clients.end())
 425     {
 426         if (package.session().is_closed())
 427         {
 428             it->second->close(package);
 429             m_clients.erase(it);
 430         }
 431         else
 432         {
 433             it->second->m_in_use = false;
 434         }
 435         m_cond_session_ready.notify_all();
 436     }
 437 }
 438
 439 yf::VirtualDB::Set::Set(BackendPtr b, std::string setname)
 440     :  m_backend(b), m_setname(setname)
 441 {
 442 }
 443
 444
 445 yf::VirtualDB::Set::Set()
 446 {
 447 }
 448
 449
 450 yf::VirtualDB::Set::~Set()
 451 {
 452 }
 453
 454 yf::VirtualDB::Map::Map(std::string database,
 455                         std::list<std::string> targets, std::string route)
 456     : m_dbpattern(database), m_targets(targets), m_route(route)
 457 {
 458 }
 459
 460 yf::VirtualDB::Map::Map()
 461 {
 462 }
 463
 464 bool yf::VirtualDB::Map::match(const std::string db) const
 465 {
 466     std::string norm_db = mp::util::database_name_normalize(db);
 467     if (yaz_match_glob(m_dbpattern.c_str(), norm_db.c_str()))
 468         return true;
 469     return false;
 470 }
 471
 472 yf::VirtualDB::VirtualDB() : m_p(new VirtualDB::Rep)
 473 {
 474     m_p->pass_vhosts = false;
 475 }
 476
 477 yf::VirtualDB::~VirtualDB() {
 478 }
 479
 480 void yf::VirtualDB::Frontend::fixup_npr_record(ODR odr, Z_NamePlusRecord *npr,
 481                                              BackendPtr b)
 482 {
 483     if (npr->databaseName)
 484     {
 485         std::string b_database = std::string(npr->databaseName);
 486
 487         // consider each of the frontend databases..
 488         std::list<std::string>::const_iterator db_it;
 489         for (db_it = b->m_frontend_databases.begin();
 490              db_it != b->m_frontend_databases.end(); db_it++)
 491         {
 492             // see which target it corresponds to.. (if any)
 493             std::list<VirtualDB::Map>::const_iterator map_it =
 494                 m_p->m_maps.begin();
 495             while (map_it != m_p->m_maps.end())
 496             {
 497                 if (map_it->match(*db_it))
 498                     break;
 499                 map_it++;
 500             }
 501             if (map_it != m_p->m_maps.end())
 502             {
 503                 std::list<std::string>::const_iterator t
 504                     = map_it->m_targets.begin();
 505                 while (t != map_it->m_targets.end())
 506                 {
 507                     if (*t == b_database)
 508                     {
 509                         npr->databaseName = odr_strdup(odr, (*db_it).c_str());
 510                         return;
 511                     }
 512                     t++;
 513                 }
 514             }
 515
 516         }
 517         db_it = b->m_frontend_databases.begin();
 518         if (db_it != b->m_frontend_databases.end())
 519         {
 520             std::string database = *db_it;
 521             npr->databaseName = odr_strdup(odr, database.c_str());
 522         }
 523     }
 524 }
 525
 526 void yf::VirtualDB::Frontend::fixup_npr_records(ODR odr, Z_Records *records,
 527                                               BackendPtr b)
 528 {
 529     if (records && records->which == Z_Records_DBOSD)
 530     {
 531         Z_NamePlusRecordList *nprlist = records->u.databaseOrSurDiagnostics;
 532         int i;
 533         for (i = 0; i < nprlist->num_records; i++)
 534         {
 535             fixup_npr_record(odr, nprlist->records[i], b);
 536         }
 537     }
 538 }
 539
 540 void yf::VirtualDB::Frontend::fixup_package(mp::Package &p, BackendPtr b)
 541 {
 542     Z_GDU *gdu = p.response().get();
 543     mp::odr odr;
 544
 545     if (gdu && gdu->which == Z_GDU_Z3950)
 546     {
 547         Z_APDU *apdu = gdu->u.z3950;
 548         if (apdu->which == Z_APDU_presentResponse)
 549         {
 550             fixup_npr_records(odr, apdu->u.presentResponse->records, b);
 551             p.response() = gdu;
 552         }
 553         else if (apdu->which == Z_APDU_searchResponse)
 554         {
 555             fixup_npr_records(odr,  apdu->u.searchResponse->records, b);
 556             p.response() = gdu;
 557         }
 558     }
 559 }
 560
 561 void yf::VirtualDB::Frontend::present(mp::Package &package, Z_APDU *apdu_req)
 562 {
 563     Z_PresentRequest *req = apdu_req->u.presentRequest;
 564     std::string resultSetId = req->resultSetId;
 565     mp::odr odr;
 566
 567     Sets_it sets_it = m_sets.find(resultSetId);
 568     if (sets_it == m_sets.end())
 569     {
 570         Z_APDU *apdu =
 571             odr.create_presentResponse(
 572                 apdu_req,
 573                 YAZ_BIB1_SPECIFIED_RESULT_SET_DOES_NOT_EXIST,
 574                 resultSetId.c_str());
 575         package.response() = apdu;
 576         return;
 577     }
 578     Session *id =
 579         new mp::Session(sets_it->second.m_backend->m_backend_session);
 580
 581     // sending present to backend
 582     Package present_package(*id, package.origin());
 583     present_package.copy_filter(package);
 584
 585     req->resultSetId = odr_strdup(odr, sets_it->second.m_setname.c_str());
 586
 587     present_package.request() = yazpp_1::GDU(apdu_req);
 588
 589     present_package.move(sets_it->second.m_backend->m_route);
 590
 591     fixup_package(present_package, sets_it->second.m_backend);
 592
 593     if (present_package.session().is_closed())
 594     {
 595         package.response() = present_package.response();
 596         package.session().close();
 597         return;
 598     }
 599     else
 600     {
 601         package.response() = present_package.response();
 602     }
 603     delete id;
 604 }
 605
 606 void yf::VirtualDB::Frontend::scan(mp::Package &package, Z_APDU *apdu_req)
 607 {
 608     Z_ScanRequest *req = apdu_req->u.scanRequest;
 609     std::string vhost;
 610     mp::odr odr;
 611
 612     std::list<std::string> databases;
 613     int i;
 614     for (i = 0; i<req->num_databaseNames; i++)
 615         databases.push_back(req->databaseNames[i]);
 616
 617     BackendPtr b;
 618     // pick up any existing backend with a database match
 619     std::list<BackendPtr>::const_iterator map_it;
 620     map_it = m_backend_list.begin();
 621     for (; map_it != m_backend_list.end(); map_it++)
 622     {
 623         BackendPtr tmp = *map_it;
 624         if (tmp->m_frontend_databases == databases)
 625             break;
 626     }
 627     if (map_it != m_backend_list.end())
 628         b = *map_it;
 629     if (!b)  // no backend yet. Must create a new one
 630     {
 631         int error_code;
 632         std::string addinfo;
 633         b = init_backend(databases, package, error_code, addinfo);
 634         if (!b)
 635         {
 636             // did not get a backend (unavailable somehow?)
 637             Z_APDU *apdu =
 638                 odr.create_scanResponse(
 639                     apdu_req, error_code, addinfo.c_str());
 640             package.response() = apdu;
 641
 642             return;
 643         }
 644     }
 645     // sending scan to backend
 646     Package scan_package(b->m_backend_session, package.origin());
 647
 648     scan_package.copy_filter(package);
 649
 650     // pick first targets spec and move the databases from it ..
 651     std::list<std::string>::const_iterator t_it = b->m_targets.begin();
 652     if (t_it != b->m_targets.end())
 653     {
 654         mp::util::set_databases_from_zurl(odr, *t_it,
 655                                                 &req->num_databaseNames,
 656                                                 &req->databaseNames);
 657     }
 658     scan_package.request() = yazpp_1::GDU(apdu_req);
 659
 660     scan_package.move(b->m_route);
 661
 662     if (scan_package.session().is_closed())
 663     {
 664         package.response() = scan_package.response();
 665         package.session().close();
 666         return;
 667     }
 668     package.response() = scan_package.response();
 669 }
 670
 671
 672 void yf::VirtualDB::add_map_db2targets(std::string db,
 673                                      std::list<std::string> targets,
 674                                      std::string route)
 675 {
 676     m_p->m_maps.push_back(
 677         VirtualDB::Map(mp::util::database_name_normalize(db), targets, route));
 678 }
 679
 680
 681 void yf::VirtualDB::add_map_db2target(std::string db,
 682                                     std::string target,
 683                                     std::string route)
 684 {
 685     std::list<std::string> targets;
 686     targets.push_back(target);
 687
 688     add_map_db2targets(db, targets, route);
 689 }
 690
 691 void yf::VirtualDB::process(mp::Package &package) const
 692 {
 693     FrontendPtr f = m_p->get_frontend(package);
 694
 695     Z_GDU *gdu = package.request().get();
 696
 697     if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
 698         Z_APDU_initRequest && !f->m_is_virtual)
 699     {
 700         Z_InitRequest *req = gdu->u.z3950->u.initRequest;
 701
 702         std::list<std::string> vhosts;
 703         mp::util::get_vhost_otherinfo(req->otherInfo, vhosts);
 704
 705         if (vhosts.size() > 0 && m_p->pass_vhosts)
 706         {
 707             package.move();
 708         }
 709         else
 710         {
 711             f->m_init_gdu = gdu;
 712
 713             mp::odr odr;
 714             Z_APDU *apdu = odr.create_initResponse(gdu->u.z3950, 0, 0);
 715             Z_InitResponse *resp = apdu->u.initResponse;
 716
 717             int i;
 718             static const int masks[] = {
 719                 Z_Options_search,
 720                 Z_Options_present,
 721                 Z_Options_namedResultSets,
 722                 Z_Options_scan,
 723                 -1
 724             };
 725             for (i = 0; masks[i] != -1; i++)
 726                 if (ODR_MASK_GET(req->options, masks[i]))
 727                     ODR_MASK_SET(resp->options, masks[i]);
 728
 729             static const int versions[] = {
 730                 Z_ProtocolVersion_1,
 731                 Z_ProtocolVersion_2,
 732                 Z_ProtocolVersion_3,
 733                 -1
 734             };
 735             for (i = 0; versions[i] != -1; i++)
 736                 if (ODR_MASK_GET(req->protocolVersion, versions[i]))
 737                     ODR_MASK_SET(resp->protocolVersion, versions[i]);
 738                 else
 739                     break;
 740
 741             *resp->preferredMessageSize = *req->preferredMessageSize;
 742             *resp->maximumRecordSize = *req->maximumRecordSize;
 743
 744             package.response() = apdu;
 745             f->m_is_virtual = true;
 746         }
 747     }
 748     else if (!f->m_is_virtual)
 749         package.move();
 750     else if (gdu && gdu->which == Z_GDU_Z3950)
 751     {
 752         Z_APDU *apdu = gdu->u.z3950;
 753         if (apdu->which == Z_APDU_initRequest)
 754         {
 755             mp::odr odr;
 756
 757             package.response() = odr.create_close(
 758                 apdu,
 759                 Z_Close_protocolError,
 760                 "double init");
 761
 762             package.session().close();
 763         }
 764         else if (apdu->which == Z_APDU_searchRequest)
 765         {
 766             f->search(package, apdu);
 767         }
 768         else if (apdu->which == Z_APDU_presentRequest)
 769         {
 770             f->present(package, apdu);
 771         }
 772         else if (apdu->which == Z_APDU_scanRequest)
 773         {
 774             f->scan(package, apdu);
 775         }
 776         else if (apdu->which == Z_APDU_close)
 777         {
 778             package.session().close();
 779         }
 780         else
 781         {
 782             mp::odr odr;
 783
 784             package.response() = odr.create_close(
 785                 apdu, Z_Close_protocolError,
 786                 "unsupported APDU in filter_virt_db");
 787
 788             package.session().close();
 789         }
 790     }
 791     m_p->release_frontend(package);
 792 }
 793
 794
 795 void mp::filter::VirtualDB::configure(const xmlNode * ptr, bool test_only)
 796 {
 797     for (ptr = ptr->children; ptr; ptr = ptr->next)
 798     {
 799         if (ptr->type != XML_ELEMENT_NODE)
 800             continue;
 801         if (!strcmp((const char *) ptr->name, "pass-vhosts"))
 802         {
 803             m_p->pass_vhosts = mp::xml::get_bool(ptr->children, false);
 804         }
 805         else if (!strcmp((const char *) ptr->name, "virtual"))
 806         {
 807             std::string database;
 808             std::list<std::string> targets;
 809             xmlNode *v_node = ptr->children;
 810             for (; v_node; v_node = v_node->next)
 811             {
 812                 if (v_node->type != XML_ELEMENT_NODE)
 813                     continue;
 814
 815                 if (mp::xml::is_element_mp(v_node, "database"))
 816                     database = mp::xml::get_text(v_node);
 817                 else if (mp::xml::is_element_mp(v_node, "target"))
 818                     targets.push_back(mp::xml::get_text(v_node));
 819                 else
 820                     throw mp::filter::FilterException
 821                         ("Bad element "
 822                          + std::string((const char *) v_node->name)
 823                          + " in virtual section"
 824                             );
 825             }
 826             std::string route = mp::xml::get_route(ptr);
 827             add_map_db2targets(database, targets, route);
 828         }
 829         else
 830         {
 831             throw mp::filter::FilterException
 832                 ("Bad element "
 833                  + std::string((const char *) ptr->name)
 834                  + " in virt_db filter");
 835         }
 836     }
 837 }
 838
 839 static mp::filter::Base* filter_creator()
 840 {
 841     return new mp::filter::VirtualDB;
 842 }
 843
 844 extern "C" {
 845     struct metaproxy_1_filter_struct metaproxy_1_filter_virt_db = {
 846         0,
 847         "virt_db",
 848         filter_creator
 849     };
 850 }
 851
 852
 853 /*
 854  * Local variables:
 855  * c-basic-offset: 4
 856  * c-file-style: "Stroustrup"
 857  * indent-tabs-mode: nil
 858  * End:
 859  * vim: shiftwidth=4 tabstop=8 expandtab
 860  */
 861