src/filter_virt_db.cpp

   1 /* This file is part of Metaproxy.
   2    Copyright (C) 2005-2009 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.hpp"
  22 #include "package.hpp"
  23
  24 #include <boost/thread/mutex.hpp>
  25 #include <boost/thread/condition.hpp>
  26 #include <boost/shared_ptr.hpp>
  27
  28 #include "util.hpp"
  29 #include "filter_virt_db.hpp"
  30
  31 #include <yaz/zgdu.h>
  32 #include <yaz/otherinfo.h>
  33 #include <yaz/diagbib1.h>
  34
  35 #include <map>
  36 #include <iostream>
  37
  38 namespace mp = metaproxy_1;
  39 namespace yf = mp::filter;
  40
  41 namespace metaproxy_1 {
  42     namespace filter {
  43
  44         struct VirtualDB::Set {
  45             Set(BackendPtr b, std::string setname);
  46             Set();
  47             ~Set();
  48
  49             BackendPtr m_backend;
  50             std::string m_setname;
  51         };
  52         struct VirtualDB::Map {
  53             Map(std::list<std::string> targets, std::string route);
  54             Map();
  55             std::list<std::string> m_targets;
  56             std::string m_route;
  57         };
  58         struct VirtualDB::Backend {
  59             mp::Session m_backend_session;
  60             std::list<std::string> m_frontend_databases;
  61             std::list<std::string> m_targets;
  62             std::string m_route;
  63             bool m_named_result_sets;
  64             int m_number_of_sets;
  65         };
  66         struct VirtualDB::Frontend {
  67             Frontend(Rep *rep);
  68             ~Frontend();
  69             mp::Session m_session;
  70             bool m_is_virtual;
  71             bool m_in_use;
  72             yazpp_1::GDU m_init_gdu;
  73             std::list<BackendPtr> m_backend_list;
  74             std::map<std::string,VirtualDB::Set> m_sets;
  75
  76             void search(Package &package, Z_APDU *apdu);
  77             void present(Package &package, Z_APDU *apdu);
  78             void scan(Package &package, Z_APDU *apdu);
  79
  80             void close(Package &package);
  81             typedef std::map<std::string,VirtualDB::Set>::iterator Sets_it;
  82
  83             void fixup_package(Package &p, BackendPtr b);
  84             void fixup_npr_record(ODR odr, Z_NamePlusRecord *npr,
  85                                   BackendPtr b);
  86             void fixup_npr_records(ODR odr, Z_Records *records,
  87                                    BackendPtr b);
  88
  89             BackendPtr lookup_backend_from_databases(
  90                 std::list<std::string> databases);
  91             BackendPtr create_backend_from_databases(
  92                 std::list<std::string> databases,
  93                 int &error_code,
  94                 std::string &failing_database);
  95
  96             BackendPtr init_backend(std::list<std::string> database,
  97                                     Package &package,
  98                                     int &error_code, std::string &addinfo);
  99             Rep *m_p;
 100         };
 101         class VirtualDB::Rep {
 102             friend class VirtualDB;
 103             friend struct Frontend;
 104
 105             FrontendPtr get_frontend(Package &package);
 106             void release_frontend(Package &package);
 107         private:
 108             std::map<std::string, VirtualDB::Map>m_maps;
 109             typedef std::map<std::string,VirtualDB::Set>::iterator Sets_it;
 110             boost::mutex m_mutex;
 111             boost::condition m_cond_session_ready;
 112             std::map<mp::Session, FrontendPtr> m_clients;
 113         };
 114     }
 115 }
 116
 117 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::lookup_backend_from_databases(
 118     std::list<std::string> databases)
 119 {
 120     std::list<BackendPtr>::const_iterator map_it;
 121     map_it = m_backend_list.begin();
 122     for (; map_it != m_backend_list.end(); map_it++)
 123         if ((*map_it)->m_frontend_databases == databases)
 124             return *map_it;
 125     BackendPtr null;
 126     return null;
 127 }
 128
 129 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::create_backend_from_databases(
 130     std::list<std::string> databases, int &error_code, std::string &addinfo)
 131 {
 132     BackendPtr b(new Backend);
 133     std::list<std::string>::const_iterator db_it = databases.begin();
 134
 135     b->m_number_of_sets = 0;
 136     b->m_frontend_databases = databases;
 137     b->m_named_result_sets = false;
 138
 139     bool first_route = true;
 140
 141     std::map<std::string,bool> targets_dedup;
 142     for (; db_it != databases.end(); db_it++)
 143     {
 144         std::map<std::string, VirtualDB::Map>::iterator map_it;
 145         map_it = m_p->m_maps.find(mp::util::database_name_normalize(*db_it));
 146         if (map_it == m_p->m_maps.end())  // database not found
 147         {
 148             error_code = YAZ_BIB1_DATABASE_DOES_NOT_EXIST;
 149             addinfo = *db_it;
 150             BackendPtr ptr;
 151             return ptr;
 152         }
 153         std::list<std::string>::const_iterator t_it =
 154             map_it->second.m_targets.begin();
 155         for (; t_it != map_it->second.m_targets.end(); t_it++) {
 156             if (!targets_dedup[*t_it])
 157             {
 158                 targets_dedup[*t_it] = true;
 159                 b->m_targets.push_back(*t_it);
 160             }
 161         }
 162
 163         // see if we have a route conflict.
 164         if (!first_route && b->m_route != map_it->second.m_route)
 165         {
 166             // we have a conflict..
 167             error_code =  YAZ_BIB1_COMBI_OF_SPECIFIED_DATABASES_UNSUPP;
 168             BackendPtr ptr;
 169             return ptr;
 170         }
 171         b->m_route = map_it->second.m_route;
 172         first_route = false;
 173     }
 174     return b;
 175 }
 176
 177 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::init_backend(
 178     std::list<std::string> databases, mp::Package &package,
 179     int &error_code, std::string &addinfo)
 180 {
 181     BackendPtr b = create_backend_from_databases(databases, error_code,
 182                                                  addinfo);
 183     if (!b)
 184         return b;
 185     Package init_package(b->m_backend_session, package.origin());
 186     init_package.copy_filter(package);
 187
 188     mp::odr odr;
 189
 190     Z_APDU *init_apdu = zget_APDU(odr, Z_APDU_initRequest);
 191
 192     mp::util::set_vhost_otherinfo(&init_apdu->u.initRequest->otherInfo, odr,
 193                                    b->m_targets);
 194     Z_InitRequest *req = init_apdu->u.initRequest;
 195
 196     // copy stuff from Frontend Init Request
 197     Z_GDU *org_gdu = m_init_gdu.get();
 198     Z_InitRequest *org_init = org_gdu->u.z3950->u.initRequest;
 199
 200     req->idAuthentication = org_init->idAuthentication;
 201     req->implementationId = org_init->implementationId;
 202     req->implementationName = org_init->implementationName;
 203     req->implementationVersion = org_init->implementationVersion;
 204
 205     ODR_MASK_SET(req->options, Z_Options_search);
 206     ODR_MASK_SET(req->options, Z_Options_present);
 207     ODR_MASK_SET(req->options, Z_Options_namedResultSets);
 208     ODR_MASK_SET(req->options, Z_Options_scan);
 209
 210     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_1);
 211     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_2);
 212     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_3);
 213
 214     init_package.request() = init_apdu;
 215
 216     init_package.move(b->m_route);  // sending init
 217
 218     Z_GDU *gdu = init_package.response().get();
 219     // we hope to get an init response
 220     if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
 221         Z_APDU_initResponse)
 222     {
 223         Z_InitResponse *res = gdu->u.z3950->u.initResponse;
 224         if (ODR_MASK_GET(res->options, Z_Options_namedResultSets))
 225         {
 226             b->m_named_result_sets = true;
 227         }
 228         if (!*res->result)
 229         {
 230             error_code = YAZ_BIB1_DATABASE_UNAVAILABLE;
 231             mp::util::get_init_diagnostics(res, error_code, addinfo);
 232             BackendPtr null;
 233             return null;
 234         }
 235     }
 236     else
 237     {
 238         error_code = YAZ_BIB1_DATABASE_UNAVAILABLE;
 239         // addinfo = database;
 240         BackendPtr null;
 241         return null;
 242     }
 243     if (init_package.session().is_closed())
 244     {
 245         error_code = YAZ_BIB1_DATABASE_UNAVAILABLE;
 246         // addinfo = database;
 247         BackendPtr null;
 248         return null;
 249     }
 250
 251     m_backend_list.push_back(b);
 252     return b;
 253 }
 254
 255 void yf::VirtualDB::Frontend::search(mp::Package &package, Z_APDU *apdu_req)
 256 {
 257     Z_SearchRequest *req = apdu_req->u.searchRequest;
 258     std::string vhost;
 259     std::string resultSetId = req->resultSetName;
 260     mp::odr odr;
 261
 262     std::list<std::string> databases;
 263     int i;
 264     for (i = 0; i<req->num_databaseNames; i++)
 265         databases.push_back(req->databaseNames[i]);
 266
 267     BackendPtr b; // null for now
 268     Sets_it sets_it = m_sets.find(req->resultSetName);
 269     if (sets_it != m_sets.end())
 270     {
 271         // result set already exist
 272         // if replace indicator is off: we return diagnostic if
 273         // result set already exist.
 274         if (*req->replaceIndicator == 0)
 275         {
 276             Z_APDU *apdu =
 277                 odr.create_searchResponse(
 278                     apdu_req,
 279                     YAZ_BIB1_RESULT_SET_EXISTS_AND_REPLACE_INDICATOR_OFF,
 280                     0);
 281             package.response() = apdu;
 282
 283             return;
 284         }
 285         sets_it->second.m_backend->m_number_of_sets--;
 286
 287         // pick up any existing backend with a database match
 288         std::list<BackendPtr>::const_iterator map_it;
 289         map_it = m_backend_list.begin();
 290         for (; map_it != m_backend_list.end(); map_it++)
 291         {
 292             BackendPtr tmp = *map_it;
 293             if (tmp->m_frontend_databases == databases)
 294                 break;
 295         }
 296         if (map_it != m_backend_list.end())
 297             b = *map_it;
 298     }
 299     else
 300     {
 301         // new result set.
 302
 303         // pick up any existing database with named result sets ..
 304         // or one which has no result sets.. yet.
 305         std::list<BackendPtr>::const_iterator map_it;
 306         map_it = m_backend_list.begin();
 307         for (; map_it != m_backend_list.end(); map_it++)
 308         {
 309             BackendPtr tmp = *map_it;
 310             if (tmp->m_frontend_databases == databases &&
 311                 (tmp->m_named_result_sets ||
 312                  tmp->m_number_of_sets == 0))
 313                 break;
 314         }
 315         if (map_it != m_backend_list.end())
 316             b = *map_it;
 317     }
 318     if (!b)  // no backend yet. Must create a new one
 319     {
 320         int error_code;
 321         std::string addinfo;
 322         b = init_backend(databases, package, error_code, addinfo);
 323         if (!b)
 324         {
 325             // did not get a backend (unavailable somehow?)
 326
 327             Z_APDU *apdu =
 328                 odr.create_searchResponse(
 329                     apdu_req, error_code, addinfo.c_str());
 330             package.response() = apdu;
 331             return;
 332         }
 333     }
 334     m_sets.erase(req->resultSetName);
 335     // sending search to backend
 336     Package search_package(b->m_backend_session, package.origin());
 337
 338     search_package.copy_filter(package);
 339
 340     std::string backend_setname;
 341     if (b->m_named_result_sets)
 342     {
 343         backend_setname = std::string(req->resultSetName);
 344     }
 345     else
 346     {
 347         backend_setname = "default";
 348         req->resultSetName = odr_strdup(odr, backend_setname.c_str());
 349     }
 350
 351     // pick first targets spec and move the databases from it ..
 352     std::list<std::string>::const_iterator t_it = b->m_targets.begin();
 353     if (t_it != b->m_targets.end())
 354     {
 355         mp::util::set_databases_from_zurl(odr, *t_it,
 356                                                 &req->num_databaseNames,
 357                                                 &req->databaseNames);
 358     }
 359
 360     *req->replaceIndicator = 1;
 361
 362     search_package.request() = yazpp_1::GDU(apdu_req);
 363
 364     search_package.move(b->m_route);
 365
 366     if (search_package.session().is_closed())
 367     {
 368         package.response() = search_package.response();
 369         package.session().close();
 370         return;
 371     }
 372     b->m_number_of_sets++;
 373
 374     m_sets[resultSetId] = VirtualDB::Set(b, backend_setname);
 375     fixup_package(search_package, b);
 376     package.response() = search_package.response();
 377 }
 378
 379 yf::VirtualDB::Frontend::Frontend(Rep *rep)
 380 {
 381     m_p = rep;
 382     m_is_virtual = false;
 383 }
 384
 385 void yf::VirtualDB::Frontend::close(mp::Package &package)
 386 {
 387     std::list<BackendPtr>::const_iterator b_it;
 388
 389     for (b_it = m_backend_list.begin(); b_it != m_backend_list.end(); b_it++)
 390     {
 391         (*b_it)->m_backend_session.close();
 392         Package close_package((*b_it)->m_backend_session, package.origin());
 393         close_package.copy_filter(package);
 394         close_package.move((*b_it)->m_route);
 395     }
 396     m_backend_list.clear();
 397 }
 398
 399 yf::VirtualDB::Frontend::~Frontend()
 400 {
 401 }
 402
 403 yf::VirtualDB::FrontendPtr yf::VirtualDB::Rep::get_frontend(mp::Package &package)
 404 {
 405     boost::mutex::scoped_lock lock(m_mutex);
 406
 407     std::map<mp::Session,yf::VirtualDB::FrontendPtr>::iterator it;
 408
 409     while(true)
 410     {
 411         it = m_clients.find(package.session());
 412         if (it == m_clients.end())
 413             break;
 414
 415         if (!it->second->m_in_use)
 416         {
 417             it->second->m_in_use = true;
 418             return it->second;
 419         }
 420         m_cond_session_ready.wait(lock);
 421     }
 422     FrontendPtr f(new Frontend(this));
 423     m_clients[package.session()] = f;
 424     f->m_in_use = true;
 425     return f;
 426 }
 427
 428 void yf::VirtualDB::Rep::release_frontend(mp::Package &package)
 429 {
 430     boost::mutex::scoped_lock lock(m_mutex);
 431     std::map<mp::Session,yf::VirtualDB::FrontendPtr>::iterator it;
 432
 433     it = m_clients.find(package.session());
 434     if (it != m_clients.end())
 435     {
 436         if (package.session().is_closed())
 437         {
 438             it->second->close(package);
 439             m_clients.erase(it);
 440         }
 441         else
 442         {
 443             it->second->m_in_use = false;
 444         }
 445         m_cond_session_ready.notify_all();
 446     }
 447 }
 448
 449 yf::VirtualDB::Set::Set(BackendPtr b, std::string setname)
 450     :  m_backend(b), m_setname(setname)
 451 {
 452 }
 453
 454
 455 yf::VirtualDB::Set::Set()
 456 {
 457 }
 458
 459
 460 yf::VirtualDB::Set::~Set()
 461 {
 462 }
 463
 464 yf::VirtualDB::Map::Map(std::list<std::string> targets, std::string route)
 465     : m_targets(targets), m_route(route)
 466 {
 467 }
 468
 469 yf::VirtualDB::Map::Map()
 470 {
 471 }
 472
 473 yf::VirtualDB::VirtualDB() : m_p(new VirtualDB::Rep)
 474 {
 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::map<std::string,VirtualDB::Map>::const_iterator map_it;
 494
 495             map_it = m_p->m_maps.find(mp::util::database_name_normalize(*db_it));
 496             if (map_it != m_p->m_maps.end())
 497             {
 498                 VirtualDB::Map m = map_it->second;
 499
 500                 std::list<std::string>::const_iterator t;
 501                 for (t = m.m_targets.begin(); t != m.m_targets.end(); t++)
 502                 {
 503                     if (*t == b_database)
 504                     {
 505                         npr->databaseName = odr_strdup(odr, (*db_it).c_str());
 506                         return;
 507                     }
 508                 }
 509             }
 510
 511         }
 512         db_it = b->m_frontend_databases.begin();
 513         if (db_it != b->m_frontend_databases.end())
 514         {
 515             std::string database = *db_it;
 516             npr->databaseName = odr_strdup(odr, database.c_str());
 517         }
 518     }
 519 }
 520
 521 void yf::VirtualDB::Frontend::fixup_npr_records(ODR odr, Z_Records *records,
 522                                               BackendPtr b)
 523 {
 524     if (records && records->which == Z_Records_DBOSD)
 525     {
 526         Z_NamePlusRecordList *nprlist = records->u.databaseOrSurDiagnostics;
 527         int i;
 528         for (i = 0; i < nprlist->num_records; i++)
 529         {
 530             fixup_npr_record(odr, nprlist->records[i], b);
 531         }
 532     }
 533 }
 534
 535 void yf::VirtualDB::Frontend::fixup_package(mp::Package &p, BackendPtr b)
 536 {
 537     Z_GDU *gdu = p.response().get();
 538     mp::odr odr;
 539
 540     if (gdu && gdu->which == Z_GDU_Z3950)
 541     {
 542         Z_APDU *apdu = gdu->u.z3950;
 543         if (apdu->which == Z_APDU_presentResponse)
 544         {
 545             fixup_npr_records(odr, apdu->u.presentResponse->records, b);
 546             p.response() = gdu;
 547         }
 548         else if (apdu->which == Z_APDU_searchResponse)
 549         {
 550             fixup_npr_records(odr,  apdu->u.searchResponse->records, b);
 551             p.response() = gdu;
 552         }
 553     }
 554 }
 555
 556 void yf::VirtualDB::Frontend::present(mp::Package &package, Z_APDU *apdu_req)
 557 {
 558     Z_PresentRequest *req = apdu_req->u.presentRequest;
 559     std::string resultSetId = req->resultSetId;
 560     mp::odr odr;
 561
 562     Sets_it sets_it = m_sets.find(resultSetId);
 563     if (sets_it == m_sets.end())
 564     {
 565         Z_APDU *apdu =
 566             odr.create_presentResponse(
 567                 apdu_req,
 568                 YAZ_BIB1_SPECIFIED_RESULT_SET_DOES_NOT_EXIST,
 569                 resultSetId.c_str());
 570         package.response() = apdu;
 571         return;
 572     }
 573     Session *id =
 574         new mp::Session(sets_it->second.m_backend->m_backend_session);
 575
 576     // sending present to backend
 577     Package present_package(*id, package.origin());
 578     present_package.copy_filter(package);
 579
 580     req->resultSetId = odr_strdup(odr, sets_it->second.m_setname.c_str());
 581
 582     present_package.request() = yazpp_1::GDU(apdu_req);
 583
 584     present_package.move(sets_it->second.m_backend->m_route);
 585
 586     fixup_package(present_package, sets_it->second.m_backend);
 587
 588     if (present_package.session().is_closed())
 589     {
 590         package.response() = present_package.response();
 591         package.session().close();
 592         return;
 593     }
 594     else
 595     {
 596         package.response() = present_package.response();
 597     }
 598     delete id;
 599 }
 600
 601 void yf::VirtualDB::Frontend::scan(mp::Package &package, Z_APDU *apdu_req)
 602 {
 603     Z_ScanRequest *req = apdu_req->u.scanRequest;
 604     std::string vhost;
 605     mp::odr odr;
 606
 607     std::list<std::string> databases;
 608     int i;
 609     for (i = 0; i<req->num_databaseNames; i++)
 610         databases.push_back(req->databaseNames[i]);
 611
 612     BackendPtr b;
 613     // pick up any existing backend with a database match
 614     std::list<BackendPtr>::const_iterator map_it;
 615     map_it = m_backend_list.begin();
 616     for (; map_it != m_backend_list.end(); map_it++)
 617     {
 618         BackendPtr tmp = *map_it;
 619         if (tmp->m_frontend_databases == databases)
 620             break;
 621     }
 622     if (map_it != m_backend_list.end())
 623         b = *map_it;
 624     if (!b)  // no backend yet. Must create a new one
 625     {
 626         int error_code;
 627         std::string addinfo;
 628         b = init_backend(databases, package, error_code, addinfo);
 629         if (!b)
 630         {
 631             // did not get a backend (unavailable somehow?)
 632             Z_APDU *apdu =
 633                 odr.create_scanResponse(
 634                     apdu_req, error_code, addinfo.c_str());
 635             package.response() = apdu;
 636
 637             return;
 638         }
 639     }
 640     // sending scan to backend
 641     Package scan_package(b->m_backend_session, package.origin());
 642
 643     scan_package.copy_filter(package);
 644
 645     // pick first targets spec and move the databases from it ..
 646     std::list<std::string>::const_iterator t_it = b->m_targets.begin();
 647     if (t_it != b->m_targets.end())
 648     {
 649         mp::util::set_databases_from_zurl(odr, *t_it,
 650                                                 &req->num_databaseNames,
 651                                                 &req->databaseNames);
 652     }
 653     scan_package.request() = yazpp_1::GDU(apdu_req);
 654
 655     scan_package.move(b->m_route);
 656
 657     if (scan_package.session().is_closed())
 658     {
 659         package.response() = scan_package.response();
 660         package.session().close();
 661         return;
 662     }
 663     package.response() = scan_package.response();
 664 }
 665
 666
 667 void yf::VirtualDB::add_map_db2targets(std::string db,
 668                                      std::list<std::string> targets,
 669                                      std::string route)
 670 {
 671     m_p->m_maps[mp::util::database_name_normalize(db)]
 672         = VirtualDB::Map(targets, route);
 673 }
 674
 675
 676 void yf::VirtualDB::add_map_db2target(std::string db,
 677                                     std::string target,
 678                                     std::string route)
 679 {
 680     std::list<std::string> targets;
 681     targets.push_back(target);
 682
 683     m_p->m_maps[mp::util::database_name_normalize(db)]
 684         = VirtualDB::Map(targets, route);
 685 }
 686
 687 void yf::VirtualDB::process(mp::Package &package) const
 688 {
 689     FrontendPtr f = m_p->get_frontend(package);
 690
 691     Z_GDU *gdu = package.request().get();
 692
 693     if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
 694         Z_APDU_initRequest && !f->m_is_virtual)
 695     {
 696         Z_InitRequest *req = gdu->u.z3950->u.initRequest;
 697
 698         std::list<std::string> vhosts;
 699         mp::util::get_vhost_otherinfo(req->otherInfo, vhosts);
 700         if (vhosts.size() == 0)
 701         {
 702             f->m_init_gdu = gdu;
 703
 704             mp::odr odr;
 705             Z_APDU *apdu = odr.create_initResponse(gdu->u.z3950, 0, 0);
 706             Z_InitResponse *resp = apdu->u.initResponse;
 707
 708             int i;
 709             static const int masks[] = {
 710                 Z_Options_search,
 711                 Z_Options_present,
 712                 Z_Options_namedResultSets,
 713                 Z_Options_scan,
 714                 -1
 715             };
 716             for (i = 0; masks[i] != -1; i++)
 717                 if (ODR_MASK_GET(req->options, masks[i]))
 718                     ODR_MASK_SET(resp->options, masks[i]);
 719
 720             static const int versions[] = {
 721                 Z_ProtocolVersion_1,
 722                 Z_ProtocolVersion_2,
 723                 Z_ProtocolVersion_3,
 724                 -1
 725             };
 726             for (i = 0; versions[i] != -1; i++)
 727                 if (ODR_MASK_GET(req->protocolVersion, versions[i]))
 728                     ODR_MASK_SET(resp->protocolVersion, versions[i]);
 729                 else
 730                     break;
 731
 732             package.response() = apdu;
 733             f->m_is_virtual = true;
 734         }
 735         else
 736             package.move();
 737     }
 738     else if (!f->m_is_virtual)
 739         package.move();
 740     else if (gdu && gdu->which == Z_GDU_Z3950)
 741     {
 742         Z_APDU *apdu = gdu->u.z3950;
 743         if (apdu->which == Z_APDU_initRequest)
 744         {
 745             mp::odr odr;
 746
 747             package.response() = odr.create_close(
 748                 apdu,
 749                 Z_Close_protocolError,
 750                 "double init");
 751
 752             package.session().close();
 753         }
 754         else if (apdu->which == Z_APDU_searchRequest)
 755         {
 756             f->search(package, apdu);
 757         }
 758         else if (apdu->which == Z_APDU_presentRequest)
 759         {
 760             f->present(package, apdu);
 761         }
 762         else if (apdu->which == Z_APDU_scanRequest)
 763         {
 764             f->scan(package, apdu);
 765         }
 766         else if (apdu->which == Z_APDU_close)
 767         {
 768             package.session().close();
 769         }
 770         else
 771         {
 772             mp::odr odr;
 773
 774             package.response() = odr.create_close(
 775                 apdu, Z_Close_protocolError,
 776                 "unsupported APDU in filter_virt_db");
 777
 778             package.session().close();
 779         }
 780     }
 781     m_p->release_frontend(package);
 782 }
 783
 784
 785 void mp::filter::VirtualDB::configure(const xmlNode * ptr, bool test_only)
 786 {
 787     for (ptr = ptr->children; ptr; ptr = ptr->next)
 788     {
 789         if (ptr->type != XML_ELEMENT_NODE)
 790             continue;
 791         if (!strcmp((const char *) ptr->name, "virtual"))
 792         {
 793             std::string database;
 794             std::list<std::string> targets;
 795             xmlNode *v_node = ptr->children;
 796             for (; v_node; v_node = v_node->next)
 797             {
 798                 if (v_node->type != XML_ELEMENT_NODE)
 799                     continue;
 800
 801                 if (mp::xml::is_element_mp(v_node, "database"))
 802                     database = mp::xml::get_text(v_node);
 803                 else if (mp::xml::is_element_mp(v_node, "target"))
 804                     targets.push_back(mp::xml::get_text(v_node));
 805                 else
 806                     throw mp::filter::FilterException
 807                         ("Bad element "
 808                          + std::string((const char *) v_node->name)
 809                          + " in virtual section"
 810                             );
 811             }
 812             std::string route = mp::xml::get_route(ptr);
 813             add_map_db2targets(database, targets, route);
 814         }
 815         else
 816         {
 817             throw mp::filter::FilterException
 818                 ("Bad element "
 819                  + std::string((const char *) ptr->name)
 820                  + " in virt_db filter");
 821         }
 822     }
 823 }
 824
 825 static mp::filter::Base* filter_creator()
 826 {
 827     return new mp::filter::VirtualDB;
 828 }
 829
 830 extern "C" {
 831     struct metaproxy_1_filter_struct metaproxy_1_filter_virt_db = {
 832         0,
 833         "virt_db",
 834         filter_creator
 835     };
 836 }
 837
 838
 839 /*
 840  * Local variables:
 841  * c-basic-offset: 4
 842  * c-file-style: "Stroustrup"
 843  * indent-tabs-mode: nil
 844  * End:
 845  * vim: shiftwidth=4 tabstop=8 expandtab
 846  */
 847