src/filter_virt_db.cpp

   1 /* $Id: filter_virt_db.cpp,v 1.53 2007-11-26 21:45:08 adam Exp $
   2    Copyright (c) 2005-2007, Index Data.
   3
   4 This file is part of Metaproxy.
   5
   6 Metaproxy is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 2, or (at your option) any later
   9 version.
  10
  11 Metaproxy is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with Metaproxy; see the file LICENSE.  If not, write to the
  18 Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  19 02111-1307, USA.
  20  */
  21 /* $Id: filter_virt_db.cpp,v 1.53 2007-11-26 21:45:08 adam Exp $
  22    Copyright (c) 2005-2007, Index Data.
  23
  24    See the LICENSE file for details
  25  */
  26
  27 #include "config.hpp"
  28
  29 #include "filter.hpp"
  30 #include "package.hpp"
  31
  32 #include <boost/thread/mutex.hpp>
  33 #include <boost/thread/condition.hpp>
  34 #include <boost/shared_ptr.hpp>
  35
  36 #include "util.hpp"
  37 #include "filter_virt_db.hpp"
  38
  39 #include <yaz/zgdu.h>
  40 #include <yaz/otherinfo.h>
  41 #include <yaz/diagbib1.h>
  42
  43 #include <map>
  44 #include <iostream>
  45
  46 namespace mp = metaproxy_1;
  47 namespace yf = mp::filter;
  48
  49 namespace metaproxy_1 {
  50     namespace filter {
  51
  52         struct VirtualDB::Set {
  53             Set(BackendPtr b, std::string setname);
  54             Set();
  55             ~Set();
  56
  57             BackendPtr m_backend;
  58             std::string m_setname;
  59         };
  60         struct VirtualDB::Map {
  61             Map(std::list<std::string> targets, std::string route);
  62             Map();
  63             std::list<std::string> m_targets;
  64             std::string m_route;
  65         };
  66         struct VirtualDB::Backend {
  67             mp::Session m_backend_session;
  68             std::list<std::string> m_frontend_databases;
  69             std::list<std::string> m_targets;
  70             std::string m_route;
  71             bool m_named_result_sets;
  72             int m_number_of_sets;
  73         };
  74         struct VirtualDB::Frontend {
  75             Frontend(Rep *rep);
  76             ~Frontend();
  77             mp::Session m_session;
  78             bool m_is_virtual;
  79             bool m_in_use;
  80             yazpp_1::GDU m_init_gdu;
  81             std::list<BackendPtr> m_backend_list;
  82             std::map<std::string,VirtualDB::Set> m_sets;
  83
  84             void search(Package &package, Z_APDU *apdu);
  85             void present(Package &package, Z_APDU *apdu);
  86             void scan(Package &package, Z_APDU *apdu);
  87
  88             void close(Package &package);
  89             typedef std::map<std::string,VirtualDB::Set>::iterator Sets_it;
  90
  91             void fixup_package(Package &p, BackendPtr b);
  92             void fixup_npr_record(ODR odr, Z_NamePlusRecord *npr,
  93                                   BackendPtr b);
  94             void fixup_npr_records(ODR odr, Z_Records *records,
  95                                    BackendPtr b);
  96
  97             BackendPtr lookup_backend_from_databases(
  98                 std::list<std::string> databases);
  99             BackendPtr create_backend_from_databases(
 100                 std::list<std::string> databases,
 101                 int &error_code,
 102                 std::string &failing_database);
 103
 104             BackendPtr init_backend(std::list<std::string> database,
 105                                     Package &package,
 106                                     int &error_code, std::string &addinfo);
 107             Rep *m_p;
 108         };
 109         class VirtualDB::Rep {
 110             friend class VirtualDB;
 111             friend struct Frontend;
 112
 113             FrontendPtr get_frontend(Package &package);
 114             void release_frontend(Package &package);
 115         private:
 116             std::map<std::string, VirtualDB::Map>m_maps;
 117             typedef std::map<std::string,VirtualDB::Set>::iterator Sets_it;
 118             boost::mutex m_mutex;
 119             boost::condition m_cond_session_ready;
 120             std::map<mp::Session, FrontendPtr> m_clients;
 121         };
 122     }
 123 }
 124
 125 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::lookup_backend_from_databases(
 126     std::list<std::string> databases)
 127 {
 128     std::list<BackendPtr>::const_iterator map_it;
 129     map_it = m_backend_list.begin();
 130     for (; map_it != m_backend_list.end(); map_it++)
 131         if ((*map_it)->m_frontend_databases == databases)
 132             return *map_it;
 133     BackendPtr null;
 134     return null;
 135 }
 136
 137 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::create_backend_from_databases(
 138     std::list<std::string> databases, int &error_code, std::string &addinfo)
 139 {
 140     BackendPtr b(new Backend);
 141     std::list<std::string>::const_iterator db_it = databases.begin();
 142
 143     b->m_number_of_sets = 0;
 144     b->m_frontend_databases = databases;
 145     b->m_named_result_sets = false;
 146
 147     bool first_route = true;
 148
 149     std::map<std::string,bool> targets_dedup;
 150     for (; db_it != databases.end(); db_it++)
 151     {
 152         std::map<std::string, VirtualDB::Map>::iterator map_it;
 153         map_it = m_p->m_maps.find(mp::util::database_name_normalize(*db_it));
 154         if (map_it == m_p->m_maps.end())  // database not found
 155         {
 156             error_code = YAZ_BIB1_DATABASE_DOES_NOT_EXIST;
 157             addinfo = *db_it;
 158             BackendPtr ptr;
 159             return ptr;
 160         }
 161         std::list<std::string>::const_iterator t_it =
 162             map_it->second.m_targets.begin();
 163         for (; t_it != map_it->second.m_targets.end(); t_it++) {
 164             if (!targets_dedup[*t_it])
 165             {
 166                 targets_dedup[*t_it] = true;
 167                 b->m_targets.push_back(*t_it);
 168             }
 169         }
 170
 171         // see if we have a route conflict.
 172         if (!first_route && b->m_route != map_it->second.m_route)
 173         {
 174             // we have a conflict..
 175             error_code =  YAZ_BIB1_COMBI_OF_SPECIFIED_DATABASES_UNSUPP;
 176             BackendPtr ptr;
 177             return ptr;
 178         }
 179         b->m_route = map_it->second.m_route;
 180         first_route = false;
 181     }
 182     return b;
 183 }
 184
 185 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::init_backend(
 186     std::list<std::string> databases, mp::Package &package,
 187     int &error_code, std::string &addinfo)
 188 {
 189     BackendPtr b = create_backend_from_databases(databases, error_code,
 190                                                  addinfo);
 191     if (!b)
 192         return b;
 193     Package init_package(b->m_backend_session, package.origin());
 194     init_package.copy_filter(package);
 195
 196     mp::odr odr;
 197
 198     Z_APDU *init_apdu = zget_APDU(odr, Z_APDU_initRequest);
 199
 200     mp::util::set_vhost_otherinfo(&init_apdu->u.initRequest->otherInfo, odr,
 201                                    b->m_targets);
 202     Z_InitRequest *req = init_apdu->u.initRequest;
 203
 204     // copy stuff from Frontend Init Request
 205     Z_GDU *org_gdu = m_init_gdu.get();
 206     Z_InitRequest *org_init = org_gdu->u.z3950->u.initRequest;
 207
 208     req->idAuthentication = org_init->idAuthentication;
 209     req->implementationId = org_init->implementationId;
 210     req->implementationName = org_init->implementationName;
 211     req->implementationVersion = org_init->implementationVersion;
 212
 213     ODR_MASK_SET(req->options, Z_Options_search);
 214     ODR_MASK_SET(req->options, Z_Options_present);
 215     ODR_MASK_SET(req->options, Z_Options_namedResultSets);
 216     ODR_MASK_SET(req->options, Z_Options_scan);
 217
 218     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_1);
 219     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_2);
 220     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_3);
 221
 222     init_package.request() = init_apdu;
 223
 224     init_package.move(b->m_route);  // sending init
 225
 226     Z_GDU *gdu = init_package.response().get();
 227     // we hope to get an init response
 228     if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
 229         Z_APDU_initResponse)
 230     {
 231         Z_InitResponse *res = gdu->u.z3950->u.initResponse;
 232         if (ODR_MASK_GET(res->options, Z_Options_namedResultSets))
 233         {
 234             b->m_named_result_sets = true;
 235         }
 236         if (!*res->result)
 237         {
 238             error_code = YAZ_BIB1_DATABASE_UNAVAILABLE;
 239             mp::util::get_init_diagnostics(res, error_code, addinfo);
 240             BackendPtr null;
 241             return null;
 242         }
 243     }
 244     else
 245     {
 246         error_code = YAZ_BIB1_DATABASE_UNAVAILABLE;
 247         // addinfo = database;
 248         BackendPtr null;
 249         return null;
 250     }
 251     if (init_package.session().is_closed())
 252     {
 253         error_code = YAZ_BIB1_DATABASE_UNAVAILABLE;
 254         // addinfo = database;
 255         BackendPtr null;
 256         return null;
 257     }
 258
 259     m_backend_list.push_back(b);
 260     return b;
 261 }
 262
 263 void yf::VirtualDB::Frontend::search(mp::Package &package, Z_APDU *apdu_req)
 264 {
 265     Z_SearchRequest *req = apdu_req->u.searchRequest;
 266     std::string vhost;
 267     std::string resultSetId = req->resultSetName;
 268     mp::odr odr;
 269
 270     std::list<std::string> databases;
 271     int i;
 272     for (i = 0; i<req->num_databaseNames; i++)
 273         databases.push_back(req->databaseNames[i]);
 274
 275     BackendPtr b; // null for now
 276     Sets_it sets_it = m_sets.find(req->resultSetName);
 277     if (sets_it != m_sets.end())
 278     {
 279         // result set already exist
 280         // if replace indicator is off: we return diagnostic if
 281         // result set already exist.
 282         if (*req->replaceIndicator == 0)
 283         {
 284             Z_APDU *apdu =
 285                 odr.create_searchResponse(
 286                     apdu_req,
 287                     YAZ_BIB1_RESULT_SET_EXISTS_AND_REPLACE_INDICATOR_OFF,
 288                     0);
 289             package.response() = apdu;
 290
 291             return;
 292         }
 293         sets_it->second.m_backend->m_number_of_sets--;
 294
 295         // pick up any existing backend with a database match
 296         std::list<BackendPtr>::const_iterator map_it;
 297         map_it = m_backend_list.begin();
 298         for (; map_it != m_backend_list.end(); map_it++)
 299         {
 300             BackendPtr tmp = *map_it;
 301             if (tmp->m_frontend_databases == databases)
 302                 break;
 303         }
 304         if (map_it != m_backend_list.end())
 305             b = *map_it;
 306     }
 307     else
 308     {
 309         // new result set.
 310
 311         // pick up any existing database with named result sets ..
 312         // or one which has no result sets.. yet.
 313         std::list<BackendPtr>::const_iterator map_it;
 314         map_it = m_backend_list.begin();
 315         for (; map_it != m_backend_list.end(); map_it++)
 316         {
 317             BackendPtr tmp = *map_it;
 318             if (tmp->m_frontend_databases == databases &&
 319                 (tmp->m_named_result_sets ||
 320                  tmp->m_number_of_sets == 0))
 321                 break;
 322         }
 323         if (map_it != m_backend_list.end())
 324             b = *map_it;
 325     }
 326     if (!b)  // no backend yet. Must create a new one
 327     {
 328         int error_code;
 329         std::string addinfo;
 330         b = init_backend(databases, package, error_code, addinfo);
 331         if (!b)
 332         {
 333             // did not get a backend (unavailable somehow?)
 334
 335             Z_APDU *apdu =
 336                 odr.create_searchResponse(
 337                     apdu_req, error_code, addinfo.c_str());
 338             package.response() = apdu;
 339             return;
 340         }
 341     }
 342     m_sets.erase(req->resultSetName);
 343     // sending search to backend
 344     Package search_package(b->m_backend_session, package.origin());
 345
 346     search_package.copy_filter(package);
 347
 348     std::string backend_setname;
 349     if (b->m_named_result_sets)
 350     {
 351         backend_setname = std::string(req->resultSetName);
 352     }
 353     else
 354     {
 355         backend_setname = "default";
 356         req->resultSetName = odr_strdup(odr, backend_setname.c_str());
 357     }
 358
 359     // pick first targets spec and move the databases from it ..
 360     std::list<std::string>::const_iterator t_it = b->m_targets.begin();
 361     if (t_it != b->m_targets.end())
 362     {
 363         mp::util::set_databases_from_zurl(odr, *t_it,
 364                                                 &req->num_databaseNames,
 365                                                 &req->databaseNames);
 366     }
 367
 368     *req->replaceIndicator = 1;
 369
 370     search_package.request() = yazpp_1::GDU(apdu_req);
 371
 372     search_package.move(b->m_route);
 373
 374     if (search_package.session().is_closed())
 375     {
 376         package.response() = search_package.response();
 377         package.session().close();
 378         return;
 379     }
 380     b->m_number_of_sets++;
 381
 382     m_sets[resultSetId] = VirtualDB::Set(b, backend_setname);
 383     fixup_package(search_package, b);
 384     package.response() = search_package.response();
 385 }
 386
 387 yf::VirtualDB::Frontend::Frontend(Rep *rep)
 388 {
 389     m_p = rep;
 390     m_is_virtual = false;
 391 }
 392
 393 void yf::VirtualDB::Frontend::close(mp::Package &package)
 394 {
 395     std::list<BackendPtr>::const_iterator b_it;
 396
 397     for (b_it = m_backend_list.begin(); b_it != m_backend_list.end(); b_it++)
 398     {
 399         (*b_it)->m_backend_session.close();
 400         Package close_package((*b_it)->m_backend_session, package.origin());
 401         close_package.copy_filter(package);
 402         close_package.move((*b_it)->m_route);
 403     }
 404     m_backend_list.clear();
 405 }
 406
 407 yf::VirtualDB::Frontend::~Frontend()
 408 {
 409 }
 410
 411 yf::VirtualDB::FrontendPtr yf::VirtualDB::Rep::get_frontend(mp::Package &package)
 412 {
 413     boost::mutex::scoped_lock lock(m_mutex);
 414
 415     std::map<mp::Session,yf::VirtualDB::FrontendPtr>::iterator it;
 416
 417     while(true)
 418     {
 419         it = m_clients.find(package.session());
 420         if (it == m_clients.end())
 421             break;
 422
 423         if (!it->second->m_in_use)
 424         {
 425             it->second->m_in_use = true;
 426             return it->second;
 427         }
 428         m_cond_session_ready.wait(lock);
 429     }
 430     FrontendPtr f(new Frontend(this));
 431     m_clients[package.session()] = f;
 432     f->m_in_use = true;
 433     return f;
 434 }
 435
 436 void yf::VirtualDB::Rep::release_frontend(mp::Package &package)
 437 {
 438     boost::mutex::scoped_lock lock(m_mutex);
 439     std::map<mp::Session,yf::VirtualDB::FrontendPtr>::iterator it;
 440
 441     it = m_clients.find(package.session());
 442     if (it != m_clients.end())
 443     {
 444         if (package.session().is_closed())
 445         {
 446             it->second->close(package);
 447             m_clients.erase(it);
 448         }
 449         else
 450         {
 451             it->second->m_in_use = false;
 452         }
 453         m_cond_session_ready.notify_all();
 454     }
 455 }
 456
 457 yf::VirtualDB::Set::Set(BackendPtr b, std::string setname)
 458     :  m_backend(b), m_setname(setname)
 459 {
 460 }
 461
 462
 463 yf::VirtualDB::Set::Set()
 464 {
 465 }
 466
 467
 468 yf::VirtualDB::Set::~Set()
 469 {
 470 }
 471
 472 yf::VirtualDB::Map::Map(std::list<std::string> targets, std::string route)
 473     : m_targets(targets), m_route(route)
 474 {
 475 }
 476
 477 yf::VirtualDB::Map::Map()
 478 {
 479 }
 480
 481 yf::VirtualDB::VirtualDB() : m_p(new VirtualDB::Rep)
 482 {
 483 }
 484
 485 yf::VirtualDB::~VirtualDB() {
 486 }
 487
 488 void yf::VirtualDB::Frontend::fixup_npr_record(ODR odr, Z_NamePlusRecord *npr,
 489                                              BackendPtr b)
 490 {
 491     if (npr->databaseName)
 492     {
 493         std::string b_database = std::string(npr->databaseName);
 494
 495         // consider each of the frontend databases..
 496         std::list<std::string>::const_iterator db_it;
 497         for (db_it = b->m_frontend_databases.begin();
 498              db_it != b->m_frontend_databases.end(); db_it++)
 499         {
 500             // see which target it corresponds to.. (if any)
 501             std::map<std::string,VirtualDB::Map>::const_iterator map_it;
 502
 503             map_it = m_p->m_maps.find(mp::util::database_name_normalize(*db_it));
 504             if (map_it != m_p->m_maps.end())
 505             {
 506                 VirtualDB::Map m = map_it->second;
 507
 508                 std::list<std::string>::const_iterator t;
 509                 for (t = m.m_targets.begin(); t != m.m_targets.end(); t++)
 510                 {
 511                     if (*t == b_database)
 512                     {
 513                         npr->databaseName = odr_strdup(odr, (*db_it).c_str());
 514                         return;
 515                     }
 516                 }
 517             }
 518
 519         }
 520         db_it = b->m_frontend_databases.begin();
 521         if (db_it != b->m_frontend_databases.end())
 522         {
 523             std::string database = *db_it;
 524             npr->databaseName = odr_strdup(odr, database.c_str());
 525         }
 526     }
 527 }
 528
 529 void yf::VirtualDB::Frontend::fixup_npr_records(ODR odr, Z_Records *records,
 530                                               BackendPtr b)
 531 {
 532     if (records && records->which == Z_Records_DBOSD)
 533     {
 534         Z_NamePlusRecordList *nprlist = records->u.databaseOrSurDiagnostics;
 535         int i;
 536         for (i = 0; i < nprlist->num_records; i++)
 537         {
 538             fixup_npr_record(odr, nprlist->records[i], b);
 539         }
 540     }
 541 }
 542
 543 void yf::VirtualDB::Frontend::fixup_package(mp::Package &p, BackendPtr b)
 544 {
 545     Z_GDU *gdu = p.response().get();
 546     mp::odr odr;
 547
 548     if (gdu && gdu->which == Z_GDU_Z3950)
 549     {
 550         Z_APDU *apdu = gdu->u.z3950;
 551         if (apdu->which == Z_APDU_presentResponse)
 552         {
 553             fixup_npr_records(odr, apdu->u.presentResponse->records, b);
 554             p.response() = gdu;
 555         }
 556         else if (apdu->which == Z_APDU_searchResponse)
 557         {
 558             fixup_npr_records(odr,  apdu->u.searchResponse->records, b);
 559             p.response() = gdu;
 560         }
 561     }
 562 }
 563
 564 void yf::VirtualDB::Frontend::present(mp::Package &package, Z_APDU *apdu_req)
 565 {
 566     Z_PresentRequest *req = apdu_req->u.presentRequest;
 567     std::string resultSetId = req->resultSetId;
 568     mp::odr odr;
 569
 570     Sets_it sets_it = m_sets.find(resultSetId);
 571     if (sets_it == m_sets.end())
 572     {
 573         Z_APDU *apdu =
 574             odr.create_presentResponse(
 575                 apdu_req,
 576                 YAZ_BIB1_SPECIFIED_RESULT_SET_DOES_NOT_EXIST,
 577                 resultSetId.c_str());
 578         package.response() = apdu;
 579         return;
 580     }
 581     Session *id =
 582         new mp::Session(sets_it->second.m_backend->m_backend_session);
 583
 584     // sending present to backend
 585     Package present_package(*id, package.origin());
 586     present_package.copy_filter(package);
 587
 588     req->resultSetId = odr_strdup(odr, sets_it->second.m_setname.c_str());
 589
 590     present_package.request() = yazpp_1::GDU(apdu_req);
 591
 592     present_package.move(sets_it->second.m_backend->m_route);
 593
 594     fixup_package(present_package, sets_it->second.m_backend);
 595
 596     if (present_package.session().is_closed())
 597     {
 598         package.response() = present_package.response();
 599         package.session().close();
 600         return;
 601     }
 602     else
 603     {
 604         package.response() = present_package.response();
 605     }
 606     delete id;
 607 }
 608
 609 void yf::VirtualDB::Frontend::scan(mp::Package &package, Z_APDU *apdu_req)
 610 {
 611     Z_ScanRequest *req = apdu_req->u.scanRequest;
 612     std::string vhost;
 613     mp::odr odr;
 614
 615     std::list<std::string> databases;
 616     int i;
 617     for (i = 0; i<req->num_databaseNames; i++)
 618         databases.push_back(req->databaseNames[i]);
 619
 620     BackendPtr b;
 621     // pick up any existing backend with a database match
 622     std::list<BackendPtr>::const_iterator map_it;
 623     map_it = m_backend_list.begin();
 624     for (; map_it != m_backend_list.end(); map_it++)
 625     {
 626         BackendPtr tmp = *map_it;
 627         if (tmp->m_frontend_databases == databases)
 628             break;
 629     }
 630     if (map_it != m_backend_list.end())
 631         b = *map_it;
 632     if (!b)  // no backend yet. Must create a new one
 633     {
 634         int error_code;
 635         std::string addinfo;
 636         b = init_backend(databases, package, error_code, addinfo);
 637         if (!b)
 638         {
 639             // did not get a backend (unavailable somehow?)
 640             Z_APDU *apdu =
 641                 odr.create_scanResponse(
 642                     apdu_req, error_code, addinfo.c_str());
 643             package.response() = apdu;
 644
 645             return;
 646         }
 647     }
 648     // sending scan to backend
 649     Package scan_package(b->m_backend_session, package.origin());
 650
 651     scan_package.copy_filter(package);
 652
 653     // pick first targets spec and move the databases from it ..
 654     std::list<std::string>::const_iterator t_it = b->m_targets.begin();
 655     if (t_it != b->m_targets.end())
 656     {
 657         mp::util::set_databases_from_zurl(odr, *t_it,
 658                                                 &req->num_databaseNames,
 659                                                 &req->databaseNames);
 660     }
 661     scan_package.request() = yazpp_1::GDU(apdu_req);
 662
 663     scan_package.move(b->m_route);
 664
 665     if (scan_package.session().is_closed())
 666     {
 667         package.response() = scan_package.response();
 668         package.session().close();
 669         return;
 670     }
 671     package.response() = scan_package.response();
 672 }
 673
 674
 675 void yf::VirtualDB::add_map_db2targets(std::string db,
 676                                      std::list<std::string> targets,
 677                                      std::string route)
 678 {
 679     m_p->m_maps[mp::util::database_name_normalize(db)]
 680         = VirtualDB::Map(targets, route);
 681 }
 682
 683
 684 void yf::VirtualDB::add_map_db2target(std::string db,
 685                                     std::string target,
 686                                     std::string route)
 687 {
 688     std::list<std::string> targets;
 689     targets.push_back(target);
 690
 691     m_p->m_maps[mp::util::database_name_normalize(db)]
 692         = VirtualDB::Map(targets, route);
 693 }
 694
 695 void yf::VirtualDB::process(mp::Package &package) const
 696 {
 697     FrontendPtr f = m_p->get_frontend(package);
 698
 699     Z_GDU *gdu = package.request().get();
 700
 701     if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
 702         Z_APDU_initRequest && !f->m_is_virtual)
 703     {
 704         Z_InitRequest *req = gdu->u.z3950->u.initRequest;
 705
 706         std::list<std::string> vhosts;
 707         mp::util::get_vhost_otherinfo(req->otherInfo, vhosts);
 708         if (vhosts.size() == 0)
 709         {
 710             f->m_init_gdu = gdu;
 711
 712             mp::odr odr;
 713             Z_APDU *apdu = odr.create_initResponse(gdu->u.z3950, 0, 0);
 714             Z_InitResponse *resp = apdu->u.initResponse;
 715
 716             int i;
 717             static const int masks[] = {
 718                 Z_Options_search,
 719                 Z_Options_present,
 720                 Z_Options_namedResultSets,
 721                 Z_Options_scan,
 722                 -1
 723             };
 724             for (i = 0; masks[i] != -1; i++)
 725                 if (ODR_MASK_GET(req->options, masks[i]))
 726                     ODR_MASK_SET(resp->options, masks[i]);
 727
 728             static const int versions[] = {
 729                 Z_ProtocolVersion_1,
 730                 Z_ProtocolVersion_2,
 731                 Z_ProtocolVersion_3,
 732                 -1
 733             };
 734             for (i = 0; versions[i] != -1; i++)
 735                 if (ODR_MASK_GET(req->protocolVersion, versions[i]))
 736                     ODR_MASK_SET(resp->protocolVersion, versions[i]);
 737                 else
 738                     break;
 739
 740             package.response() = apdu;
 741             f->m_is_virtual = true;
 742         }
 743         else
 744             package.move();
 745     }
 746     else if (!f->m_is_virtual)
 747         package.move();
 748     else if (gdu && gdu->which == Z_GDU_Z3950)
 749     {
 750         Z_APDU *apdu = gdu->u.z3950;
 751         if (apdu->which == Z_APDU_initRequest)
 752         {
 753             mp::odr odr;
 754
 755             package.response() = odr.create_close(
 756                 apdu,
 757                 Z_Close_protocolError,
 758                 "double init");
 759
 760             package.session().close();
 761         }
 762         else if (apdu->which == Z_APDU_searchRequest)
 763         {
 764             f->search(package, apdu);
 765         }
 766         else if (apdu->which == Z_APDU_presentRequest)
 767         {
 768             f->present(package, apdu);
 769         }
 770         else if (apdu->which == Z_APDU_scanRequest)
 771         {
 772             f->scan(package, apdu);
 773         }
 774         else if (apdu->which == Z_APDU_close)
 775         {
 776             package.session().close();
 777         }
 778         else
 779         {
 780             mp::odr odr;
 781
 782             package.response() = odr.create_close(
 783                 apdu, Z_Close_protocolError,
 784                 "unsupported APDU in filter_virt_db");
 785
 786             package.session().close();
 787         }
 788     }
 789     m_p->release_frontend(package);
 790 }
 791
 792
 793 void mp::filter::VirtualDB::configure(const xmlNode * ptr)
 794 {
 795     for (ptr = ptr->children; ptr; ptr = ptr->next)
 796     {
 797         if (ptr->type != XML_ELEMENT_NODE)
 798             continue;
 799         if (!strcmp((const char *) ptr->name, "virtual"))
 800         {
 801             std::string database;
 802             std::list<std::string> targets;
 803             xmlNode *v_node = ptr->children;
 804             for (; v_node; v_node = v_node->next)
 805             {
 806                 if (v_node->type != XML_ELEMENT_NODE)
 807                     continue;
 808
 809                 if (mp::xml::is_element_mp(v_node, "database"))
 810                     database = mp::xml::get_text(v_node);
 811                 else if (mp::xml::is_element_mp(v_node, "target"))
 812                     targets.push_back(mp::xml::get_text(v_node));
 813                 else
 814                     throw mp::filter::FilterException
 815                         ("Bad element "
 816                          + std::string((const char *) v_node->name)
 817                          + " in virtual section"
 818                             );
 819             }
 820             std::string route = mp::xml::get_route(ptr);
 821             add_map_db2targets(database, targets, route);
 822         }
 823         else
 824         {
 825             throw mp::filter::FilterException
 826                 ("Bad element "
 827                  + std::string((const char *) ptr->name)
 828                  + " in virt_db filter");
 829         }
 830     }
 831 }
 832
 833 static mp::filter::Base* filter_creator()
 834 {
 835     return new mp::filter::VirtualDB;
 836 }
 837
 838 extern "C" {
 839     struct metaproxy_1_filter_struct metaproxy_1_filter_virt_db = {
 840         0,
 841         "virt_db",
 842         filter_creator
 843     };
 844 }
 845
 846
 847 /*
 848  * Local variables:
 849  * c-basic-offset: 4
 850  * indent-tabs-mode: nil
 851  * c-file-style: "stroustrup"
 852  * End:
 853  * vim: shiftwidth=4 tabstop=8 expandtab
 854  */