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 #include "torus.hpp"
  30
  31 #include <yaz/zgdu.h>
  32 #include <yaz/otherinfo.h>
  33 #include <yaz/diagbib1.h>
  34 #include <yaz/match_glob.h>
  35 #include <yaz/log.h>
  36
  37 #include <map>
  38 #include <iostream>
  39
  40 namespace mp = metaproxy_1;
  41 namespace yf = mp::filter;
  42
  43 namespace metaproxy_1 {
  44     namespace filter {
  45
  46         struct VirtualDB::Set {
  47             Set(BackendPtr b, std::string setname);
  48             Set();
  49             ~Set();
  50
  51             BackendPtr m_backend;
  52             std::string m_setname;
  53         };
  54         struct VirtualDB::Map {
  55             Map(std::string database, std::list<std::string> targets, std::string route);
  56             Map(std::string database, std::string target, std::string route);
  57             Map();
  58             bool match(const std::string db) const;
  59             std::string m_dbpattern;
  60             std::list<std::string> m_targets;
  61             std::string m_route;
  62         public:
  63             std::string m_query_encoding;
  64         };
  65         struct VirtualDB::Backend {
  66             mp::Session m_backend_session;
  67             std::list<std::string> m_frontend_databases;
  68             std::list<std::string> m_targets;
  69             std::string m_route;
  70             bool m_named_result_sets;
  71             int m_number_of_sets;
  72         };
  73         struct VirtualDB::Frontend {
  74             Frontend(Rep *rep);
  75             ~Frontend();
  76             mp::Session m_session;
  77             bool m_is_virtual;
  78             bool m_in_use;
  79             yazpp_1::GDU m_init_gdu;
  80             std::list<BackendPtr> m_backend_list;
  81             std::map<std::string,VirtualDB::Set> m_sets;
  82
  83             void search(Package &package, Z_APDU *apdu);
  84             void present(Package &package, Z_APDU *apdu);
  85             void scan(Package &package, Z_APDU *apdu);
  86             int relay_apdu(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             void refresh_torus();
 116         private:
 117             std::list<VirtualDB::Map>m_maps;
 118             typedef std::map<std::string,VirtualDB::Set>::iterator Sets_it;
 119             boost::mutex m_mutex;
 120             boost::condition m_cond_session_ready;
 121             std::map<mp::Session, FrontendPtr> m_clients;
 122             bool pass_vhosts;
 123             mp::Torus torus;
 124         };
 125     }
 126 }
 127
 128 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::lookup_backend_from_databases(
 129     std::list<std::string> databases)
 130 {
 131     std::list<BackendPtr>::const_iterator map_it;
 132     map_it = m_backend_list.begin();
 133     for (; map_it != m_backend_list.end(); map_it++)
 134         if ((*map_it)->m_frontend_databases == databases)
 135             return *map_it;
 136     BackendPtr null;
 137     return null;
 138 }
 139
 140 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::create_backend_from_databases(
 141     std::list<std::string> databases, int &error_code, std::string &addinfo)
 142 {
 143     BackendPtr b(new Backend);
 144     std::list<std::string>::const_iterator db_it = databases.begin();
 145
 146     b->m_number_of_sets = 0;
 147     b->m_frontend_databases = databases;
 148     b->m_named_result_sets = false;
 149
 150     bool first_route = true;
 151
 152     std::map<std::string,bool> targets_dedup;
 153     for (; db_it != databases.end(); db_it++)
 154     {
 155         std::list<VirtualDB::Map>::const_iterator map_it;
 156         map_it = m_p->m_maps.begin();
 157         while (map_it != m_p->m_maps.end())
 158         {
 159             if (map_it->match(*db_it))
 160                 break;
 161             map_it++;
 162         }
 163
 164         if (map_it == m_p->m_maps.end())  // database not found
 165         {
 166             error_code = YAZ_BIB1_DATABASE_DOES_NOT_EXIST;
 167             addinfo = *db_it;
 168             BackendPtr ptr;
 169             return ptr;
 170         }
 171         std::list<std::string>::const_iterator t_it =
 172             map_it->m_targets.begin();
 173         for (; t_it != map_it->m_targets.end(); t_it++) {
 174             if (!targets_dedup[*t_it])
 175             {
 176                 targets_dedup[*t_it] = true;
 177                 b->m_targets.push_back(*t_it);
 178             }
 179         }
 180
 181         // see if we have a route conflict.
 182         if (!first_route && b->m_route != map_it->m_route)
 183         {
 184             // we have a conflict..
 185             error_code =  YAZ_BIB1_COMBI_OF_SPECIFIED_DATABASES_UNSUPP;
 186             BackendPtr ptr;
 187             return ptr;
 188         }
 189         b->m_route = map_it->m_route;
 190         first_route = false;
 191     }
 192     return b;
 193 }
 194
 195 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::init_backend(
 196     std::list<std::string> databases, mp::Package &package,
 197     int &error_code, std::string &addinfo)
 198 {
 199     BackendPtr b = create_backend_from_databases(databases, error_code,
 200                                                  addinfo);
 201     if (!b)
 202         return b;
 203     Package init_package(b->m_backend_session, package.origin());
 204     init_package.copy_filter(package);
 205
 206     mp::odr odr;
 207
 208     Z_APDU *init_apdu = zget_APDU(odr, Z_APDU_initRequest);
 209
 210     mp::util::set_vhost_otherinfo(&init_apdu->u.initRequest->otherInfo, odr,
 211                                    b->m_targets);
 212     Z_InitRequest *req = init_apdu->u.initRequest;
 213
 214     // copy stuff from Frontend Init Request
 215     Z_GDU *org_gdu = m_init_gdu.get();
 216     Z_InitRequest *org_init = org_gdu->u.z3950->u.initRequest;
 217
 218     req->idAuthentication = org_init->idAuthentication;
 219     req->implementationId = org_init->implementationId;
 220     req->implementationName = org_init->implementationName;
 221     req->implementationVersion = org_init->implementationVersion;
 222     *req->preferredMessageSize = *org_init->preferredMessageSize;
 223     *req->maximumRecordSize = *org_init->maximumRecordSize;
 224
 225     ODR_MASK_SET(req->options, Z_Options_search);
 226     ODR_MASK_SET(req->options, Z_Options_present);
 227     ODR_MASK_SET(req->options, Z_Options_namedResultSets);
 228     ODR_MASK_SET(req->options, Z_Options_scan);
 229
 230     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_1);
 231     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_2);
 232     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_3);
 233
 234     init_package.request() = init_apdu;
 235
 236     init_package.move(b->m_route);  // sending init
 237
 238     Z_GDU *gdu = init_package.response().get();
 239     // we hope to get an init response
 240     error_code = YAZ_BIB1_DATABASE_UNAVAILABLE;
 241     if (gdu && gdu->which == Z_GDU_Z3950
 242         && gdu->u.z3950->which == Z_APDU_initResponse
 243         && *gdu->u.z3950->u.initResponse->result)
 244     {
 245         Z_InitResponse *res = gdu->u.z3950->u.initResponse;
 246         if (ODR_MASK_GET(res->options, Z_Options_namedResultSets))
 247         {
 248             b->m_named_result_sets = true;
 249         }
 250         if (*res->result && !init_package.session().is_closed())
 251         {
 252             m_backend_list.push_back(b);
 253             return b;
 254         }
 255         mp::util::get_init_diagnostics(res, error_code, addinfo);
 256     }
 257     if (!init_package.session().is_closed())
 258     {
 259         Package close_package(b->m_backend_session, package.origin());
 260         close_package.copy_filter(package);
 261         close_package.session().close();
 262         close_package.move(b->m_route);  // closing it
 263     }
 264     BackendPtr null;
 265     return null;
 266 }
 267
 268 void yf::VirtualDB::Frontend::search(mp::Package &package, Z_APDU *apdu_req)
 269 {
 270     Z_SearchRequest *req = apdu_req->u.searchRequest;
 271     std::string vhost;
 272     std::string resultSetId = req->resultSetName;
 273     mp::odr odr;
 274
 275     std::list<std::string> databases;
 276     int i;
 277     for (i = 0; i<req->num_databaseNames; i++)
 278         databases.push_back(req->databaseNames[i]);
 279
 280     Sets_it sets_it = m_sets.find(req->resultSetName);
 281     if (sets_it != m_sets.end())
 282     {
 283         // result set already exist
 284         // if replace indicator is off: we return diagnostic if
 285         // result set already exist.
 286         if (*req->replaceIndicator == 0)
 287         {
 288             Z_APDU *apdu =
 289                 odr.create_searchResponse(
 290                     apdu_req,
 291                     YAZ_BIB1_RESULT_SET_EXISTS_AND_REPLACE_INDICATOR_OFF,
 292                     0);
 293             package.response() = apdu;
 294
 295             return;
 296         }
 297         sets_it->second.m_backend->m_number_of_sets--;
 298     }
 299     // pick up any existing database with named result sets ..
 300     // or one which has no result sets.. yet.
 301     BackendPtr b; // null for now
 302     std::list<BackendPtr>::const_iterator map_it;
 303     map_it = m_backend_list.begin();
 304     for (; map_it != m_backend_list.end(); map_it++)
 305     {
 306         BackendPtr tmp = *map_it;
 307         if (tmp->m_frontend_databases == databases &&
 308             (tmp->m_named_result_sets ||
 309              tmp->m_number_of_sets == 0))
 310         {
 311             b = *map_it;
 312             break;
 313         }
 314     }
 315     if (!b)  // no backend yet. Must create a new one
 316     {
 317         int error_code;
 318         std::string addinfo;
 319         b = init_backend(databases, package, error_code, addinfo);
 320         if (!b)
 321         {
 322             // did not get a backend (unavailable somehow?)
 323
 324             Z_APDU *apdu =
 325                 odr.create_searchResponse(
 326                     apdu_req, error_code, addinfo.c_str());
 327             package.response() = apdu;
 328             return;
 329         }
 330     }
 331     m_sets.erase(req->resultSetName);
 332     // sending search to backend
 333     Package search_package(b->m_backend_session, package.origin());
 334
 335     search_package.copy_filter(package);
 336
 337     std::string backend_setname;
 338     if (b->m_named_result_sets)
 339     {
 340         backend_setname = std::string(req->resultSetName);
 341     }
 342     else
 343     {
 344         backend_setname = "default";
 345         req->resultSetName = odr_strdup(odr, backend_setname.c_str());
 346     }
 347
 348     // pick first targets spec and move the databases from it ..
 349     std::list<std::string>::const_iterator t_it = b->m_targets.begin();
 350     if (t_it != b->m_targets.end())
 351     {
 352         mp::util::set_databases_from_zurl(odr, *t_it,
 353                                                 &req->num_databaseNames,
 354                                                 &req->databaseNames);
 355     }
 356
 357     *req->replaceIndicator = 1;
 358
 359     search_package.request() = yazpp_1::GDU(apdu_req);
 360
 361     search_package.move(b->m_route);
 362
 363     if (search_package.session().is_closed())
 364     {
 365         package.response() = search_package.response();
 366         package.session().close();
 367         return;
 368     }
 369     b->m_number_of_sets++;
 370
 371     m_sets[resultSetId] = VirtualDB::Set(b, backend_setname);
 372     fixup_package(search_package, b);
 373     package.response() = search_package.response();
 374 }
 375
 376 yf::VirtualDB::Frontend::Frontend(Rep *rep)
 377 {
 378     m_p = rep;
 379     m_is_virtual = false;
 380 }
 381
 382 void yf::VirtualDB::Frontend::close(mp::Package &package)
 383 {
 384     std::list<BackendPtr>::const_iterator b_it;
 385
 386     for (b_it = m_backend_list.begin(); b_it != m_backend_list.end(); b_it++)
 387     {
 388         (*b_it)->m_backend_session.close();
 389         Package close_package((*b_it)->m_backend_session, package.origin());
 390         close_package.copy_filter(package);
 391         close_package.move((*b_it)->m_route);
 392     }
 393     m_backend_list.clear();
 394 }
 395
 396 yf::VirtualDB::Frontend::~Frontend()
 397 {
 398 }
 399
 400 yf::VirtualDB::FrontendPtr yf::VirtualDB::Rep::get_frontend(mp::Package &package)
 401 {
 402     boost::mutex::scoped_lock lock(m_mutex);
 403
 404     std::map<mp::Session,yf::VirtualDB::FrontendPtr>::iterator it;
 405
 406     while(true)
 407     {
 408         it = m_clients.find(package.session());
 409         if (it == m_clients.end())
 410             break;
 411
 412         if (!it->second->m_in_use)
 413         {
 414             it->second->m_in_use = true;
 415             return it->second;
 416         }
 417         m_cond_session_ready.wait(lock);
 418     }
 419     FrontendPtr f(new Frontend(this));
 420     m_clients[package.session()] = f;
 421     f->m_in_use = true;
 422     return f;
 423 }
 424
 425 void yf::VirtualDB::Rep::release_frontend(mp::Package &package)
 426 {
 427     boost::mutex::scoped_lock lock(m_mutex);
 428     std::map<mp::Session,yf::VirtualDB::FrontendPtr>::iterator it;
 429
 430     it = m_clients.find(package.session());
 431     if (it != m_clients.end())
 432     {
 433         if (package.session().is_closed())
 434         {
 435             it->second->close(package);
 436             m_clients.erase(it);
 437         }
 438         else
 439         {
 440             it->second->m_in_use = false;
 441         }
 442         m_cond_session_ready.notify_all();
 443     }
 444 }
 445
 446 void yf::VirtualDB::Rep::refresh_torus(void)
 447 {
 448     xmlDoc *doc = torus.get_doc();
 449     if (!doc)
 450         return;
 451
 452     xmlNode *ptr1 = xmlDocGetRootElement(doc);
 453     if (!ptr1)
 454         return ;
 455
 456     for (ptr1 = ptr1->children; ptr1; ptr1 = ptr1->next)
 457     {
 458         if (ptr1->type != XML_ELEMENT_NODE)
 459             continue;
 460         if (!strcmp((const char *) ptr1->name, "record"))
 461         {
 462             xmlNode *ptr2 = ptr1;
 463             for (ptr2 = ptr2->children; ptr2; ptr2 = ptr2->next)
 464             {
 465                 if (ptr2->type != XML_ELEMENT_NODE)
 466                     continue;
 467                 if (!strcmp((const char *) ptr2->name, "layer"))
 468                 {
 469                     std::string database;
 470                     std::string target;
 471                     std::string route;
 472                     std::string solr;
 473                     std::string query_encoding;
 474                     xmlNode *ptr3 = ptr2;
 475                     for (ptr3 = ptr3->children; ptr3; ptr3 = ptr3->next)
 476                     {
 477                         if (ptr3->type != XML_ELEMENT_NODE)
 478                             continue;
 479                         if (!strcmp((const char *) ptr3->name, "id"))
 480                         {
 481                             database = mp::xml::get_text(ptr3);
 482                         }
 483                         else if (!strcmp((const char *) ptr3->name, "zurl"))
 484                         {
 485                             target = mp::xml::get_text(ptr3);
 486                         }
 487                         else if (!strcmp((const char *) ptr3->name, "sru"))
 488                         {
 489                             solr = mp::xml::get_text(ptr3);
 490                         }
 491                         else if (!strcmp((const char *) ptr3->name,
 492                                          "queryEncoding"))
 493                         {
 494                             query_encoding = mp::xml::get_text(ptr3);
 495                         }
 496                     }
 497                     if (solr.length() == 0 &&
 498                         database.length() && target.length())
 499                     {
 500                         VirtualDB::Map vmap(
 501                             mp::util::database_name_normalize(database),
 502                             target, route);
 503                         vmap.m_query_encoding = query_encoding;
 504                         m_maps.push_back(vmap);
 505                     }
 506                 }
 507             }
 508         }
 509     }
 510 }
 511
 512 yf::VirtualDB::Set::Set(BackendPtr b, std::string setname)
 513     :  m_backend(b), m_setname(setname)
 514 {
 515 }
 516
 517
 518 yf::VirtualDB::Set::Set()
 519 {
 520 }
 521
 522
 523 yf::VirtualDB::Set::~Set()
 524 {
 525 }
 526
 527 yf::VirtualDB::Map::Map(std::string database,
 528                         std::list<std::string> targets, std::string route)
 529     : m_dbpattern(database), m_targets(targets), m_route(route)
 530 {
 531 }
 532
 533 yf::VirtualDB::Map::Map(std::string database,
 534                         std::string target, std::string route)
 535     : m_dbpattern(database), m_route(route)
 536 {
 537     m_targets.push_back(target);
 538 }
 539
 540
 541 yf::VirtualDB::Map::Map()
 542 {
 543 }
 544
 545 bool yf::VirtualDB::Map::match(const std::string db) const
 546 {
 547     std::string norm_db = mp::util::database_name_normalize(db);
 548     if (yaz_match_glob(m_dbpattern.c_str(), norm_db.c_str()))
 549         return true;
 550     return false;
 551 }
 552
 553 yf::VirtualDB::VirtualDB() : m_p(new VirtualDB::Rep)
 554 {
 555     m_p->pass_vhosts = false;
 556 }
 557
 558 yf::VirtualDB::~VirtualDB() {
 559 }
 560
 561 void yf::VirtualDB::Frontend::fixup_npr_record(ODR odr, Z_NamePlusRecord *npr,
 562                                              BackendPtr b)
 563 {
 564     if (npr->databaseName)
 565     {
 566         std::string b_database = std::string(npr->databaseName);
 567
 568         // consider each of the frontend databases..
 569         std::list<std::string>::const_iterator db_it;
 570         for (db_it = b->m_frontend_databases.begin();
 571              db_it != b->m_frontend_databases.end(); db_it++)
 572         {
 573             // see which target it corresponds to.. (if any)
 574             std::list<VirtualDB::Map>::const_iterator map_it =
 575                 m_p->m_maps.begin();
 576             while (map_it != m_p->m_maps.end())
 577             {
 578                 if (map_it->match(*db_it))
 579                     break;
 580                 map_it++;
 581             }
 582             if (map_it != m_p->m_maps.end())
 583             {
 584                 std::list<std::string>::const_iterator t
 585                     = map_it->m_targets.begin();
 586                 while (t != map_it->m_targets.end())
 587                 {
 588                     if (*t == b_database)
 589                     {
 590                         npr->databaseName = odr_strdup(odr, (*db_it).c_str());
 591                         return;
 592                     }
 593                     t++;
 594                 }
 595             }
 596
 597         }
 598         db_it = b->m_frontend_databases.begin();
 599         if (db_it != b->m_frontend_databases.end())
 600         {
 601             std::string database = *db_it;
 602             npr->databaseName = odr_strdup(odr, database.c_str());
 603         }
 604     }
 605 }
 606
 607 void yf::VirtualDB::Frontend::fixup_npr_records(ODR odr, Z_Records *records,
 608                                               BackendPtr b)
 609 {
 610     if (records && records->which == Z_Records_DBOSD)
 611     {
 612         Z_NamePlusRecordList *nprlist = records->u.databaseOrSurDiagnostics;
 613         int i;
 614         for (i = 0; i < nprlist->num_records; i++)
 615         {
 616             fixup_npr_record(odr, nprlist->records[i], b);
 617         }
 618     }
 619 }
 620
 621 void yf::VirtualDB::Frontend::fixup_package(mp::Package &p, BackendPtr b)
 622 {
 623     Z_GDU *gdu = p.response().get();
 624     mp::odr odr;
 625
 626     if (gdu && gdu->which == Z_GDU_Z3950)
 627     {
 628         Z_APDU *apdu = gdu->u.z3950;
 629         if (apdu->which == Z_APDU_presentResponse)
 630         {
 631             fixup_npr_records(odr, apdu->u.presentResponse->records, b);
 632             p.response() = gdu;
 633         }
 634         else if (apdu->which == Z_APDU_searchResponse)
 635         {
 636             fixup_npr_records(odr,  apdu->u.searchResponse->records, b);
 637             p.response() = gdu;
 638         }
 639     }
 640 }
 641
 642 void yf::VirtualDB::Frontend::present(mp::Package &package, Z_APDU *apdu_req)
 643 {
 644     Z_PresentRequest *req = apdu_req->u.presentRequest;
 645     std::string resultSetId = req->resultSetId;
 646     mp::odr odr;
 647
 648     Sets_it sets_it = m_sets.find(resultSetId);
 649     if (sets_it == m_sets.end())
 650     {
 651         Z_APDU *apdu =
 652             odr.create_presentResponse(
 653                 apdu_req,
 654                 YAZ_BIB1_SPECIFIED_RESULT_SET_DOES_NOT_EXIST,
 655                 resultSetId.c_str());
 656         package.response() = apdu;
 657         return;
 658     }
 659     Session *id =
 660         new mp::Session(sets_it->second.m_backend->m_backend_session);
 661
 662     // sending present to backend
 663     Package present_package(*id, package.origin());
 664     present_package.copy_filter(package);
 665
 666     req->resultSetId = odr_strdup(odr, sets_it->second.m_setname.c_str());
 667
 668     present_package.request() = yazpp_1::GDU(apdu_req);
 669
 670     present_package.move(sets_it->second.m_backend->m_route);
 671
 672     fixup_package(present_package, sets_it->second.m_backend);
 673
 674     if (present_package.session().is_closed())
 675     {
 676         package.response() = present_package.response();
 677         package.session().close();
 678         return;
 679     }
 680     else
 681     {
 682         package.response() = present_package.response();
 683     }
 684     delete id;
 685 }
 686
 687 int yf::VirtualDB::Frontend::relay_apdu(mp::Package &package, Z_APDU *apdu_req)
 688 {
 689     int no = 0;
 690     std::list<BackendPtr>::const_iterator map_it;
 691     map_it = m_backend_list.begin();
 692     for (; map_it != m_backend_list.end(); map_it++)
 693     {
 694         BackendPtr b = *map_it;
 695
 696         Package relay_package(b->m_backend_session, package.origin());
 697         relay_package.copy_filter(package);
 698
 699         relay_package.request() = yazpp_1::GDU(apdu_req);
 700
 701         relay_package.move(b->m_route);
 702         package.response() = relay_package.response();
 703         no++;
 704     }
 705     return no;
 706 }
 707
 708 void yf::VirtualDB::Frontend::scan(mp::Package &package, Z_APDU *apdu_req)
 709 {
 710     Z_ScanRequest *req = apdu_req->u.scanRequest;
 711     std::string vhost;
 712     mp::odr odr;
 713
 714     std::list<std::string> databases;
 715     int i;
 716     for (i = 0; i<req->num_databaseNames; i++)
 717         databases.push_back(req->databaseNames[i]);
 718
 719     BackendPtr b;
 720     // pick up any existing backend with a database match
 721     std::list<BackendPtr>::const_iterator map_it;
 722     map_it = m_backend_list.begin();
 723     for (; map_it != m_backend_list.end(); map_it++)
 724     {
 725         BackendPtr tmp = *map_it;
 726         if (tmp->m_frontend_databases == databases)
 727             break;
 728     }
 729     if (map_it != m_backend_list.end())
 730         b = *map_it;
 731     if (!b)  // no backend yet. Must create a new one
 732     {
 733         int error_code;
 734         std::string addinfo;
 735         b = init_backend(databases, package, error_code, addinfo);
 736         if (!b)
 737         {
 738             // did not get a backend (unavailable somehow?)
 739             Z_APDU *apdu =
 740                 odr.create_scanResponse(
 741                     apdu_req, error_code, addinfo.c_str());
 742             package.response() = apdu;
 743
 744             return;
 745         }
 746     }
 747     // sending scan to backend
 748     Package scan_package(b->m_backend_session, package.origin());
 749
 750     scan_package.copy_filter(package);
 751
 752     // pick first targets spec and move the databases from it ..
 753     std::list<std::string>::const_iterator t_it = b->m_targets.begin();
 754     if (t_it != b->m_targets.end())
 755     {
 756         mp::util::set_databases_from_zurl(odr, *t_it,
 757                                                 &req->num_databaseNames,
 758                                                 &req->databaseNames);
 759     }
 760     scan_package.request() = yazpp_1::GDU(apdu_req);
 761
 762     scan_package.move(b->m_route);
 763
 764     if (scan_package.session().is_closed())
 765     {
 766         package.response() = scan_package.response();
 767         package.session().close();
 768         return;
 769     }
 770     package.response() = scan_package.response();
 771 }
 772
 773
 774 void yf::VirtualDB::add_map_db2targets(std::string db,
 775                                        std::list<std::string> targets,
 776                                        std::string route)
 777 {
 778     m_p->m_maps.push_back(
 779         VirtualDB::Map(mp::util::database_name_normalize(db), targets, route));
 780 }
 781
 782
 783 void yf::VirtualDB::add_map_db2target(std::string db,
 784                                       std::string target,
 785                                       std::string route)
 786
 787 {
 788     m_p->m_maps.push_back(
 789         VirtualDB::Map(mp::util::database_name_normalize(db), target, route));
 790 }
 791
 792 void yf::VirtualDB::process(mp::Package &package) const
 793 {
 794     FrontendPtr f = m_p->get_frontend(package);
 795
 796     Z_GDU *gdu = package.request().get();
 797
 798     if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
 799         Z_APDU_initRequest && !f->m_is_virtual)
 800     {
 801         Z_InitRequest *req = gdu->u.z3950->u.initRequest;
 802
 803         std::list<std::string> vhosts;
 804         mp::util::get_vhost_otherinfo(req->otherInfo, vhosts);
 805
 806         if (vhosts.size() > 0 && m_p->pass_vhosts)
 807         {
 808             package.move();
 809         }
 810         else
 811         {
 812             f->m_init_gdu = gdu;
 813
 814             mp::odr odr;
 815             Z_APDU *apdu = odr.create_initResponse(gdu->u.z3950, 0, 0);
 816             Z_InitResponse *resp = apdu->u.initResponse;
 817
 818             int i;
 819             static const int masks[] = {
 820                 Z_Options_search,
 821                 Z_Options_present,
 822                 Z_Options_namedResultSets,
 823                 Z_Options_scan,
 824                 -1
 825             };
 826             for (i = 0; masks[i] != -1; i++)
 827                 if (ODR_MASK_GET(req->options, masks[i]))
 828                     ODR_MASK_SET(resp->options, masks[i]);
 829
 830             static const int versions[] = {
 831                 Z_ProtocolVersion_1,
 832                 Z_ProtocolVersion_2,
 833                 Z_ProtocolVersion_3,
 834                 -1
 835             };
 836             for (i = 0; versions[i] != -1; i++)
 837                 if (ODR_MASK_GET(req->protocolVersion, versions[i]))
 838                     ODR_MASK_SET(resp->protocolVersion, versions[i]);
 839                 else
 840                     break;
 841
 842             *resp->preferredMessageSize = *req->preferredMessageSize;
 843             *resp->maximumRecordSize = *req->maximumRecordSize;
 844
 845             package.response() = apdu;
 846             f->m_is_virtual = true;
 847         }
 848     }
 849     else if (!f->m_is_virtual)
 850         package.move();
 851     else if (gdu && gdu->which == Z_GDU_Z3950)
 852     {
 853         Z_APDU *apdu = gdu->u.z3950;
 854         if (apdu->which == Z_APDU_initRequest)
 855         {
 856             mp::odr odr;
 857
 858             package.response() = odr.create_close(
 859                 apdu,
 860                 Z_Close_protocolError,
 861                 "double init");
 862
 863             package.session().close();
 864         }
 865         else if (apdu->which == Z_APDU_searchRequest)
 866         {
 867             f->search(package, apdu);
 868         }
 869         else if (apdu->which == Z_APDU_presentRequest)
 870         {
 871             f->present(package, apdu);
 872         }
 873         else if (apdu->which == Z_APDU_scanRequest)
 874         {
 875             f->scan(package, apdu);
 876         }
 877         else if (apdu->which == Z_APDU_close)
 878         {
 879             if (f->relay_apdu(package, apdu) == 0)
 880             {
 881                 mp::odr odr;
 882
 883                 package.response() = odr.create_close(
 884                     apdu, Z_Close_finished, "virt_db");
 885
 886                 package.session().close();
 887             }
 888         }
 889         else
 890         {
 891             mp::odr odr;
 892
 893             package.response() = odr.create_close(
 894                 apdu, Z_Close_protocolError,
 895                 "unsupported APDU in filter_virt_db");
 896
 897             package.session().close();
 898         }
 899     }
 900     m_p->release_frontend(package);
 901 }
 902
 903 void mp::filter::VirtualDB::configure(const xmlNode * ptr, bool test_only)
 904 {
 905     for (ptr = ptr->children; ptr; ptr = ptr->next)
 906     {
 907         if (ptr->type != XML_ELEMENT_NODE)
 908             continue;
 909         if (!strcmp((const char *) ptr->name, "pass-vhosts"))
 910         {
 911             m_p->pass_vhosts = mp::xml::get_bool(ptr->children, false);
 912         }
 913         else if (!strcmp((const char *) ptr->name, "virtual"))
 914         {
 915             std::string query_encoding;
 916             std::string database;
 917             std::list<std::string> targets;
 918             xmlNode *v_node = ptr->children;
 919             for (; v_node; v_node = v_node->next)
 920             {
 921                 if (v_node->type != XML_ELEMENT_NODE)
 922                     continue;
 923
 924                 if (mp::xml::is_element_mp(v_node, "database"))
 925                     database = mp::xml::get_text(v_node);
 926                 else if (mp::xml::is_element_mp(v_node, "target"))
 927                     targets.push_back(mp::xml::get_text(v_node));
 928                 else if (mp::xml::is_element_mp(v_node, "query-encoding"))
 929                     targets.push_back(mp::xml::get_text(v_node));
 930                 else
 931                     throw mp::filter::FilterException
 932                         ("Bad element "
 933                          + std::string((const char *) v_node->name)
 934                          + " in virtual section"
 935                             );
 936             }
 937             std::string route = mp::xml::get_route(ptr);
 938
 939             VirtualDB::Map vmap(mp::util::database_name_normalize(database),
 940                                 targets, route);
 941             vmap.m_query_encoding = query_encoding;
 942             m_p->m_maps.push_back(vmap);
 943         }
 944         else if (!strcmp((const char *) ptr->name, "torus"))
 945         {
 946             std::string url;
 947             const struct _xmlAttr *attr;
 948             for (attr = ptr->properties; attr; attr = attr->next)
 949             {
 950                 if (!strcmp((const char *) attr->name, "url"))
 951                     url = mp::xml::get_text(attr->children);
 952                 else
 953                     throw mp::filter::FilterException(
 954                         "Bad attribute " + std::string((const char *)
 955                                                        attr->name));
 956             }
 957             m_p->torus.read_searchables(url);
 958             m_p->refresh_torus();
 959         }
 960         else
 961         {
 962             throw mp::filter::FilterException
 963                 ("Bad element "
 964                  + std::string((const char *) ptr->name)
 965                  + " in virt_db filter");
 966         }
 967     }
 968 }
 969
 970 static mp::filter::Base* filter_creator()
 971 {
 972     return new mp::filter::VirtualDB;
 973 }
 974
 975 extern "C" {
 976     struct metaproxy_1_filter_struct metaproxy_1_filter_virt_db = {
 977         0,
 978         "virt_db",
 979         filter_creator
 980     };
 981 }
 982
 983
 984 /*
 985  * Local variables:
 986  * c-basic-offset: 4
 987  * c-file-style: "Stroustrup"
 988  * indent-tabs-mode: nil
 989  * End:
 990  * vim: shiftwidth=4 tabstop=8 expandtab
 991  */
 992