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();
  57             bool match(const std::string db) const;
  58             std::string m_dbpattern;
  59             std::list<std::string> m_targets;
  60             std::string m_route;
  61         };
  62         struct VirtualDB::Backend {
  63             mp::Session m_backend_session;
  64             std::list<std::string> m_frontend_databases;
  65             std::list<std::string> m_targets;
  66             std::string m_route;
  67             bool m_named_result_sets;
  68             int m_number_of_sets;
  69         };
  70         struct VirtualDB::Frontend {
  71             Frontend(Rep *rep);
  72             ~Frontend();
  73             mp::Session m_session;
  74             bool m_is_virtual;
  75             bool m_in_use;
  76             yazpp_1::GDU m_init_gdu;
  77             std::list<BackendPtr> m_backend_list;
  78             std::map<std::string,VirtualDB::Set> m_sets;
  79
  80             void search(Package &package, Z_APDU *apdu);
  81             void present(Package &package, Z_APDU *apdu);
  82             void scan(Package &package, Z_APDU *apdu);
  83             int relay_apdu(Package &package, Z_APDU *apdu);
  84
  85             void close(Package &package);
  86             typedef std::map<std::string,VirtualDB::Set>::iterator Sets_it;
  87
  88             void fixup_package(Package &p, BackendPtr b);
  89             void fixup_npr_record(ODR odr, Z_NamePlusRecord *npr,
  90                                   BackendPtr b);
  91             void fixup_npr_records(ODR odr, Z_Records *records,
  92                                    BackendPtr b);
  93
  94             BackendPtr lookup_backend_from_databases(
  95                 std::list<std::string> databases);
  96             BackendPtr create_backend_from_databases(
  97                 std::list<std::string> databases,
  98                 int &error_code,
  99                 std::string &failing_database);
 100
 101             BackendPtr init_backend(std::list<std::string> database,
 102                                     Package &package,
 103                                     int &error_code, std::string &addinfo);
 104             Rep *m_p;
 105         };
 106         class VirtualDB::Rep {
 107             friend class VirtualDB;
 108             friend struct Frontend;
 109
 110             FrontendPtr get_frontend(Package &package);
 111             void release_frontend(Package &package);
 112         private:
 113             std::list<VirtualDB::Map>m_maps;
 114             typedef std::map<std::string,VirtualDB::Set>::iterator Sets_it;
 115             boost::mutex m_mutex;
 116             boost::condition m_cond_session_ready;
 117             std::map<mp::Session, FrontendPtr> m_clients;
 118             bool pass_vhosts;
 119             mp::Torus torus;
 120         };
 121     }
 122 }
 123
 124 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::lookup_backend_from_databases(
 125     std::list<std::string> databases)
 126 {
 127     std::list<BackendPtr>::const_iterator map_it;
 128     map_it = m_backend_list.begin();
 129     for (; map_it != m_backend_list.end(); map_it++)
 130         if ((*map_it)->m_frontend_databases == databases)
 131             return *map_it;
 132     BackendPtr null;
 133     return null;
 134 }
 135
 136 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::create_backend_from_databases(
 137     std::list<std::string> databases, int &error_code, std::string &addinfo)
 138 {
 139     BackendPtr b(new Backend);
 140     std::list<std::string>::const_iterator db_it = databases.begin();
 141
 142     b->m_number_of_sets = 0;
 143     b->m_frontend_databases = databases;
 144     b->m_named_result_sets = false;
 145
 146     bool first_route = true;
 147
 148     std::map<std::string,bool> targets_dedup;
 149     for (; db_it != databases.end(); db_it++)
 150     {
 151         std::list<VirtualDB::Map>::const_iterator map_it;
 152         map_it = m_p->m_maps.begin();
 153         while (map_it != m_p->m_maps.end())
 154         {
 155             if (map_it->match(*db_it))
 156                 break;
 157             map_it++;
 158         }
 159
 160         if (map_it == m_p->m_maps.end())  // database not found
 161         {
 162             error_code = YAZ_BIB1_DATABASE_DOES_NOT_EXIST;
 163             addinfo = *db_it;
 164             BackendPtr ptr;
 165             return ptr;
 166         }
 167         std::list<std::string>::const_iterator t_it =
 168             map_it->m_targets.begin();
 169         for (; t_it != map_it->m_targets.end(); t_it++) {
 170             if (!targets_dedup[*t_it])
 171             {
 172                 targets_dedup[*t_it] = true;
 173                 b->m_targets.push_back(*t_it);
 174             }
 175         }
 176
 177         // see if we have a route conflict.
 178         if (!first_route && b->m_route != map_it->m_route)
 179         {
 180             // we have a conflict..
 181             error_code =  YAZ_BIB1_COMBI_OF_SPECIFIED_DATABASES_UNSUPP;
 182             BackendPtr ptr;
 183             return ptr;
 184         }
 185         b->m_route = map_it->m_route;
 186         first_route = false;
 187     }
 188     return b;
 189 }
 190
 191 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::init_backend(
 192     std::list<std::string> databases, mp::Package &package,
 193     int &error_code, std::string &addinfo)
 194 {
 195     BackendPtr b = create_backend_from_databases(databases, error_code,
 196                                                  addinfo);
 197     if (!b)
 198         return b;
 199     Package init_package(b->m_backend_session, package.origin());
 200     init_package.copy_filter(package);
 201
 202     mp::odr odr;
 203
 204     Z_APDU *init_apdu = zget_APDU(odr, Z_APDU_initRequest);
 205
 206     mp::util::set_vhost_otherinfo(&init_apdu->u.initRequest->otherInfo, odr,
 207                                    b->m_targets);
 208     Z_InitRequest *req = init_apdu->u.initRequest;
 209
 210     // copy stuff from Frontend Init Request
 211     Z_GDU *org_gdu = m_init_gdu.get();
 212     Z_InitRequest *org_init = org_gdu->u.z3950->u.initRequest;
 213
 214     req->idAuthentication = org_init->idAuthentication;
 215     req->implementationId = org_init->implementationId;
 216     req->implementationName = org_init->implementationName;
 217     req->implementationVersion = org_init->implementationVersion;
 218     *req->preferredMessageSize = *org_init->preferredMessageSize;
 219     *req->maximumRecordSize = *org_init->maximumRecordSize;
 220
 221     ODR_MASK_SET(req->options, Z_Options_search);
 222     ODR_MASK_SET(req->options, Z_Options_present);
 223     ODR_MASK_SET(req->options, Z_Options_namedResultSets);
 224     ODR_MASK_SET(req->options, Z_Options_scan);
 225
 226     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_1);
 227     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_2);
 228     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_3);
 229
 230     init_package.request() = init_apdu;
 231
 232     init_package.move(b->m_route);  // sending init
 233
 234     Z_GDU *gdu = init_package.response().get();
 235     // we hope to get an init response
 236     error_code = YAZ_BIB1_DATABASE_UNAVAILABLE;
 237     if (gdu && gdu->which == Z_GDU_Z3950
 238         && gdu->u.z3950->which == Z_APDU_initResponse
 239         && *gdu->u.z3950->u.initResponse->result)
 240     {
 241         Z_InitResponse *res = gdu->u.z3950->u.initResponse;
 242         if (ODR_MASK_GET(res->options, Z_Options_namedResultSets))
 243         {
 244             b->m_named_result_sets = true;
 245         }
 246         if (*res->result && !init_package.session().is_closed())
 247         {
 248             m_backend_list.push_back(b);
 249             return b;
 250         }
 251         mp::util::get_init_diagnostics(res, error_code, addinfo);
 252     }
 253     if (!init_package.session().is_closed())
 254     {
 255         Package close_package(b->m_backend_session, package.origin());
 256         close_package.copy_filter(package);
 257         close_package.session().close();
 258         close_package.move(b->m_route);  // closing it
 259     }
 260     BackendPtr null;
 261     return null;
 262 }
 263
 264 void yf::VirtualDB::Frontend::search(mp::Package &package, Z_APDU *apdu_req)
 265 {
 266     Z_SearchRequest *req = apdu_req->u.searchRequest;
 267     std::string vhost;
 268     std::string resultSetId = req->resultSetName;
 269     mp::odr odr;
 270
 271     std::list<std::string> databases;
 272     int i;
 273     for (i = 0; i<req->num_databaseNames; i++)
 274         databases.push_back(req->databaseNames[i]);
 275
 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 database with named result sets ..
 296     // or one which has no result sets.. yet.
 297     BackendPtr b; // null for now
 298     std::list<BackendPtr>::const_iterator map_it;
 299     map_it = m_backend_list.begin();
 300     for (; map_it != m_backend_list.end(); map_it++)
 301     {
 302         BackendPtr tmp = *map_it;
 303         if (tmp->m_frontend_databases == databases &&
 304             (tmp->m_named_result_sets ||
 305              tmp->m_number_of_sets == 0))
 306         {
 307             b = *map_it;
 308             break;
 309         }
 310     }
 311     if (!b)  // no backend yet. Must create a new one
 312     {
 313         int error_code;
 314         std::string addinfo;
 315         b = init_backend(databases, package, error_code, addinfo);
 316         if (!b)
 317         {
 318             // did not get a backend (unavailable somehow?)
 319
 320             Z_APDU *apdu =
 321                 odr.create_searchResponse(
 322                     apdu_req, error_code, addinfo.c_str());
 323             package.response() = apdu;
 324             return;
 325         }
 326     }
 327     m_sets.erase(req->resultSetName);
 328     // sending search to backend
 329     Package search_package(b->m_backend_session, package.origin());
 330
 331     search_package.copy_filter(package);
 332
 333     std::string backend_setname;
 334     if (b->m_named_result_sets)
 335     {
 336         backend_setname = std::string(req->resultSetName);
 337     }
 338     else
 339     {
 340         backend_setname = "default";
 341         req->resultSetName = odr_strdup(odr, backend_setname.c_str());
 342     }
 343
 344     // pick first targets spec and move the databases from it ..
 345     std::list<std::string>::const_iterator t_it = b->m_targets.begin();
 346     if (t_it != b->m_targets.end())
 347     {
 348         mp::util::set_databases_from_zurl(odr, *t_it,
 349                                                 &req->num_databaseNames,
 350                                                 &req->databaseNames);
 351     }
 352
 353     *req->replaceIndicator = 1;
 354
 355     search_package.request() = yazpp_1::GDU(apdu_req);
 356
 357     search_package.move(b->m_route);
 358
 359     if (search_package.session().is_closed())
 360     {
 361         package.response() = search_package.response();
 362         package.session().close();
 363         return;
 364     }
 365     b->m_number_of_sets++;
 366
 367     m_sets[resultSetId] = VirtualDB::Set(b, backend_setname);
 368     fixup_package(search_package, b);
 369     package.response() = search_package.response();
 370 }
 371
 372 yf::VirtualDB::Frontend::Frontend(Rep *rep)
 373 {
 374     m_p = rep;
 375     m_is_virtual = false;
 376 }
 377
 378 void yf::VirtualDB::Frontend::close(mp::Package &package)
 379 {
 380     std::list<BackendPtr>::const_iterator b_it;
 381
 382     for (b_it = m_backend_list.begin(); b_it != m_backend_list.end(); b_it++)
 383     {
 384         (*b_it)->m_backend_session.close();
 385         Package close_package((*b_it)->m_backend_session, package.origin());
 386         close_package.copy_filter(package);
 387         close_package.move((*b_it)->m_route);
 388     }
 389     m_backend_list.clear();
 390 }
 391
 392 yf::VirtualDB::Frontend::~Frontend()
 393 {
 394 }
 395
 396 yf::VirtualDB::FrontendPtr yf::VirtualDB::Rep::get_frontend(mp::Package &package)
 397 {
 398     boost::mutex::scoped_lock lock(m_mutex);
 399
 400     std::map<mp::Session,yf::VirtualDB::FrontendPtr>::iterator it;
 401
 402     while(true)
 403     {
 404         it = m_clients.find(package.session());
 405         if (it == m_clients.end())
 406             break;
 407
 408         if (!it->second->m_in_use)
 409         {
 410             it->second->m_in_use = true;
 411             return it->second;
 412         }
 413         m_cond_session_ready.wait(lock);
 414     }
 415     FrontendPtr f(new Frontend(this));
 416     m_clients[package.session()] = f;
 417     f->m_in_use = true;
 418     return f;
 419 }
 420
 421 void yf::VirtualDB::Rep::release_frontend(mp::Package &package)
 422 {
 423     boost::mutex::scoped_lock lock(m_mutex);
 424     std::map<mp::Session,yf::VirtualDB::FrontendPtr>::iterator it;
 425
 426     it = m_clients.find(package.session());
 427     if (it != m_clients.end())
 428     {
 429         if (package.session().is_closed())
 430         {
 431             it->second->close(package);
 432             m_clients.erase(it);
 433         }
 434         else
 435         {
 436             it->second->m_in_use = false;
 437         }
 438         m_cond_session_ready.notify_all();
 439     }
 440 }
 441
 442 void yf::VirtualDB::refresh_torus(void)
 443 {
 444     xmlDoc *doc = m_p->torus.get_doc();
 445     xmlNode *ptr1 = 0;
 446     if (doc && (ptr1 = xmlDocGetRootElement(doc)))
 447     {
 448         for (ptr1 = ptr1->children; ptr1; ptr1 = ptr1->next)
 449         {
 450             if (ptr1->type != XML_ELEMENT_NODE)
 451                 continue;
 452             if (!strcmp((const char *) ptr1->name, "record"))
 453             {
 454                 xmlNode *ptr2 = ptr1;
 455                 for (ptr2 = ptr2->children; ptr2; ptr2 = ptr2->next)
 456                 {
 457                     if (ptr2->type != XML_ELEMENT_NODE)
 458                         continue;
 459                     if (!strcmp((const char *) ptr2->name, "layer"))
 460                     {
 461                         std::string database;
 462                         std::string target;
 463                         std::string route;
 464                         std::string solr;
 465                         xmlNode *ptr3 = ptr2;
 466                         for (ptr3 = ptr3->children; ptr3; ptr3 = ptr3->next)
 467                         {
 468                             if (ptr3->type != XML_ELEMENT_NODE)
 469                                 continue;
 470                             if (!strcmp((const char *) ptr3->name, "id"))
 471                             {
 472                                 database = mp::xml::get_text(ptr3);
 473                             }
 474                             else if (!strcmp((const char *) ptr3->name, "zurl"))
 475                             {
 476                                 target = mp::xml::get_text(ptr3);
 477                             }
 478                             else if (!strcmp((const char *) ptr3->name, "sru"))
 479                             {
 480                                 solr = mp::xml::get_text(ptr3);
 481                             }
 482                         }
 483                         if (solr.length() == 0 &&
 484                             database.length() && target.length())
 485                         {
 486                             add_map_db2target(database, target, route);
 487                         }
 488                     }
 489                 }
 490             }
 491         }
 492     }
 493 }
 494
 495 yf::VirtualDB::Set::Set(BackendPtr b, std::string setname)
 496     :  m_backend(b), m_setname(setname)
 497 {
 498 }
 499
 500
 501 yf::VirtualDB::Set::Set()
 502 {
 503 }
 504
 505
 506 yf::VirtualDB::Set::~Set()
 507 {
 508 }
 509
 510 yf::VirtualDB::Map::Map(std::string database,
 511                         std::list<std::string> targets, std::string route)
 512     : m_dbpattern(database), m_targets(targets), m_route(route)
 513 {
 514 }
 515
 516 yf::VirtualDB::Map::Map()
 517 {
 518 }
 519
 520 bool yf::VirtualDB::Map::match(const std::string db) const
 521 {
 522     std::string norm_db = mp::util::database_name_normalize(db);
 523     if (yaz_match_glob(m_dbpattern.c_str(), norm_db.c_str()))
 524         return true;
 525     return false;
 526 }
 527
 528 yf::VirtualDB::VirtualDB() : m_p(new VirtualDB::Rep)
 529 {
 530     m_p->pass_vhosts = false;
 531 }
 532
 533 yf::VirtualDB::~VirtualDB() {
 534 }
 535
 536 void yf::VirtualDB::Frontend::fixup_npr_record(ODR odr, Z_NamePlusRecord *npr,
 537                                              BackendPtr b)
 538 {
 539     if (npr->databaseName)
 540     {
 541         std::string b_database = std::string(npr->databaseName);
 542
 543         // consider each of the frontend databases..
 544         std::list<std::string>::const_iterator db_it;
 545         for (db_it = b->m_frontend_databases.begin();
 546              db_it != b->m_frontend_databases.end(); db_it++)
 547         {
 548             // see which target it corresponds to.. (if any)
 549             std::list<VirtualDB::Map>::const_iterator map_it =
 550                 m_p->m_maps.begin();
 551             while (map_it != m_p->m_maps.end())
 552             {
 553                 if (map_it->match(*db_it))
 554                     break;
 555                 map_it++;
 556             }
 557             if (map_it != m_p->m_maps.end())
 558             {
 559                 std::list<std::string>::const_iterator t
 560                     = map_it->m_targets.begin();
 561                 while (t != map_it->m_targets.end())
 562                 {
 563                     if (*t == b_database)
 564                     {
 565                         npr->databaseName = odr_strdup(odr, (*db_it).c_str());
 566                         return;
 567                     }
 568                     t++;
 569                 }
 570             }
 571
 572         }
 573         db_it = b->m_frontend_databases.begin();
 574         if (db_it != b->m_frontend_databases.end())
 575         {
 576             std::string database = *db_it;
 577             npr->databaseName = odr_strdup(odr, database.c_str());
 578         }
 579     }
 580 }
 581
 582 void yf::VirtualDB::Frontend::fixup_npr_records(ODR odr, Z_Records *records,
 583                                               BackendPtr b)
 584 {
 585     if (records && records->which == Z_Records_DBOSD)
 586     {
 587         Z_NamePlusRecordList *nprlist = records->u.databaseOrSurDiagnostics;
 588         int i;
 589         for (i = 0; i < nprlist->num_records; i++)
 590         {
 591             fixup_npr_record(odr, nprlist->records[i], b);
 592         }
 593     }
 594 }
 595
 596 void yf::VirtualDB::Frontend::fixup_package(mp::Package &p, BackendPtr b)
 597 {
 598     Z_GDU *gdu = p.response().get();
 599     mp::odr odr;
 600
 601     if (gdu && gdu->which == Z_GDU_Z3950)
 602     {
 603         Z_APDU *apdu = gdu->u.z3950;
 604         if (apdu->which == Z_APDU_presentResponse)
 605         {
 606             fixup_npr_records(odr, apdu->u.presentResponse->records, b);
 607             p.response() = gdu;
 608         }
 609         else if (apdu->which == Z_APDU_searchResponse)
 610         {
 611             fixup_npr_records(odr,  apdu->u.searchResponse->records, b);
 612             p.response() = gdu;
 613         }
 614     }
 615 }
 616
 617 void yf::VirtualDB::Frontend::present(mp::Package &package, Z_APDU *apdu_req)
 618 {
 619     Z_PresentRequest *req = apdu_req->u.presentRequest;
 620     std::string resultSetId = req->resultSetId;
 621     mp::odr odr;
 622
 623     Sets_it sets_it = m_sets.find(resultSetId);
 624     if (sets_it == m_sets.end())
 625     {
 626         Z_APDU *apdu =
 627             odr.create_presentResponse(
 628                 apdu_req,
 629                 YAZ_BIB1_SPECIFIED_RESULT_SET_DOES_NOT_EXIST,
 630                 resultSetId.c_str());
 631         package.response() = apdu;
 632         return;
 633     }
 634     Session *id =
 635         new mp::Session(sets_it->second.m_backend->m_backend_session);
 636
 637     // sending present to backend
 638     Package present_package(*id, package.origin());
 639     present_package.copy_filter(package);
 640
 641     req->resultSetId = odr_strdup(odr, sets_it->second.m_setname.c_str());
 642
 643     present_package.request() = yazpp_1::GDU(apdu_req);
 644
 645     present_package.move(sets_it->second.m_backend->m_route);
 646
 647     fixup_package(present_package, sets_it->second.m_backend);
 648
 649     if (present_package.session().is_closed())
 650     {
 651         package.response() = present_package.response();
 652         package.session().close();
 653         return;
 654     }
 655     else
 656     {
 657         package.response() = present_package.response();
 658     }
 659     delete id;
 660 }
 661
 662 int yf::VirtualDB::Frontend::relay_apdu(mp::Package &package, Z_APDU *apdu_req)
 663 {
 664     int no = 0;
 665     std::list<BackendPtr>::const_iterator map_it;
 666     map_it = m_backend_list.begin();
 667     for (; map_it != m_backend_list.end(); map_it++)
 668     {
 669         BackendPtr b = *map_it;
 670
 671         Package relay_package(b->m_backend_session, package.origin());
 672         relay_package.copy_filter(package);
 673
 674         relay_package.request() = yazpp_1::GDU(apdu_req);
 675
 676         relay_package.move(b->m_route);
 677         package.response() = relay_package.response();
 678         no++;
 679     }
 680     return no;
 681 }
 682
 683 void yf::VirtualDB::Frontend::scan(mp::Package &package, Z_APDU *apdu_req)
 684 {
 685     Z_ScanRequest *req = apdu_req->u.scanRequest;
 686     std::string vhost;
 687     mp::odr odr;
 688
 689     std::list<std::string> databases;
 690     int i;
 691     for (i = 0; i<req->num_databaseNames; i++)
 692         databases.push_back(req->databaseNames[i]);
 693
 694     BackendPtr b;
 695     // pick up any existing backend with a database match
 696     std::list<BackendPtr>::const_iterator map_it;
 697     map_it = m_backend_list.begin();
 698     for (; map_it != m_backend_list.end(); map_it++)
 699     {
 700         BackendPtr tmp = *map_it;
 701         if (tmp->m_frontend_databases == databases)
 702             break;
 703     }
 704     if (map_it != m_backend_list.end())
 705         b = *map_it;
 706     if (!b)  // no backend yet. Must create a new one
 707     {
 708         int error_code;
 709         std::string addinfo;
 710         b = init_backend(databases, package, error_code, addinfo);
 711         if (!b)
 712         {
 713             // did not get a backend (unavailable somehow?)
 714             Z_APDU *apdu =
 715                 odr.create_scanResponse(
 716                     apdu_req, error_code, addinfo.c_str());
 717             package.response() = apdu;
 718
 719             return;
 720         }
 721     }
 722     // sending scan to backend
 723     Package scan_package(b->m_backend_session, package.origin());
 724
 725     scan_package.copy_filter(package);
 726
 727     // pick first targets spec and move the databases from it ..
 728     std::list<std::string>::const_iterator t_it = b->m_targets.begin();
 729     if (t_it != b->m_targets.end())
 730     {
 731         mp::util::set_databases_from_zurl(odr, *t_it,
 732                                                 &req->num_databaseNames,
 733                                                 &req->databaseNames);
 734     }
 735     scan_package.request() = yazpp_1::GDU(apdu_req);
 736
 737     scan_package.move(b->m_route);
 738
 739     if (scan_package.session().is_closed())
 740     {
 741         package.response() = scan_package.response();
 742         package.session().close();
 743         return;
 744     }
 745     package.response() = scan_package.response();
 746 }
 747
 748
 749 void yf::VirtualDB::add_map_db2targets(std::string db,
 750                                        std::list<std::string> targets,
 751                                        std::string route)
 752 {
 753     m_p->m_maps.push_back(
 754         VirtualDB::Map(mp::util::database_name_normalize(db), targets, route));
 755 }
 756
 757
 758 void yf::VirtualDB::add_map_db2target(std::string db,
 759                                       std::string target,
 760                                       std::string route)
 761 {
 762     std::list<std::string> targets;
 763     targets.push_back(target);
 764
 765     add_map_db2targets(db, targets, route);
 766 }
 767
 768 void yf::VirtualDB::process(mp::Package &package) const
 769 {
 770     FrontendPtr f = m_p->get_frontend(package);
 771
 772     Z_GDU *gdu = package.request().get();
 773
 774     if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
 775         Z_APDU_initRequest && !f->m_is_virtual)
 776     {
 777         Z_InitRequest *req = gdu->u.z3950->u.initRequest;
 778
 779         std::list<std::string> vhosts;
 780         mp::util::get_vhost_otherinfo(req->otherInfo, vhosts);
 781
 782         if (vhosts.size() > 0 && m_p->pass_vhosts)
 783         {
 784             package.move();
 785         }
 786         else
 787         {
 788             f->m_init_gdu = gdu;
 789
 790             mp::odr odr;
 791             Z_APDU *apdu = odr.create_initResponse(gdu->u.z3950, 0, 0);
 792             Z_InitResponse *resp = apdu->u.initResponse;
 793
 794             int i;
 795             static const int masks[] = {
 796                 Z_Options_search,
 797                 Z_Options_present,
 798                 Z_Options_namedResultSets,
 799                 Z_Options_scan,
 800                 -1
 801             };
 802             for (i = 0; masks[i] != -1; i++)
 803                 if (ODR_MASK_GET(req->options, masks[i]))
 804                     ODR_MASK_SET(resp->options, masks[i]);
 805
 806             static const int versions[] = {
 807                 Z_ProtocolVersion_1,
 808                 Z_ProtocolVersion_2,
 809                 Z_ProtocolVersion_3,
 810                 -1
 811             };
 812             for (i = 0; versions[i] != -1; i++)
 813                 if (ODR_MASK_GET(req->protocolVersion, versions[i]))
 814                     ODR_MASK_SET(resp->protocolVersion, versions[i]);
 815                 else
 816                     break;
 817
 818             *resp->preferredMessageSize = *req->preferredMessageSize;
 819             *resp->maximumRecordSize = *req->maximumRecordSize;
 820
 821             package.response() = apdu;
 822             f->m_is_virtual = true;
 823         }
 824     }
 825     else if (!f->m_is_virtual)
 826         package.move();
 827     else if (gdu && gdu->which == Z_GDU_Z3950)
 828     {
 829         Z_APDU *apdu = gdu->u.z3950;
 830         if (apdu->which == Z_APDU_initRequest)
 831         {
 832             mp::odr odr;
 833
 834             package.response() = odr.create_close(
 835                 apdu,
 836                 Z_Close_protocolError,
 837                 "double init");
 838
 839             package.session().close();
 840         }
 841         else if (apdu->which == Z_APDU_searchRequest)
 842         {
 843             f->search(package, apdu);
 844         }
 845         else if (apdu->which == Z_APDU_presentRequest)
 846         {
 847             f->present(package, apdu);
 848         }
 849         else if (apdu->which == Z_APDU_scanRequest)
 850         {
 851             f->scan(package, apdu);
 852         }
 853         else if (apdu->which == Z_APDU_close)
 854         {
 855             if (f->relay_apdu(package, apdu) == 0)
 856             {
 857                 mp::odr odr;
 858
 859                 package.response() = odr.create_close(
 860                     apdu, Z_Close_finished, "virt_db");
 861
 862                 package.session().close();
 863             }
 864         }
 865         else
 866         {
 867             mp::odr odr;
 868
 869             package.response() = odr.create_close(
 870                 apdu, Z_Close_protocolError,
 871                 "unsupported APDU in filter_virt_db");
 872
 873             package.session().close();
 874         }
 875     }
 876     m_p->release_frontend(package);
 877 }
 878
 879 void mp::filter::VirtualDB::configure(const xmlNode * ptr, bool test_only)
 880 {
 881     for (ptr = ptr->children; ptr; ptr = ptr->next)
 882     {
 883         if (ptr->type != XML_ELEMENT_NODE)
 884             continue;
 885         if (!strcmp((const char *) ptr->name, "pass-vhosts"))
 886         {
 887             m_p->pass_vhosts = mp::xml::get_bool(ptr->children, false);
 888         }
 889         else if (!strcmp((const char *) ptr->name, "virtual"))
 890         {
 891             std::string database;
 892             std::list<std::string> targets;
 893             xmlNode *v_node = ptr->children;
 894             for (; v_node; v_node = v_node->next)
 895             {
 896                 if (v_node->type != XML_ELEMENT_NODE)
 897                     continue;
 898
 899                 if (mp::xml::is_element_mp(v_node, "database"))
 900                     database = mp::xml::get_text(v_node);
 901                 else if (mp::xml::is_element_mp(v_node, "target"))
 902                     targets.push_back(mp::xml::get_text(v_node));
 903                 else
 904                     throw mp::filter::FilterException
 905                         ("Bad element "
 906                          + std::string((const char *) v_node->name)
 907                          + " in virtual section"
 908                             );
 909             }
 910             std::string route = mp::xml::get_route(ptr);
 911             add_map_db2targets(database, targets, route);
 912         }
 913         else if (!strcmp((const char *) ptr->name, "torus"))
 914         {
 915             std::string url;
 916             const struct _xmlAttr *attr;
 917             for (attr = ptr->properties; attr; attr = attr->next)
 918             {
 919                 if (!strcmp((const char *) attr->name, "url"))
 920                     url = mp::xml::get_text(attr->children);
 921                 else
 922                     throw mp::filter::FilterException(
 923                         "Bad attribute " + std::string((const char *)
 924                                                        attr->name));
 925             }
 926             m_p->torus.read_searchables(url);
 927             refresh_torus();
 928         }
 929         else
 930         {
 931             throw mp::filter::FilterException
 932                 ("Bad element "
 933                  + std::string((const char *) ptr->name)
 934                  + " in virt_db filter");
 935         }
 936     }
 937 }
 938
 939 static mp::filter::Base* filter_creator()
 940 {
 941     return new mp::filter::VirtualDB;
 942 }
 943
 944 extern "C" {
 945     struct metaproxy_1_filter_struct metaproxy_1_filter_virt_db = {
 946         0,
 947         "virt_db",
 948         filter_creator
 949     };
 950 }
 951
 952
 953 /*
 954  * Local variables:
 955  * c-basic-offset: 4
 956  * c-file-style: "Stroustrup"
 957  * indent-tabs-mode: nil
 958  * End:
 959  * vim: shiftwidth=4 tabstop=8 expandtab
 960  */
 961