src/filter_multi.cpp

   1 /* $Id: filter_multi.cpp,v 1.7 2006-01-18 09:20:30 adam Exp $
   2    Copyright (c) 2005, Index Data.
   3
   4 %LICENSE%
   5  */
   6
   7 #include "config.hpp"
   8
   9 #include "filter.hpp"
  10 #include "package.hpp"
  11
  12 #include <boost/thread/thread.hpp>
  13 #include <boost/thread/mutex.hpp>
  14 #include <boost/thread/condition.hpp>
  15 #include <boost/shared_ptr.hpp>
  16
  17 #include "util.hpp"
  18 #include "filter_multi.hpp"
  19
  20 #include <yaz/zgdu.h>
  21 #include <yaz/otherinfo.h>
  22 #include <yaz/diagbib1.h>
  23
  24 #include <map>
  25 #include <iostream>
  26
  27 namespace yf = yp2::filter;
  28
  29 namespace yp2 {
  30     namespace filter {
  31
  32         struct Multi::BackendSet {
  33             BackendPtr m_backend;
  34             int m_count;
  35             bool operator < (const BackendSet &k) const;
  36         };
  37         struct Multi::FrontendSet {
  38             struct PresentJob {
  39                 BackendPtr m_backend;
  40                 int m_pos;
  41                 int m_inside_pos;
  42             };
  43             FrontendSet(std::string setname);
  44             FrontendSet();
  45             ~FrontendSet();
  46
  47             void round_robin(int pos, int number, std::list<PresentJob> &job);
  48
  49             std::list<BackendSet> m_backend_sets;
  50             std::string m_setname;
  51         };
  52         struct Multi::Backend {
  53             PackagePtr m_package;
  54             std::string m_backend_database;
  55             std::string m_vhost;
  56             std::string m_route;
  57             void operator() (void);  // thread operation
  58         };
  59         struct Multi::Frontend {
  60             Frontend(Rep *rep);
  61             ~Frontend();
  62             bool m_is_multi;
  63             bool m_in_use;
  64             std::list<BackendPtr> m_backend_list;
  65             std::map<std::string,Multi::FrontendSet> m_sets;
  66
  67             void multi_move(std::list<BackendPtr> &blist);
  68             void init(Package &package, Z_GDU *gdu);
  69             void close(Package &package);
  70             void search(Package &package, Z_APDU *apdu);
  71             void present(Package &package, Z_APDU *apdu);
  72             void scan(Package &package, Z_APDU *apdu);
  73             Rep *m_p;
  74         };
  75         struct Multi::Map {
  76             Map(std::list<std::string> hosts, std::string route);
  77             Map();
  78             std::list<std::string> m_hosts;
  79             std::string m_route;
  80         };
  81         class Multi::Rep {
  82             friend class Multi;
  83             friend class Frontend;
  84
  85             FrontendPtr get_frontend(Package &package);
  86             void release_frontend(Package &package);
  87         private:
  88             boost::mutex m_sessions_mutex;
  89             std::map<std::string, Multi::Map>m_maps;
  90             std::map<std::string,std::string> m_target_route;
  91             boost::mutex m_mutex;
  92             boost::condition m_cond_session_ready;
  93             std::map<yp2::Session, FrontendPtr> m_clients;
  94         };
  95     }
  96 }
  97
  98 using namespace yp2;
  99
 100 bool yf::Multi::BackendSet::operator < (const BackendSet &k) const
 101 {
 102     return m_count < k.m_count;
 103 }
 104
 105 yf::Multi::Frontend::Frontend(Rep *rep)
 106 {
 107     m_p = rep;
 108     m_is_multi = false;
 109 }
 110
 111 yf::Multi::Frontend::~Frontend()
 112 {
 113 }
 114
 115 yf::Multi::FrontendPtr yf::Multi::Rep::get_frontend(Package &package)
 116 {
 117     boost::mutex::scoped_lock lock(m_mutex);
 118
 119     std::map<yp2::Session,yf::Multi::FrontendPtr>::iterator it;
 120
 121     while(true)
 122     {
 123         it = m_clients.find(package.session());
 124         if (it == m_clients.end())
 125             break;
 126
 127         if (!it->second->m_in_use)
 128         {
 129             it->second->m_in_use = true;
 130             return it->second;
 131         }
 132         m_cond_session_ready.wait(lock);
 133     }
 134     FrontendPtr f(new Frontend(this));
 135     m_clients[package.session()] = f;
 136     f->m_in_use = true;
 137     return f;
 138 }
 139
 140 void yf::Multi::Rep::release_frontend(Package &package)
 141 {
 142     boost::mutex::scoped_lock lock(m_mutex);
 143     std::map<yp2::Session,yf::Multi::FrontendPtr>::iterator it;
 144
 145     it = m_clients.find(package.session());
 146     if (it != m_clients.end())
 147     {
 148         if (package.session().is_closed())
 149         {
 150             it->second->close(package);
 151             m_clients.erase(it);
 152         }
 153         else
 154         {
 155             it->second->m_in_use = false;
 156         }
 157         m_cond_session_ready.notify_all();
 158     }
 159 }
 160
 161 yf::Multi::FrontendSet::FrontendSet(std::string setname)
 162     :  m_setname(setname)
 163 {
 164 }
 165
 166
 167 yf::Multi::FrontendSet::FrontendSet()
 168 {
 169 }
 170
 171
 172 yf::Multi::FrontendSet::~FrontendSet()
 173 {
 174 }
 175
 176 yf::Multi::Map::Map(std::list<std::string> hosts, std::string route)
 177     : m_hosts(hosts), m_route(route)
 178 {
 179 }
 180
 181 yf::Multi::Map::Map()
 182 {
 183 }
 184
 185 yf::Multi::Multi() : m_p(new Multi::Rep)
 186 {
 187 }
 188
 189 yf::Multi::~Multi() {
 190 }
 191
 192
 193 void yf::Multi::add_map_host2hosts(std::string host,
 194                                    std::list<std::string> hosts,
 195                                    std::string route)
 196 {
 197     m_p->m_maps[host] = Multi::Map(hosts, route);
 198 }
 199
 200 void yf::Multi::Backend::operator() (void)
 201 {
 202     m_package->move(m_route);
 203 }
 204
 205 void yf::Multi::Frontend::close(Package &package)
 206 {
 207     std::list<BackendPtr>::const_iterator bit;
 208     for (bit = m_backend_list.begin(); bit != m_backend_list.end(); bit++)
 209     {
 210         BackendPtr b = *bit;
 211
 212         b->m_package->copy_filter(package);
 213         b->m_package->request() = (Z_GDU *) 0;
 214         b->m_package->session().close();
 215         b->m_package->move(b->m_route);
 216     }
 217 }
 218
 219 void yf::Multi::Frontend::multi_move(std::list<BackendPtr> &blist)
 220 {
 221     std::list<BackendPtr>::const_iterator bit;
 222     boost::thread_group g;
 223     for (bit = blist.begin(); bit != blist.end(); bit++)
 224     {
 225         g.add_thread(new boost::thread(**bit));
 226     }
 227     g.join_all();
 228 }
 229
 230
 231 void yf::Multi::FrontendSet::round_robin(int start, int number,
 232                                          std::list<PresentJob> &jobs)
 233 {
 234     int fetched = 0;
 235     int p = 1;
 236     bool eof = true;
 237
 238     std::list<int> pos;
 239     std::list<int> inside_pos;
 240     std::list<BackendSet>::const_iterator bsit;
 241     for (bsit = m_backend_sets.begin(); bsit != m_backend_sets.end(); bsit++)
 242     {
 243         pos.push_back(1);
 244         inside_pos.push_back(0);
 245     }
 246
 247     std::list<int>::iterator psit = pos.begin();
 248     std::list<int>::iterator esit = inside_pos.begin();
 249     bsit = m_backend_sets.begin();
 250     while (fetched < number)
 251     {
 252         if (bsit == m_backend_sets.end())
 253         {
 254             psit = pos.begin();
 255             esit = inside_pos.begin();
 256             bsit = m_backend_sets.begin();
 257             if (eof)
 258                 break;
 259             eof = true;
 260         }
 261         if (*psit <= bsit->m_count)
 262         {
 263             if (p >= start)
 264             {
 265                 PresentJob job;
 266                 job.m_backend = bsit->m_backend;
 267                 job.m_pos = *psit;
 268                 job.m_inside_pos = *esit;
 269                 jobs.push_back(job);
 270                 (*esit)++;
 271                 fetched++;
 272             }
 273             (*psit)++;
 274             p++;
 275             eof = false;
 276         }
 277         psit++;
 278         esit++;
 279         bsit++;
 280     }
 281 }
 282
 283 void yf::Multi::Frontend::init(Package &package, Z_GDU *gdu)
 284 {
 285     Z_InitRequest *req = gdu->u.z3950->u.initRequest;
 286
 287     std::list<std::string> targets;
 288
 289     yp2::util::get_vhost_otherinfo(&req->otherInfo, false, targets);
 290
 291     if (targets.size() < 1)
 292     {
 293         package.move();
 294         return;
 295     }
 296
 297     std::list<std::string>::const_iterator t_it = targets.begin();
 298     for (; t_it != targets.end(); t_it++)
 299     {
 300         Session s;
 301         Backend *b = new Backend;
 302         b->m_vhost = *t_it;
 303
 304         b->m_route = m_p->m_target_route[*t_it];
 305         // b->m_route unset
 306         b->m_package = PackagePtr(new Package(s, package.origin()));
 307
 308         m_backend_list.push_back(BackendPtr(b));
 309     }
 310     m_is_multi = true;
 311
 312     // create init request
 313     std::list<BackendPtr>::const_iterator bit;
 314     for (bit = m_backend_list.begin(); bit != m_backend_list.end(); bit++)
 315     {
 316         yp2::odr odr;
 317         BackendPtr b = *bit;
 318         Z_APDU *init_apdu = zget_APDU(odr, Z_APDU_initRequest);
 319
 320         yaz_oi_set_string_oidval(&init_apdu->u.initRequest->otherInfo, odr,
 321                                  VAL_PROXY, 1, b->m_vhost.c_str());
 322
 323         Z_InitRequest *req = init_apdu->u.initRequest;
 324
 325         ODR_MASK_SET(req->options, Z_Options_search);
 326         ODR_MASK_SET(req->options, Z_Options_present);
 327         ODR_MASK_SET(req->options, Z_Options_namedResultSets);
 328         ODR_MASK_SET(req->options, Z_Options_scan);
 329
 330         ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_1);
 331         ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_2);
 332         ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_3);
 333
 334         b->m_package->request() = init_apdu;
 335
 336         b->m_package->copy_filter(package);
 337     }
 338     multi_move(m_backend_list);
 339
 340     // create the frontend init response based on each backend init response
 341     yp2::odr odr;
 342
 343     Z_APDU *f_apdu = odr.create_initResponse(gdu->u.z3950, 0, 0);
 344     Z_InitResponse *f_resp = f_apdu->u.initResponse;
 345
 346     ODR_MASK_SET(f_resp->options, Z_Options_search);
 347     ODR_MASK_SET(f_resp->options, Z_Options_present);
 348     ODR_MASK_SET(f_resp->options, Z_Options_namedResultSets);
 349
 350     ODR_MASK_SET(f_resp->protocolVersion, Z_ProtocolVersion_1);
 351     ODR_MASK_SET(f_resp->protocolVersion, Z_ProtocolVersion_2);
 352     ODR_MASK_SET(f_resp->protocolVersion, Z_ProtocolVersion_3);
 353
 354     for (bit = m_backend_list.begin(); bit != m_backend_list.end(); bit++)
 355     {
 356         PackagePtr p = (*bit)->m_package;
 357
 358         if (p->session().is_closed()) // if any backend closes, close frontend
 359             package.session().close();
 360         Z_GDU *gdu = p->response().get();
 361         if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
 362             Z_APDU_initResponse)
 363         {
 364             int i;
 365             Z_APDU *b_apdu = gdu->u.z3950;
 366             Z_InitResponse *b_resp = b_apdu->u.initResponse;
 367
 368             // common options for all backends
 369             for (i = 0; i <= Z_Options_stringSchema; i++)
 370             {
 371                 if (!ODR_MASK_GET(b_resp->options, i))
 372                     ODR_MASK_CLEAR(f_resp->options, i);
 373             }
 374             // common protocol version
 375             for (i = 0; i <= Z_ProtocolVersion_3; i++)
 376                 if (!ODR_MASK_GET(b_resp->protocolVersion, i))
 377                     ODR_MASK_CLEAR(f_resp->protocolVersion, i);
 378             // reject if any of the backends reject
 379             if (!*b_resp->result)
 380                 *f_resp->result = 0;
 381         }
 382         else
 383         {
 384             // if any target does not return init return that (close or
 385             // similar )
 386             package.response() = p->response();
 387             return;
 388         }
 389     }
 390     package.response() = f_apdu;
 391 }
 392
 393 void yf::Multi::Frontend::search(Package &package, Z_APDU *apdu_req)
 394 {
 395     // create search request
 396     Z_SearchRequest *req = apdu_req->u.searchRequest;
 397
 398     // save these for later
 399     int smallSetUpperBound = *req->smallSetUpperBound;
 400     int largeSetLowerBound = *req->largeSetLowerBound;
 401     int mediumSetPresentNumber = *req->mediumSetPresentNumber;
 402
 403     // they are altered now - to disable piggyback
 404     *req->smallSetUpperBound = 0;
 405     *req->largeSetLowerBound = 1;
 406     *req->mediumSetPresentNumber = 1;
 407
 408     int default_num_db = req->num_databaseNames;
 409     char **default_db = req->databaseNames;
 410
 411     std::list<BackendPtr>::const_iterator bit;
 412     for (bit = m_backend_list.begin(); bit != m_backend_list.end(); bit++)
 413     {
 414         PackagePtr p = (*bit)->m_package;
 415         yp2::odr odr;
 416
 417         if (!yp2::util::set_databases_from_zurl(odr, (*bit)->m_vhost,
 418                                                 &req->num_databaseNames,
 419                                                 &req->databaseNames))
 420         {
 421             req->num_databaseNames = default_num_db;
 422             req->databaseNames = default_db;
 423         }
 424         p->request() = apdu_req;
 425         p->copy_filter(package);
 426     }
 427     multi_move(m_backend_list);
 428
 429     // look at each response
 430     FrontendSet resultSet(std::string(req->resultSetName));
 431
 432     int result_set_size = 0;
 433     Z_Records *z_records_diag = 0;  // no diagnostics (yet)
 434     for (bit = m_backend_list.begin(); bit != m_backend_list.end(); bit++)
 435     {
 436         PackagePtr p = (*bit)->m_package;
 437
 438         if (p->session().is_closed()) // if any backend closes, close frontend
 439             package.session().close();
 440
 441         Z_GDU *gdu = p->response().get();
 442         if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
 443             Z_APDU_searchResponse)
 444         {
 445             Z_APDU *b_apdu = gdu->u.z3950;
 446             Z_SearchResponse *b_resp = b_apdu->u.searchResponse;
 447
 448             // see we get any errors (AKA diagnstics)
 449             if (b_resp->records)
 450             {
 451                 if (b_resp->records->which == Z_Records_NSD
 452                     || b_resp->records->which == Z_Records_multipleNSD)
 453                     z_records_diag = b_resp->records;
 454                 // we may set this multiple times (TOO BAD!)
 455             }
 456             BackendSet backendSet;
 457             backendSet.m_backend = *bit;
 458             backendSet.m_count = *b_resp->resultCount;
 459             result_set_size += *b_resp->resultCount;
 460             resultSet.m_backend_sets.push_back(backendSet);
 461         }
 462         else
 463         {
 464             // if any target does not return search response - return that
 465             package.response() = p->response();
 466             return;
 467         }
 468     }
 469
 470     yp2::odr odr;
 471     Z_APDU *f_apdu = odr.create_searchResponse(apdu_req, 0, 0);
 472     Z_SearchResponse *f_resp = f_apdu->u.searchResponse;
 473
 474     *f_resp->resultCount = result_set_size;
 475     if (z_records_diag)
 476     {
 477         // search error
 478         f_resp->records = z_records_diag;
 479         package.response() = f_apdu;
 480         return;
 481     }
 482     // assume OK
 483     m_sets[resultSet.m_setname] = resultSet;
 484
 485     int number;
 486     yp2::util::piggyback(smallSetUpperBound,
 487                          largeSetLowerBound,
 488                          mediumSetPresentNumber,
 489                          result_set_size,
 490                          number);
 491     Package pp(package.session(), package.origin());
 492     if (number > 0)
 493     {
 494         pp.copy_filter(package);
 495         Z_APDU *p_apdu = zget_APDU(odr, Z_APDU_presentRequest);
 496         Z_PresentRequest *p_req = p_apdu->u.presentRequest;
 497         p_req->preferredRecordSyntax = req->preferredRecordSyntax;
 498         p_req->resultSetId = req->resultSetName;
 499         *p_req->resultSetStartPoint = 1;
 500         *p_req->numberOfRecordsRequested = number;
 501         pp.request() = p_apdu;
 502         present(pp, p_apdu);
 503
 504         if (pp.session().is_closed())
 505             package.session().close();
 506
 507         Z_GDU *gdu = pp.response().get();
 508         if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
 509             Z_APDU_presentResponse)
 510         {
 511             Z_PresentResponse *p_res = gdu->u.z3950->u.presentResponse;
 512             f_resp->records = p_res->records;
 513             *f_resp->numberOfRecordsReturned =
 514                 *p_res->numberOfRecordsReturned;
 515             *f_resp->nextResultSetPosition =
 516                 *p_res->nextResultSetPosition;
 517         }
 518         else
 519         {
 520             package.response() = pp.response();
 521             return;
 522         }
 523     }
 524     package.response() = f_apdu; // in this scope because of p
 525 }
 526
 527 void yf::Multi::Frontend::present(Package &package, Z_APDU *apdu_req)
 528 {
 529     // create present request
 530     Z_PresentRequest *req = apdu_req->u.presentRequest;
 531
 532     Sets_it it;
 533     it = m_sets.find(std::string(req->resultSetId));
 534     if (it == m_sets.end())
 535     {
 536         yp2::odr odr;
 537         Z_APDU *apdu =
 538             odr.create_presentResponse(
 539                 apdu_req,
 540                 YAZ_BIB1_SPECIFIED_RESULT_SET_DOES_NOT_EXIST,
 541                 req->resultSetId);
 542         package.response() = apdu;
 543         return;
 544     }
 545     std::list<Multi::FrontendSet::PresentJob> jobs;
 546     int start = *req->resultSetStartPoint;
 547     int number = *req->numberOfRecordsRequested;
 548     it->second.round_robin(start, number, jobs);
 549
 550     std::list<BackendPtr> present_backend_list;
 551
 552     std::list<BackendSet>::const_iterator bsit;
 553     bsit = it->second.m_backend_sets.begin();
 554     for (; bsit != it->second.m_backend_sets.end(); bsit++)
 555     {
 556         std::list<Multi::FrontendSet::PresentJob>::const_iterator jit;
 557         int start = -1;
 558         int end = -1;
 559
 560         for (jit = jobs.begin(); jit != jobs.end(); jit++)
 561         {
 562             if (jit->m_backend == bsit->m_backend)
 563             {
 564                 if (start == -1 || jit->m_pos < start)
 565                     start = jit->m_pos;
 566                 if (end == -1 || jit->m_pos > end)
 567                     end = jit->m_pos;
 568             }
 569         }
 570         if (start != -1)
 571         {
 572             PackagePtr p = bsit->m_backend->m_package;
 573
 574             *req->resultSetStartPoint = start;
 575             *req->numberOfRecordsRequested = end - start + 1;
 576
 577             p->request() = apdu_req;
 578             p->copy_filter(package);
 579
 580             present_backend_list.push_back(bsit->m_backend);
 581         }
 582     }
 583     multi_move(present_backend_list);
 584
 585     // look at each response
 586     Z_Records *z_records_diag = 0;
 587
 588     std::list<BackendPtr>::const_iterator pbit = present_backend_list.begin();
 589     for (; pbit != present_backend_list.end(); pbit++)
 590     {
 591         PackagePtr p = (*pbit)->m_package;
 592
 593         if (p->session().is_closed()) // if any backend closes, close frontend
 594             package.session().close();
 595
 596         Z_GDU *gdu = p->response().get();
 597         if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
 598             Z_APDU_presentResponse)
 599         {
 600             Z_APDU *b_apdu = gdu->u.z3950;
 601             Z_PresentResponse *b_resp = b_apdu->u.presentResponse;
 602
 603             // see we get any errors (AKA diagnstics)
 604             if (b_resp->records)
 605             {
 606                 if (b_resp->records->which != Z_Records_DBOSD)
 607                     z_records_diag = b_resp->records;
 608                 // we may set this multiple times (TOO BAD!)
 609             }
 610         }
 611         else
 612         {
 613             // if any target does not return present response - return that
 614             package.response() = p->response();
 615             return;
 616         }
 617     }
 618
 619     yp2::odr odr;
 620     Z_APDU *f_apdu = odr.create_presentResponse(apdu_req, 0, 0);
 621     Z_PresentResponse *f_resp = f_apdu->u.presentResponse;
 622
 623     if (z_records_diag)
 624     {
 625         f_resp->records = z_records_diag;
 626         *f_resp->presentStatus = Z_PresentStatus_failure;
 627     }
 628     else
 629     {
 630         f_resp->records = (Z_Records *) odr_malloc(odr, sizeof(Z_Records));
 631         Z_Records * records = f_resp->records;
 632         records->which = Z_Records_DBOSD;
 633         records->u.databaseOrSurDiagnostics =
 634             (Z_NamePlusRecordList *)
 635             odr_malloc(odr, sizeof(Z_NamePlusRecordList));
 636         Z_NamePlusRecordList *nprl = records->u.databaseOrSurDiagnostics;
 637         nprl->num_records = jobs.size();
 638         nprl->records = (Z_NamePlusRecord**)
 639             odr_malloc(odr, sizeof(Z_NamePlusRecord *) * nprl->num_records);
 640         int i = 0;
 641         std::list<Multi::FrontendSet::PresentJob>::const_iterator jit;
 642         for (jit = jobs.begin(); jit != jobs.end(); jit++)
 643         {
 644             PackagePtr p = jit->m_backend->m_package;
 645
 646             Z_GDU *gdu = p->response().get();
 647             Z_APDU *b_apdu = gdu->u.z3950;
 648             Z_PresentResponse *b_resp = b_apdu->u.presentResponse;
 649
 650             nprl->records[i++] =
 651                 b_resp->records->u.databaseOrSurDiagnostics->
 652                 records[jit->m_inside_pos];
 653         }
 654         *f_resp->nextResultSetPosition = start + i;
 655         *f_resp->numberOfRecordsReturned = i;
 656     }
 657     package.response() = f_apdu;
 658 }
 659
 660 void yf::Multi::Frontend::scan(Package &package, Z_APDU *apdu_req)
 661 {
 662     if (m_backend_list.size() > 1)
 663     {
 664         yp2::odr odr;
 665         Z_APDU *f_apdu =
 666             odr.create_scanResponse(
 667                 apdu_req, YAZ_BIB1_COMBI_OF_SPECIFIED_DATABASES_UNSUPP, 0);
 668         package.response() = f_apdu;
 669         return;
 670     }
 671     Z_ScanRequest *req = apdu_req->u.scanRequest;
 672
 673     int default_num_db = req->num_databaseNames;
 674     char **default_db = req->databaseNames;
 675
 676     std::list<BackendPtr>::const_iterator bit;
 677     for (bit = m_backend_list.begin(); bit != m_backend_list.end(); bit++)
 678     {
 679         PackagePtr p = (*bit)->m_package;
 680         yp2::odr odr;
 681
 682         if (!yp2::util::set_databases_from_zurl(odr, (*bit)->m_vhost,
 683                                                 &req->num_databaseNames,
 684                                                 &req->databaseNames))
 685         {
 686             req->num_databaseNames = default_num_db;
 687             req->databaseNames = default_db;
 688         }
 689         p->request() = apdu_req;
 690         p->copy_filter(package);
 691     }
 692     multi_move(m_backend_list);
 693
 694     for (bit = m_backend_list.begin(); bit != m_backend_list.end(); bit++)
 695     {
 696         PackagePtr p = (*bit)->m_package;
 697
 698         if (p->session().is_closed()) // if any backend closes, close frontend
 699             package.session().close();
 700
 701         Z_GDU *gdu = p->response().get();
 702         if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
 703             Z_APDU_scanResponse)
 704         {
 705             package.response() = p->response();
 706             break;
 707         }
 708         else
 709         {
 710             // if any target does not return scan response - return that
 711             package.response() = p->response();
 712             return;
 713         }
 714     }
 715 }
 716
 717 void yf::Multi::process(Package &package) const
 718 {
 719     FrontendPtr f = m_p->get_frontend(package);
 720
 721     Z_GDU *gdu = package.request().get();
 722
 723     if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
 724         Z_APDU_initRequest && !f->m_is_multi)
 725     {
 726         f->init(package, gdu);
 727     }
 728     else if (!f->m_is_multi)
 729         package.move();
 730     else if (gdu && gdu->which == Z_GDU_Z3950)
 731     {
 732         Z_APDU *apdu = gdu->u.z3950;
 733         if (apdu->which == Z_APDU_initRequest)
 734         {
 735             yp2::odr odr;
 736
 737             package.response() = odr.create_close(
 738                 apdu,
 739                 Z_Close_protocolError,
 740                 "double init");
 741
 742             package.session().close();
 743         }
 744         else if (apdu->which == Z_APDU_searchRequest)
 745         {
 746             f->search(package, apdu);
 747         }
 748         else if (apdu->which == Z_APDU_presentRequest)
 749         {
 750             f->present(package, apdu);
 751         }
 752         else if (apdu->which == Z_APDU_scanRequest)
 753         {
 754             f->scan(package, apdu);
 755         }
 756         else
 757         {
 758             yp2::odr odr;
 759
 760             package.response() = odr.create_close(
 761                 apdu, Z_Close_protocolError,
 762                 "unsupported APDU in filter multi");
 763
 764             package.session().close();
 765         }
 766     }
 767     m_p->release_frontend(package);
 768 }
 769
 770 void yp2::filter::Multi::configure(const xmlNode * ptr)
 771 {
 772     for (ptr = ptr->children; ptr; ptr = ptr->next)
 773     {
 774         if (ptr->type != XML_ELEMENT_NODE)
 775             continue;
 776         if (!strcmp((const char *) ptr->name, "target"))
 777         {
 778             std::string route = yp2::xml::get_route(ptr);
 779             std::string target = yp2::xml::get_text(ptr);
 780             std::cout << "route=" << route << " target=" << target << "\n";
 781             m_p->m_target_route[target] = route;
 782         }
 783         else if (!strcmp((const char *) ptr->name, "virtual"))
 784         {
 785             std::list<std::string> targets;
 786             std::string vhost;
 787             xmlNode *v_node = ptr->children;
 788             for (; v_node; v_node = v_node->next)
 789             {
 790                 if (v_node->type != XML_ELEMENT_NODE)
 791                     continue;
 792
 793                 if (yp2::xml::is_element_yp2(v_node, "vhost"))
 794                     vhost = yp2::xml::get_text(v_node);
 795                 else if (yp2::xml::is_element_yp2(v_node, "target"))
 796                     targets.push_back(yp2::xml::get_text(v_node));
 797                 else
 798                     throw yp2::filter::FilterException
 799                         ("Bad element "
 800                          + std::string((const char *) v_node->name)
 801                          + " in virtual section"
 802                             );
 803             }
 804             std::string route = yp2::xml::get_route(ptr);
 805             add_map_host2hosts(vhost, targets, route);
 806             std::list<std::string>::const_iterator it;
 807             for (it = targets.begin(); it != targets.end(); it++)
 808             {
 809                 std::cout << "Add " << vhost << "->" << *it
 810                           << "," << route << "\n";
 811             }
 812         }
 813         else
 814         {
 815             throw yp2::filter::FilterException
 816                 ("Bad element "
 817                  + std::string((const char *) ptr->name)
 818                  + " in virt_db filter");
 819         }
 820     }
 821 }
 822
 823 static yp2::filter::Base* filter_creator()
 824 {
 825     return new yp2::filter::Multi;
 826 }
 827
 828 extern "C" {
 829     struct yp2_filter_struct yp2_filter_multi = {
 830         0,
 831         "multi",
 832         filter_creator
 833     };
 834 }
 835
 836
 837 /*
 838  * Local variables:
 839  * c-basic-offset: 4
 840  * indent-tabs-mode: nil
 841  * c-file-style: "stroustrup"
 842  * End:
 843  * vim: shiftwidth=4 tabstop=8 expandtab
 844  */