multi: init handshake always return init response
[metaproxy-moved-to-github.git] / src / filter_multi.cpp
1 /* This file is part of Metaproxy.
2    Copyright (C) 2005-2010 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 <yaz/log.h>
20
21 #include "config.hpp"
22
23 #include <metaproxy/filter.hpp>
24 #include <metaproxy/package.hpp>
25
26 #include <boost/thread/thread.hpp>
27 #include <boost/thread/mutex.hpp>
28 #include <boost/thread/condition.hpp>
29 #include <boost/shared_ptr.hpp>
30
31 #include <metaproxy/util.hpp>
32 #include "filter_multi.hpp"
33
34 #include <yaz/zgdu.h>
35 #include <yaz/otherinfo.h>
36 #include <yaz/diagbib1.h>
37 #include <yaz/match_glob.h>
38
39 #include <vector>
40 #include <algorithm>
41 #include <map>
42 #include <iostream>
43
44 namespace mp = metaproxy_1;
45 namespace yf = mp::filter;
46
47 namespace metaproxy_1 {
48     namespace filter {
49         enum multi_merge_type {
50             round_robin,
51             serve_order
52         };
53         struct Multi::BackendSet {
54             BackendPtr m_backend;
55             int m_count;
56             bool operator < (const BackendSet &k) const;
57             bool operator == (const BackendSet &k) const;
58         };
59         struct Multi::ScanTermInfo {
60             std::string m_norm_term;
61             std::string m_display_term;
62             int m_count;
63             bool operator < (const ScanTermInfo &) const;
64             bool operator == (const ScanTermInfo &) const;
65             Z_Entry *get_entry(ODR odr);
66         };
67         struct Multi::FrontendSet {
68             class PresentJob {
69             public:
70                 BackendPtr m_backend;
71                 int m_pos; // position for backend (1=first, 2=second,..
72                 int m_start; // present request start
73                 PresentJob(BackendPtr ptr, int pos) : 
74                     m_backend(ptr), m_pos(pos), m_start(0) {};
75             };
76             FrontendSet(std::string setname);
77             FrontendSet();
78             ~FrontendSet();
79
80             void round_robin(int pos, int number, std::list<PresentJob> &job);
81             void serve_order(int pos, int number, std::list<PresentJob> &job);
82
83             std::list<BackendSet> m_backend_sets;
84             std::string m_setname;
85         };
86         struct Multi::Backend {
87             PackagePtr m_package;
88             std::string m_backend_database;
89             std::string m_vhost;
90             std::string m_route;
91             void operator() (void);  // thread operation
92         };
93         struct Multi::Frontend {
94             Frontend(Rep *rep);
95             ~Frontend();
96             bool m_is_multi;
97             bool m_in_use;
98             std::list<BackendPtr> m_backend_list;
99             std::map<std::string,Multi::FrontendSet> m_sets;
100
101             void multi_move(std::list<BackendPtr> &blist);
102             void init(Package &package, Z_GDU *gdu);
103             void close(Package &package);
104             void search(Package &package, Z_APDU *apdu);
105             void present(Package &package, Z_APDU *apdu);
106             void scan1(Package &package, Z_APDU *apdu);
107             void scan2(Package &package, Z_APDU *apdu);
108             Rep *m_p;
109         };            
110         class Multi::Map {
111             std::string m_target_pattern;
112             std::string m_route;
113         public:
114             Map(std::string pattern, std::string route) : 
115                 m_target_pattern(pattern), m_route(route) {};
116             bool match(const std::string target, std::string *ret) const {
117                 if (yaz_match_glob(m_target_pattern.c_str(), target.c_str()))
118                 {
119                     *ret = m_route;
120                     return true;
121                 }
122                 return false;
123             };
124         };
125         class Multi::Rep {
126             friend class Multi;
127             friend struct Frontend;
128             
129             Rep();
130             FrontendPtr get_frontend(Package &package);
131             void release_frontend(Package &package);
132         private:
133             std::list<Multi::Map> m_route_patterns;
134             boost::mutex m_mutex;
135             boost::condition m_cond_session_ready;
136             std::map<mp::Session, FrontendPtr> m_clients;
137             bool m_hide_unavailable;
138             multi_merge_type m_merge_type;
139         };
140     }
141 }
142
143 yf::Multi::Rep::Rep()
144 {
145     m_hide_unavailable = false;
146     m_merge_type = round_robin;
147 }
148
149 bool yf::Multi::BackendSet::operator < (const BackendSet &k) const
150 {
151     return m_count < k.m_count;
152 }
153
154 yf::Multi::Frontend::Frontend(Rep *rep)
155 {
156     m_p = rep;
157     m_is_multi = false;
158 }
159
160 yf::Multi::Frontend::~Frontend()
161 {
162 }
163
164 yf::Multi::FrontendPtr yf::Multi::Rep::get_frontend(mp::Package &package)
165 {
166     boost::mutex::scoped_lock lock(m_mutex);
167
168     std::map<mp::Session,yf::Multi::FrontendPtr>::iterator it;
169     
170     while(true)
171     {
172         it = m_clients.find(package.session());
173         if (it == m_clients.end())
174             break;
175         
176         if (!it->second->m_in_use)
177         {
178             it->second->m_in_use = true;
179             return it->second;
180         }
181         m_cond_session_ready.wait(lock);
182     }
183     FrontendPtr f(new Frontend(this));
184     m_clients[package.session()] = f;
185     f->m_in_use = true;
186     return f;
187 }
188
189 void yf::Multi::Rep::release_frontend(mp::Package &package)
190 {
191     boost::mutex::scoped_lock lock(m_mutex);
192     std::map<mp::Session,yf::Multi::FrontendPtr>::iterator it;
193     
194     it = m_clients.find(package.session());
195     if (it != m_clients.end())
196     {
197         if (package.session().is_closed())
198         {
199             it->second->close(package);
200             m_clients.erase(it);
201         }
202         else
203         {
204             it->second->m_in_use = false;
205         }
206         m_cond_session_ready.notify_all();
207     }
208 }
209
210 yf::Multi::FrontendSet::FrontendSet(std::string setname)
211     :  m_setname(setname)
212 {
213 }
214
215
216 yf::Multi::FrontendSet::FrontendSet()
217 {
218 }
219
220
221 yf::Multi::FrontendSet::~FrontendSet()
222 {
223 }
224
225 yf::Multi::Multi() : m_p(new Multi::Rep)
226 {
227 }
228
229 yf::Multi::~Multi() {
230 }
231
232
233 void yf::Multi::Backend::operator() (void) 
234 {
235     m_package->move(m_route);
236 }
237
238
239 void yf::Multi::Frontend::close(mp::Package &package)
240 {
241     std::list<BackendPtr>::const_iterator bit;
242     for (bit = m_backend_list.begin(); bit != m_backend_list.end(); bit++)
243     {
244         BackendPtr b = *bit;
245
246         b->m_package->copy_filter(package);
247         b->m_package->request() = (Z_GDU *) 0;
248         b->m_package->session().close();
249         b->m_package->move(b->m_route);
250     }
251 }
252
253 void yf::Multi::Frontend::multi_move(std::list<BackendPtr> &blist)
254 {
255     std::list<BackendPtr>::const_iterator bit;
256     boost::thread_group g;
257     for (bit = blist.begin(); bit != blist.end(); bit++)
258     {
259         g.add_thread(new boost::thread(**bit));
260     }
261     g.join_all();
262 }
263
264 void yf::Multi::FrontendSet::serve_order(int start, int number,
265                                          std::list<PresentJob> &jobs)
266 {
267     int i;
268     for (i = 0; i < number; i++)
269     {
270         std::list<BackendSet>::const_iterator bsit;
271         int voffset = 0;
272         int offset = start + i - 1;
273         for (bsit = m_backend_sets.begin(); bsit != m_backend_sets.end(); 
274              bsit++)
275         {
276             if (offset >= voffset && offset < voffset + bsit->m_count)
277             {
278                 PresentJob job(bsit->m_backend, offset - voffset + 1);
279                 jobs.push_back(job);
280                 break;
281             }
282             voffset += bsit->m_count;
283         }
284     }
285 }
286
287 void yf::Multi::FrontendSet::round_robin(int start, int number,
288                                          std::list<PresentJob> &jobs)
289 {
290     std::list<int> pos;
291     std::list<BackendSet>::const_iterator bsit;
292     for (bsit = m_backend_sets.begin(); bsit != m_backend_sets.end(); bsit++)
293     {
294         pos.push_back(1);
295     }
296
297     int p = 1;
298 #if 1
299     // optimization step!
300     int omin = 0;
301     while(true)
302     {
303         int min = 0;
304         int no_left = 0;
305         // find min count for each set which is > omin
306         for (bsit = m_backend_sets.begin(); bsit != m_backend_sets.end(); bsit++)
307         {
308             if (bsit->m_count > omin)
309             {
310                 if (no_left == 0 || bsit->m_count < min)
311                     min = bsit->m_count;
312                 no_left++;
313             }
314         }
315         if (no_left == 0) // if nothing greater than omin, bail out.
316             break;
317         int skip = no_left * min;
318         if (p + skip > start)  // step gets us "into" present range?
319         {
320             // Yes. skip until start.. Rounding off is deliberate!
321             min = (start-p) / no_left;
322             p += no_left * min;
323             
324             // update positions in each set..
325             std::list<int>::iterator psit = pos.begin();
326             for (psit = pos.begin(); psit != pos.end(); psit++)
327                 *psit += min;
328             break;
329         }
330         // skip on each set.. before "present range"..
331         p = p + skip;
332         
333         std::list<int>::iterator psit = pos.begin();
334         for (psit = pos.begin(); psit != pos.end(); psit++)
335             *psit += min;
336         
337         omin = min; // update so we consider next class (with higher count)
338     }
339 #endif
340     int fetched = 0;
341     bool more = true;
342     while (more)
343     {
344         more = false;
345         std::list<int>::iterator psit = pos.begin();
346         bsit = m_backend_sets.begin();
347
348         for (; bsit != m_backend_sets.end(); psit++,bsit++)
349         {
350             if (fetched >= number)
351             {
352                 more = false;
353                 break;
354             }
355             if (*psit <= bsit->m_count)
356             {
357                 if (p >= start)
358                 {
359                     PresentJob job(bsit->m_backend, *psit);
360                     jobs.push_back(job);
361                     fetched++;
362                 }
363                 (*psit)++;
364                 p++;
365                 more = true;
366             }
367         }
368     }
369 }
370
371 void yf::Multi::Frontend::init(mp::Package &package, Z_GDU *gdu)
372 {
373     Z_InitRequest *req = gdu->u.z3950->u.initRequest;
374
375     std::list<std::string> targets;
376
377     mp::util::get_vhost_otherinfo(req->otherInfo, targets);
378
379     if (targets.size() < 1)
380     {
381         package.move();
382         return;
383     }
384
385     std::list<std::string>::const_iterator t_it = targets.begin();
386     for (; t_it != targets.end(); t_it++)
387     {
388         Session s;
389         Backend *b = new Backend;
390         b->m_vhost = *t_it;
391
392         std::list<Multi::Map>::const_iterator it =
393             m_p->m_route_patterns.begin();
394         while (it != m_p->m_route_patterns.end()) {
395             if (it->match(*t_it, &b->m_route))
396                 break;
397             it++;
398         }
399         // b->m_route = m_p->m_target_route[*t_it];
400         // b->m_route unset
401         b->m_package = PackagePtr(new Package(s, package.origin()));
402
403         m_backend_list.push_back(BackendPtr(b));
404     }
405     m_is_multi = true;
406
407     // create init request 
408     std::list<BackendPtr>::iterator bit;
409     for (bit = m_backend_list.begin(); bit != m_backend_list.end(); bit++)
410     {
411         mp::odr odr;
412         BackendPtr b = *bit;
413         Z_APDU *init_apdu = zget_APDU(odr, Z_APDU_initRequest);
414         
415         std::list<std::string>vhost_one;
416         vhost_one.push_back(b->m_vhost);
417         mp::util::set_vhost_otherinfo(&init_apdu->u.initRequest->otherInfo,
418                                        odr, vhost_one);
419
420         Z_InitRequest *req = init_apdu->u.initRequest;
421         
422         ODR_MASK_SET(req->options, Z_Options_search);
423         ODR_MASK_SET(req->options, Z_Options_present);
424         ODR_MASK_SET(req->options, Z_Options_namedResultSets);
425         ODR_MASK_SET(req->options, Z_Options_scan);
426         
427         ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_1);
428         ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_2);
429         ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_3);
430         
431         b->m_package->request() = init_apdu;
432
433         b->m_package->copy_filter(package);
434     }
435     multi_move(m_backend_list);
436
437     // create the frontend init response based on each backend init response
438     mp::odr odr;
439
440     Z_APDU *f_apdu = odr.create_initResponse(gdu->u.z3950, 0, 0);
441     Z_InitResponse *f_resp = f_apdu->u.initResponse;
442
443     ODR_MASK_SET(f_resp->options, Z_Options_search);
444     ODR_MASK_SET(f_resp->options, Z_Options_present);
445     ODR_MASK_SET(f_resp->options, Z_Options_namedResultSets);
446     
447     ODR_MASK_SET(f_resp->protocolVersion, Z_ProtocolVersion_1);
448     ODR_MASK_SET(f_resp->protocolVersion, Z_ProtocolVersion_2);
449     ODR_MASK_SET(f_resp->protocolVersion, Z_ProtocolVersion_3);
450
451     int no_failed = 0;
452     int no_succeeded = 0;
453     for (bit = m_backend_list.begin(); bit != m_backend_list.end(); )
454     {
455         PackagePtr p = (*bit)->m_package;
456         
457         if (p->session().is_closed())
458         {
459             // failed. Remove from list and increment number of failed
460             no_failed++;
461             bit = m_backend_list.erase(bit);
462             continue;
463         }
464         Z_GDU *gdu = p->response().get();
465         if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
466             Z_APDU_initResponse)
467         {
468             int i;
469             Z_APDU *b_apdu = gdu->u.z3950;
470             Z_InitResponse *b_resp = b_apdu->u.initResponse;
471
472             // common options for all backends
473             for (i = 0; i <= Z_Options_stringSchema; i++)
474             {
475                 if (!ODR_MASK_GET(b_resp->options, i))
476                     ODR_MASK_CLEAR(f_resp->options, i);
477             }
478             // common protocol version
479             for (i = 0; i <= Z_ProtocolVersion_3; i++)
480                 if (!ODR_MASK_GET(b_resp->protocolVersion, i))
481                     ODR_MASK_CLEAR(f_resp->protocolVersion, i);
482             if (*b_resp->result)
483                 no_succeeded++;
484             else
485                 no_failed++;
486         }
487         else
488             no_failed++;
489         bit++;
490     }
491     if (m_p->m_hide_unavailable)
492     {
493         if (no_succeeded == 0)
494         {
495             *f_resp->result = 0;
496             package.session().close();
497         }
498     }
499     else
500     {
501         if (no_failed)
502         {
503             *f_resp->result = 0;
504             package.session().close();
505         }
506     }
507     package.response() = f_apdu;
508 }
509
510 void yf::Multi::Frontend::search(mp::Package &package, Z_APDU *apdu_req)
511 {
512     // create search request 
513     Z_SearchRequest *req = apdu_req->u.searchRequest;
514
515     // save these for later
516     int smallSetUpperBound = *req->smallSetUpperBound;
517     int largeSetLowerBound = *req->largeSetLowerBound;
518     int mediumSetPresentNumber = *req->mediumSetPresentNumber;
519     
520     // they are altered now - to disable piggyback
521     *req->smallSetUpperBound = 0;
522     *req->largeSetLowerBound = 1;
523     *req->mediumSetPresentNumber = 1;
524
525     int default_num_db = req->num_databaseNames;
526     char **default_db = req->databaseNames;
527
528     std::list<BackendPtr>::const_iterator bit;
529     for (bit = m_backend_list.begin(); bit != m_backend_list.end(); bit++)
530     {
531         PackagePtr p = (*bit)->m_package;
532         mp::odr odr;
533     
534         if (!mp::util::set_databases_from_zurl(odr, (*bit)->m_vhost,
535                                                 &req->num_databaseNames,
536                                                 &req->databaseNames))
537         {
538             req->num_databaseNames = default_num_db;
539             req->databaseNames = default_db;
540         }
541         p->request() = apdu_req;
542         p->copy_filter(package);
543     }
544     multi_move(m_backend_list);
545
546     // look at each response
547     FrontendSet resultSet(std::string(req->resultSetName));
548
549     int result_set_size = 0;
550     Z_Records *z_records_diag = 0;  // no diagnostics (yet)
551     for (bit = m_backend_list.begin(); bit != m_backend_list.end(); bit++)
552     {
553         PackagePtr p = (*bit)->m_package;
554         
555         if (p->session().is_closed()) // if any backend closes, close frontend
556             package.session().close();
557         
558         Z_GDU *gdu = p->response().get();
559         if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
560             Z_APDU_searchResponse)
561         {
562             Z_APDU *b_apdu = gdu->u.z3950;
563             Z_SearchResponse *b_resp = b_apdu->u.searchResponse;
564          
565             // see we get any errors (AKA diagnstics)
566             if (b_resp->records)
567             {
568                 if (b_resp->records->which == Z_Records_NSD
569                     || b_resp->records->which == Z_Records_multipleNSD)
570                     z_records_diag = b_resp->records;
571                 // we may set this multiple times (TOO BAD!)
572             }
573             BackendSet backendSet;
574             backendSet.m_backend = *bit;
575             backendSet.m_count = *b_resp->resultCount;
576             result_set_size += *b_resp->resultCount;
577             resultSet.m_backend_sets.push_back(backendSet);
578         }
579         else
580         {
581             // if any target does not return search response - return that 
582             package.response() = p->response();
583             return;
584         }
585     }
586
587     mp::odr odr;
588     Z_APDU *f_apdu = odr.create_searchResponse(apdu_req, 0, 0);
589     Z_SearchResponse *f_resp = f_apdu->u.searchResponse;
590
591     *f_resp->resultCount = result_set_size;
592     if (z_records_diag)
593     {
594         // search error
595         f_resp->records = z_records_diag;
596         package.response() = f_apdu;
597         return;
598     }
599     // assume OK
600     m_sets[resultSet.m_setname] = resultSet;
601
602     int number;
603     mp::util::piggyback(smallSetUpperBound,
604                          largeSetLowerBound,
605                          mediumSetPresentNumber,
606                          result_set_size,
607                          number);
608     Package pp(package.session(), package.origin());
609     if (number > 0)
610     {
611         pp.copy_filter(package);
612         Z_APDU *p_apdu = zget_APDU(odr, Z_APDU_presentRequest);
613         Z_PresentRequest *p_req = p_apdu->u.presentRequest;
614         p_req->preferredRecordSyntax = req->preferredRecordSyntax;
615         p_req->resultSetId = req->resultSetName;
616         *p_req->resultSetStartPoint = 1;
617         *p_req->numberOfRecordsRequested = number;
618         pp.request() = p_apdu;
619         present(pp, p_apdu);
620         
621         if (pp.session().is_closed())
622             package.session().close();
623         
624         Z_GDU *gdu = pp.response().get();
625         if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
626             Z_APDU_presentResponse)
627         {
628             Z_PresentResponse *p_res = gdu->u.z3950->u.presentResponse;
629             f_resp->records = p_res->records;
630             *f_resp->numberOfRecordsReturned = 
631                 *p_res->numberOfRecordsReturned;
632             *f_resp->nextResultSetPosition = 
633                 *p_res->nextResultSetPosition;
634         }
635         else 
636         {
637             package.response() = pp.response(); 
638             return;
639         }
640     }
641     package.response() = f_apdu; // in this scope because of p
642 }
643
644 void yf::Multi::Frontend::present(mp::Package &package, Z_APDU *apdu_req)
645 {
646     // create present request 
647     Z_PresentRequest *req = apdu_req->u.presentRequest;
648
649     Sets_it it;
650     it = m_sets.find(std::string(req->resultSetId));
651     if (it == m_sets.end())
652     {
653         mp::odr odr;
654         Z_APDU *apdu = 
655             odr.create_presentResponse(
656                 apdu_req,
657                 YAZ_BIB1_SPECIFIED_RESULT_SET_DOES_NOT_EXIST,
658                 req->resultSetId);
659         package.response() = apdu;
660         return;
661     }
662     std::list<Multi::FrontendSet::PresentJob> jobs;
663     int start = *req->resultSetStartPoint;
664     int number = *req->numberOfRecordsRequested;
665
666     if (m_p->m_merge_type == round_robin)
667         it->second.round_robin(start, number, jobs);
668     else if (m_p->m_merge_type == serve_order)
669         it->second.serve_order(start, number, jobs);
670
671     if (0)
672     {
673         std::list<Multi::FrontendSet::PresentJob>::const_iterator jit;
674         for (jit = jobs.begin(); jit != jobs.end(); jit++)
675         {
676             yaz_log(YLOG_LOG, "job pos=%d", jit->m_pos);
677         }
678     }
679
680     std::list<BackendPtr> present_backend_list;
681
682     std::list<BackendSet>::const_iterator bsit;
683     bsit = it->second.m_backend_sets.begin();
684     for (; bsit != it->second.m_backend_sets.end(); bsit++)
685     {
686         int start = -1;
687         int end = -1;
688         {
689             std::list<Multi::FrontendSet::PresentJob>::const_iterator jit;
690             for (jit = jobs.begin(); jit != jobs.end(); jit++)
691             {
692                 if (jit->m_backend == bsit->m_backend)
693                 {
694                     if (start == -1 || jit->m_pos < start)
695                         start = jit->m_pos;
696                     if (end == -1 || jit->m_pos > end)
697                         end = jit->m_pos;
698                 }
699             }
700         }
701         if (start != -1)
702         {
703             std::list<Multi::FrontendSet::PresentJob>::iterator jit;
704             for (jit = jobs.begin(); jit != jobs.end(); jit++)
705             {
706                 if (jit->m_backend == bsit->m_backend)
707                 {
708                     if (jit->m_pos >= start && jit->m_pos <= end)
709                         jit->m_start = start;
710                 }
711             }
712
713             PackagePtr p = bsit->m_backend->m_package;
714
715             *req->resultSetStartPoint = start;
716             *req->numberOfRecordsRequested = end - start + 1;
717             
718             p->request() = apdu_req;
719             p->copy_filter(package);
720
721             present_backend_list.push_back(bsit->m_backend);
722         }
723     }
724     multi_move(present_backend_list);
725
726     // look at each response
727     Z_Records *z_records_diag = 0;
728
729     std::list<BackendPtr>::const_iterator pbit = present_backend_list.begin();
730     for (; pbit != present_backend_list.end(); pbit++)
731     {
732         PackagePtr p = (*pbit)->m_package;
733         
734         if (p->session().is_closed()) // if any backend closes, close frontend
735             package.session().close();
736         
737         Z_GDU *gdu = p->response().get();
738         if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
739             Z_APDU_presentResponse)
740         {
741             Z_APDU *b_apdu = gdu->u.z3950;
742             Z_PresentResponse *b_resp = b_apdu->u.presentResponse;
743          
744             // see we get any errors (AKA diagnstics)
745             if (b_resp->records)
746             {
747                 if (b_resp->records->which != Z_Records_DBOSD)
748                     z_records_diag = b_resp->records;
749                 // we may set this multiple times (TOO BAD!)
750             }
751         }
752         else
753         {
754             // if any target does not return present response - return that 
755             package.response() = p->response();
756             return;
757         }
758     }
759
760     mp::odr odr;
761     Z_APDU *f_apdu = odr.create_presentResponse(apdu_req, 0, 0);
762     Z_PresentResponse *f_resp = f_apdu->u.presentResponse;
763
764     if (z_records_diag)
765     {
766         f_resp->records = z_records_diag;
767         *f_resp->presentStatus = Z_PresentStatus_failure;
768     }
769     else if (number < 0 || (size_t) number > jobs.size())
770     {
771         f_apdu = 
772             odr.create_presentResponse(
773                 apdu_req,
774                 YAZ_BIB1_PRESENT_REQUEST_OUT_OF_RANGE,
775                 0);
776     }
777     else
778     {
779         f_resp->records = (Z_Records *) odr_malloc(odr, sizeof(Z_Records));
780         Z_Records * records = f_resp->records;
781         records->which = Z_Records_DBOSD;
782         records->u.databaseOrSurDiagnostics =
783             (Z_NamePlusRecordList *)
784             odr_malloc(odr, sizeof(Z_NamePlusRecordList));
785         Z_NamePlusRecordList *nprl = records->u.databaseOrSurDiagnostics;
786         nprl->num_records = jobs.size();
787         nprl->records = (Z_NamePlusRecord**)
788             odr_malloc(odr, sizeof(Z_NamePlusRecord *) * nprl->num_records);
789         int i = 0;
790         std::list<Multi::FrontendSet::PresentJob>::const_iterator jit;
791         for (jit = jobs.begin(); jit != jobs.end(); jit++, i++)
792         {
793             PackagePtr p = jit->m_backend->m_package;
794             
795             Z_GDU *gdu = p->response().get();
796             Z_APDU *b_apdu = gdu->u.z3950;
797             Z_PresentResponse *b_resp = b_apdu->u.presentResponse;
798
799             nprl->records[i] = (Z_NamePlusRecord*)
800                 odr_malloc(odr, sizeof(Z_NamePlusRecord));
801             int inside_pos = jit->m_pos - jit->m_start;
802             if (inside_pos >= b_resp->records->
803                 u.databaseOrSurDiagnostics->num_records)
804                 break;
805             *nprl->records[i] = *b_resp->records->
806                 u.databaseOrSurDiagnostics->records[inside_pos];
807             nprl->records[i]->databaseName =
808                     odr_strdup(odr, jit->m_backend->m_vhost.c_str());
809         }
810         nprl->num_records = i; // usually same as jobs.size();
811         *f_resp->nextResultSetPosition = start + i;
812         *f_resp->numberOfRecordsReturned = i;
813     }
814     package.response() = f_apdu;
815 }
816
817 void yf::Multi::Frontend::scan1(mp::Package &package, Z_APDU *apdu_req)
818 {
819     if (m_backend_list.size() > 1)
820     {
821         mp::odr odr;
822         Z_APDU *f_apdu = 
823             odr.create_scanResponse(
824                 apdu_req, YAZ_BIB1_COMBI_OF_SPECIFIED_DATABASES_UNSUPP, 0);
825         package.response() = f_apdu;
826         return;
827     }
828     Z_ScanRequest *req = apdu_req->u.scanRequest;
829
830     int default_num_db = req->num_databaseNames;
831     char **default_db = req->databaseNames;
832
833     std::list<BackendPtr>::const_iterator bit;
834     for (bit = m_backend_list.begin(); bit != m_backend_list.end(); bit++)
835     {
836         PackagePtr p = (*bit)->m_package;
837         mp::odr odr;
838     
839         if (!mp::util::set_databases_from_zurl(odr, (*bit)->m_vhost,
840                                                 &req->num_databaseNames,
841                                                 &req->databaseNames))
842         {
843             req->num_databaseNames = default_num_db;
844             req->databaseNames = default_db;
845         }
846         p->request() = apdu_req;
847         p->copy_filter(package);
848     }
849     multi_move(m_backend_list);
850
851     for (bit = m_backend_list.begin(); bit != m_backend_list.end(); bit++)
852     {
853         PackagePtr p = (*bit)->m_package;
854         
855         if (p->session().is_closed()) // if any backend closes, close frontend
856             package.session().close();
857         
858         Z_GDU *gdu = p->response().get();
859         if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
860             Z_APDU_scanResponse)
861         {
862             package.response() = p->response();
863             break;
864         }
865         else
866         {
867             // if any target does not return scan response - return that 
868             package.response() = p->response();
869             return;
870         }
871     }
872 }
873
874 bool yf::Multi::ScanTermInfo::operator < (const ScanTermInfo &k) const
875 {
876     return m_norm_term < k.m_norm_term;
877 }
878
879 bool yf::Multi::ScanTermInfo::operator == (const ScanTermInfo &k) const
880 {
881     return m_norm_term == k.m_norm_term;
882 }
883
884 Z_Entry *yf::Multi::ScanTermInfo::get_entry(ODR odr)
885 {
886     Z_Entry *e = (Z_Entry *)odr_malloc(odr, sizeof(*e));
887     e->which = Z_Entry_termInfo;
888     Z_TermInfo *t;
889     t = e->u.termInfo = (Z_TermInfo *) odr_malloc(odr, sizeof(*t));
890     t->suggestedAttributes = 0;
891     t->displayTerm = 0;
892     t->alternativeTerm = 0;
893     t->byAttributes = 0;
894     t->otherTermInfo = 0;
895     t->globalOccurrences = odr_intdup(odr, m_count);
896     t->term = (Z_Term *)
897         odr_malloc(odr, sizeof(*t->term));
898     t->term->which = Z_Term_general;
899     Odr_oct *o;
900     t->term->u.general = o = (Odr_oct *)odr_malloc(odr, sizeof(Odr_oct));
901
902     o->len = o->size = m_norm_term.size();
903     o->buf = (unsigned char *) odr_malloc(odr, o->len);
904     memcpy(o->buf, m_norm_term.c_str(), o->len);
905     return e;
906 }
907
908 void yf::Multi::Frontend::scan2(mp::Package &package, Z_APDU *apdu_req)
909 {
910     Z_ScanRequest *req = apdu_req->u.scanRequest;
911
912     int default_num_db = req->num_databaseNames;
913     char **default_db = req->databaseNames;
914
915     std::list<BackendPtr>::const_iterator bit;
916     for (bit = m_backend_list.begin(); bit != m_backend_list.end(); bit++)
917     {
918         PackagePtr p = (*bit)->m_package;
919         mp::odr odr;
920     
921         if (!mp::util::set_databases_from_zurl(odr, (*bit)->m_vhost,
922                                                 &req->num_databaseNames,
923                                                 &req->databaseNames))
924         {
925             req->num_databaseNames = default_num_db;
926             req->databaseNames = default_db;
927         }
928         p->request() = apdu_req;
929         p->copy_filter(package);
930     }
931     multi_move(m_backend_list);
932
933     ScanTermInfoList entries_before;
934     ScanTermInfoList entries_after;
935     int no_before = 0;
936     int no_after = 0;
937
938     for (bit = m_backend_list.begin(); bit != m_backend_list.end(); bit++)
939     {
940         PackagePtr p = (*bit)->m_package;
941         
942         if (p->session().is_closed()) // if any backend closes, close frontend
943             package.session().close();
944         
945         Z_GDU *gdu = p->response().get();
946         if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
947             Z_APDU_scanResponse)
948         {
949             Z_ScanResponse *res = gdu->u.z3950->u.scanResponse;
950
951             if (res->entries && res->entries->nonsurrogateDiagnostics)
952             {
953                 // failure
954                 mp::odr odr;
955                 Z_APDU *f_apdu = odr.create_scanResponse(apdu_req, 1, 0);
956                 Z_ScanResponse *f_res = f_apdu->u.scanResponse;
957
958                 f_res->entries->nonsurrogateDiagnostics = 
959                     res->entries->nonsurrogateDiagnostics;
960                 f_res->entries->num_nonsurrogateDiagnostics = 
961                     res->entries->num_nonsurrogateDiagnostics;
962
963                 package.response() = f_apdu;
964                 return;
965             }
966
967             if (res->entries && res->entries->entries)
968             {
969                 Z_Entry **entries = res->entries->entries;
970                 int num_entries = res->entries->num_entries;
971                 int position = 1;
972                 if (req->preferredPositionInResponse)
973                     position = *req->preferredPositionInResponse;
974                 if (res->positionOfTerm)
975                     position = *res->positionOfTerm;
976
977                 // before
978                 int i;
979                 for (i = 0; i<position-1 && i<num_entries; i++)
980                 {
981                     Z_Entry *ent = entries[i];
982
983                     if (ent->which == Z_Entry_termInfo)
984                     {
985                         ScanTermInfo my;
986
987                         Odr_int *occur = ent->u.termInfo->globalOccurrences;
988                         my.m_count = occur ? *occur : 0;
989
990                         if (ent->u.termInfo->term->which == Z_Term_general)
991                         {
992                             my.m_norm_term = std::string(
993                                 (const char *)
994                                 ent->u.termInfo->term->u.general->buf,
995                                 ent->u.termInfo->term->u.general->len);
996                         }
997                         if (my.m_norm_term.length())
998                         {
999                             ScanTermInfoList::iterator it = 
1000                                 entries_before.begin();
1001                             while (it != entries_before.end() && my <*it)
1002                                 it++;
1003                             if (my == *it)
1004                             {
1005                                 it->m_count += my.m_count;
1006                             }
1007                             else
1008                             {
1009                                 entries_before.insert(it, my);
1010                                 no_before++;
1011                             }
1012                         }
1013                     }
1014                 }
1015                 // after
1016                 if (position <= 0)
1017                     i = 0;
1018                 else
1019                     i = position-1;
1020                 for ( ; i<num_entries; i++)
1021                 {
1022                     Z_Entry *ent = entries[i];
1023
1024                     if (ent->which == Z_Entry_termInfo)
1025                     {
1026                         ScanTermInfo my;
1027
1028                         Odr_int *occur = ent->u.termInfo->globalOccurrences;
1029                         my.m_count = occur ? *occur : 0;
1030
1031                         if (ent->u.termInfo->term->which == Z_Term_general)
1032                         {
1033                             my.m_norm_term = std::string(
1034                                 (const char *)
1035                                 ent->u.termInfo->term->u.general->buf,
1036                                 ent->u.termInfo->term->u.general->len);
1037                         }
1038                         if (my.m_norm_term.length())
1039                         {
1040                             ScanTermInfoList::iterator it = 
1041                                 entries_after.begin();
1042                             while (it != entries_after.end() && *it < my)
1043                                 it++;
1044                             if (my == *it)
1045                             {
1046                                 it->m_count += my.m_count;
1047                             }
1048                             else
1049                             {
1050                                 entries_after.insert(it, my);
1051                                 no_after++;
1052                             }
1053                         }
1054                     }
1055                 }
1056
1057             }                
1058         }
1059         else
1060         {
1061             // if any target does not return scan response - return that 
1062             package.response() = p->response();
1063             return;
1064         }
1065     }
1066
1067     if (false)
1068     {
1069         std::cout << "BEFORE\n";
1070         ScanTermInfoList::iterator it = entries_before.begin();
1071         for(; it != entries_before.end(); it++)
1072         {
1073             std::cout << " " << it->m_norm_term << " " << it->m_count << "\n";
1074         }
1075         
1076         std::cout << "AFTER\n";
1077         it = entries_after.begin();
1078         for(; it != entries_after.end(); it++)
1079         {
1080             std::cout << " " << it->m_norm_term << " " << it->m_count << "\n";
1081         }
1082     }
1083
1084     if (false)
1085     {
1086         mp::odr odr;
1087         Z_APDU *f_apdu = odr.create_scanResponse(apdu_req, 1, "not implemented");
1088         package.response() = f_apdu;
1089     }
1090     else
1091     {
1092         mp::odr odr;
1093         Z_APDU *f_apdu = odr.create_scanResponse(apdu_req, 0, 0);
1094         Z_ScanResponse *resp = f_apdu->u.scanResponse;
1095         
1096         int number_returned = *req->numberOfTermsRequested;
1097         int position_returned = *req->preferredPositionInResponse;
1098         
1099         resp->entries->num_entries = number_returned;
1100         resp->entries->entries = (Z_Entry**)
1101             odr_malloc(odr, sizeof(Z_Entry*) * number_returned);
1102         int i;
1103
1104         int lbefore = entries_before.size();
1105         if (lbefore < position_returned-1)
1106             position_returned = lbefore+1;
1107
1108         ScanTermInfoList::iterator it = entries_before.begin();
1109         for (i = 0; i<position_returned-1 && it != entries_before.end(); i++, it++)
1110         {
1111             resp->entries->entries[position_returned-2-i] = it->get_entry(odr);
1112         }
1113
1114         it = entries_after.begin();
1115
1116         if (position_returned <= 0)
1117             i = 0;
1118         else
1119             i = position_returned-1;
1120         for (; i<number_returned && it != entries_after.end(); i++, it++)
1121         {
1122             resp->entries->entries[i] = it->get_entry(odr);
1123         }
1124
1125         number_returned = i;
1126
1127         resp->positionOfTerm = odr_intdup(odr, position_returned);
1128         resp->numberOfEntriesReturned = odr_intdup(odr, number_returned);
1129         resp->entries->num_entries = number_returned;
1130
1131         package.response() = f_apdu;
1132     }
1133 }
1134
1135
1136 void yf::Multi::process(mp::Package &package) const
1137 {
1138     FrontendPtr f = m_p->get_frontend(package);
1139
1140     Z_GDU *gdu = package.request().get();
1141     
1142     if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
1143         Z_APDU_initRequest && !f->m_is_multi)
1144     {
1145         f->init(package, gdu);
1146     }
1147     else if (!f->m_is_multi)
1148         package.move();
1149     else if (gdu && gdu->which == Z_GDU_Z3950)
1150     {
1151         Z_APDU *apdu = gdu->u.z3950;
1152         if (apdu->which == Z_APDU_initRequest)
1153         {
1154             mp::odr odr;
1155             
1156             package.response() = odr.create_close(
1157                 apdu,
1158                 Z_Close_protocolError,
1159                 "double init");
1160             
1161             package.session().close();
1162         }
1163         else if (apdu->which == Z_APDU_searchRequest)
1164         {
1165             f->search(package, apdu);
1166         }
1167         else if (apdu->which == Z_APDU_presentRequest)
1168         {
1169             f->present(package, apdu);
1170         }
1171         else if (apdu->which == Z_APDU_scanRequest)
1172         {
1173             f->scan2(package, apdu);
1174         }
1175         else
1176         {
1177             mp::odr odr;
1178             
1179             package.response() = odr.create_close(
1180                 apdu, Z_Close_protocolError,
1181                 "unsupported APDU in filter multi");
1182             
1183             package.session().close();
1184         }
1185     }
1186     m_p->release_frontend(package);
1187 }
1188
1189 void mp::filter::Multi::configure(const xmlNode * ptr, bool test_only)
1190 {
1191     for (ptr = ptr->children; ptr; ptr = ptr->next)
1192     {
1193         if (ptr->type != XML_ELEMENT_NODE)
1194             continue;
1195         if (!strcmp((const char *) ptr->name, "target"))
1196         {
1197             std::string route = mp::xml::get_route(ptr);
1198             std::string target = mp::xml::get_text(ptr);
1199             m_p->m_route_patterns.push_back(Multi::Map(target, route));
1200         }
1201         else if (!strcmp((const char *) ptr->name, "hideunavailable"))
1202         {
1203             m_p->m_hide_unavailable = true;
1204         }
1205         else if (!strcmp((const char *) ptr->name, "mergetype"))
1206         {
1207             std::string mergetype = mp::xml::get_text(ptr);
1208             if (mergetype == "roundrobin")
1209                 m_p->m_merge_type = round_robin;
1210             else if (mergetype == "serveorder")
1211                 m_p->m_merge_type = serve_order;
1212             else
1213                 throw mp::filter::FilterException
1214                     ("Bad mergetype "  + mergetype + " in multi filter");
1215
1216         }
1217         else
1218         {
1219             throw mp::filter::FilterException
1220                 ("Bad element " 
1221                  + std::string((const char *) ptr->name)
1222                  + " in multi filter");
1223         }
1224     }
1225 }
1226
1227 static mp::filter::Base* filter_creator()
1228 {
1229     return new mp::filter::Multi;
1230 }
1231
1232 extern "C" {
1233     struct metaproxy_1_filter_struct metaproxy_1_filter_multi = {
1234         0,
1235         "multi",
1236         filter_creator
1237     };
1238 }
1239
1240
1241 /*
1242  * Local variables:
1243  * c-basic-offset: 4
1244  * c-file-style: "Stroustrup"
1245  * indent-tabs-mode: nil
1246  * End:
1247  * vim: shiftwidth=4 tabstop=8 expandtab
1248  */
1249