For filter_virt_db return proper diagnostics if backend closes connection
[metaproxy-moved-to-github.git] / src / filter_virt_db.cpp
1 /* $Id: filter_virt_db.cpp,v 1.7 2005-10-25 22:44:39 adam Exp $
2    Copyright (c) 2005, Index Data.
3
4 %LICENSE%
5  */
6
7 #include "config.hpp"
8
9 #include "filter.hpp"
10 #include "router.hpp"
11 #include "package.hpp"
12
13 #include <boost/thread/mutex.hpp>
14
15 #include "filter_virt_db.hpp"
16
17 #include <yaz/zgdu.h>
18 #include <yaz/log.h>
19 #include <yaz/otherinfo.h>
20 #include <yaz/diagbib1.h>
21
22 #include <list>
23 #include <map>
24 #include <iostream>
25
26 namespace yf = yp2::filter;
27
28 namespace yp2 {
29     namespace filter {
30         struct Virt_db_set {
31             Virt_db_set(yp2::Session &id, std::string setname,
32                         std::string vhost);
33             Virt_db_set();
34             ~Virt_db_set();
35
36             yp2::Session m_backend_session;
37             std::string m_setname;
38             std::string m_vhost;
39         };
40         struct Virt_db_session {
41             Virt_db_session(yp2::Session &id, bool use_vhost);
42             Virt_db_session();
43             yp2::Session m_session;
44             bool m_use_vhost;
45             std::map<std::string,Virt_db_set> m_sets;
46         };
47         struct Virt_db_map {
48             Virt_db_map(std::string vhost);
49             Virt_db_map();
50             std::string m_vhost;
51         };
52         class Virt_db::Rep {
53             friend class Virt_db;
54             
55             void release_session(Package &package);
56             void init(Package &package, Z_APDU *apdu, bool &move_later);
57             void search(Package &package, Z_APDU *apdu, bool &move_later);
58             void present(Package &package, Z_APDU *apdu, bool &move_later);
59         private:
60             boost::mutex m_sessions_mutex;
61             std::map<yp2::Session,Virt_db_session>m_sessions;
62             std::map<std::string, Virt_db_map>m_maps;
63
64             typedef std::map<yp2::Session,Virt_db_session>::iterator Ses_it;
65             typedef std::map<std::string,Virt_db_set>::iterator Sets_it;
66         };
67     }
68 }
69
70 yf::Virt_db_set::Virt_db_set(yp2::Session &id, std::string setname,
71                              std::string vhost)
72     :   m_backend_session(id), m_setname(setname), m_vhost(vhost)
73 {
74 }
75
76
77 yf::Virt_db_set::Virt_db_set()
78 {
79 }
80
81
82 yf::Virt_db_set::~Virt_db_set()
83 {
84 }
85
86 yf::Virt_db_map::Virt_db_map(std::string vhost)
87     : m_vhost(vhost) 
88 {
89 }
90
91 yf::Virt_db_map::Virt_db_map()
92 {
93 }
94
95 yf::Virt_db_session::Virt_db_session()
96     : m_use_vhost(false)
97 {
98
99 }
100
101 yf::Virt_db_session::Virt_db_session(yp2::Session &id,
102                                      bool use_vhost) :
103     m_session(id) , m_use_vhost(use_vhost)
104 {
105
106 }
107
108 yf::Virt_db::Virt_db() {
109     m_p = new Virt_db::Rep;
110 }
111
112 yf::Virt_db::~Virt_db() {
113     delete m_p;
114 }
115
116 void yf::Virt_db::Rep::release_session(Package &package)
117 {
118     boost::mutex::scoped_lock lock(m_sessions_mutex);
119     
120     m_sessions.erase(package.session());
121 }
122
123 void yf::Virt_db::Rep::present(Package &package, Z_APDU *apdu, bool &move_later){
124     Session *id = 0;
125     std::string resultSetId;
126     Z_PresentRequest *req = apdu->u.presentRequest;
127     {
128         resultSetId = req->resultSetId;
129         boost::mutex::scoped_lock lock(m_sessions_mutex);
130         
131         Ses_it it = m_sessions.find(package.session());
132         if (it == m_sessions.end())
133         {
134             ODR odr = odr_createmem(ODR_ENCODE);
135             
136             Z_APDU *apdu = zget_APDU(odr, Z_APDU_close);
137             
138             *apdu->u.close->closeReason = Z_Close_protocolError;
139             apdu->u.close->diagnosticInformation =
140                 odr_strdup(odr, "no session for present request");
141             
142             package.response() = apdu;
143             package.session().close();
144             odr_destroy(odr);
145             assert(false);
146             return;
147         }
148         if (it->second.m_use_vhost)
149         {
150             move_later = true;
151             return;
152         }
153         Sets_it sets_it = it->second.m_sets.find(resultSetId);
154         if (sets_it == it->second.m_sets.end())
155         {
156             ODR odr = odr_createmem(ODR_ENCODE);
157             Z_APDU *apdu = zget_APDU(odr, Z_APDU_presentResponse);
158             
159             Z_Records *rec = (Z_Records *) odr_malloc(odr, sizeof(Z_Records));
160             apdu->u.presentResponse->records = rec;
161             rec->which = Z_Records_NSD;
162             rec->u.nonSurrogateDiagnostic =
163                 zget_DefaultDiagFormat(
164                     odr,
165                     YAZ_BIB1_SPECIFIED_RESULT_SET_DOES_NOT_EXIST,
166                     resultSetId.c_str());
167             package.response() = apdu;
168             odr_destroy(odr);
169             return;
170         }
171         id = new yp2::Session(sets_it->second.m_backend_session);
172     }
173     ODR odr = odr_createmem(ODR_ENCODE);
174     
175     // sending present to backend
176     Package present_package(*id, package.origin());
177     present_package.copy_filter(package);
178     
179     req->resultSetId = odr_strdup(odr, "default");
180     present_package.request() = yazpp_1::GDU(apdu);
181
182     odr_destroy(odr);
183
184     present_package.move();
185
186     if (present_package.session().is_closed())
187     {
188         ODR odr = odr_createmem(ODR_ENCODE);
189         Z_APDU *apdu = zget_APDU(odr, Z_APDU_presentResponse);
190         
191         Z_Records *rec = (Z_Records *) odr_malloc(odr, sizeof(Z_Records));
192         apdu->u.presentResponse->records = rec;
193         rec->which = Z_Records_NSD;
194         rec->u.nonSurrogateDiagnostic =
195             zget_DefaultDiagFormat(
196                 odr,
197                 YAZ_BIB1_RESULT_SET_NO_LONGER_EXISTS_UNILATERALLY_DELETED_BY_,
198                 resultSetId.c_str());
199         package.response() = apdu;
200         
201         odr_destroy(odr);
202
203         boost::mutex::scoped_lock lock(m_sessions_mutex);
204         Ses_it it = m_sessions.find(package.session());
205         if (it != m_sessions.end())
206             it->second.m_sets.erase(resultSetId);
207     }
208     else
209     {
210         package.response() = present_package.response();
211     }
212     delete id;
213 }
214
215 void yf::Virt_db::Rep::search(Package &package, Z_APDU *apdu, bool &move_later)
216 {
217     Z_SearchRequest *req = apdu->u.searchRequest;
218     std::string vhost;
219     std::string database;
220     {
221         boost::mutex::scoped_lock lock(m_sessions_mutex);
222
223         Ses_it it = m_sessions.find(package.session());
224         if (it == m_sessions.end())
225         {
226             ODR odr = odr_createmem(ODR_ENCODE);
227             
228             Z_APDU *apdu = zget_APDU(odr, Z_APDU_close);
229             
230             *apdu->u.close->closeReason = Z_Close_protocolError;
231             apdu->u.close->diagnosticInformation =
232                 odr_strdup(odr, "no session for search request");
233             
234             package.response() = apdu;
235             package.session().close();
236             odr_destroy(odr);
237             return;
238         }
239         if (it->second.m_use_vhost)
240         {
241             move_later = true;
242             return;
243         }
244         if (req->num_databaseNames != 1)
245         {   // exactly one database must be specified
246             ODR odr = odr_createmem(ODR_ENCODE);
247             Z_APDU *apdu = zget_APDU(odr, Z_APDU_searchResponse);
248             
249             Z_Records *rec = (Z_Records *) odr_malloc(odr, sizeof(Z_Records));
250             apdu->u.searchResponse->records = rec;
251             rec->which = Z_Records_NSD;
252             rec->u.nonSurrogateDiagnostic =
253                 zget_DefaultDiagFormat(
254                     odr, YAZ_BIB1_TOO_MANY_DATABASES_SPECIFIED, 0);
255             package.response() = apdu;
256             
257             odr_destroy(odr);
258             return;
259         }
260         database = req->databaseNames[0];
261         std::map<std::string, Virt_db_map>::iterator map_it;
262         map_it = m_maps.find(database);
263         if (map_it == m_maps.end()) 
264         {   // no map for database: return diagnostic
265             ODR odr = odr_createmem(ODR_ENCODE);
266             Z_APDU *apdu = zget_APDU(odr, Z_APDU_searchResponse);
267             
268             Z_Records *rec = (Z_Records *) odr_malloc(odr, sizeof(Z_Records));
269             apdu->u.searchResponse->records = rec;
270             rec->which = Z_Records_NSD;
271             rec->u.nonSurrogateDiagnostic =
272                 zget_DefaultDiagFormat(
273                     odr, YAZ_BIB1_DATABASE_UNAVAILABLE, database.c_str());
274             package.response() = apdu;
275             
276             odr_destroy(odr);
277             return;
278         }
279         if (*req->replaceIndicator == 0)
280         {
281             Sets_it sets_it = it->second.m_sets.find(req->resultSetName);
282             if (sets_it != it->second.m_sets.end())
283             {
284                 ODR odr = odr_createmem(ODR_ENCODE);
285                 Z_APDU *apdu = zget_APDU(odr, Z_APDU_searchResponse);
286                 
287                 Z_Records *rec = (Z_Records *) odr_malloc(odr, sizeof(Z_Records));
288                 apdu->u.searchResponse->records = rec;
289                 rec->which = Z_Records_NSD;
290                 rec->u.nonSurrogateDiagnostic =
291                     zget_DefaultDiagFormat(
292                         odr,
293                         YAZ_BIB1_RESULT_SET_EXISTS_AND_REPLACE_INDICATOR_OFF,
294                         0);
295                 package.response() = apdu;
296                 
297                 odr_destroy(odr);
298                 return;
299             }
300         }
301         it->second.m_sets.erase(req->resultSetName);
302         vhost = map_it->second.m_vhost;
303     }
304     // we might look for an existing session with same vhost
305     Session id;
306     const char *vhost_cstr = vhost.c_str();
307     if (true)
308     {  // sending init to backend
309         Package init_package(id, package.origin());
310         init_package.copy_filter(package);
311         
312         ODR odr = odr_createmem(ODR_ENCODE);
313         Z_APDU *init_apdu = zget_APDU(odr, Z_APDU_initRequest);
314         
315         yaz_oi_set_string_oidval(&init_apdu->u.initRequest->otherInfo, odr,
316                                  VAL_PROXY, 1, vhost_cstr);
317         
318         init_package.request() = init_apdu;
319         odr_destroy(odr);
320
321         init_package.move();  // sending init 
322
323         if (init_package.session().is_closed())
324         {
325             ODR odr = odr_createmem(ODR_ENCODE);
326             Z_APDU *apdu = zget_APDU(odr, Z_APDU_searchResponse);
327             
328             Z_Records *rec = (Z_Records *) odr_malloc(odr, sizeof(Z_Records));
329             apdu->u.searchResponse->records = rec;
330             rec->which = Z_Records_NSD;
331             rec->u.nonSurrogateDiagnostic =
332                 zget_DefaultDiagFormat(
333                     odr, YAZ_BIB1_DATABASE_UNAVAILABLE, database.c_str());
334             package.response() = apdu;
335             
336             odr_destroy(odr);
337         }
338     }
339     // sending search to backend
340     Package search_package(id, package.origin());
341
342     search_package.copy_filter(package);
343     const char *sep = strchr(vhost_cstr, '/');
344     ODR odr = odr_createmem(ODR_ENCODE);
345     if (sep)
346         req->databaseNames[0] = odr_strdup(odr, sep+1);
347
348     *req->replaceIndicator = 1;
349     req->resultSetName = odr_strdup(odr, "default");
350     search_package.request() = yazpp_1::GDU(apdu);
351     
352     odr_destroy(odr);
353     
354     search_package.move();
355
356     if (search_package.session().is_closed())
357     {
358         ODR odr = odr_createmem(ODR_ENCODE);
359         Z_APDU *apdu = zget_APDU(odr, Z_APDU_searchResponse);
360         
361         Z_Records *rec = (Z_Records *) odr_malloc(odr, sizeof(Z_Records));
362         apdu->u.searchResponse->records = rec;
363         rec->which = Z_Records_NSD;
364         rec->u.nonSurrogateDiagnostic =
365             zget_DefaultDiagFormat(
366                 odr, YAZ_BIB1_DATABASE_UNAVAILABLE, database.c_str());
367         package.response() = apdu;
368         
369         odr_destroy(odr);
370         return;
371     }
372     package.response() = search_package.response();
373     
374     boost::mutex::scoped_lock lock(m_sessions_mutex);
375     Ses_it it = m_sessions.find(package.session());
376     if (it != m_sessions.end())
377         it->second.m_sets[req->resultSetName] =
378             Virt_db_set(id, req->resultSetName, vhost);
379 }
380
381 void yf::Virt_db::Rep::init(Package &package, Z_APDU *apdu, bool &move_later)
382 {
383     release_session(package);
384     boost::mutex::scoped_lock lock(m_sessions_mutex);
385
386     Z_InitRequest *req = apdu->u.initRequest;
387     
388     const char *vhost =
389         yaz_oi_get_string_oidval(&req->otherInfo, VAL_PROXY, 1, 0);
390     if (!vhost)
391     {
392         ODR odr = odr_createmem(ODR_ENCODE);
393         
394         Z_APDU *apdu = zget_APDU(odr, Z_APDU_initResponse);
395         Z_InitResponse *resp = apdu->u.initResponse;
396         
397         int i;
398         static const int masks[] = {
399             Z_Options_search, Z_Options_present, Z_Options_namedResultSets, -1 
400         };
401         for (i = 0; masks[i] != -1; i++)
402             if (ODR_MASK_GET(req->options, masks[i]))
403                 ODR_MASK_SET(resp->options, masks[i]);
404         
405         static const int versions[] = {
406             Z_ProtocolVersion_1,
407             Z_ProtocolVersion_2,
408             Z_ProtocolVersion_3,
409             -1
410         };
411         for (i = 0; versions[i] != -1; i++)
412             if (ODR_MASK_GET(req->protocolVersion, versions[i]))
413                 ODR_MASK_SET(resp->protocolVersion, versions[i]);
414             else
415                 break;
416
417         package.response() = apdu;
418         
419         odr_destroy(odr);
420
421         m_sessions[package.session()] = Virt_db_session(package.session(), false);
422     }
423     else
424     {
425         m_sessions[package.session()] = Virt_db_session(package.session(), true);
426         move_later = true;
427     }
428 }
429
430 void yf::Virt_db::add_map_db2vhost(std::string db, std::string vhost)
431 {
432     m_p->m_maps[db] = Virt_db_map(vhost);
433 }
434
435 void yf::Virt_db::process(Package &package) const
436 {
437     Z_GDU *gdu = package.request().get();
438
439     if (!gdu || gdu->which != Z_GDU_Z3950)
440         package.move();
441     else
442     {
443         bool move_later = false;
444         Z_APDU *apdu = gdu->u.z3950;
445         if (apdu->which == Z_APDU_initRequest)
446         {
447             m_p->init(package, apdu, move_later);
448         }
449         else if (apdu->which == Z_APDU_searchRequest)
450         {
451             m_p->search(package, apdu, move_later);
452         }
453         else if (apdu->which == Z_APDU_presentRequest)
454         {
455             m_p->present(package, apdu, move_later);
456         }
457         else
458         {
459             ODR odr = odr_createmem(ODR_ENCODE);
460             
461             Z_APDU *apdu = zget_APDU(odr, Z_APDU_close);
462             
463             *apdu->u.close->closeReason = Z_Close_protocolError;
464
465             apdu->u.close->diagnosticInformation =
466                 odr_strdup(odr, "unsupported APDU in filter_virt_db");
467             
468             package.response() = apdu;
469             package.session().close();
470             odr_destroy(odr);
471         }
472         if (move_later)
473             package.move();
474     }
475     if (package.session().is_closed())
476         m_p->release_session(package);
477 }
478
479
480 /*
481  * Local variables:
482  * c-basic-offset: 4
483  * indent-tabs-mode: nil
484  * c-file-style: "stroustrup"
485  * End:
486  * vim: shiftwidth=4 tabstop=8 expandtab
487  */