src/filter_sparql.cpp

   1 /* This file is part of Metaproxy.
   2    Copyright (C) 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 <metaproxy/package.hpp>
  20 #include <metaproxy/util.hpp>
  21 #include <yaz/log.h>
  22 #include <yaz/srw.h>
  23 #include <yaz/diagbib1.h>
  24 #include <yaz/match_glob.h>
  25 #include <boost/scoped_ptr.hpp>
  26 #include <boost/thread/mutex.hpp>
  27 #include <boost/thread/condition.hpp>
  28 #include <boost/algorithm/string.hpp>
  29 #include "sparql.h"
  30
  31 #include <yaz/zgdu.h>
  32
  33 namespace mp = metaproxy_1;
  34 namespace yf = mp::filter;
  35
  36 namespace metaproxy_1 {
  37     namespace filter {
  38         class SPARQL : public Base {
  39             class Session;
  40             class Rep;
  41             class Conf;
  42             class Result;
  43             class FrontendSet;
  44
  45             typedef boost::shared_ptr<Session> SessionPtr;
  46             typedef boost::shared_ptr<Conf> ConfPtr;
  47
  48             typedef boost::shared_ptr<FrontendSet> FrontendSetPtr;
  49             typedef std::map<std::string,FrontendSetPtr> FrontendSets;
  50         public:
  51             SPARQL();
  52             ~SPARQL();
  53             void process(metaproxy_1::Package & package) const;
  54             void configure(const xmlNode * ptr, bool test_only,
  55                            const char *path);
  56             SessionPtr get_session(Package &package, Z_APDU **apdu) const;
  57             void release_session(Package &package) const;
  58             boost::scoped_ptr<Rep> m_p;
  59             std::list<ConfPtr> db_conf;
  60         };
  61         class SPARQL::Conf {
  62         public:
  63             std::string db;
  64             std::string uri;
  65             std::string schema;
  66             yaz_sparql_t s;
  67             ~Conf();
  68         };
  69         class SPARQL::Rep {
  70             friend class SPARQL;
  71             boost::condition m_cond_session_ready;
  72             boost::mutex m_mutex;
  73             std::map<mp::Session,SessionPtr> m_clients;
  74         };
  75         class SPARQL::Result {
  76         public:
  77             Result();
  78             ~Result();
  79         private:
  80             friend class FrontendSet;
  81             friend class Session;
  82             ConfPtr conf;
  83             xmlDoc *doc;
  84         };
  85         class SPARQL::FrontendSet {
  86         private:
  87             friend class Session;
  88             Odr_int hits;
  89             std::string db;
  90             std::list<Result> results;
  91         };
  92         class SPARQL::Session {
  93         public:
  94             Session(const SPARQL *);
  95             ~Session();
  96             void handle_z(Package &package, Z_APDU *apdu);
  97             Z_APDU *search(mp::Package &package,
  98                            Z_APDU *apdu_req,
  99                            mp::odr &odr,
 100                            const char *sparql_query,
 101                            ConfPtr conf, FrontendSetPtr fset);
 102             int invoke_sparql(mp::Package &package,
 103                               const char *sparql_query,
 104                               ConfPtr conf,
 105                               WRBUF w);
 106
 107             Z_Records *fetch(
 108                 Package &package,
 109                 FrontendSetPtr fset,
 110                 ODR odr, Odr_oid *preferredRecordSyntax,
 111                 Z_ElementSetNames *esn,
 112                 int start, int number, int &error_code, std::string &addinfo,
 113                 int *number_returned, int *next_position);
 114             bool m_in_use;
 115         private:
 116             bool m_support_named_result_sets;
 117             FrontendSets m_frontend_sets;
 118             const SPARQL *m_sparql;
 119         };
 120     }
 121 }
 122
 123 yf::SPARQL::Result::~Result()
 124 {
 125     if (doc)
 126         xmlFreeDoc(doc);
 127 }
 128
 129 yf::SPARQL::Result::Result()
 130 {
 131     doc = 0;
 132 }
 133
 134 yf::SPARQL::SPARQL() : m_p(new Rep)
 135 {
 136 }
 137
 138 yf::SPARQL::~SPARQL()
 139 {
 140 }
 141
 142 void yf::SPARQL::configure(const xmlNode *xmlnode, bool test_only,
 143                            const char *path)
 144 {
 145     const xmlNode *ptr = xmlnode->children;
 146     std::string uri;
 147
 148     for (; ptr; ptr = ptr->next)
 149     {
 150         if (ptr->type != XML_ELEMENT_NODE)
 151             continue;
 152         if (!strcmp((const char *) ptr->name, "defaults"))
 153         {
 154             const struct _xmlAttr *attr;
 155             for (attr = ptr->properties; attr; attr = attr->next)
 156             {
 157                 if (!strcmp((const char *) attr->name, "uri"))
 158                     uri = mp::xml::get_text(attr->children);
 159                 else
 160                     throw mp::filter::FilterException(
 161                         "Bad attribute " + std::string((const char *)
 162                                                        attr->name));
 163             }
 164         }
 165         else if (!strcmp((const char *) ptr->name, "db"))
 166         {
 167             yaz_sparql_t s = yaz_sparql_create();
 168             ConfPtr conf(new Conf);
 169             conf->s = s;
 170             conf->uri = uri;
 171
 172             const struct _xmlAttr *attr;
 173             for (attr = ptr->properties; attr; attr = attr->next)
 174             {
 175                 if (!strcmp((const char *) attr->name, "path"))
 176                     conf->db = mp::xml::get_text(attr->children);
 177                 else if (!strcmp((const char *) attr->name, "uri"))
 178                     conf->uri = mp::xml::get_text(attr->children);
 179                 else if (!strcmp((const char *) attr->name, "schema"))
 180                     conf->schema = mp::xml::get_text(attr->children);
 181                 else if (!strcmp((const char *) attr->name, "include"))
 182                 {
 183                     std::vector<std::string> dbs;
 184                     std::string db = mp::xml::get_text(attr->children);
 185                     boost::split(dbs, db, boost::is_any_of(" \t"));
 186                     size_t i;
 187                     for (i = 0; i < dbs.size(); i++)
 188                     {
 189                         if (dbs[i].length() == 0)
 190                             continue;
 191                         std::list<ConfPtr>::const_iterator it = db_conf.begin();
 192                         while (1)
 193                             if (it == db_conf.end())
 194                             {
 195                                 throw mp::filter::FilterException(
 196                                     "include db not found: " + dbs[i]);
 197                             }
 198                             else if (dbs[i].compare((*it)->db) == 0)
 199                             {
 200                                 yaz_sparql_include(s, (*it)->s);
 201                                 break;
 202                             }
 203                             else
 204                                 it++;
 205                     }
 206                 }
 207                 else
 208                     throw mp::filter::FilterException(
 209                         "Bad attribute " + std::string((const char *)
 210                                                        attr->name));
 211             }
 212             xmlNode *p = ptr->children;
 213             for (; p; p = p->next)
 214             {
 215                 if (p->type != XML_ELEMENT_NODE)
 216                     continue;
 217                 std::string name = (const char *) p->name;
 218                 const struct _xmlAttr *attr;
 219                 for (attr = p->properties; attr; attr = attr->next)
 220                 {
 221                     if (!strcmp((const char *) attr->name, "type"))
 222                     {
 223                         name.append(".");
 224                         name.append(mp::xml::get_text(attr->children));
 225                     }
 226                     else
 227                         throw mp::filter::FilterException(
 228                             "Bad attribute " + std::string((const char *)
 229                                                            attr->name));
 230                 }
 231                 std::string value = mp::xml::get_text(p);
 232                 if (yaz_sparql_add_pattern(s, name.c_str(), value.c_str()))
 233                 {
 234                     throw mp::filter::FilterException(
 235                         "Bad SPARQL config " + name);
 236                 }
 237             }
 238             if (!conf->uri.length())
 239             {
 240                 throw mp::filter::FilterException("Missing uri");
 241             }
 242             if (!conf->db.length())
 243             {
 244                 throw mp::filter::FilterException("Missing path");
 245             }
 246             db_conf.push_back(conf);
 247         }
 248         else
 249         {
 250             throw mp::filter::FilterException
 251                 ("Bad element "
 252                  + std::string((const char *) ptr->name)
 253                  + " in sparql filter");
 254         }
 255     }
 256 }
 257
 258 yf::SPARQL::Conf::~Conf()
 259 {
 260     yaz_sparql_destroy(s);
 261 }
 262
 263 yf::SPARQL::Session::Session(const SPARQL *sparql) :
 264     m_in_use(true),
 265     m_support_named_result_sets(false),
 266     m_sparql(sparql)
 267 {
 268 }
 269
 270 yf::SPARQL::Session::~Session()
 271 {
 272 }
 273
 274 yf::SPARQL::SessionPtr yf::SPARQL::get_session(Package & package,
 275                                                Z_APDU **apdu) const
 276 {
 277     SessionPtr ptr0;
 278
 279     Z_GDU *gdu = package.request().get();
 280
 281     boost::mutex::scoped_lock lock(m_p->m_mutex);
 282
 283     std::map<mp::Session,SPARQL::SessionPtr>::iterator it;
 284
 285     if (gdu && gdu->which == Z_GDU_Z3950)
 286         *apdu = gdu->u.z3950;
 287     else
 288         *apdu = 0;
 289
 290     while (true)
 291     {
 292         it = m_p->m_clients.find(package.session());
 293         if (it == m_p->m_clients.end())
 294             break;
 295         if (!it->second->m_in_use)
 296         {
 297             it->second->m_in_use = true;
 298             return it->second;
 299         }
 300         m_p->m_cond_session_ready.wait(lock);
 301     }
 302     if (!*apdu)
 303         return ptr0;
 304
 305     // new Z39.50 session ..
 306     SessionPtr p(new Session(this));
 307     m_p->m_clients[package.session()] = p;
 308     return p;
 309 }
 310
 311 void yf::SPARQL::release_session(Package &package) const
 312 {
 313     boost::mutex::scoped_lock lock(m_p->m_mutex);
 314     std::map<mp::Session,SessionPtr>::iterator it;
 315
 316     it = m_p->m_clients.find(package.session());
 317     if (it != m_p->m_clients.end())
 318     {
 319         it->second->m_in_use = false;
 320
 321         if (package.session().is_closed())
 322             m_p->m_clients.erase(it);
 323         m_p->m_cond_session_ready.notify_all();
 324     }
 325 }
 326
 327 static bool get_result(xmlDoc *doc, Odr_int *sz, Odr_int pos, xmlDoc **ndoc)
 328 {
 329     xmlNode *ptr = xmlDocGetRootElement(doc);
 330     xmlNode *q0;
 331     Odr_int cur = 0;
 332
 333     if (ndoc)
 334         *ndoc = xmlNewDoc(BAD_CAST "1.0");
 335
 336     if (ptr->type == XML_ELEMENT_NODE &&
 337         !strcmp((const char *) ptr->name, "RDF"))
 338     {
 339         if (ndoc)
 340         {
 341             q0 = xmlCopyNode(ptr, 2);
 342             xmlDocSetRootElement(*ndoc, q0);
 343         }
 344         ptr = ptr->children;
 345
 346         while (ptr && ptr->type != XML_ELEMENT_NODE)
 347             ptr = ptr->next;
 348         if (ptr && ptr->type == XML_ELEMENT_NODE &&
 349             !strcmp((const char *) ptr->name, "Description"))
 350         {
 351             xmlNode *p = ptr->children;
 352
 353             while (p && p->type != XML_ELEMENT_NODE)
 354                 p = p->next;
 355             if (p && p->type == XML_ELEMENT_NODE &&
 356                 !strcmp((const char *) p->name, "type"))
 357             { /* SELECT RESULT */
 358                 for (ptr = ptr->children; ptr; ptr = ptr->next)
 359                     if (ptr->type == XML_ELEMENT_NODE &&
 360                         !strcmp((const char *) ptr->name, "solution"))
 361                     {
 362                         if (cur++ == pos)
 363                         {
 364                             if (ndoc)
 365                             {
 366                                 xmlNode *q1 = xmlCopyNode(ptr, 1);
 367                                 xmlAddChild(q0, q1);
 368                             }
 369                             break;
 370                         }
 371                     }
 372             }
 373             else
 374             {   /* CONSTRUCT result */
 375                 for (; ptr; ptr = ptr->next)
 376                     if (ptr->type == XML_ELEMENT_NODE &&
 377                         !strcmp((const char *) ptr->name, "Description"))
 378                     {
 379                         if (cur++ == pos)
 380                         {
 381                             if (ndoc)
 382                             {
 383                                 xmlNode *q1 = xmlCopyNode(ptr, 1);
 384                                 xmlAddChild(q0, q1);
 385                             }
 386                             return true;
 387                         }
 388                     }
 389             }
 390         }
 391     }
 392     else
 393     {
 394         for (; ptr; ptr = ptr->next)
 395             if (ptr->type == XML_ELEMENT_NODE &&
 396                 !strcmp((const char *) ptr->name, "sparql"))
 397                 break;
 398         if (ptr)
 399         {
 400             if (ndoc)
 401             {
 402                 q0 = xmlCopyNode(ptr, 2);
 403                 xmlDocSetRootElement(*ndoc, q0);
 404             }
 405             for (ptr = ptr->children; ptr; ptr = ptr->next)
 406                 if (ptr->type == XML_ELEMENT_NODE &&
 407                     !strcmp((const char *) ptr->name, "results"))
 408                     break;
 409         }
 410         if (ptr)
 411         {
 412             xmlNode *q1 = 0;
 413             if (ndoc)
 414             {
 415                 q1 = xmlCopyNode(ptr, 0);
 416                 xmlAddChild(q0, q1);
 417             }
 418             for (ptr = ptr->children; ptr; ptr = ptr->next)
 419                 if (ptr->type == XML_ELEMENT_NODE &&
 420                     !strcmp((const char *) ptr->name, "result"))
 421                 {
 422                     if (cur++ == pos)
 423                     {
 424                         if (ndoc)
 425                         {
 426                             xmlNode *q2 = xmlCopyNode(ptr, 1);
 427                             xmlAddChild(q1, q2);
 428                         }
 429                         return true;
 430                     }
 431                 }
 432         }
 433     }
 434     if (sz)
 435         *sz = cur;
 436     return false;
 437 }
 438
 439 Z_Records *yf::SPARQL::Session::fetch(
 440     Package &package,
 441     FrontendSetPtr fset,
 442     ODR odr, Odr_oid *preferredRecordSyntax,
 443     Z_ElementSetNames *esn,
 444     int start, int number, int &error_code, std::string &addinfo,
 445     int *number_returned, int *next_position)
 446 {
 447     Z_Records *rec = (Z_Records *) odr_malloc(odr, sizeof(Z_Records));
 448     std::list<Result>::iterator it = fset->results.begin();
 449     const char *schema = 0;
 450     bool uri_lookup = false;
 451     if (esn && esn->which == Z_ElementSetNames_generic)
 452         schema = esn->u.generic;
 453
 454     for (; it != fset->results.end(); it++)
 455     {
 456         if (yaz_sparql_lookup_schema(it->conf->s, schema))
 457         {
 458             uri_lookup = true;
 459             break;
 460         }
 461         if (!schema || !strcmp(esn->u.generic, it->conf->schema.c_str()))
 462             break;
 463     }
 464     if (it == fset->results.end())
 465     {
 466         rec->which = Z_Records_NSD;
 467         rec->u.nonSurrogateDiagnostic =
 468             zget_DefaultDiagFormat(
 469                 odr,
 470                 YAZ_BIB1_SPECIFIED_ELEMENT_SET_NAME_NOT_VALID_FOR_SPECIFIED_,
 471                 schema);
 472         return rec;
 473     }
 474     rec->which = Z_Records_DBOSD;
 475     rec->u.databaseOrSurDiagnostics = (Z_NamePlusRecordList *)
 476         odr_malloc(odr, sizeof(Z_NamePlusRecordList));
 477     rec->u.databaseOrSurDiagnostics->records = (Z_NamePlusRecord **)
 478         odr_malloc(odr, sizeof(Z_NamePlusRecord *) * number);
 479     int i;
 480     for (i = 0; i < number; i++)
 481     {
 482         rec->u.databaseOrSurDiagnostics->records[i] = (Z_NamePlusRecord *)
 483             odr_malloc(odr, sizeof(Z_NamePlusRecord));
 484         Z_NamePlusRecord *npr = rec->u.databaseOrSurDiagnostics->records[i];
 485         npr->databaseName = odr_strdup(odr, fset->db.c_str());
 486         npr->which = Z_NamePlusRecord_databaseRecord;
 487         xmlDoc *ndoc = 0;
 488
 489         if (!get_result(it->doc, 0, start - 1 + i, &ndoc))
 490         {
 491             if (ndoc)
 492                 xmlFreeDoc(ndoc);
 493             break;
 494         }
 495         xmlNode *ndoc_root = xmlDocGetRootElement(ndoc);
 496         if (!ndoc_root)
 497         {
 498             xmlFreeDoc(ndoc);
 499             break;
 500         }
 501         if (uri_lookup)
 502         {
 503             std::string uri;
 504             xmlNode *n = ndoc_root;
 505             while (n)
 506             {
 507                 if (n->type == XML_ELEMENT_NODE)
 508                 {
 509                     //if (!strcmp((const char *) n->name, "uri"))
 510                     if (!strcmp((const char *) n->name, "uri") ||
 511                         !strcmp((const char *) n->name, "bnode") )
 512                     {
 513                         uri = mp::xml::get_text(n->children);
 514
 515                     }
 516                     n = n->children;
 517                 }
 518                 else
 519                     n = n->next;
 520             }
 521             if (!uri.length())
 522             {
 523                 rec->which = Z_Records_NSD;
 524                 rec->u.nonSurrogateDiagnostic =
 525                     zget_DefaultDiagFormat(
 526                         odr,
 527                         YAZ_BIB1_SYSTEM_ERROR_IN_PRESENTING_RECORDS, 0);
 528                 xmlFreeDoc(ndoc);
 529                 return rec;
 530             }
 531             else
 532             {
 533                 mp::wrbuf addinfo, query, w;
 534                 int error = yaz_sparql_from_uri_wrbuf(it->conf->s,
 535                                                       addinfo, query,
 536                                                       uri.c_str(), schema);
 537                 if (!error)
 538                 {
 539                     yaz_log(YLOG_LOG, "query=%s", query.c_str());
 540                     error = invoke_sparql(package, query.c_str(),
 541                                           it->conf, w);
 542                 }
 543                 if (error)
 544                 {
 545                     rec->which = Z_Records_NSD;
 546                     rec->u.nonSurrogateDiagnostic =
 547                         zget_DefaultDiagFormat(
 548                             odr,
 549                             error,
 550                             addinfo.len() ? addinfo.c_str() : 0);
 551                     xmlFreeDoc(ndoc);
 552                     return rec;
 553                 }
 554                 npr->u.databaseRecord =
 555                     z_ext_record_xml(odr, w.c_str(), w.len());
 556             }
 557         }
 558         else
 559         {
 560             xmlBufferPtr buf = xmlBufferCreate();
 561             xmlNodeDump(buf, ndoc, ndoc_root, 0, 0);
 562             yaz_log(YLOG_LOG, "record %s %.*s", uri_lookup ? "uri" : "normal",
 563                     (int) buf->use, (const char *) buf->content);
 564             npr->u.databaseRecord =
 565                 z_ext_record_xml(odr, (const char *) buf->content, buf->use);
 566             xmlBufferFree(buf);
 567         }
 568         xmlFreeDoc(ndoc);
 569     }
 570     rec->u.databaseOrSurDiagnostics->num_records = i;
 571     *number_returned = i;
 572     if (start + number > fset->hits)
 573         *next_position = 0;
 574     else
 575         *next_position = start + number;
 576     return rec;
 577 }
 578
 579 int yf::SPARQL::Session::invoke_sparql(mp::Package &package,
 580                                        const char *sparql_query,
 581                                        ConfPtr conf,
 582                                        WRBUF w)
 583 {
 584     Package http_package(package.session(), package.origin());
 585     mp::odr odr;
 586
 587     http_package.copy_filter(package);
 588     Z_GDU *gdu = z_get_HTTP_Request_uri(odr, conf->uri.c_str(), 0, 1);
 589
 590     z_HTTP_header_add(odr, &gdu->u.HTTP_Request->headers,
 591                       "Content-Type", "application/x-www-form-urlencoded");
 592     z_HTTP_header_add(odr, &gdu->u.HTTP_Request->headers,
 593                       "Accept", "application/sparql-results+xml,"
 594                       "application/rdf+xml");
 595     const char *names[2];
 596     names[0] = "query";
 597     names[1] = 0;
 598     const char *values[1];
 599     values[0] = sparql_query;
 600     char *path = 0;
 601     yaz_array_to_uri(&path, odr, (char **) names, (char **) values);
 602
 603     gdu->u.HTTP_Request->content_buf = path;
 604     gdu->u.HTTP_Request->content_len = strlen(path);
 605
 606     yaz_log(YLOG_LOG, "sparql: HTTP request\n%s", sparql_query);
 607
 608     http_package.request() = gdu;
 609     http_package.move();
 610
 611     Z_GDU *gdu_resp = http_package.response().get();
 612
 613     if (!gdu_resp || gdu_resp->which != Z_GDU_HTTP_Response)
 614     {
 615         wrbuf_puts(w, "no HTTP response from backend");
 616         return YAZ_BIB1_TEMPORARY_SYSTEM_ERROR;
 617     }
 618     else if (gdu_resp->u.HTTP_Response->code != 200)
 619     {
 620         wrbuf_printf(w, "sparql: HTTP error %d from backend",
 621                      gdu_resp->u.HTTP_Response->code);
 622         return YAZ_BIB1_TEMPORARY_SYSTEM_ERROR;
 623     }
 624     Z_HTTP_Response *resp = gdu_resp->u.HTTP_Response;
 625     wrbuf_write(w, resp->content_buf, resp->content_len);
 626     return 0;
 627 }
 628
 629 Z_APDU *yf::SPARQL::Session::search(mp::Package &package,
 630                                     Z_APDU *apdu_req,
 631                                     mp::odr &odr,
 632                                     const char *sparql_query,
 633                                     ConfPtr conf, FrontendSetPtr fset)
 634 {
 635     Z_SearchRequest *req = apdu_req->u.searchRequest;
 636     Z_APDU *apdu_res = 0;
 637     mp::wrbuf w;
 638
 639     int error = invoke_sparql(package, sparql_query, conf, w);
 640     if (error)
 641     {
 642         apdu_res = odr.create_searchResponse(apdu_req, error,
 643                                              w.len() ?
 644                                              w.c_str() : 0);
 645     }
 646     else
 647     {
 648         xmlDocPtr doc = xmlParseMemory(w.c_str(), w.len());
 649         if (!doc)
 650         {
 651             apdu_res = odr.create_searchResponse(
 652                 apdu_req,
 653                 YAZ_BIB1_TEMPORARY_SYSTEM_ERROR,
 654                 "invalid XML from backendbackend");
 655         }
 656         else
 657         {
 658             Result result;
 659             Z_Records *records = 0;
 660             int number_returned = 0;
 661             int next_position = 0;
 662             int error_code = 0;
 663             std::string addinfo;
 664
 665             result.doc = doc;
 666             result.conf = conf;
 667             fset->results.push_back(result);
 668             yaz_log(YLOG_LOG, "saving sparql result xmldoc=%p", doc);
 669
 670             get_result(result.doc, &fset->hits, -1, 0);
 671             m_frontend_sets[req->resultSetName] = fset;
 672
 673             result.doc = 0;
 674
 675             Odr_int number = 0;
 676             const char *element_set_name = 0;
 677             mp::util::piggyback_sr(req, fset->hits, number, &element_set_name);
 678             if (number)
 679             {
 680                 Z_ElementSetNames *esn;
 681
 682                 if (number > *req->smallSetUpperBound)
 683                     esn = req->mediumSetElementSetNames;
 684                 else
 685                     esn = req->smallSetElementSetNames;
 686                 records = fetch(package, fset,
 687                                 odr, req->preferredRecordSyntax, esn,
 688                                 1, number,
 689                                 error_code, addinfo,
 690                                 &number_returned,
 691                                 &next_position);
 692             }
 693             if (error_code)
 694             {
 695                 apdu_res =
 696                     odr.create_searchResponse(
 697                         apdu_req, error_code, addinfo.c_str());
 698             }
 699             else
 700             {
 701                 apdu_res =
 702                     odr.create_searchResponse(apdu_req, 0, 0);
 703                 Z_SearchResponse *resp = apdu_res->u.searchResponse;
 704                 *resp->resultCount = fset->hits;
 705                 *resp->numberOfRecordsReturned = number_returned;
 706                 *resp->nextResultSetPosition = next_position;
 707                 resp->records = records;
 708             }
 709         }
 710     }
 711     return apdu_res;
 712 }
 713
 714 void yf::SPARQL::Session::handle_z(mp::Package &package, Z_APDU *apdu_req)
 715 {
 716     mp::odr odr;
 717     Z_APDU *apdu_res = 0;
 718     if (apdu_req->which == Z_APDU_initRequest)
 719     {
 720         apdu_res = odr.create_initResponse(apdu_req, 0, 0);
 721         Z_InitRequest *req = apdu_req->u.initRequest;
 722         Z_InitResponse *resp = apdu_res->u.initResponse;
 723
 724         resp->implementationName = odr_strdup(odr, "sparql");
 725         if (ODR_MASK_GET(req->options, Z_Options_namedResultSets))
 726             m_support_named_result_sets = true;
 727         int i;
 728         static const int masks[] = {
 729             Z_Options_search, Z_Options_present,
 730             Z_Options_namedResultSets, -1
 731         };
 732         for (i = 0; masks[i] != -1; i++)
 733             if (ODR_MASK_GET(req->options, masks[i]))
 734                 ODR_MASK_SET(resp->options, masks[i]);
 735         static const int versions[] = {
 736             Z_ProtocolVersion_1,
 737             Z_ProtocolVersion_2,
 738             Z_ProtocolVersion_3,
 739             -1
 740         };
 741         for (i = 0; versions[i] != -1; i++)
 742             if (ODR_MASK_GET(req->protocolVersion, versions[i]))
 743                 ODR_MASK_SET(resp->protocolVersion, versions[i]);
 744             else
 745                 break;
 746         *resp->preferredMessageSize = *req->preferredMessageSize;
 747         *resp->maximumRecordSize = *req->maximumRecordSize;
 748     }
 749     else if (apdu_req->which == Z_APDU_close)
 750     {
 751         apdu_res = odr.create_close(apdu_req,
 752                                     Z_Close_finished, 0);
 753         package.session().close();
 754     }
 755     else if (apdu_req->which == Z_APDU_searchRequest)
 756     {
 757         Z_SearchRequest *req = apdu_req->u.searchRequest;
 758
 759         FrontendSets::iterator fset_it =
 760             m_frontend_sets.find(req->resultSetName);
 761         if (fset_it != m_frontend_sets.end())
 762         {
 763             // result set already exist
 764             // if replace indicator is off: we return diagnostic if
 765             // result set already exist.
 766             if (*req->replaceIndicator == 0)
 767             {
 768                 Z_APDU *apdu =
 769                     odr.create_searchResponse(
 770                         apdu_req,
 771                         YAZ_BIB1_RESULT_SET_EXISTS_AND_REPLACE_INDICATOR_OFF,
 772                         0);
 773                 package.response() = apdu;
 774             }
 775             m_frontend_sets.erase(fset_it);
 776         }
 777         if (req->query->which != Z_Query_type_1)
 778         {
 779             apdu_res = odr.create_searchResponse(
 780                 apdu_req, YAZ_BIB1_QUERY_TYPE_UNSUPP, 0);
 781         }
 782         else if (req->num_databaseNames != 1)
 783         {
 784             apdu_res = odr.create_searchResponse(
 785                 apdu_req,
 786                 YAZ_BIB1_ACCESS_TO_SPECIFIED_DATABASE_DENIED, 0);
 787         }
 788         else
 789         {
 790             std::string db = req->databaseNames[0];
 791             std::list<ConfPtr>::const_iterator it;
 792             FrontendSetPtr fset(new FrontendSet);
 793
 794             m_frontend_sets.erase(req->resultSetName);
 795             fset->db = db;
 796             it = m_sparql->db_conf.begin();
 797             for (; it != m_sparql->db_conf.end(); it++)
 798                 if ((*it)->schema.length() > 0
 799                     && yaz_match_glob((*it)->db.c_str(), db.c_str()))
 800                 {
 801                     mp::wrbuf addinfo_wr;
 802                     mp::wrbuf sparql_wr;
 803                     int error =
 804                         yaz_sparql_from_rpn_wrbuf((*it)->s,
 805                                                   addinfo_wr, sparql_wr,
 806                                                   req->query->u.type_1);
 807                     if (error)
 808                     {
 809                         apdu_res = odr.create_searchResponse(
 810                             apdu_req, error,
 811                             addinfo_wr.len() ? addinfo_wr.c_str() : 0);
 812                     }
 813                     else
 814                     {
 815                         Z_APDU *apdu_1 = search(package, apdu_req, odr,
 816                                                 sparql_wr.c_str(), *it,
 817                                                 fset);
 818                         if (!apdu_res)
 819                             apdu_res = apdu_1;
 820                     }
 821                 }
 822             if (apdu_res == 0)
 823             {
 824                 apdu_res = odr.create_searchResponse(
 825                     apdu_req, YAZ_BIB1_DATABASE_DOES_NOT_EXIST, db.c_str());
 826             }
 827         }
 828     }
 829     else if (apdu_req->which == Z_APDU_presentRequest)
 830     {
 831         Z_PresentRequest *req = apdu_req->u.presentRequest;
 832         FrontendSets::iterator fset_it =
 833             m_frontend_sets.find(req->resultSetId);
 834         if (fset_it == m_frontend_sets.end())
 835         {
 836             apdu_res =
 837                 odr.create_presentResponse(
 838                     apdu_req, YAZ_BIB1_SPECIFIED_RESULT_SET_DOES_NOT_EXIST,
 839                     req->resultSetId);
 840             package.response() = apdu_res;
 841             return;
 842         }
 843         int number_returned = 0;
 844         int next_position = 0;
 845         int error_code = 0;
 846         std::string addinfo;
 847         Z_ElementSetNames *esn = 0;
 848         if (req->recordComposition)
 849         {
 850             if (req->recordComposition->which == Z_RecordComp_simple)
 851                 esn = req->recordComposition->u.simple;
 852             else
 853             {
 854                 apdu_res =
 855                     odr.create_presentResponse(
 856                         apdu_req,
 857                         YAZ_BIB1_ONLY_A_SINGLE_ELEMENT_SET_NAME_SUPPORTED,
 858                         0);
 859                 package.response() = apdu_res;
 860                 return;
 861             }
 862         }
 863         Z_Records *records = fetch(
 864             package,
 865             fset_it->second,
 866             odr, req->preferredRecordSyntax, esn,
 867             *req->resultSetStartPoint, *req->numberOfRecordsRequested,
 868             error_code, addinfo,
 869             &number_returned,
 870             &next_position);
 871         if (error_code)
 872         {
 873             apdu_res =
 874                 odr.create_presentResponse(apdu_req, error_code,
 875                                            addinfo.c_str());
 876         }
 877         else
 878         {
 879             apdu_res =
 880                 odr.create_presentResponse(apdu_req, 0, 0);
 881             Z_PresentResponse *resp = apdu_res->u.presentResponse;
 882             resp->records = records;
 883             *resp->numberOfRecordsReturned = number_returned;
 884             *resp->nextResultSetPosition = next_position;
 885         }
 886     }
 887     else
 888     {
 889         apdu_res = odr.create_close(apdu_req,
 890                                     Z_Close_protocolError,
 891                                     "sparql: unhandled APDU");
 892         package.session().close();
 893     }
 894
 895     assert(apdu_res);
 896     package.response() = apdu_res;
 897 }
 898
 899 void yf::SPARQL::process(mp::Package &package) const
 900 {
 901     Z_APDU *apdu;
 902     SessionPtr p = get_session(package, &apdu);
 903     if (p && apdu)
 904     {
 905         p->handle_z(package, apdu);
 906     }
 907     else
 908         package.move();
 909     release_session(package);
 910 }
 911
 912 static mp::filter::Base* filter_creator()
 913 {
 914     return new mp::filter::SPARQL;
 915 }
 916
 917 extern "C" {
 918     struct metaproxy_1_filter_struct metaproxy_1_filter_sparql = {
 919         0,
 920         "sparql",
 921         filter_creator
 922     };
 923 }
 924
 925
 926 /*
 927  * Local variables:
 928  * c-basic-offset: 4
 929  * c-file-style: "Stroustrup"
 930  * indent-tabs-mode: nil
 931  * End:
 932  * vim: shiftwidth=4 tabstop=8 expandtab
 933  */
 934