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 "sparql.h"
  29
  30 #include <yaz/zgdu.h>
  31
  32 namespace mp = metaproxy_1;
  33 namespace yf = mp::filter;
  34
  35 namespace metaproxy_1 {
  36     namespace filter {
  37         class SPARQL : public Base {
  38             class Session;
  39             class Rep;
  40             class Conf;
  41             class FrontendSet;
  42
  43             typedef boost::shared_ptr<Session> SessionPtr;
  44             typedef boost::shared_ptr<Conf> ConfPtr;
  45
  46             typedef boost::shared_ptr<FrontendSet> FrontendSetPtr;
  47             typedef std::map<std::string,FrontendSetPtr> FrontendSets;
  48         public:
  49             SPARQL();
  50             ~SPARQL();
  51             void process(metaproxy_1::Package & package) const;
  52             void configure(const xmlNode * ptr, bool test_only,
  53                            const char *path);
  54             SessionPtr get_session(Package &package, Z_APDU **apdu) const;
  55             void release_session(Package &package) const;
  56             boost::scoped_ptr<Rep> m_p;
  57             std::list<ConfPtr> db_conf;
  58         };
  59         class SPARQL::Conf {
  60         public:
  61             std::string db;
  62             std::string uri;
  63             yaz_sparql_t s;
  64             ~Conf();
  65         };
  66         class SPARQL::Rep {
  67             friend class SPARQL;
  68             boost::condition m_cond_session_ready;
  69             boost::mutex m_mutex;
  70             std::map<mp::Session,SessionPtr> m_clients;
  71         };
  72         class SPARQL::FrontendSet {
  73         public:
  74             FrontendSet();
  75             ~FrontendSet();
  76         private:
  77             friend class Session;
  78             Odr_int hits;
  79             xmlDoc *doc;
  80         };
  81         class SPARQL::Session {
  82         public:
  83             Session(const SPARQL *);
  84             ~Session();
  85             void handle_z(Package &package, Z_APDU *apdu);
  86             Z_APDU *run_sparql(mp::Package &package,
  87                                Z_APDU *apdu_req,
  88                                mp::odr &odr,
  89                                const char *sparql_query,
  90                                const char *uri);
  91             bool m_in_use;
  92         private:
  93             bool m_support_named_result_sets;
  94             FrontendSets m_frontend_sets;
  95             const SPARQL *m_sparql;
  96         };
  97     }
  98 }
  99
 100 yf::SPARQL::FrontendSet::~FrontendSet()
 101 {
 102     if (doc)
 103         xmlFreeDoc(doc);
 104 }
 105
 106 yf::SPARQL::FrontendSet::FrontendSet()
 107 {
 108     doc = 0;
 109 }
 110
 111 yf::SPARQL::SPARQL() : m_p(new Rep)
 112 {
 113 }
 114
 115 yf::SPARQL::~SPARQL()
 116 {
 117 }
 118
 119 void yf::SPARQL::configure(const xmlNode *xmlnode, bool test_only,
 120                            const char *path)
 121 {
 122     const xmlNode *ptr = xmlnode->children;
 123
 124     for (; ptr; ptr = ptr->next)
 125     {
 126         if (ptr->type != XML_ELEMENT_NODE)
 127             continue;
 128         if (!strcmp((const char *) ptr->name, "db"))
 129         {
 130             yaz_sparql_t s = yaz_sparql_create();
 131             ConfPtr conf(new Conf);
 132             conf->s = s;
 133
 134             const struct _xmlAttr *attr;
 135             for (attr = ptr->properties; attr; attr = attr->next)
 136             {
 137                 if (!strcmp((const char *) attr->name, "path"))
 138                     conf->db = mp::xml::get_text(attr->children);
 139                 else if (!strcmp((const char *) attr->name, "uri"))
 140                     conf->uri = mp::xml::get_text(attr->children);
 141                 else
 142                     throw mp::filter::FilterException(
 143                         "Bad attribute " + std::string((const char *)
 144                                                        attr->name));
 145             }
 146             xmlNode *p = ptr->children;
 147             for (; p; p = p->next)
 148             {
 149                 if (p->type != XML_ELEMENT_NODE)
 150                     continue;
 151                 std::string name = (const char *) p->name;
 152                 const struct _xmlAttr *attr;
 153                 for (attr = p->properties; attr; attr = attr->next)
 154                 {
 155                     if (!strcmp((const char *) attr->name, "type"))
 156                     {
 157                         name.append(".");
 158                         name.append(mp::xml::get_text(attr->children));
 159                     }
 160                     else
 161                         throw mp::filter::FilterException(
 162                             "Bad attribute " + std::string((const char *)
 163                                                            attr->name));
 164                 }
 165                 std::string value = mp::xml::get_text(p);
 166                 if (yaz_sparql_add_pattern(s, name.c_str(), value.c_str()))
 167                 {
 168                     throw mp::filter::FilterException(
 169                         "Bad SPARQL config " + name);
 170                 }
 171             }
 172             if (!conf->uri.length())
 173             {
 174                 throw mp::filter::FilterException("Missing uri");
 175             }
 176             if (!conf->db.length())
 177             {
 178                 throw mp::filter::FilterException("Missing path");
 179             }
 180             db_conf.push_back(conf);
 181         }
 182         else
 183         {
 184             throw mp::filter::FilterException
 185                 ("Bad element "
 186                  + std::string((const char *) ptr->name)
 187                  + " in sparql filter");
 188         }
 189     }
 190 }
 191
 192 yf::SPARQL::Conf::~Conf()
 193 {
 194     yaz_sparql_destroy(s);
 195 }
 196
 197 yf::SPARQL::Session::Session(const SPARQL *sparql) :
 198     m_in_use(true),
 199     m_support_named_result_sets(false),
 200     m_sparql(sparql)
 201 {
 202 }
 203
 204 yf::SPARQL::Session::~Session()
 205 {
 206 }
 207
 208 yf::SPARQL::SessionPtr yf::SPARQL::get_session(Package & package,
 209                                                Z_APDU **apdu) const
 210 {
 211     SessionPtr ptr0;
 212
 213     Z_GDU *gdu = package.request().get();
 214
 215     boost::mutex::scoped_lock lock(m_p->m_mutex);
 216
 217     std::map<mp::Session,SPARQL::SessionPtr>::iterator it;
 218
 219     if (gdu && gdu->which == Z_GDU_Z3950)
 220         *apdu = gdu->u.z3950;
 221     else
 222         *apdu = 0;
 223
 224     while (true)
 225     {
 226         it = m_p->m_clients.find(package.session());
 227         if (it == m_p->m_clients.end())
 228             break;
 229         if (!it->second->m_in_use)
 230         {
 231             it->second->m_in_use = true;
 232             return it->second;
 233         }
 234         m_p->m_cond_session_ready.wait(lock);
 235     }
 236     if (!*apdu)
 237         return ptr0;
 238
 239     // new Z39.50 session ..
 240     SessionPtr p(new Session(this));
 241     m_p->m_clients[package.session()] = p;
 242     return p;
 243 }
 244
 245 void yf::SPARQL::release_session(Package &package) const
 246 {
 247     boost::mutex::scoped_lock lock(m_p->m_mutex);
 248     std::map<mp::Session,SessionPtr>::iterator it;
 249
 250     it = m_p->m_clients.find(package.session());
 251     if (it != m_p->m_clients.end())
 252     {
 253         it->second->m_in_use = false;
 254
 255         if (package.session().is_closed())
 256             m_p->m_clients.erase(it);
 257         m_p->m_cond_session_ready.notify_all();
 258     }
 259 }
 260
 261 Z_APDU *yf::SPARQL::Session::run_sparql(mp::Package &package,
 262                                         Z_APDU *apdu_req,
 263                                         mp::odr &odr,
 264                                         const char *sparql_query,
 265                                         const char *uri)
 266 {
 267     Package http_package(package.session(), package.origin());
 268
 269     http_package.copy_filter(package);
 270     Z_GDU *gdu = z_get_HTTP_Request_uri(odr, uri, 0, 1);
 271
 272     z_HTTP_header_add(odr, &gdu->u.HTTP_Request->headers,
 273                       "Content-Type", "application/x-www-form-urlencoded");
 274     const char *names[2];
 275     names[0] = "query";
 276     names[1] = 0;
 277     const char *values[1];
 278     values[0] = sparql_query;
 279     char *path = 0;
 280     yaz_array_to_uri(&path, odr, (char **) names, (char **) values);
 281
 282     gdu->u.HTTP_Request->content_buf = path;
 283     gdu->u.HTTP_Request->content_len = strlen(path);
 284
 285     yaz_log(YLOG_LOG, "sparql: HTTP request\n%s", sparql_query);
 286
 287     http_package.request() = gdu;
 288     http_package.move();
 289
 290     Z_GDU *gdu_resp = http_package.response().get();
 291     Z_APDU *apdu_res = 0;
 292     if (gdu_resp && gdu_resp->which == Z_GDU_HTTP_Response)
 293     {
 294         Z_HTTP_Response *resp = gdu_resp->u.HTTP_Response;
 295         FrontendSetPtr fset(new FrontendSet);
 296
 297         fset->doc = xmlParseMemory(resp->content_buf, resp->content_len);
 298         if (!fset->doc)
 299             apdu_res = odr.create_searchResponse(apdu_req,
 300                                              YAZ_BIB1_TEMPORARY_SYSTEM_ERROR,
 301                                              "invalid XML from backendbackend");
 302         else
 303         {
 304             apdu_res = odr.create_searchResponse(apdu_req, 0, 0);
 305
 306             m_frontend_sets[apdu_req->u.searchRequest->resultSetName] = fset;
 307         }
 308     }
 309     else
 310     {
 311         yaz_log(YLOG_LOG, "sparql: no HTTP response");
 312         apdu_res = odr.create_searchResponse(apdu_req,
 313                                              YAZ_BIB1_TEMPORARY_SYSTEM_ERROR,
 314                                              "no HTTP response from backend");
 315     }
 316     return apdu_res;
 317 }
 318
 319 void yf::SPARQL::Session::handle_z(mp::Package &package, Z_APDU *apdu_req)
 320 {
 321     mp::odr odr;
 322     Z_APDU *apdu_res = 0;
 323     if (apdu_req->which == Z_APDU_initRequest)
 324     {
 325         apdu_res = odr.create_initResponse(apdu_req, 0, 0);
 326         Z_InitRequest *req = apdu_req->u.initRequest;
 327         Z_InitResponse *resp = apdu_res->u.initResponse;
 328
 329         resp->implementationName = odr_strdup(odr, "sparql");
 330         if (ODR_MASK_GET(req->options, Z_Options_namedResultSets))
 331             m_support_named_result_sets = true;
 332         int i;
 333         static const int masks[] = {
 334             Z_Options_search, Z_Options_present,
 335             Z_Options_namedResultSets, -1
 336         };
 337         for (i = 0; masks[i] != -1; i++)
 338             if (ODR_MASK_GET(req->options, masks[i]))
 339                 ODR_MASK_SET(resp->options, masks[i]);
 340         static const int versions[] = {
 341             Z_ProtocolVersion_1,
 342             Z_ProtocolVersion_2,
 343             Z_ProtocolVersion_3,
 344             -1
 345         };
 346         for (i = 0; versions[i] != -1; i++)
 347             if (ODR_MASK_GET(req->protocolVersion, versions[i]))
 348                 ODR_MASK_SET(resp->protocolVersion, versions[i]);
 349             else
 350                 break;
 351         *resp->preferredMessageSize = *req->preferredMessageSize;
 352         *resp->maximumRecordSize = *req->maximumRecordSize;
 353     }
 354     else if (apdu_req->which == Z_APDU_close)
 355     {
 356         apdu_res = odr.create_close(apdu_req,
 357                                     Z_Close_finished, 0);
 358         package.session().close();
 359     }
 360     else if (apdu_req->which == Z_APDU_searchRequest)
 361     {
 362         Z_SearchRequest *req = apdu_req->u.searchRequest;
 363
 364         FrontendSets::iterator fset_it =
 365             m_frontend_sets.find(req->resultSetName);
 366         if (fset_it != m_frontend_sets.end())
 367         {
 368             // result set already exist
 369             // if replace indicator is off: we return diagnostic if
 370             // result set already exist.
 371             if (*req->replaceIndicator == 0)
 372             {
 373                 Z_APDU *apdu =
 374                     odr.create_searchResponse(
 375                         apdu_req,
 376                         YAZ_BIB1_RESULT_SET_EXISTS_AND_REPLACE_INDICATOR_OFF,
 377                         0);
 378                 package.response() = apdu_res;
 379             }
 380             m_frontend_sets.erase(fset_it);
 381         }
 382         if (req->query->which != Z_Query_type_1)
 383         {
 384             apdu_res = odr.create_searchResponse(
 385                 apdu_req, YAZ_BIB1_QUERY_TYPE_UNSUPP, 0);
 386         }
 387         else if (req->num_databaseNames != 1)
 388         {
 389             apdu_res = odr.create_searchResponse(
 390                 apdu_req,
 391                 YAZ_BIB1_ACCESS_TO_SPECIFIED_DATABASE_DENIED, 0);
 392         }
 393         else
 394         {
 395             std::string db = req->databaseNames[0];
 396             std::list<ConfPtr>::const_iterator it;
 397
 398             it = m_sparql->db_conf.begin();
 399             for (; it != m_sparql->db_conf.end(); it++)
 400                 if (yaz_match_glob((*it)->db.c_str(), db.c_str()))
 401                     break;
 402             if (it == m_sparql->db_conf.end())
 403             {
 404                 apdu_res = odr.create_searchResponse(
 405                     apdu_req, YAZ_BIB1_DATABASE_DOES_NOT_EXIST, db.c_str());
 406             }
 407             else
 408             {
 409                 WRBUF addinfo_wr = wrbuf_alloc();
 410                 WRBUF sparql_wr = wrbuf_alloc();
 411                 int error =
 412                     yaz_sparql_from_rpn_wrbuf((*it)->s,
 413                                               addinfo_wr, sparql_wr,
 414                                               req->query->u.type_1);
 415                 if (error)
 416                 {
 417                     apdu_res = odr.create_searchResponse(
 418                         apdu_req, error,
 419                         wrbuf_len(addinfo_wr) ?
 420                         wrbuf_cstr(addinfo_wr) : 0);
 421                 }
 422                 else
 423                 {
 424                     apdu_res = run_sparql(package, apdu_req, odr,
 425                                           wrbuf_cstr(sparql_wr),
 426                                           (*it)->uri.c_str());
 427                 }
 428                 wrbuf_destroy(addinfo_wr);
 429                 wrbuf_destroy(sparql_wr);
 430             }
 431         }
 432     }
 433     else
 434     {
 435         apdu_res = odr.create_close(apdu_req,
 436                                     Z_Close_protocolError,
 437                                     "sparql: unhandled APDU");
 438         package.session().close();
 439     }
 440
 441     assert(apdu_res);
 442     package.response() = apdu_res;
 443 }
 444
 445 void yf::SPARQL::process(mp::Package &package) const
 446 {
 447     Z_APDU *apdu;
 448     SessionPtr p = get_session(package, &apdu);
 449     if (p && apdu)
 450     {
 451         p->handle_z(package, apdu);
 452     }
 453     else
 454         package.move();
 455     release_session(package);
 456 }
 457
 458 static mp::filter::Base* filter_creator()
 459 {
 460     return new mp::filter::SPARQL;
 461 }
 462
 463 extern "C" {
 464     struct metaproxy_1_filter_struct metaproxy_1_filter_sparql = {
 465         0,
 466         "sparql",
 467         filter_creator
 468     };
 469 }
 470
 471
 472 /*
 473  * Local variables:
 474  * c-basic-offset: 4
 475  * c-file-style: "Stroustrup"
 476  * indent-tabs-mode: nil
 477  * End:
 478  * vim: shiftwidth=4 tabstop=8 expandtab
 479  */
 480