src/filter_record_transform.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 "config.hpp"
  20 #include "filter_record_transform.hpp"
  21 #include <metaproxy/package.hpp>
  22 #include <metaproxy/util.hpp>
  23 #include "gduutil.hpp"
  24
  25 #include <yaz/diagbib1.h>
  26 #include <yaz/zgdu.h>
  27 #include <yaz/retrieval.h>
  28
  29 #include <iostream>
  30
  31 namespace mp = metaproxy_1;
  32 namespace yf = mp::filter;
  33 namespace mp_util = metaproxy_1::util;
  34
  35 namespace metaproxy_1 {
  36     namespace filter {
  37         class RecordTransform::Impl {
  38         public:
  39             Impl();
  40             ~Impl();
  41             void process(metaproxy_1::Package & package) const;
  42             void configure(const xmlNode * xml_node);
  43         private:
  44             yaz_retrieval_t m_retrieval;
  45         };
  46     }
  47 }
  48
  49 // define Pimpl wrapper forwarding to Impl
  50
  51 yf::RecordTransform::RecordTransform() : m_p(new Impl)
  52 {
  53 }
  54
  55 yf::RecordTransform::~RecordTransform()
  56 {  // must have a destructor because of boost::scoped_ptr
  57 }
  58
  59 void yf::RecordTransform::configure(const xmlNode *xmlnode, bool test_only)
  60 {
  61     m_p->configure(xmlnode);
  62 }
  63
  64 void yf::RecordTransform::process(mp::Package &package) const
  65 {
  66     m_p->process(package);
  67 }
  68
  69
  70 // define Implementation stuff
  71
  72
  73
  74 yf::RecordTransform::Impl::Impl()
  75 {
  76     m_retrieval = yaz_retrieval_create();
  77     assert(m_retrieval);
  78 }
  79
  80 yf::RecordTransform::Impl::~Impl()
  81 {
  82     if (m_retrieval)
  83         yaz_retrieval_destroy(m_retrieval);
  84 }
  85
  86 void yf::RecordTransform::Impl::configure(const xmlNode *xml_node)
  87 {
  88     //const char *srcdir = getenv("srcdir");
  89     //if (srcdir)
  90     //    yaz_retrieval_set_path(m_retrieval, srcdir);
  91
  92     if (!xml_node)
  93         throw mp::XMLError("RecordTransform filter config: empty XML DOM");
  94
  95     // parsing down to retrieval node, which can be any of the children nodes
  96     xmlNode *retrieval_node;
  97     for (retrieval_node = xml_node->children;
  98          retrieval_node;
  99          retrieval_node = retrieval_node->next)
 100     {
 101         if (retrieval_node->type != XML_ELEMENT_NODE)
 102             continue;
 103         if (0 == strcmp((const char *) retrieval_node->name, "retrievalinfo"))
 104             break;
 105     }
 106
 107     // read configuration
 108     if ( 0 != yaz_retrieval_configure(m_retrieval, retrieval_node)){
 109         std::string msg("RecordTransform filter config: ");
 110         msg += yaz_retrieval_get_error(m_retrieval);
 111         throw mp::XMLError(msg);
 112     }
 113 }
 114
 115 void yf::RecordTransform::Impl::process(mp::Package &package) const
 116 {
 117
 118     Z_GDU *gdu_req = package.request().get();
 119
 120     // only working on z3950 present packages
 121     if (!gdu_req
 122         || !(gdu_req->which == Z_GDU_Z3950)
 123         || !(gdu_req->u.z3950->which == Z_APDU_presentRequest))
 124     {
 125         package.move();
 126         return;
 127     }
 128
 129     // getting original present request
 130     Z_PresentRequest *pr_req = gdu_req->u.z3950->u.presentRequest;
 131
 132     // setting up ODR's for memory during encoding/decoding
 133     //mp::odr odr_de(ODR_DECODE);
 134     mp::odr odr_en(ODR_ENCODE);
 135
 136     // setting up variables for conversion state
 137     yaz_record_conv_t rc = 0;
 138     int ret_code;
 139
 140     const char *input_schema = 0;
 141     Odr_oid *input_syntax = 0;
 142
 143     if(pr_req->recordComposition){
 144         input_schema
 145             = mp_util::record_composition_to_esn(pr_req->recordComposition);
 146     }
 147     if(pr_req->preferredRecordSyntax){
 148         input_syntax = pr_req->preferredRecordSyntax;
 149     }
 150
 151     const char *match_schema = 0;
 152     Odr_oid *match_syntax = 0;
 153
 154     const char *backend_schema = 0;
 155     Odr_oid *backend_syntax = 0;
 156
 157     ret_code
 158         = yaz_retrieval_request(m_retrieval,
 159                                 input_schema, input_syntax,
 160                                 &match_schema, &match_syntax,
 161                                 &rc,
 162                                 &backend_schema, &backend_syntax);
 163
 164     // error handling
 165     if (ret_code != 0)
 166     {
 167         // need to construct present error package and send back
 168
 169         Z_APDU *apdu = 0;
 170
 171         const char *details = 0;
 172         if (ret_code == -1) /* error ? */
 173         {
 174            details = yaz_retrieval_get_error(m_retrieval);
 175            apdu = odr_en.create_presentResponse(
 176                gdu_req->u.z3950,
 177                YAZ_BIB1_SYSTEM_ERROR_IN_PRESENTING_RECORDS, details);
 178         }
 179         else if (ret_code == 1 || ret_code == 3)
 180         {
 181             details = input_schema;
 182             apdu = odr_en.create_presentResponse(
 183                 gdu_req->u.z3950,
 184                 YAZ_BIB1_ELEMENT_SET_NAMES_UNSUPP, details);
 185         }
 186         else if (ret_code == 2)
 187         {
 188             char oidbuf[OID_STR_MAX];
 189             oid_oid_to_dotstring(input_syntax, oidbuf);
 190             details = odr_strdup(odr_en, oidbuf);
 191
 192             apdu = odr_en.create_presentResponse(
 193                 gdu_req->u.z3950,
 194                 YAZ_BIB1_RECORD_SYNTAX_UNSUPP, details);
 195         }
 196         package.response() = apdu;
 197         return;
 198     }
 199
 200     // now re-coding the z3950 backend present request
 201
 202     if (backend_syntax)
 203         pr_req->preferredRecordSyntax = odr_oiddup(odr_en, backend_syntax);
 204     else
 205         pr_req->preferredRecordSyntax = 0;
 206
 207
 208     // z3950'fy record schema
 209     if (backend_schema)
 210     {
 211         pr_req->recordComposition
 212             = (Z_RecordComposition *)
 213               odr_malloc(odr_en, sizeof(Z_RecordComposition));
 214         pr_req->recordComposition->which
 215             = Z_RecordComp_simple;
 216         pr_req->recordComposition->u.simple
 217             = (Z_ElementSetNames *)
 218                odr_malloc(odr_en, sizeof(Z_ElementSetNames));
 219         pr_req->recordComposition->u.simple->which = Z_ElementSetNames_generic;
 220         pr_req->recordComposition->u.simple->u.generic
 221             = odr_strdup(odr_en, backend_schema);
 222     }
 223
 224     // attaching Z3950 package to filter chain
 225     package.request() = gdu_req;
 226
 227     package.move();
 228
 229    //check successful Z3950 present response
 230     Z_GDU *gdu_res = package.response().get();
 231     if (!gdu_res || gdu_res->which != Z_GDU_Z3950
 232         || gdu_res->u.z3950->which != Z_APDU_presentResponse
 233         || !gdu_res->u.z3950->u.presentResponse)
 234
 235     {
 236         package.session().close();
 237         return;
 238     }
 239
 240
 241     // everything fine, continuing
 242     // std::cout << "z3950_present_request OK\n";
 243     // std::cout << "back z3950 " << *gdu_res << "\n";
 244
 245     Z_PresentResponse * pr_res = gdu_res->u.z3950->u.presentResponse;
 246
 247     // let non surrogate dioagnostics in Z3950 present response package
 248     // pass to frontend - just return
 249     if (pr_res->records
 250         && pr_res->records->which == Z_Records_NSD
 251         && pr_res->records->u.nonSurrogateDiagnostic)
 252     {
 253         // we might do more clever tricks to "reverse"
 254         // these error(s).
 255
 256         //*pr_res->records->u.nonSurrogateDiagnostic->condition =
 257         // YAZ_BIB1_SYSTEM_ERROR_IN_PRESENTING_RECORDS;
 258     }
 259
 260     // record transformation must take place
 261     if (rc && pr_res
 262         && pr_res->numberOfRecordsReturned
 263         && *(pr_res->numberOfRecordsReturned) > 0
 264         && pr_res->records
 265         && pr_res->records->which == Z_Records_DBOSD
 266         && pr_res->records->u.databaseOrSurDiagnostics->num_records)
 267     {
 268          //transform all records
 269          for (int i = 0;
 270               i < pr_res->records->u.databaseOrSurDiagnostics->num_records;
 271               i++)
 272          {
 273              Z_NamePlusRecord *npr
 274                  = pr_res->records->u.databaseOrSurDiagnostics->records[i];
 275              if (npr->which == Z_NamePlusRecord_databaseRecord)
 276              {
 277                  WRBUF output_record = wrbuf_alloc();
 278                  Z_External *r = npr->u.databaseRecord;
 279                  int ret_trans = 0;
 280                  if (r->which == Z_External_OPAC)
 281                  {
 282 #if YAZ_VERSIONL >= 0x030011
 283                      ret_trans =
 284                          yaz_record_conv_opac_record(rc, r->u.opac,
 285                                                      output_record);
 286 #else
 287                      ;
 288 #endif
 289                  }
 290                  else if (r->which == Z_External_octet)
 291                  {
 292                      ret_trans =
 293                          yaz_record_conv_record(rc, (const char *)
 294                                                 r->u.octet_aligned->buf,
 295                                                 r->u.octet_aligned->len,
 296                                                 output_record);
 297                  }
 298                  if (ret_trans == 0)
 299                  {
 300                      npr->u.databaseRecord =
 301                          z_ext_record_oid(odr_en, match_syntax,
 302                                           wrbuf_buf(output_record),
 303                                           wrbuf_len(output_record));
 304                  }
 305                  else
 306                  {
 307                      pr_res->records->
 308                          u.databaseOrSurDiagnostics->records[i]
 309                          =  zget_surrogateDiagRec(
 310                              odr_en, npr->databaseName,
 311                              YAZ_BIB1_SYSTEM_ERROR_IN_PRESENTING_RECORDS,
 312                              yaz_record_conv_get_error(rc));
 313                  }
 314                  wrbuf_destroy(output_record);
 315              }
 316          }
 317     }
 318     package.response() = gdu_res;
 319     return;
 320 }
 321
 322
 323 static mp::filter::Base* filter_creator()
 324 {
 325     return new mp::filter::RecordTransform;
 326 }
 327
 328 extern "C" {
 329     struct metaproxy_1_filter_struct metaproxy_1_filter_record_transform = {
 330         0,
 331         "record_transform",
 332         filter_creator
 333     };
 334 }
 335
 336
 337 /*
 338  * Local variables:
 339  * c-basic-offset: 4
 340  * c-file-style: "Stroustrup"
 341  * indent-tabs-mode: nil
 342  * End:
 343  * vim: shiftwidth=4 tabstop=8 expandtab
 344  */
 345