src/filter_record_transform.cpp

   1 /* This file is part of Metaproxy.
   2    Copyright (C) 2005-2012 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, const char *path);
  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                                     const char *path)
  61 {
  62     m_p->configure(xmlnode, path);
  63 }
  64
  65 void yf::RecordTransform::process(mp::Package &package) const
  66 {
  67     m_p->process(package);
  68 }
  69
  70
  71 // define Implementation stuff
  72
  73
  74
  75 yf::RecordTransform::Impl::Impl()
  76 {
  77     m_retrieval = yaz_retrieval_create();
  78     assert(m_retrieval);
  79 }
  80
  81 yf::RecordTransform::Impl::~Impl()
  82 {
  83     if (m_retrieval)
  84         yaz_retrieval_destroy(m_retrieval);
  85 }
  86
  87 void yf::RecordTransform::Impl::configure(const xmlNode *xml_node,
  88                                           const char *path)
  89 {
  90     yaz_retrieval_set_path(m_retrieval, path);
  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     {
 110         std::string msg("RecordTransform filter config: ");
 111         msg += yaz_retrieval_get_error(m_retrieval);
 112         throw mp::XMLError(msg);
 113     }
 114 }
 115
 116 void yf::RecordTransform::Impl::process(mp::Package &package) const
 117 {
 118
 119     Z_GDU *gdu_req = package.request().get();
 120
 121     // only working on z3950 present packages
 122     if (!gdu_req
 123         || !(gdu_req->which == Z_GDU_Z3950)
 124         || !(gdu_req->u.z3950->which == Z_APDU_presentRequest))
 125     {
 126         package.move();
 127         return;
 128     }
 129
 130     // getting original present request
 131     Z_PresentRequest *pr_req = gdu_req->u.z3950->u.presentRequest;
 132
 133     // setting up ODR's for memory during encoding/decoding
 134     //mp::odr odr_de(ODR_DECODE);
 135     mp::odr odr_en(ODR_ENCODE);
 136
 137     // setting up variables for conversion state
 138     yaz_record_conv_t rc = 0;
 139
 140     const char *input_schema = 0;
 141     Odr_oid *input_syntax = 0;
 142
 143     if (pr_req->recordComposition)
 144     {
 145         input_schema
 146             = mp_util::record_composition_to_esn(pr_req->recordComposition);
 147     }
 148     if (pr_req->preferredRecordSyntax)
 149     {
 150         input_syntax = pr_req->preferredRecordSyntax;
 151     }
 152
 153     const char *match_schema = 0;
 154     Odr_oid *match_syntax = 0;
 155
 156     const char *backend_schema = 0;
 157     Odr_oid *backend_syntax = 0;
 158
 159     int ret_code
 160         = yaz_retrieval_request(m_retrieval,
 161                                 input_schema, input_syntax,
 162                                 &match_schema, &match_syntax,
 163                                 &rc,
 164                                 &backend_schema, &backend_syntax);
 165
 166     // error handling
 167     if (ret_code != 0)
 168     {
 169         // need to construct present error package and send back
 170
 171         Z_APDU *apdu = 0;
 172
 173         const char *details = 0;
 174         if (ret_code == -1) /* error ? */
 175         {
 176            details = yaz_retrieval_get_error(m_retrieval);
 177            apdu = odr_en.create_presentResponse(
 178                gdu_req->u.z3950,
 179                YAZ_BIB1_SYSTEM_ERROR_IN_PRESENTING_RECORDS, details);
 180         }
 181         else if (ret_code == 1 || ret_code == 3)
 182         {
 183             details = input_schema;
 184             apdu = odr_en.create_presentResponse(
 185                 gdu_req->u.z3950,
 186                 YAZ_BIB1_ELEMENT_SET_NAMES_UNSUPP, details);
 187         }
 188         else if (ret_code == 2)
 189         {
 190             char oidbuf[OID_STR_MAX];
 191             oid_oid_to_dotstring(input_syntax, oidbuf);
 192             details = odr_strdup(odr_en, oidbuf);
 193
 194             apdu = odr_en.create_presentResponse(
 195                 gdu_req->u.z3950,
 196                 YAZ_BIB1_RECORD_SYNTAX_UNSUPP, details);
 197         }
 198         package.response() = apdu;
 199         return;
 200     }
 201
 202     // now re-coding the z3950 backend present request
 203     if (backend_syntax)
 204         pr_req->preferredRecordSyntax = odr_oiddup(odr_en, backend_syntax);
 205     else
 206         pr_req->preferredRecordSyntax = 0;
 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     Z_PresentResponse * pr_res = gdu_res->u.z3950->u.presentResponse;
 241
 242     // record transformation must take place
 243     if (rc && pr_res
 244         && pr_res->numberOfRecordsReturned
 245         && *(pr_res->numberOfRecordsReturned) > 0
 246         && pr_res->records
 247         && pr_res->records->which == Z_Records_DBOSD
 248         && pr_res->records->u.databaseOrSurDiagnostics->num_records)
 249     {
 250          // transform all records
 251          for (int i = 0;
 252               i < pr_res->records->u.databaseOrSurDiagnostics->num_records;
 253               i++)
 254          {
 255              Z_NamePlusRecord *npr
 256                  = pr_res->records->u.databaseOrSurDiagnostics->records[i];
 257              if (npr->which == Z_NamePlusRecord_databaseRecord)
 258              {
 259                  WRBUF output_record = wrbuf_alloc();
 260                  Z_External *r = npr->u.databaseRecord;
 261                  int ret_trans = 0;
 262                  if (r->which == Z_External_OPAC)
 263                  {
 264                      ret_trans =
 265                          yaz_record_conv_opac_record(rc, r->u.opac,
 266                                                      output_record);
 267                  }
 268                  else if (r->which == Z_External_octet)
 269                  {
 270                      ret_trans =
 271                          yaz_record_conv_record(rc, (const char *)
 272                                                 r->u.octet_aligned->buf,
 273                                                 r->u.octet_aligned->len,
 274                                                 output_record);
 275                  }
 276                  if (ret_trans == 0)
 277                  {
 278                      npr->u.databaseRecord =
 279                          z_ext_record_oid(odr_en, match_syntax,
 280                                           wrbuf_buf(output_record),
 281                                           wrbuf_len(output_record));
 282                  }
 283                  else
 284                  {
 285                      pr_res->records->
 286                          u.databaseOrSurDiagnostics->records[i]
 287                          =  zget_surrogateDiagRec(
 288                              odr_en, npr->databaseName,
 289                              YAZ_BIB1_SYSTEM_ERROR_IN_PRESENTING_RECORDS,
 290                              yaz_record_conv_get_error(rc));
 291                  }
 292                  wrbuf_destroy(output_record);
 293              }
 294          }
 295     }
 296     package.response() = gdu_res;
 297     return;
 298 }
 299
 300
 301 static mp::filter::Base* filter_creator()
 302 {
 303     return new mp::filter::RecordTransform;
 304 }
 305
 306 extern "C" {
 307     struct metaproxy_1_filter_struct metaproxy_1_filter_record_transform = {
 308         0,
 309         "record_transform",
 310         filter_creator
 311     };
 312 }
 313
 314
 315 /*
 316  * Local variables:
 317  * c-basic-offset: 4
 318  * c-file-style: "Stroustrup"
 319  * indent-tabs-mode: nil
 320  * End:
 321  * vim: shiftwidth=4 tabstop=8 expandtab
 322  */
 323