src/filter_cql_rpn.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 "config.hpp"
  20 #include <metaproxy/util.hpp>
  21
  22 #include <metaproxy/filter.hpp>
  23 #include <metaproxy/package.hpp>
  24
  25 #include "filter_cql_rpn.hpp"
  26
  27 #include <yazpp/z-query.h>
  28 #include <yaz/cql.h>
  29 #include <yazpp/cql2rpn.h>
  30 #include <yaz/zgdu.h>
  31 #include <yaz/diagbib1.h>
  32 #include <yaz/srw.h>
  33 #include <yaz/tpath.h>
  34 #include <yaz/oid_std.h>
  35
  36 namespace mp = metaproxy_1;
  37 namespace yf = metaproxy_1::filter;
  38
  39 namespace metaproxy_1 {
  40     namespace filter {
  41         class CQLtoRPN::Impl {
  42         public:
  43             Impl();
  44             ~Impl();
  45             void process(metaproxy_1::Package & package);
  46             void configure(const xmlNode *ptr, const char *path);
  47         private:
  48             yazpp_1::Yaz_cql2rpn m_cql2rpn;
  49             bool reverse;
  50         };
  51     }
  52 }
  53
  54
  55 // define Pimpl wrapper forwarding to Impl
  56
  57 yf::CQLtoRPN::CQLtoRPN() : m_p(new Impl)
  58 {
  59 }
  60
  61 yf::CQLtoRPN::~CQLtoRPN()
  62 {  // must have a destructor because of boost::scoped_ptr
  63 }
  64
  65 void yf::CQLtoRPN::configure(const xmlNode *xmlnode, bool test_only,
  66                              const char *path)
  67 {
  68     m_p->configure(xmlnode, path);
  69 }
  70
  71 void yf::CQLtoRPN::process(mp::Package &package) const
  72 {
  73     m_p->process(package);
  74 }
  75
  76
  77 // define Implementation stuff
  78
  79 yf::CQLtoRPN::Impl::Impl() : reverse(false)
  80 {
  81 }
  82
  83 yf::CQLtoRPN::Impl::~Impl()
  84 {
  85 }
  86
  87 void yf::CQLtoRPN::Impl::configure(const xmlNode *xmlnode, const char *path)
  88 {
  89
  90     /*
  91       <filter type="cql_rpn">
  92       <conversion file="pqf.properties"/>
  93       </filter>
  94     */
  95
  96     std::string fname;
  97     for (xmlnode = xmlnode->children; xmlnode; xmlnode = xmlnode->next)
  98     {
  99         if (xmlnode->type != XML_ELEMENT_NODE)
 100             continue;
 101         if (!strcmp((const char *) xmlnode->name, "conversion"))
 102         {
 103             const struct _xmlAttr *attr;
 104             for (attr = xmlnode->properties; attr; attr = attr->next)
 105             {
 106                 if (!strcmp((const char *) attr->name, "file"))
 107                     fname = mp::xml::get_text(attr);
 108                 else if (!strcmp((const char *) attr->name, "reverse"))
 109                 {
 110                     reverse = mp::xml::get_bool(attr->children, 0);
 111                 }
 112                 else
 113                     throw mp::filter::FilterException(
 114                         "Bad attribute " + std::string((const char *)
 115                                                        attr->name));
 116             }
 117         }
 118         else
 119         {
 120             throw mp::filter::FilterException("Bad element "
 121                                                + std::string((const char *)
 122                                                              xmlnode->name));
 123         }
 124     }
 125     if (fname.length() == 0)
 126     {
 127         throw mp::filter::FilterException("Missing conversion configuration "
 128                                           "for filter cql_rpn");
 129     }
 130
 131
 132     char fullpath[1024];
 133     if (!yaz_filepath_resolve(fname.c_str(), path, 0, fullpath))
 134     {
 135         throw mp::filter::FilterException("Could not open " + fname);
 136     }
 137     int error = 0;
 138     if (!m_cql2rpn.parse_spec_file(fullpath, &error))
 139     {
 140         throw mp::filter::FilterException("Bad or missing "
 141                                           "CQL to RPN configuration "
 142                                           + fname);
 143     }
 144 }
 145
 146 void yf::CQLtoRPN::Impl::process(mp::Package &package)
 147 {
 148     Z_GDU *gdu = package.request().get();
 149
 150     if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
 151         Z_APDU_searchRequest)
 152     {
 153         Z_APDU *apdu_req = gdu->u.z3950;
 154         Z_SearchRequest *sr = gdu->u.z3950->u.searchRequest;
 155         if (reverse && sr->query && sr->query->which == Z_Query_type_1)
 156         {
 157             char *addinfo = 0;
 158             mp::odr odr;
 159             WRBUF cql = wrbuf_alloc();
 160
 161             int r = m_cql2rpn.rpn2cql_transform(sr->query->u.type_1, cql,
 162                                                 odr, &addinfo);
 163             if (r)
 164             {
 165                 Z_APDU *f_apdu =
 166                     odr.create_searchResponse(apdu_req, r, addinfo);
 167                 package.response() = f_apdu;
 168                 return;
 169             }
 170             else
 171             {
 172                 Z_External *ext = (Z_External *)
 173                     odr_malloc(odr, sizeof(*ext));
 174                 ext->direct_reference = odr_oiddup(odr,
 175                                                    yaz_oid_userinfo_cql);
 176                 ext->indirect_reference = 0;
 177                 ext->descriptor = 0;
 178                 ext->which = Z_External_CQL;
 179                 ext->u.cql = odr_strdup(odr, wrbuf_cstr(cql));
 180
 181                 sr->query->which = Z_Query_type_104;
 182                 sr->query->u.type_104 = ext;
 183
 184                 package.request() = gdu;
 185             }
 186             wrbuf_destroy(cql);
 187         }
 188         if (!reverse && sr->query && sr->query->which == Z_Query_type_104 &&
 189             sr->query->u.type_104->which == Z_External_CQL)
 190         {
 191             char *addinfo = 0;
 192             Z_RPNQuery *rpnquery = 0;
 193             mp::odr odr;
 194
 195             int r = m_cql2rpn.query_transform(sr->query->u.type_104->u.cql,
 196                                                  &rpnquery, odr,
 197                                                  &addinfo);
 198             if (r == -3)
 199             {
 200                 Z_APDU *f_apdu =
 201                     odr.create_searchResponse(
 202                         apdu_req,
 203                         YAZ_BIB1_PERMANENT_SYSTEM_ERROR,
 204                         "cql_rpn: missing CQL to RPN configuration");
 205                 package.response() = f_apdu;
 206                 return;
 207             }
 208             else if (r)
 209             {
 210                 int error_code = yaz_diag_srw_to_bib1(r);
 211
 212                 Z_APDU *f_apdu =
 213                     odr.create_searchResponse(apdu_req, error_code, addinfo);
 214                 package.response() = f_apdu;
 215                 return;
 216             }
 217             else
 218             {   // conversion OK
 219
 220                 sr->query->which = Z_Query_type_1;
 221                 sr->query->u.type_1 = rpnquery;
 222                 package.request() = gdu;
 223             }
 224         }
 225     }
 226     package.move();
 227 }
 228
 229
 230 static mp::filter::Base* filter_creator()
 231 {
 232     return new mp::filter::CQLtoRPN;
 233 }
 234
 235 extern "C" {
 236     struct metaproxy_1_filter_struct metaproxy_1_filter_cql_rpn = {
 237         0,
 238         "cql_rpn",
 239         filter_creator
 240     };
 241 }
 242
 243 /*
 244  * Local variables:
 245  * c-basic-offset: 4
 246  * c-file-style: "Stroustrup"
 247  * indent-tabs-mode: nil
 248  * End:
 249  * vim: shiftwidth=4 tabstop=8 expandtab
 250  */
 251