src/filter_query_rewrite.cpp

   1 /* $Id: filter_query_rewrite.cpp,v 1.4 2006-03-15 14:55:17 adam Exp $
   2    Copyright (c) 2005, Index Data.
   3
   4 %LICENSE%
   5  */
   6
   7
   8 #include "config.hpp"
   9 #include "filter.hpp"
  10 #include "package.hpp"
  11
  12 //#include <boost/thread/mutex.hpp>
  13 #include <boost/regex.hpp>
  14
  15 #include "util.hpp"
  16 #include "filter_query_rewrite.hpp"
  17
  18 #include <yaz/zgdu.h>
  19 #include <yaz/xmlquery.h>
  20 #include <yaz/diagbib1.h>
  21
  22 #include <libxslt/xsltutils.h>
  23 #include <libxslt/transform.h>
  24
  25 namespace yf = yp2::filter;
  26
  27 namespace yp2 {
  28     namespace filter {
  29         class QueryRewrite::Rep {
  30         public:
  31             Rep();
  32             ~Rep();
  33             void process(yp2::Package &package) const;
  34             void configure(const xmlNode * ptr);
  35         private:
  36             xsltStylesheetPtr m_stylesheet;
  37         };
  38     }
  39 }
  40
  41 yf::QueryRewrite::Rep::Rep()
  42 {
  43     m_stylesheet = 0;
  44 }
  45
  46 yf::QueryRewrite::Rep::~Rep()
  47 {
  48     if (m_stylesheet)
  49         xsltFreeStylesheet(m_stylesheet);
  50 }
  51
  52 yf::QueryRewrite::QueryRewrite() : m_p(new Rep)
  53 {
  54 }
  55
  56 yf::QueryRewrite::~QueryRewrite()
  57 {  // must have a destructor because of boost::scoped_ptr
  58 }
  59
  60 void yf::QueryRewrite::process(yp2::Package &package) const
  61 {
  62     m_p->process(package);
  63 }
  64
  65 void yp2::filter::QueryRewrite::configure(const xmlNode *ptr)
  66 {
  67     m_p->configure(ptr);
  68 }
  69
  70 void yf::QueryRewrite::Rep::process(yp2::Package &package) const
  71 {
  72     Z_GDU *gdu = package.request().get();
  73
  74     if (gdu && gdu->which == Z_GDU_Z3950)
  75     {
  76         Z_APDU *apdu_req = gdu->u.z3950;
  77         if (apdu_req->which == Z_APDU_searchRequest)
  78         {
  79             int error_code = 0;
  80             const char *addinfo = 0;
  81             yp2::odr odr;
  82             Z_SearchRequest *req = apdu_req->u.searchRequest;
  83
  84             xmlDocPtr doc_input = 0;
  85             yaz_query2xml(req->query, &doc_input);
  86
  87             if (!doc_input)
  88             {
  89                 error_code = YAZ_BIB1_MALFORMED_QUERY;
  90                 addinfo = "converion from Query to XML failed";
  91             }
  92             else
  93             {
  94                 if (m_stylesheet)
  95                 {
  96                     xmlDocPtr doc_res = xsltApplyStylesheet(m_stylesheet,
  97                                                             doc_input, 0);
  98                     if (!doc_res)
  99                     {
 100                         error_code = YAZ_BIB1_MALFORMED_QUERY;
 101                         addinfo = "XSLT transform failed for query";
 102                     }
 103                     else
 104                     {
 105                         const xmlNode *root_element = xmlDocGetRootElement(doc_res);
 106                         yaz_xml2query(root_element, &req->query, odr,
 107                                       &error_code, &addinfo);
 108                         xmlFreeDoc(doc_res);
 109                     }
 110                 }
 111                 xmlFreeDoc(doc_input);
 112             }
 113             package.request() = gdu;
 114             if (error_code)
 115             {
 116                 Z_APDU *f_apdu =
 117                     odr.create_searchResponse(apdu_req, error_code, addinfo);
 118                 package.response() = f_apdu;
 119                 return;
 120             }
 121         }
 122     }
 123     package.move();
 124 }
 125
 126 void yp2::filter::QueryRewrite::Rep::configure(const xmlNode *ptr)
 127 {
 128     for (ptr = ptr->children; ptr; ptr = ptr->next)
 129     {
 130         if (ptr->type != XML_ELEMENT_NODE)
 131             continue;
 132         if (!strcmp((const char *) ptr->name, "xslt"))
 133         {
 134             if (m_stylesheet)
 135             {
 136                 throw yp2::filter::FilterException
 137                     ("Only one xslt element allowed in query_rewrite filter");
 138             }
 139
 140             std::string fname = yp2::xml::get_text(ptr);
 141             m_stylesheet = xsltParseStylesheetFile(BAD_CAST fname.c_str());
 142             if (!m_stylesheet)
 143             {
 144                 throw yp2::filter::FilterException
 145                     ("Failed to read stylesheet "
 146                      + fname
 147                      + " in query_rewrite filter");
 148             }
 149         }
 150         else
 151         {
 152             throw yp2::filter::FilterException
 153                 ("Bad element "
 154                  + std::string((const char *) ptr->name)
 155                  + " in query_rewrite filter");
 156         }
 157     }
 158 }
 159
 160 static yp2::filter::Base* filter_creator()
 161 {
 162     return new yp2::filter::QueryRewrite;
 163 }
 164
 165 extern "C" {
 166     struct yp2_filter_struct yp2_filter_query_rewrite = {
 167         0,
 168         "query-rewrite",
 169         filter_creator
 170     };
 171 }
 172
 173 /*
 174  * Local variables:
 175  * c-basic-offset: 4
 176  * indent-tabs-mode: nil
 177  * c-file-style: "stroustrup"
 178  * End:
 179  * vim: shiftwidth=4 tabstop=8 expandtab
 180  */