filter_sru_to_z3950.cpp

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/* This file is part of Metaproxy.
   Copyright (C) Index Data
 
Metaproxy is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.
 
Metaproxy is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.
 
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/
 
// make std::min actually work on Windows
#define NOMINMAX 1
 
#include "config.hpp"
#include <metaproxy/package.hpp>
#include <metaproxy/util.hpp>
#include "gduutil.hpp"
#include "sru_util.hpp"
#include "filter_sru_to_z3950.hpp"
 
#include <yaz/srw.h>
#include <yaz/pquery.h>
#include <yaz/oid_db.h>
#include <yaz/log.h>
#include <yaz/otherinfo.h>
#include <yaz/facet.h>
 
#include <boost/thread/mutex.hpp>
#include <boost/thread/condition.hpp>
 
#include <iostream>
#include <sstream>
#include <string>
#include <map>
 
namespace mp = metaproxy_1;
namespace mp_util = metaproxy_1::util;
namespace yf = mp::filter;
 
namespace metaproxy_1 {
    namespace filter {
        class SRUtoZ3950::Frontend : boost::noncopyable {
            friend class Impl;
            bool m_in_use;
        public:
            Frontend();
            ~Frontend();
        };
        class SRUtoZ3950::Impl {
        public:
            Impl();
            void configure(const xmlNode *xmlnode);
            void process(metaproxy_1::Package &package);
        private:
            FrontendPtr get_frontend(mp::Package &package);
            void release_frontend(mp::Package &package);
            std::map<std::string, const xmlNode *> m_database_explain;
            std::string default_stylesheet;
 
            typedef std::map<std::string, int> ActiveUrlMap;
 
            boost::mutex m_mutex_session;
            boost::condition m_cond_session_ready;
            std::map<mp::Session, FrontendPtr> m_clients;
            int conf_max_recs;
        private:
            void sru(metaproxy_1::Package &package, Z_GDU *zgdu_req);
            int z3950_build_query(
                mp::odr &odr_en, Z_Query *z_query,
                const Z_SRW_searchRetrieveRequest *req
                ) const;
 
            bool z3950_init_request(
                mp::Package &package,
                mp::odr &odr_en,
                std::string zurl,
                Z_SRW_PDU *sru_pdu_res,
                const Z_SRW_PDU *sru_pdu_req
                ) const;
 
            bool z3950_close_request(mp::Package &package) const;
 
            bool z3950_search_request(
                mp::Package &package,
                mp::Package &z3950_package,
                mp::odr &odr_en,
                Z_SRW_PDU *sru_pdu_res,
                Z_SRW_searchRetrieveRequest const *sr_req,
                std::string zurl,
                std::string db_append
                ) const;
 
            bool z3950_present_request(
                mp::Package &package,
                mp::odr &odr_en,
                Z_SRW_PDU *sru_pdu_res,
                Z_SRW_searchRetrieveRequest const *sr_req
                ) const;
 
            bool z3950_to_srw_diagnostics_ok(
                mp::odr &odr_en,
                Z_SRW_searchRetrieveResponse *srw_res,
                Z_Records *records
                ) const;
 
            int z3950_to_srw_diag(
                mp::odr &odr_en,
                Z_SRW_searchRetrieveResponse *srw_res,
                Z_DefaultDiagFormat *ddf
                ) const;
 
        };
    }
}
 
yf::SRUtoZ3950::SRUtoZ3950() : m_p(new Impl)
{
}
 
yf::SRUtoZ3950::~SRUtoZ3950()
{  // must have a destructor because of boost::scoped_ptr
}
 
void yf::SRUtoZ3950::configure(const xmlNode *xmlnode, bool test_only,
                               const char *path)
{
    m_p->configure(xmlnode);
}
 
void yf::SRUtoZ3950::process(mp::Package &package) const
{
    m_p->process(package);
}
 
yf::SRUtoZ3950::Impl::Impl()
{
    conf_max_recs = 0;
}
 
void yf::SRUtoZ3950::Impl::configure(const xmlNode *confignode)
{
    const xmlNode * dbnode;
 
    for (dbnode = confignode->children; dbnode; dbnode = dbnode->next)
    {
        if (dbnode->type != XML_ELEMENT_NODE)
            continue;
 
        if (!strcmp((const char *) dbnode->name, "database"))
        {
            std::string database;
 
            for (struct _xmlAttr *attr = dbnode->properties;
                 attr; attr = attr->next)
            {
                mp::xml::check_attribute(attr, "", "name");
                database = mp::xml::get_text(attr);
 
                const xmlNode *explainnode;
                for (explainnode = dbnode->children;
                     explainnode; explainnode = explainnode->next)
                {
                    if (explainnode->type == XML_ELEMENT_NODE)
                    {
                        m_database_explain.insert(
                            std::make_pair(database, explainnode));
                        break;
                    }
                }
            }
        }
        else if (!strcmp((const char *) dbnode->name, "stylesheet"))
        {
            default_stylesheet = mp::xml::get_text(dbnode);
        }
        else if (!strcmp((const char *) dbnode->name, "limit"))
        {
            const struct _xmlAttr *attr;
            for (attr = dbnode->properties; attr; attr = attr->next)
            {
                if (!strcmp((const char *) attr->name, "retrieve"))
                    conf_max_recs =
                        mp::xml::get_int(attr->children, 0);
                else
                    throw mp::filter::FilterException(
                        "Bad attribute " + std::string((const char *)
                                                       attr->name));
            }
        }
        else
        {
            throw mp::filter::FilterException
                ("Bad element "
                 + std::string((const char *) dbnode->name)
                 + " in sru_z3950"
                    );
        }
    }
}
 
void yf::SRUtoZ3950::Impl::sru(mp::Package &package, Z_GDU *zgdu_req)
{
    bool ok = true;
 
    mp::odr odr_de(ODR_DECODE);
    Z_SRW_PDU *sru_pdu_req = 0;
 
    mp::odr odr_en(ODR_ENCODE);
 
    // determine database with the HTTP header information only
    mp_util::SRUServerInfo sruinfo = mp_util::get_sru_server_info(package);
    std::map<std::string, const xmlNode *>::iterator idbexp;
    idbexp = m_database_explain.find(sruinfo.database);
 
    // assign explain config XML DOM node if database is known
    const xmlNode *explainnode = 0;
    if (idbexp != m_database_explain.end())
    {
        explainnode = idbexp->second;
    }
 
    // decode SRU request
    Z_SOAP *soap = 0;
    char *charset = 0;
    const char *stylesheet = 0;
    Z_SRW_diagnostic *diagnostic = 0;
    int num_diagnostic = 0;
 
    // filter acts as sink for non-valid SRU requests
    if (! (sru_pdu_req = mp_util::decode_sru_request(package, odr_de, odr_en,
                                                     &diagnostic,
                                                     &num_diagnostic, &soap,
                                                     charset)))
    {
        if (soap)
        {
            Z_SRW_PDU *sru_pdu_res = yaz_srw_get(odr_en,
                                                 Z_SRW_explain_response);
            sru_pdu_res->u.explain_response->diagnostics = diagnostic;
            sru_pdu_res->u.explain_response->num_diagnostics = num_diagnostic;
            mp_util::build_sru_explain(package, odr_en, sru_pdu_res,
                                       sruinfo, explainnode);
            mp_util::build_sru_response(package, odr_en, soap,
                                        sru_pdu_res, charset, stylesheet);
        }
        else
        {
            metaproxy_1::odr odr;
            Z_GDU *zgdu_res =
                odr.create_HTTP_Response(package.session(),
                                         zgdu_req->u.HTTP_Request, 400);
            package.response() = zgdu_res;
        }
        return;
    }
 
    bool enable_package_log = false;
    std::string zurl;
    std::string dbargs;
    Z_SRW_extra_arg *arg;
 
    for ( arg = sru_pdu_req->extra_args; arg; arg = arg->next)
        if (!strcmp(arg->name, "x-target"))
        {
            zurl = std::string(arg->value);
        }
        else if (!strcmp(arg->name, "x-max-sockets"))
        {
            package.origin().set_max_sockets(atoi(arg->value));
        }
        else if (!strcmp(arg->name, "x-session-id"))
        {
            package.origin().set_custom_session(arg->value);
        }
        else if (!strcmp(arg->name, "x-log-enable"))
        {
            if (*arg->value == '1')
            {
                enable_package_log = true;
                package.log_enable();
            }
        }
        else if (!strncmp(arg->name, "x-client-", 9) && arg->value)
        {
            if (dbargs.length())
                dbargs += '&';
            dbargs += mp_util::uri_encode(arg->name + 9);
            dbargs += '=';
            dbargs += mp_util::uri_encode(arg->value);
        }
 
    assert(sru_pdu_req);
 
    Package z3950_package(package.session(), package.origin());
    z3950_package.copy_filter(package);
 
    Z_SRW_PDU *sru_pdu_res = 0;
    if (sru_pdu_req->which == Z_SRW_explain_request)
    {
        Z_SRW_explainRequest *er_req = sru_pdu_req->u.explain_request;
        stylesheet = er_req->stylesheet;
        sru_pdu_res = yaz_srw_get_pdu_e(odr_en, Z_SRW_explain_response,
                                        sru_pdu_req);
        sru_pdu_res->u.explain_response->diagnostics = diagnostic;
        sru_pdu_res->u.explain_response->num_diagnostics = num_diagnostic;
        mp_util::build_sru_explain(package, odr_en, sru_pdu_res,
                                   sruinfo, explainnode, er_req);
    }
    else if (sru_pdu_req->which == Z_SRW_searchRetrieve_request)
    {
        Z_SRW_searchRetrieveRequest *sr_req = sru_pdu_req->u.request;
        stylesheet = sr_req->stylesheet;
        sru_pdu_res = yaz_srw_get_pdu_e(odr_en, Z_SRW_searchRetrieve_response,
                                        sru_pdu_req);
        sru_pdu_res->u.response->diagnostics = diagnostic;
        sru_pdu_res->u.response->num_diagnostics = num_diagnostic;
 
        // checking that we have a query
        ok = mp_util::check_sru_query_exists(package, odr_en,
                                             sru_pdu_res, sr_req);
 
        if (ok && z3950_init_request(package, odr_en,
                                     zurl, sru_pdu_res, sru_pdu_req))
        {
            ok = z3950_search_request(package, z3950_package, odr_en,
                                      sru_pdu_res, sr_req, zurl, dbargs);
 
            if (ok
                && sru_pdu_res->u.response->numberOfRecords
                && *(sru_pdu_res->u.response->numberOfRecords))
 
                ok = z3950_present_request(package, odr_en,
                                           sru_pdu_res,
                                           sr_req);
            z3950_close_request(package);
        }
    }
    else if (sru_pdu_req->which == Z_SRW_scan_request)
    {
        stylesheet = sru_pdu_req->u.scan_request->stylesheet;
        sru_pdu_res = yaz_srw_get_pdu_e(odr_en, Z_SRW_scan_response,
                                        sru_pdu_req);
        sru_pdu_res->u.scan_response->diagnostics = diagnostic;
        sru_pdu_res->u.scan_response->num_diagnostics = num_diagnostic;
 
        // we do not do scan at the moment, therefore issuing a diagnostic
        yaz_add_srw_diagnostic(odr_en, 
                               &sru_pdu_res->u.scan_response->diagnostics,
                               &sru_pdu_res->u.scan_response->num_diagnostics,
                               YAZ_SRW_UNSUPP_OPERATION, "scan");
    }
    else
    {
        sru_pdu_res =
            yaz_srw_get_pdu_e(odr_en, Z_SRW_explain_response, sru_pdu_req);
        sru_pdu_res->u.explain_response->diagnostics = diagnostic;
        sru_pdu_res->u.explain_response->num_diagnostics = num_diagnostic;
        yaz_add_srw_diagnostic(odr_en, &diagnostic, &num_diagnostic,
                               YAZ_SRW_UNSUPP_OPERATION, "unknown");
    }
    if (enable_package_log)
    {
        std::string l;
        package.log_reset(l);
        if (l.length())
        {
            mp::wrbuf w;
 
            wrbuf_puts(w, "<log>\n");
            wrbuf_xmlputs(w, l.c_str());
            wrbuf_puts(w, "</log>");
 
            sru_pdu_res->extraResponseData_len = w.len();
            sru_pdu_res->extraResponseData_buf =
                odr_strdup(odr_en, wrbuf_cstr(w));
        }
    }
    if (!stylesheet && default_stylesheet.length())
        stylesheet = default_stylesheet.c_str();
 
    // build and send SRU response
    mp_util::build_sru_response(package, odr_en, soap,
                                sru_pdu_res, charset, stylesheet);
}
 
 
yf::SRUtoZ3950::Frontend::Frontend() :  m_in_use(true)
{
}
 
yf::SRUtoZ3950::Frontend::~Frontend()
{
}
 
 
yf::SRUtoZ3950::FrontendPtr yf::SRUtoZ3950::Impl::get_frontend(
    mp::Package &package)
{
    boost::mutex::scoped_lock lock(m_mutex_session);
 
    std::map<mp::Session,yf::SRUtoZ3950::FrontendPtr>::iterator it;
 
    while (true)
    {
        it = m_clients.find(package.session());
        if (it == m_clients.end())
            break;
 
        if (!it->second->m_in_use)
        {
            it->second->m_in_use = true;
            return it->second;
        }
        m_cond_session_ready.wait(lock);
    }
    FrontendPtr f(new Frontend);
    m_clients[package.session()] = f;
    f->m_in_use = true;
    return f;
}
 
void yf::SRUtoZ3950::Impl::release_frontend(mp::Package &package)
{
    boost::mutex::scoped_lock lock(m_mutex_session);
    std::map<mp::Session,FrontendPtr>::iterator it;
 
    it = m_clients.find(package.session());
    if (it != m_clients.end())
    {
        if (package.session().is_closed())
        {
            m_clients.erase(it);
        }
        else
        {
            it->second->m_in_use = false;
        }
        m_cond_session_ready.notify_all();
    }
}
 
void yf::SRUtoZ3950::Impl::process(mp::Package &package)
{
    FrontendPtr f = get_frontend(package);
 
    Z_GDU *zgdu_req = package.request().get();
 
    if (zgdu_req && zgdu_req->which == Z_GDU_HTTP_Request)
    {
        sru(package, zgdu_req);
    }
    else
    {
        package.move();
    }
    release_frontend(package);
}
 
bool
yf::SRUtoZ3950::Impl::z3950_init_request(mp::Package &package,
                                         mp::odr &odr_en,
                                         std::string zurl,
                                         Z_SRW_PDU *sru_pdu_res,
                                         const Z_SRW_PDU *sru_pdu_req) const
{
    // prepare Z3950 package
    Package z3950_package(package.session(), package.origin());
    z3950_package.copy_filter(package);
 
    // set initRequest APDU
    Z_APDU *apdu = zget_APDU(odr_en, Z_APDU_initRequest);
    Z_InitRequest *init_req = apdu->u.initRequest;
 
    Z_IdAuthentication *auth = NULL;
    if (sru_pdu_req->username && !sru_pdu_req->password)
    {
        auth = (Z_IdAuthentication *) odr_malloc(odr_en, sizeof(Z_IdAuthentication));
        auth->which = Z_IdAuthentication_open;
        auth->u.open = odr_strdup(odr_en, sru_pdu_req->username);
    }
    else if (sru_pdu_req->username && sru_pdu_req->password)
    {
        auth = (Z_IdAuthentication *) odr_malloc(odr_en, sizeof(Z_IdAuthentication));
        auth->which = Z_IdAuthentication_idPass;
        auth->u.idPass = (Z_IdPass *) odr_malloc(odr_en, sizeof(Z_IdPass));
        auth->u.idPass->groupId = NULL;
        auth->u.idPass->password = odr_strdup(odr_en, sru_pdu_req->password);
        auth->u.idPass->userId = odr_strdup(odr_en, sru_pdu_req->username);
    }
 
    init_req->idAuthentication = auth;
 
    *init_req->preferredMessageSize = 10*1024*1024;
    *init_req->maximumRecordSize = 10*1024*1024;
 
    ODR_MASK_SET(init_req->options, Z_Options_search);
    ODR_MASK_SET(init_req->options, Z_Options_present);
    ODR_MASK_SET(init_req->options, Z_Options_namedResultSets);
    ODR_MASK_SET(init_req->options, Z_Options_scan);
 
    ODR_MASK_SET(init_req->protocolVersion, Z_ProtocolVersion_1);
    ODR_MASK_SET(init_req->protocolVersion, Z_ProtocolVersion_2);
    ODR_MASK_SET(init_req->protocolVersion, Z_ProtocolVersion_3);
 
    if (zurl.length())
    {
        std::string host;
        std::list<std::string> dblist;
        mp_util::split_zurl(zurl, host, dblist);
        mp_util::set_vhost_otherinfo(&init_req->otherInfo, odr_en, host, 1);
    }
 
    Z_GDU *zgdu_req = package.request().get();
    if (zgdu_req->which == Z_GDU_HTTP_Request)
    {
        Z_HTTP_Request *hreq = zgdu_req->u.HTTP_Request;
        const char *peer_name =
            z_HTTP_header_lookup(hreq->headers, "X-Forwarded-For");
        if (peer_name)
        {
            yaz_oi_set_string_oid(&init_req->otherInfo, odr_en,
                                  yaz_oid_userinfo_client_ip, 1, peer_name);
        }
    }
 
    z3950_package.request() = apdu;
 
    // send Z3950 package
    z3950_package.move();
 
    // check successful initResponse
    Z_GDU *z3950_gdu = z3950_package.response().get();
 
    int error = YAZ_SRW_SYSTEM_TEMPORARILY_UNAVAILABLE;
    const char *addinfo = 0;
    if (z3950_gdu && z3950_gdu->which == Z_GDU_Z3950
        && z3950_gdu->u.z3950->which == Z_APDU_initResponse)
    {
        Z_InitResponse *initrs = z3950_gdu->u.z3950->u.initResponse;
        if (*initrs->result)
            return true;
        int no = 0;
        while (1)
        {
            Z_DefaultDiagFormat *df = yaz_decode_init_diag(no, initrs);
 
            if (!df)
                break;
            yaz_add_srw_diagnostic(odr_en,
                                   &(sru_pdu_res->u.response->diagnostics),
                                   &(sru_pdu_res->u.response->num_diagnostics),
                                   yaz_diag_bib1_to_srw(*df->condition),
                                   df->u.v2Addinfo);
            no++;
        }
        if (no)
            return false; // got least one diagnostic from init
 
        // we just have result=false.
        error = YAZ_SRW_AUTHENTICATION_ERROR;
    }
    else
        addinfo = "sru_z3950: expected initResponse";
    yaz_add_srw_diagnostic(odr_en,
                           &(sru_pdu_res->u.response->diagnostics),
                           &(sru_pdu_res->u.response->num_diagnostics),
                           error, addinfo);
    return false;
}
 
bool yf::SRUtoZ3950::Impl::z3950_close_request(mp::Package &package) const
{
    Package z3950_package(package.session(), package.origin());
    z3950_package.copy_filter(package);
    z3950_package.session().close();
 
    z3950_package.move();
 
    if (z3950_package.session().is_closed())
    {
        return true;
    }
    return false;
}
 
bool yf::SRUtoZ3950::Impl::z3950_search_request(mp::Package &package,
                                                mp::Package &z3950_package,
                                                mp::odr &odr_en,
                                                Z_SRW_PDU *sru_pdu_res,
                                                Z_SRW_searchRetrieveRequest
                                                const *sr_req,
                                                std::string zurl,
                                                std::string dbappend) const
{
 
    assert(sru_pdu_res->u.response);
 
    Z_APDU *apdu = zget_APDU(odr_en, Z_APDU_searchRequest);
    Z_SearchRequest *z_searchRequest = apdu->u.searchRequest;
 
    if (!mp_util::set_databases_from_zurl(odr_en, zurl,
                                          &z_searchRequest->num_databaseNames,
                                          &z_searchRequest->databaseNames))
    {
        std::string db;
 
        if (sr_req->database)
            db = sr_req->database;
        else
            db = "Default";
 
        if (dbappend.length())
        {
            db += ",";
            db += dbappend;
        }
        z_searchRequest->num_databaseNames = 1;
        z_searchRequest->databaseNames = (char**)
            odr_malloc(odr_en, sizeof(char *));
        z_searchRequest->databaseNames[0] = odr_strdup(odr_en, db.c_str());
    }
    if (sr_req->facetList)
    {
        Z_OtherInformation **oi = &z_searchRequest->additionalSearchInfo;
        yaz_oi_set_facetlist(oi, odr_en, sr_req->facetList);
    }
    Z_Query *z_query = (Z_Query *) odr_malloc(odr_en, sizeof(Z_Query));
    z_searchRequest->query = z_query;
 
    int sru_diagnostic = z3950_build_query(odr_en, z_query, sr_req);
    if (sru_diagnostic)
    {
        yaz_add_srw_diagnostic(odr_en,
                               &(sru_pdu_res->u.response->diagnostics),
                               &(sru_pdu_res->u.response->num_diagnostics),
                               sru_diagnostic,
                               "query");
        return false;
    }
 
    z3950_package.request() = apdu;
 
    z3950_package.move();
 
    Z_GDU *z3950_gdu = z3950_package.response().get();
 
    if (!z3950_gdu || z3950_gdu->which != Z_GDU_Z3950
        || z3950_gdu->u.z3950->which != Z_APDU_searchResponse
        || !z3950_gdu->u.z3950->u.searchResponse
        || !z3950_gdu->u.z3950->u.searchResponse->searchStatus)
    {
        yaz_add_srw_diagnostic(odr_en,
                               &(sru_pdu_res->u.response->diagnostics),
                               &(sru_pdu_res->u.response->num_diagnostics),
                               YAZ_SRW_SYSTEM_TEMPORARILY_UNAVAILABLE, 0);
        return false;
    }
 
    Z_SearchResponse *sr = z3950_gdu->u.z3950->u.searchResponse;
 
    if (!z3950_to_srw_diagnostics_ok(odr_en, sru_pdu_res->u.response,
                                     sr->records))
    {
        return false;
    }
    Z_FacetList *fl = yaz_oi_get_facetlist(&sr->additionalSearchInfo);
    if (!fl)
        fl =  yaz_oi_get_facetlist(&sr->otherInfo);
    sru_pdu_res->u.response->facetList = fl;
    sru_pdu_res->u.response->numberOfRecords
        = odr_intdup(odr_en, *sr->resultCount);
    return true;
}
 
bool yf::SRUtoZ3950::Impl::z3950_present_request(
    mp::Package &package,
    mp::odr &odr_en,
    Z_SRW_PDU *sru_pdu_res,
    const Z_SRW_searchRetrieveRequest *sr_req)
    const
{
    assert(sru_pdu_res->u.response);
    int start = 1;
    int max_recs = 0;
 
    if (!sr_req)
        return false;
 
    if (sr_req->maximumRecords)
        max_recs = *sr_req->maximumRecords;
    if (sr_req->startRecord)
        start = *sr_req->startRecord;
 
    // no need to work if nobody wants record ..
    if (max_recs == 0)
        return true;
 
    bool send_z3950_present = true;
 
    // recordXPath unsupported.
    if (sr_req->recordXPath)
    {
        send_z3950_present = false;
        yaz_add_srw_diagnostic(odr_en,
                               &(sru_pdu_res->u.response->diagnostics),
                               &(sru_pdu_res->u.response->num_diagnostics),
                               YAZ_SRW_XPATH_RETRIEVAL_UNSUPP, 0);
    }
 
    // resultSetTTL unsupported.
    // resultSetIdleTime in response
    if (sr_req->resultSetTTL)
    {
        send_z3950_present = false;
        yaz_add_srw_diagnostic(odr_en,
                               &(sru_pdu_res->u.response->diagnostics),
                               &(sru_pdu_res->u.response->num_diagnostics),
                               YAZ_SRW_RESULT_SETS_UNSUPP, 0);
    }
 
    // sort unsupported
    if (sr_req->sort_type != Z_SRW_sort_type_none)
    {
        send_z3950_present = false;
        yaz_add_srw_diagnostic(odr_en,
                               &(sru_pdu_res->u.response->diagnostics),
                               &(sru_pdu_res->u.response->num_diagnostics),
                               YAZ_SRW_SORT_UNSUPP, 0);
    }
 
    // start record requested negative, or larger than number of records
    if (start < 0 || start > *sru_pdu_res->u.response->numberOfRecords)
    {
        send_z3950_present = false;
        yaz_add_srw_diagnostic(odr_en,
                               &(sru_pdu_res->u.response->diagnostics),
                               &(sru_pdu_res->u.response->num_diagnostics),
                               YAZ_SRW_FIRST_RECORD_POSITION_OUT_OF_RANGE, 0);
    }
 
    // maximumRecords requested negative
    if (max_recs < 0)
    {
        send_z3950_present = false;
        yaz_add_srw_diagnostic(odr_en,
                               &(sru_pdu_res->u.response->diagnostics),
                               &(sru_pdu_res->u.response->num_diagnostics),
                               YAZ_SRW_UNSUPP_PARAMETER_VALUE,
                               "maximumRecords");
    }
 
    // exit on all these above diagnostics
    if (!send_z3950_present)
        return false;
 
    if (conf_max_recs > 0 && max_recs > conf_max_recs)
        max_recs = conf_max_recs;
 
    if (max_recs > *sru_pdu_res->u.response->numberOfRecords - start)
        max_recs = *sru_pdu_res->u.response->numberOfRecords - start + 1;
 
    Z_SRW_searchRetrieveResponse *sru_res = sru_pdu_res->u.response;
    sru_res->records = (Z_SRW_record *)
        odr_malloc(odr_en, max_recs * sizeof(Z_SRW_record));
    int num = 0;
    while (num < max_recs)
    {
        // now packaging the z3950 present request
        Package z3950_package(package.session(), package.origin());
        z3950_package.copy_filter(package);
        Z_APDU *apdu = zget_APDU(odr_en, Z_APDU_presentRequest);
 
        assert(apdu->u.presentRequest);
 
        *apdu->u.presentRequest->resultSetStartPoint = start + num;
        *apdu->u.presentRequest->numberOfRecordsRequested = max_recs - num;
 
        // set response packing to be same as "request" packing..
        int record_packing = Z_SRW_recordPacking_XML;
        if (sr_req->recordPacking && 's' == *(sr_req->recordPacking))
            record_packing = Z_SRW_recordPacking_string;
 
        // RecordSyntax will always be XML
        apdu->u.presentRequest->preferredRecordSyntax
            = odr_oiddup(odr_en, yaz_oid_recsyn_xml);
 
        // z3950'fy record schema
        if (sr_req->recordSchema)
        {
            apdu->u.presentRequest->recordComposition
                = (Z_RecordComposition *)
                odr_malloc(odr_en, sizeof(Z_RecordComposition));
            apdu->u.presentRequest->recordComposition->which
                = Z_RecordComp_simple;
            apdu->u.presentRequest->recordComposition->u.simple
                = mp_util::build_esn_from_schema(odr_en,
                                                 (const char *)
                                                 sr_req->recordSchema);
        }
 
        // attaching Z3950 package to filter chain
        z3950_package.request() = apdu;
 
        // sending Z30.50 present request
        z3950_package.move();
 
        //check successful Z3950 present response
        Z_GDU *z3950_gdu = z3950_package.response().get();
        if (!z3950_gdu || z3950_gdu->which != Z_GDU_Z3950
            || z3950_gdu->u.z3950->which != Z_APDU_presentResponse
            || !z3950_gdu->u.z3950->u.presentResponse)
 
        {
            yaz_add_srw_diagnostic(odr_en,
                                   &(sru_pdu_res->u.response->diagnostics),
                                   &(sru_pdu_res->u.response->num_diagnostics),
                                   YAZ_SRW_SYSTEM_TEMPORARILY_UNAVAILABLE, 0);
            return false;
        }
        // everything fine, continuing
 
        Z_PresentResponse *pr = z3950_gdu->u.z3950->u.presentResponse;
 
        // checking non surrogate diagnostics in Z3950 present response package
        if (!z3950_to_srw_diagnostics_ok(odr_en, sru_pdu_res->u.response,
                                         pr->records))
            return false;
 
        // if anything but database or surrogate diagnostics, stop
        if (!pr->records || pr->records->which != Z_Records_DBOSD)
            break;
        else
        {
            // inserting all records
            int returned_recs =
                pr->records->u.databaseOrSurDiagnostics->num_records;
            for (int i = 0; i < returned_recs; i++)
            {
                int position = i + *apdu->u.presentRequest->resultSetStartPoint;
                Z_NamePlusRecord *npr
                    = pr->records->u.databaseOrSurDiagnostics->records[i];
 
                sru_res->records[i + num].recordPacking = record_packing;
 
                if (npr->which == Z_NamePlusRecord_surrogateDiagnostic)
                {
                    Z_DiagRec *p = npr->u.surrogateDiagnostic;
                    if (p->which == Z_DiagRec_defaultFormat)
                    {
                        Z_DefaultDiagFormat *df = p->u.defaultFormat;
                        int c = yaz_diag_bib1_to_srw(*df->condition);
 
                        yaz_mk_sru_surrogate(
                            odr_en, sru_res->records + i + num, position,
                            c, df->u.v2Addinfo);
                    }
                    else
                    {
                        yaz_mk_sru_surrogate(
                            odr_en, sru_res->records + i + num, position,
                            YAZ_SRW_RECORD_TEMPORARILY_UNAVAILABLE, 0);
                    }
                }
                else if (npr->which == Z_NamePlusRecord_databaseRecord &&
                    npr->u.databaseRecord->direct_reference
                    && !oid_oidcmp(npr->u.databaseRecord->direct_reference,
                                   yaz_oid_recsyn_xml))
                {
                    // got XML record back
                    Z_External *r = npr->u.databaseRecord;
                    sru_res->records[i + num].recordPosition =
                        odr_intdup(odr_en, position);
                    sru_res->records[i + num].recordSchema = sr_req->recordSchema;
                    sru_res->records[i + num].recordData_buf
                        = odr_strdupn(odr_en,
                                      (const char *)r->u.octet_aligned->buf,
                                      r->u.octet_aligned->len);
                    sru_res->records[i + num].recordData_len
                        = r->u.octet_aligned->len;
                }
                else
                {
                    // not XML or no database record at all
                    yaz_mk_sru_surrogate(
                        odr_en, sru_res->records + i + num, position,
                        YAZ_SRW_RECORD_NOT_AVAILABLE_IN_THIS_SCHEMA, 0);
                }
            }
            num += returned_recs;
        }
    }
    sru_res->num_records = num;
    if (start - 1 + num < *sru_pdu_res->u.response->numberOfRecords)
        sru_res->nextRecordPosition =
            odr_intdup(odr_en, start + num);
    return true;
}
 
int yf::SRUtoZ3950::Impl::z3950_build_query(
    mp::odr &odr_en, Z_Query *z_query,
    const Z_SRW_searchRetrieveRequest *req
    ) const
{
    if (!strcmp(req->queryType, "cql"))
    {
        Z_External *ext = (Z_External *)
            odr_malloc(odr_en, sizeof(*ext));
        ext->direct_reference =
            odr_getoidbystr(odr_en, "1.2.840.10003.16.2");
        ext->indirect_reference = 0;
        ext->descriptor = 0;
        ext->which = Z_External_CQL;
        ext->u.cql = odr_strdup(odr_en, req->query);
 
        z_query->which = Z_Query_type_104;
        z_query->u.type_104 =  ext;
        return 0;
    }
 
    if (!strcmp(req->queryType, "pqf"))
    {
        Z_RPNQuery *RPNquery;
        YAZ_PQF_Parser pqf_parser;
 
        pqf_parser = yaz_pqf_create ();
 
        RPNquery = yaz_pqf_parse (pqf_parser, odr_en, req->query);
        yaz_pqf_destroy(pqf_parser);
 
        if (!RPNquery)
            return YAZ_SRW_QUERY_SYNTAX_ERROR;
 
        z_query->which = Z_Query_type_1;
        z_query->u.type_1 =  RPNquery;
 
        return 0;
    }
 
    if (!strcmp(req->queryType, "ccl"))
    {
        z_query->which = Z_Query_type_2;
        z_query->u.type_2 = odr_create_Odr_oct(odr_en, req->query,
                                               strlen(req->query));
        return 0;
    }
 
    return YAZ_SRW_MANDATORY_PARAMETER_NOT_SUPPLIED;
}
 
bool yf::SRUtoZ3950::Impl::z3950_to_srw_diagnostics_ok(
    mp::odr &odr_en,
    Z_SRW_searchRetrieveResponse
    *sru_res,
    Z_Records *records) const
{
    // checking non surrogate diagnostics in Z3950 present response package
    if (records
        && records->which == Z_Records_NSD
        && records->u.nonSurrogateDiagnostic)
    {
        z3950_to_srw_diag(odr_en, sru_res,
                          records->u.nonSurrogateDiagnostic);
        return false;
    }
    return true;
}
 
int yf::SRUtoZ3950::Impl::z3950_to_srw_diag(
    mp::odr &odr_en,
    Z_SRW_searchRetrieveResponse *sru_res,
    Z_DefaultDiagFormat *ddf) const
{
    int bib1_code = *ddf->condition;
    sru_res->num_diagnostics = 1;
    sru_res->diagnostics = (Z_SRW_diagnostic *)
        odr_malloc(odr_en, sizeof(*sru_res->diagnostics));
    yaz_mk_std_diagnostic(odr_en, sru_res->diagnostics,
                          yaz_diag_bib1_to_srw(bib1_code),
                          ddf->u.v2Addinfo);
    return 0;
}
 
static mp::filter::Base* filter_creator()
{
    return new mp::filter::SRUtoZ3950;
}
 
extern "C" {
    struct metaproxy_1_filter_struct metaproxy_1_filter_sru_z3950 = {
        0,
        "sru_z3950",
        filter_creator
    };
}
 
 
/*
 * Local variables:
 * c-basic-offset: 4
 * c-file-style: "Stroustrup"
 * indent-tabs-mode: nil
 * End:
 * vim: shiftwidth=4 tabstop=8 expandtab
 */