filter_record_transform.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
*/
 
#include "config.hpp"
#include "filter_record_transform.hpp"
#include <metaproxy/package.hpp>
#include <metaproxy/util.hpp>
#include "gduutil.hpp"
 
#include <yaz/diagbib1.h>
#include <yaz/zgdu.h>
#include <yaz/retrieval.h>
#include <yaz/oid_db.h>
 
#include <boost/thread/mutex.hpp>
 
#if HAVE_USEMARCON
#include <usemarconlib.h>
#include <defines.h>
#endif
 
#include <iostream>
 
namespace mp = metaproxy_1;
namespace yf = mp::filter;
namespace mp_util = metaproxy_1::util;
 
namespace metaproxy_1 {
    namespace filter {
        class RecordTransform::Impl {
        public:
            Impl();
            ~Impl();
            void process(metaproxy_1::Package & package) const;
            void configure(const xmlNode * xml_node, const char *path);
        private:
            yaz_retrieval_t m_retrieval;
        };
    }
}
 
#if HAVE_USEMARCON
struct info_usemarcon {
    boost::mutex m_mutex;
 
    char *stage1;
    char *stage2;
 
    Usemarcon *usemarcon1;
    Usemarcon *usemarcon2;
};
 
static int convert_usemarcon(void *info, WRBUF record, WRBUF wr_error)
{
    struct info_usemarcon *p = (struct info_usemarcon *) info;
 
    boost::mutex::scoped_lock lock(p->m_mutex);
 
    if (p->usemarcon1)
    {
        char *converted;
        size_t convlen;
        int res;
 
        p->usemarcon1->SetMarcRecord(wrbuf_buf(record), wrbuf_len(record));
        res = p->usemarcon1->Convert();
        if (res != 0)
        {
            wrbuf_printf(wr_error, "usemarcon stage1 failed res=%d", res);
            return -1;
        }
        p->usemarcon1->GetMarcRecord(converted, convlen);
 
        if (p->usemarcon2)
        {
            p->usemarcon2->SetMarcRecord(converted, convlen);
 
            res = p->usemarcon2->Convert();
            free(converted);
            if (res != 0)
            {
                wrbuf_printf(wr_error, "usemarcon stage2 failed res=%d",
                             res);
                return -1;
            }
            p->usemarcon2->GetMarcRecord(converted, convlen);
        }
        wrbuf_rewind(record);
        wrbuf_write(record, converted, convlen);
        free(converted);
    }
    return 0;
}
 
static void destroy_usemarcon(void *info)
{
    struct info_usemarcon *p = (struct info_usemarcon *) info;
 
    delete p->usemarcon1;
    delete p->usemarcon2;
    xfree(p->stage1);
    xfree(p->stage2);
    delete p;
}
 
static void *construct_usemarcon(const xmlNode *ptr, const char *path,
                                 WRBUF wr_error)
{
    struct _xmlAttr *attr;
    if (strcmp((const char *) ptr->name, "usemarcon"))
        return 0;
 
    struct info_usemarcon *p = new(struct info_usemarcon);
    p->stage1 = 0;
    p->stage2 = 0;
    p->usemarcon1 = 0;
    p->usemarcon2 = 0;
 
    for (attr = ptr->properties; attr; attr = attr->next)
    {
        if (!xmlStrcmp(attr->name, BAD_CAST "stage1") &&
            attr->children && attr->children->type == XML_TEXT_NODE)
            p->stage1 = xstrdup((const char *) attr->children->content);
        else if (!xmlStrcmp(attr->name, BAD_CAST "stage2") &&
            attr->children && attr->children->type == XML_TEXT_NODE)
            p->stage2 = xstrdup((const char *) attr->children->content);
        else
        {
            wrbuf_printf(wr_error, "Bad attribute '%s'"
                         "Expected stage1 or stage2.", attr->name);
            destroy_usemarcon(p);
            return 0;
        }
    }
 
    if (p->stage1)
    {
        p->usemarcon1 = new Usemarcon();
        p->usemarcon1->SetIniFileName(p->stage1);
    }
    if (p->stage2)
    {
        p->usemarcon2 = new Usemarcon();
        p->usemarcon2->SetIniFileName(p->stage2);
    }
    return p;
}
 
static void type_usemarcon(struct yaz_record_conv_type *t)
{
    t->next = 0;
    t->construct = construct_usemarcon;
    t->convert = convert_usemarcon;
    t->destroy = destroy_usemarcon;
}
#endif
 
// define Pimpl wrapper forwarding to Impl
 
yf::RecordTransform::RecordTransform() : m_p(new Impl)
{
}
 
yf::RecordTransform::~RecordTransform()
{  // must have a destructor because of boost::scoped_ptr
}
 
void yf::RecordTransform::configure(const xmlNode *xmlnode, bool test_only,
                                    const char *path)
{
    m_p->configure(xmlnode, path);
}
 
void yf::RecordTransform::process(mp::Package &package) const
{
    m_p->process(package);
}
 
 
yf::RecordTransform::Impl::Impl()
{
    m_retrieval = yaz_retrieval_create();
    assert(m_retrieval);
}
 
yf::RecordTransform::Impl::~Impl()
{
    if (m_retrieval)
        yaz_retrieval_destroy(m_retrieval);
}
 
void yf::RecordTransform::Impl::configure(const xmlNode *xml_node,
                                          const char *path)
{
    yaz_retrieval_set_path(m_retrieval, path);
 
    if (!xml_node)
        throw mp::XMLError("RecordTransform filter config: empty XML DOM");
 
    // parsing down to retrieval node, which can be any of the children nodes
    xmlNode *retrieval_node;
    for (retrieval_node = xml_node->children;
         retrieval_node;
         retrieval_node = retrieval_node->next)
    {
        if (retrieval_node->type != XML_ELEMENT_NODE)
            continue;
        if (0 == strcmp((const char *) retrieval_node->name, "retrievalinfo"))
            break;
    }
 
#if HAVE_USEMARCON
    struct yaz_record_conv_type mt;
    type_usemarcon(&mt);
    struct yaz_record_conv_type *t = &mt;
#else
    struct yaz_record_conv_type *t = 0;
#endif
 
    // read configuration
    if (0 != yaz_retrieval_configure_t(m_retrieval, retrieval_node, t))
    {
        std::string msg("RecordTransform filter config: ");
        msg += yaz_retrieval_get_error(m_retrieval);
        throw mp::XMLError(msg);
    }
}
 
static void convert_npr(yaz_record_conv_t rc,
                        Odr_oid *match_syntax,
                        ODR odr_en,
                        Z_NamePlusRecordList *records, int i)
{
    Z_NamePlusRecord *npr = records->records[i];
    const char *details = 0;
    mp::wrbuf output_record;
    Z_External *r = npr->u.databaseRecord;
    int ret_trans = -1;
    if (npr->which != Z_NamePlusRecord_databaseRecord)
        return;
    r = npr->u.databaseRecord;
    if (r->which == Z_External_OPAC)
    {
        ret_trans = yaz_record_conv_opac_record(rc, r->u.opac,
                                                output_record);
        details = yaz_record_conv_get_error(rc);
    }
    else if (r->which == Z_External_octet)
    {
        ret_trans =
            yaz_record_conv_record(
                rc, (const char *) r->u.octet_aligned->buf,
                r->u.octet_aligned->len, output_record);
        details = yaz_record_conv_get_error(rc);
    }
    else
    {
        details = "unsupported record type for record_conv";
    }
    if (ret_trans)
    {
        records->records[i] =
            zget_surrogateDiagRec(
                odr_en, npr->databaseName,
                YAZ_BIB1_SYSTEM_ERROR_IN_PRESENTING_RECORDS,
                details);
    }
    else
    {
        if (!oid_oidcmp(match_syntax, yaz_oid_recsyn_opac))
        {
            yaz_iconv_t cd = 0;
            yaz_marc_t mt = yaz_marc_create();
            Z_OPACRecord *opac = 0;
            const char *output_charset =
                yaz_record_get_output_charset(rc);
            if (output_charset)
                cd = yaz_iconv_open(output_charset, "utf-8");
            if (yaz_xml_to_opac(mt, output_record.buf(),
                                output_record.len(),
                                &opac, cd,
                                ((ODR )odr_en)->mem, 0)
                && opac)
            {
                npr->u.databaseRecord =
                    z_ext_record_oid(odr_en, match_syntax,
                                     (const char *) opac, -1);
            }
            else
            {
                records->records[i] =
                    zget_surrogateDiagRec(
                        odr_en, npr->databaseName,
                        YAZ_BIB1_SYSTEM_ERROR_IN_PRESENTING_RECORDS,
                        "XML to OPAC conversion failed");
            }
            yaz_marc_destroy(mt);
        }
        else
        {
            npr->u.databaseRecord = z_ext_record_oid(odr_en, match_syntax,
                                                     output_record.buf(),
                                                     output_record.len());
        }
    }
}
 
void yf::RecordTransform::Impl::process(mp::Package &package) const
{
 
    Z_GDU *gdu_req = package.request().get();
    Z_PresentRequest *pr_req = 0;
    Z_SearchRequest *sr_req = 0;
 
    const char *input_schema = 0;
    Odr_oid *input_syntax = 0;
 
    if (gdu_req && gdu_req->which == Z_GDU_Z3950 &&
        gdu_req->u.z3950->which == Z_APDU_presentRequest)
    {
        pr_req = gdu_req->u.z3950->u.presentRequest;
 
        input_schema =
            mp_util::record_composition_to_esn(pr_req->recordComposition);
        input_syntax = pr_req->preferredRecordSyntax;
    }
    else if (gdu_req && gdu_req->which == Z_GDU_Z3950 &&
             gdu_req->u.z3950->which == Z_APDU_searchRequest)
    {
        sr_req = gdu_req->u.z3950->u.searchRequest;
 
        input_syntax = sr_req->preferredRecordSyntax;
 
        // we don't know how many hits we're going to get and therefore
        // the effective element set name.. Therefore we can only allow
        // two cases.. Both equal or absent.. If not, we'll just have to
        // disable the piggyback!
        if (sr_req->smallSetElementSetNames
            &&
            sr_req->mediumSetElementSetNames
            &&
            sr_req->smallSetElementSetNames->which == Z_ElementSetNames_generic
            &&
            sr_req->mediumSetElementSetNames->which == Z_ElementSetNames_generic
            &&
            !strcmp(sr_req->smallSetElementSetNames->u.generic,
                    sr_req->mediumSetElementSetNames->u.generic))
        {
            input_schema = sr_req->smallSetElementSetNames->u.generic;
        }
        else if (*sr_req->largeSetLowerBound > 1
                 && !sr_req->smallSetElementSetNames && !sr_req->mediumSetElementSetNames)
            ; // input_schema is 0 already
        else
        {
            // disable piggyback (perhaps it was disabled already)
            *sr_req->smallSetUpperBound = 0;
            *sr_req->largeSetLowerBound = 1;
            *sr_req->mediumSetPresentNumber = 0;
            package.move();
            return;
        }
        // we can handle it in record_transform.
    }
    else
    {
        package.move();
        return;
    }
 
    mp::odr odr_en(ODR_ENCODE);
 
    // setting up variables for conversion state
    yaz_record_conv_t rc = 0;
 
    const char *match_schema = 0;
    Odr_oid *match_syntax = 0;
 
    const char *backend_schema = 0;
    Odr_oid *backend_syntax = 0;
 
    int ret_code
        = yaz_retrieval_request(m_retrieval,
                                input_schema, input_syntax,
                                &match_schema, &match_syntax,
                                &rc,
                                &backend_schema, &backend_syntax);
    // error handling
    if (ret_code != 0)
    {
        int error_code;
        const char *details = 0;
 
        if (ret_code == -1) /* error ? */
        {
            details = yaz_retrieval_get_error(m_retrieval);
            error_code = YAZ_BIB1_SYSTEM_ERROR_IN_PRESENTING_RECORDS;
        }
        else if (ret_code == 1 || ret_code == 3)
        {
            details = input_schema;
            error_code = YAZ_BIB1_ELEMENT_SET_NAMES_UNSUPP;
        }
        else if (ret_code == 2)
        {
            char oidbuf[OID_STR_MAX];
            oid_oid_to_dotstring(input_syntax, oidbuf);
            details = odr_strdup(odr_en, oidbuf);
            error_code = YAZ_BIB1_RECORD_SYNTAX_UNSUPP;
        }
        else
        {
            char *tmp = (char*) odr_malloc(odr_en, 80);
            sprintf(tmp,
                    "record_transform: yaz_retrieval_get_error returned %d",
                    ret_code);
            details = tmp;
            error_code = YAZ_BIB1_UNSPECIFIED_ERROR;
        }
        Z_APDU *apdu;
        if (sr_req)
        {
            apdu = odr_en.create_searchResponse(
                gdu_req->u.z3950, error_code, details);
        }
        else
        {
            apdu = odr_en.create_presentResponse(
                gdu_req->u.z3950, error_code, details);
        }
        package.response() = apdu;
        return;
    }
 
    if (sr_req)
    {
        if (backend_syntax)
            sr_req->preferredRecordSyntax = odr_oiddup(odr_en, backend_syntax);
        else
            sr_req->preferredRecordSyntax = 0;
 
        if (backend_schema)
        {
            sr_req->smallSetElementSetNames
                = (Z_ElementSetNames *)
                odr_malloc(odr_en, sizeof(Z_ElementSetNames));
            sr_req->smallSetElementSetNames->which = Z_ElementSetNames_generic;
            sr_req->smallSetElementSetNames->u.generic
                = odr_strdup(odr_en, backend_schema);
            sr_req->mediumSetElementSetNames = sr_req->smallSetElementSetNames;
        }
        else
        {
            sr_req->smallSetElementSetNames = 0;
            sr_req->mediumSetElementSetNames = 0;
        }
    }
    else if (pr_req)
    {
        if (backend_syntax)
            pr_req->preferredRecordSyntax = odr_oiddup(odr_en, backend_syntax);
        else
            pr_req->preferredRecordSyntax = 0;
 
        if (backend_schema)
        {
            pr_req->recordComposition
                = (Z_RecordComposition *)
                odr_malloc(odr_en, sizeof(Z_RecordComposition));
            pr_req->recordComposition->which
                = Z_RecordComp_simple;
            pr_req->recordComposition->u.simple
                = (Z_ElementSetNames *)
                odr_malloc(odr_en, sizeof(Z_ElementSetNames));
            pr_req->recordComposition->u.simple->which = Z_ElementSetNames_generic;
            pr_req->recordComposition->u.simple->u.generic
                = odr_strdup(odr_en, backend_schema);
        }
        else
            pr_req->recordComposition = 0;
    }
 
    // attaching Z3950 package to filter chain
    package.request() = gdu_req;
 
    package.move();
 
    Z_GDU *gdu_res = package.response().get();
 
    // see if we have a records list to patch!
    Z_NamePlusRecordList *records = 0;
    if (gdu_res && gdu_res->which == Z_GDU_Z3950 &&
        gdu_res->u.z3950->which == Z_APDU_presentResponse)
    {
        Z_PresentResponse * pr_res = gdu_res->u.z3950->u.presentResponse;
 
        if (rc && pr_res
            && pr_res->numberOfRecordsReturned
            && *(pr_res->numberOfRecordsReturned) > 0
            && pr_res->records
            && pr_res->records->which == Z_Records_DBOSD)
        {
            records = pr_res->records->u.databaseOrSurDiagnostics;
        }
    }
    if (gdu_res && gdu_res->which == Z_GDU_Z3950 &&
        gdu_res->u.z3950->which == Z_APDU_searchResponse)
    {
        Z_SearchResponse *sr_res = gdu_res->u.z3950->u.searchResponse;
 
        if (rc && sr_res
            && sr_res->numberOfRecordsReturned
            && *(sr_res->numberOfRecordsReturned) > 0
            && sr_res->records
            && sr_res->records->which == Z_Records_DBOSD)
        {
            records = sr_res->records->u.databaseOrSurDiagnostics;
        }
    }
 
    if (records)
    {
        int i;
        for (i = 0; i < records->num_records; i++)
            convert_npr(rc, match_syntax, odr_en, records, i);
        package.response() = gdu_res;
    }
    return;
}
 
static mp::filter::Base* filter_creator()
{
    return new mp::filter::RecordTransform;
}
 
extern "C" {
    struct metaproxy_1_filter_struct metaproxy_1_filter_record_transform = {
        0,
        "record_transform",
        filter_creator
    };
}
 
 
/*
 * Local variables:
 * c-basic-offset: 4
 * c-file-style: "Stroustrup"
 * indent-tabs-mode: nil
 * End:
 * vim: shiftwidth=4 tabstop=8 expandtab
 */