X-Git-Url: http://git.indexdata.com/?a=blobdiff_plain;f=src%2Ffilter_session_shared.cpp;h=cd6a237de2aa1dbb6f9ff24ccd339331a3ee046a;hb=575099e940a170b75b8d2caad5e2cafe39ed89bb;hp=f25ab3c0ffec04f22eb6e57b681b661b4897d3d5;hpb=f7cf9c4139ed621ba8027a384df7cd58dbee4a50;p=metaproxy-moved-to-github.git

diff --git a/src/filter_session_shared.cpp b/src/filter_session_shared.cpp
index f25ab3c..cd6a237 100644
--- a/src/filter_session_shared.cpp
+++ b/src/filter_session_shared.cpp
@@ -1,8 +1,20 @@
-/* $Id: filter_session_shared.cpp,v 1.9 2006-05-16 11:53:54 adam Exp $
-   Copyright (c) 2005-2006, Index Data.
+/* This file is part of Metaproxy.
+   Copyright (C) 2005-2009 Index Data
 
-%LICENSE%
- */
+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"
 
@@ -11,7 +23,10 @@
 
 #include <boost/thread/mutex.hpp>
 #include <boost/thread/condition.hpp>
+#include <boost/thread/thread.hpp>
+#include <boost/thread/xtime.hpp>
 #include <boost/shared_ptr.hpp>
+#include <boost/format.hpp>
 
 #include "util.hpp"
 #include "filter_session_shared.hpp"
@@ -20,86 +35,202 @@
 #include <yaz/zgdu.h>
 #include <yaz/otherinfo.h>
 #include <yaz/diagbib1.h>
-
+#include <yazpp/z-query.h>
+#include <yazpp/record-cache.h>
 #include <map>
 #include <iostream>
+#include <time.h>
 
 namespace mp = metaproxy_1;
-namespace yf = mp::filter;
+namespace yf = metaproxy_1::filter;
 
 namespace metaproxy_1 {
 
     namespace filter {
-        int memcmp2(const void *buf1, int len1, const void *buf2, int len2);
-
+        // key for session.. We'll only share sessions with same InitKey
         class SessionShared::InitKey {
         public:
             bool operator < (const SessionShared::InitKey &k) const;
             InitKey(Z_InitRequest *req);
+            InitKey(const InitKey &);
+            ~InitKey();
         private:
             char *m_idAuthentication_buf;
             int m_idAuthentication_size;
             char *m_otherInfo_buf;
             int m_otherInfo_size;
-            mp::odr m_odr;
-
-            std::list<std::string> m_targets;
+            ODR m_odr;
         };
-        class SessionShared::BackendClass {
+        // worker thread .. for expiry of sessions
+        class SessionShared::Worker {
+        public:
+            Worker(SessionShared::Rep *rep);
+            void operator() (void);
+        private:
+            SessionShared::Rep *m_p;
+        };
+        // backend result set
+        class SessionShared::BackendSet {
+        public:
+            std::string m_result_set_id;
+            Databases m_databases;
+            int m_result_set_size;
+            yazpp_1::Yaz_Z_Query m_query;
+            time_t m_time_last_use;
+            void timestamp();
+            yazpp_1::RecordCache m_record_cache;
+            BackendSet(
+                const std::string &result_set_id,
+                const Databases &databases,
+                const yazpp_1::Yaz_Z_Query &query);
+            bool search(
+                Package &frontend_package,
+                const Z_APDU *apdu_req,
+                const BackendInstancePtr bp,
+                Z_Records **z_records);
+        };
+        // backend connection instance
+        class SessionShared::BackendInstance {
+            friend class Rep;
+            friend class BackendClass;
+            friend class BackendSet;
+        public:
+            mp::Session m_session;
+            BackendSetList m_sets;
+            bool m_in_use;
+            int m_sequence_this;
+            int m_result_set_sequence;
+            time_t m_time_last_use;
+            mp::Package * m_close_package;
+            ~BackendInstance();
+        };
+        // backends of some class (all with same InitKey)
+        class SessionShared::BackendClass : boost::noncopyable {
+            friend class Rep;
+            friend struct Frontend;
+            bool m_named_result_sets;
+            BackendInstanceList m_backend_list;
+            BackendInstancePtr create_backend(const Package &package);
+            void remove_backend(BackendInstancePtr b);
+            BackendInstancePtr get_backend(const Package &package);
+            void use_backend(BackendInstancePtr b);
+            void release_backend(BackendInstancePtr b);
+            void expire_class();
+            yazpp_1::GDU m_init_request;
             yazpp_1::GDU m_init_response;
+            boost::mutex m_mutex_backend_class;
+            int m_sequence_top;
+            time_t m_backend_set_ttl;
+            time_t m_backend_expiry_ttl;
+            size_t m_backend_set_max;
+        public:
+            BackendClass(const yazpp_1::GDU &init_request,
+                         int resultset_ttl,
+                         int resultset_max,
+                         int session_ttl);
+            ~BackendClass();
+        };
+        // frontend result set
+        class SessionShared::FrontendSet {
+            Databases m_databases;
+            yazpp_1::Yaz_Z_Query m_query;
+        public:
+            const Databases &get_databases();
+            const yazpp_1::Yaz_Z_Query &get_query();
+            FrontendSet(
+                const Databases &databases,
+                const yazpp_1::Yaz_Z_Query &query);
+            FrontendSet();
         };
+        // frontend session
         struct SessionShared::Frontend {
-            void init(Package &package, Z_GDU *gdu);
             Frontend(Rep *rep);
             ~Frontend();
-            mp::Session m_session;
             bool m_is_virtual;
             bool m_in_use;
+            Z_Options m_init_options;
+            void search(Package &package, Z_APDU *apdu);
+            void present(Package &package, Z_APDU *apdu);
+            void scan(Package &package, Z_APDU *apdu);
+
+            void get_set(mp::Package &package,
+                         const Z_APDU *apdu_req,
+                         const Databases &databases,
+                         yazpp_1::Yaz_Z_Query &query,
+                         BackendInstancePtr &found_backend,
+                         BackendSetPtr &found_set);
+            void override_set(BackendInstancePtr &found_backend,
+                              std::string &result_set_id);
 
-            void close(Package &package);
             Rep *m_p;
+            BackendClassPtr m_backend_class;
+            FrontendSets m_frontend_sets;
         };            
+        // representation
         class SessionShared::Rep {
             friend class SessionShared;
             friend struct Frontend;
             
             FrontendPtr get_frontend(Package &package);
             void release_frontend(Package &package);
+            Rep();
+        public:
+            void expire();
         private:
+            void init(Package &package, const Z_GDU *gdu,
+                      FrontendPtr frontend);
             boost::mutex m_mutex;
             boost::condition m_cond_session_ready;
             std::map<mp::Session, FrontendPtr> m_clients;
 
-            typedef std::map<InitKey,BackendClass> BackendClassMap;
             BackendClassMap m_backend_map;
+            boost::mutex m_mutex_backend_map;
+            boost::thread_group m_thrds;
+            int m_resultset_ttl;
+            int m_resultset_max;
+            int m_session_ttl;
         };
     }
 }
 
-int yf::memcmp2(const void *buf1, int len1,
-                const void *buf2, int len2)
+yf::SessionShared::FrontendSet::FrontendSet(
+    const Databases &databases,
+    const yazpp_1::Yaz_Z_Query &query)
+    : m_databases(databases), m_query(query)
+{
+}
+
+const yf::SessionShared::Databases & 
+yf::SessionShared::FrontendSet::get_databases()
+{
+    return m_databases;
+}
+
+const yazpp_1::Yaz_Z_Query& yf::SessionShared::FrontendSet::get_query()
 {
-    int d = len1 - len2;
+    return m_query;
+}
 
-    // compare buffer (common length)
-    int c = memcmp(buf1, buf2, d > 0 ? len2 : len1);
-    if (c > 0)
-        return 1;
-    else if (c < 0)
-        return -1;
+yf::SessionShared::InitKey::InitKey(const InitKey &k)
+{
+    m_odr = odr_createmem(ODR_ENCODE);
     
-    // compare (remaining bytes)
-    if (d > 0)
-        return 1;
-    else if (d < 0)
-        return -1;
-    return 0;
+    m_idAuthentication_size =  k.m_idAuthentication_size;
+    m_idAuthentication_buf = (char*)odr_malloc(m_odr, m_idAuthentication_size);
+    memcpy(m_idAuthentication_buf, k.m_idAuthentication_buf,
+           m_idAuthentication_size);
+
+    m_otherInfo_size =  k.m_otherInfo_size;
+    m_otherInfo_buf = (char*)odr_malloc(m_odr, m_otherInfo_size);
+    memcpy(m_otherInfo_buf, k.m_otherInfo_buf,
+           m_otherInfo_size);
 }
 
 yf::SessionShared::InitKey::InitKey(Z_InitRequest *req)
 {
+    m_odr = odr_createmem(ODR_ENCODE);
+
     Z_IdAuthentication *t = req->idAuthentication;
-    
     z_IdAuthentication(m_odr, &t, 1, 0);
     m_idAuthentication_buf =
         odr_getbuf(m_odr, &m_idAuthentication_size, 0);
@@ -109,19 +240,25 @@ yf::SessionShared::InitKey::InitKey(Z_InitRequest *req)
     m_otherInfo_buf = odr_getbuf(m_odr, &m_otherInfo_size, 0);
 }
 
+yf::SessionShared::InitKey::~InitKey()
+{
+    odr_destroy(m_odr);
+}
+
 bool yf::SessionShared::InitKey::operator < (const SessionShared::InitKey &k)
     const 
 {
     int c;
-    c = memcmp2((void*) m_idAuthentication_buf, m_idAuthentication_size,
-                (void*) k.m_idAuthentication_buf, k.m_idAuthentication_size);
+    c = mp::util::memcmp2(
+        (void*) m_idAuthentication_buf, m_idAuthentication_size,
+        (void*) k.m_idAuthentication_buf, k.m_idAuthentication_size);
     if (c < 0)
         return true;
     else if (c > 0)
         return false;
 
-    c = memcmp2((void*) m_otherInfo_buf, m_otherInfo_size,
-                (void*) k.m_otherInfo_buf, k.m_otherInfo_size);
+    c = mp::util::memcmp2((void*) m_otherInfo_buf, m_otherInfo_size,
+                          (void*) k.m_otherInfo_buf, k.m_otherInfo_size);
     if (c < 0)
         return true;
     else if (c > 0)
@@ -129,50 +266,764 @@ bool yf::SessionShared::InitKey::operator < (const SessionShared::InitKey &k)
     return false;
 }
 
-void yf::SessionShared::Frontend::init(mp::Package &package, Z_GDU *gdu)
+void yf::SessionShared::BackendClass::release_backend(BackendInstancePtr b)
+{
+    boost::mutex::scoped_lock lock(m_mutex_backend_class);
+    b->m_in_use = false;
+}
+
+
+void yf::SessionShared::BackendClass::remove_backend(BackendInstancePtr b)
+{
+    BackendInstanceList::iterator it = m_backend_list.begin();
+    
+    while (it != m_backend_list.end())
+    {
+        if (*it == b)
+        {
+             mp::odr odr;
+            (*it)->m_close_package->response() = odr.create_close(
+                0, Z_Close_lackOfActivity, 0);
+            (*it)->m_close_package->session().close();
+            (*it)->m_close_package->move();
+            
+            it = m_backend_list.erase(it);
+        }
+        else
+            it++;
+    }
+}
+
+
+
+yf::SessionShared::BackendInstancePtr 
+yf::SessionShared::BackendClass::get_backend(
+    const mp::Package &frontend_package)
+{
+    {
+        boost::mutex::scoped_lock lock(m_mutex_backend_class);
+        
+        BackendInstanceList::const_iterator it = m_backend_list.begin();
+        
+        BackendInstancePtr backend1; // null
+        
+        for (; it != m_backend_list.end(); it++)
+        {
+            if (!(*it)->m_in_use)
+            {
+                if (!backend1 
+                    || (*it)->m_sequence_this < backend1->m_sequence_this)
+                    backend1 = *it;
+            }
+        }
+        if (backend1)
+        {
+            use_backend(backend1);
+            return backend1;
+        }
+    }
+    return create_backend(frontend_package);
+}
+
+void yf::SessionShared::BackendClass::use_backend(BackendInstancePtr backend)
+{
+    backend->m_in_use = true;
+    time(&backend->m_time_last_use);
+    backend->m_sequence_this = m_sequence_top++;
+}
+
+yf::SessionShared::BackendInstance::~BackendInstance()
+{
+    delete m_close_package;
+}
+
+yf::SessionShared::BackendInstancePtr yf::SessionShared::BackendClass::create_backend(
+    const mp::Package &frontend_package)
+{
+    BackendInstancePtr bp(new BackendInstance);
+    BackendInstancePtr null;
+
+    bp->m_close_package =
+        new mp::Package(bp->m_session, frontend_package.origin());
+    bp->m_close_package->copy_filter(frontend_package);
+
+    Package init_package(bp->m_session, frontend_package.origin());
+
+    init_package.copy_filter(frontend_package);
+
+    yazpp_1::GDU actual_init_request = m_init_request;
+    Z_GDU *init_pdu = actual_init_request.get();
+
+    assert(init_pdu->which == Z_GDU_Z3950);
+    assert(init_pdu->u.z3950->which == Z_APDU_initRequest);
+
+    Z_InitRequest *req = init_pdu->u.z3950->u.initRequest;
+    ODR_MASK_ZERO(req->options);
+
+    ODR_MASK_SET(req->options, Z_Options_search);
+    ODR_MASK_SET(req->options, Z_Options_present);
+    ODR_MASK_SET(req->options, Z_Options_namedResultSets);
+    ODR_MASK_SET(req->options, Z_Options_scan);
+
+    ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_1);
+    ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_2);
+    ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_3);
+
+    init_package.request() = init_pdu;
+
+    init_package.move();
+
+    boost::mutex::scoped_lock lock(m_mutex_backend_class);
+
+    m_named_result_sets = false;
+    Z_GDU *gdu = init_package.response().get();
+    if (!init_package.session().is_closed()
+        && gdu && gdu->which == Z_GDU_Z3950 
+        && gdu->u.z3950->which == Z_APDU_initResponse)
+    {
+        Z_InitResponse *res = gdu->u.z3950->u.initResponse;
+        if (!*res->result)
+            return null;
+        m_init_response = gdu->u.z3950;
+        if (ODR_MASK_GET(res->options, Z_Options_namedResultSets))
+        {
+            m_named_result_sets = true;
+        }
+    }
+    else
+    {
+        // did not receive an init response or closed
+        return null;
+    }
+    bp->m_in_use = true;
+    time(&bp->m_time_last_use);
+    bp->m_sequence_this = 0;
+    bp->m_result_set_sequence = 0;
+    m_backend_list.push_back(bp);
+
+    return bp;
+}
+
+
+yf::SessionShared::BackendClass::BackendClass(const yazpp_1::GDU &init_request,
+                                              int resultset_ttl,
+                                              int resultset_max,
+                                              int session_ttl)
+    : m_named_result_sets(false), m_init_request(init_request),
+      m_sequence_top(0), m_backend_set_ttl(resultset_ttl),
+      m_backend_expiry_ttl(session_ttl), m_backend_set_max(resultset_max)
+{}
+
+yf::SessionShared::BackendClass::~BackendClass()
+{}
+
+void yf::SessionShared::Rep::init(mp::Package &package, const Z_GDU *gdu,
+                                  FrontendPtr frontend)
 {
     Z_InitRequest *req = gdu->u.z3950->u.initRequest;
 
-    std::list<std::string> targets;
+    frontend->m_is_virtual = true;
+    frontend->m_init_options = *req->options;
+    InitKey k(req);
+    {
+        boost::mutex::scoped_lock lock(m_mutex_backend_map);
+        BackendClassMap::const_iterator it;
+        it = m_backend_map.find(k);
+        if (it == m_backend_map.end())
+        {
+            BackendClassPtr b(new BackendClass(gdu->u.z3950,
+                                               m_resultset_ttl,
+                                               m_resultset_max,
+                                               m_session_ttl));
+            m_backend_map[k] = b;
+            frontend->m_backend_class = b;
+        }
+        else
+        {
+            frontend->m_backend_class = it->second;            
+        }
+    }
+    BackendClassPtr bc = frontend->m_backend_class;
+    BackendInstancePtr backend = bc->get_backend(package);
+    
+    mp::odr odr;
+    if (!backend)
+    {
+        Z_APDU *apdu = odr.create_initResponse(gdu->u.z3950, 0, 0);
+        *apdu->u.initResponse->result = 0;
+        package.response() = apdu;
+        package.session().close();
+    }
+    else
+    {
+        boost::mutex::scoped_lock lock(bc->m_mutex_backend_class);
+        yazpp_1::GDU init_response = bc->m_init_response;
+        Z_GDU *response_gdu = init_response.get();
+        mp::util::transfer_referenceId(odr, gdu->u.z3950,
+                                       response_gdu->u.z3950);
+
+        Z_Options *server_options =
+            response_gdu->u.z3950->u.initResponse->options;
+        Z_Options *client_options = &frontend->m_init_options;
+
+        int i;
+        for (i = 0; i<30; i++)
+            if (!ODR_MASK_GET(client_options, i))
+                ODR_MASK_CLEAR(server_options, i);
+        package.response() = init_response;
+    }
+    if (backend)
+        bc->release_backend(backend);
+}
+
+void yf::SessionShared::BackendSet::timestamp()
+{
+    time(&m_time_last_use);
+}
+
+yf::SessionShared::BackendSet::BackendSet(
+    const std::string &result_set_id,
+    const Databases &databases,
+    const yazpp_1::Yaz_Z_Query &query) :
+    m_result_set_id(result_set_id),
+    m_databases(databases), m_result_set_size(0), m_query(query) 
+{
+    timestamp();
+}
+
+static int get_diagnostic(Z_DefaultDiagFormat *r)
+{
+    return *r->condition;
+}
+
+bool yf::SessionShared::BackendSet::search(
+    mp::Package &frontend_package,
+    const Z_APDU *frontend_apdu,
+    const BackendInstancePtr bp,
+    Z_Records **z_records)
+{
+    Package search_package(bp->m_session, frontend_package.origin());
+
+    search_package.copy_filter(frontend_package);
+
+    mp::odr odr;
+    Z_APDU *apdu_req = zget_APDU(odr, Z_APDU_searchRequest);
+    Z_SearchRequest *req = apdu_req->u.searchRequest;
 
-    mp::util::get_vhost_otherinfo(&req->otherInfo, false, targets);
+    req->resultSetName = odr_strdup(odr, m_result_set_id.c_str());
+    req->query = m_query.get_Z_Query();
 
-    if (targets.size() < 1)
+    req->num_databaseNames = m_databases.size();
+    req->databaseNames = (char**) 
+        odr_malloc(odr, req->num_databaseNames * sizeof(char *));
+    Databases::const_iterator it = m_databases.begin();
+    size_t i = 0;
+    for (; it != m_databases.end(); it++)
+        req->databaseNames[i++] = odr_strdup(odr, it->c_str());
+
+    search_package.request() = apdu_req;
+
+    search_package.move();
+
+    Z_GDU *gdu = search_package.response().get();
+    if (!search_package.session().is_closed()
+        && gdu && gdu->which == Z_GDU_Z3950 
+        && gdu->u.z3950->which == Z_APDU_searchResponse)
     {
-        package.move();
+        Z_SearchResponse *b_resp = gdu->u.z3950->u.searchResponse;
+        *z_records = b_resp->records;
+        m_result_set_size = *b_resp->resultCount;
+        return true;
+    }
+    Z_APDU *f_apdu = 0;
+    if (frontend_apdu->which == Z_APDU_searchRequest)
+        f_apdu = odr.create_searchResponse(
+            frontend_apdu, YAZ_BIB1_TEMPORARY_SYSTEM_ERROR, 0);
+    else if (frontend_apdu->which == Z_APDU_presentRequest)
+        f_apdu = odr.create_presentResponse(
+            frontend_apdu, YAZ_BIB1_TEMPORARY_SYSTEM_ERROR, 0);
+    else
+        f_apdu = odr.create_close(
+            frontend_apdu, YAZ_BIB1_TEMPORARY_SYSTEM_ERROR, 0);
+    frontend_package.response() = f_apdu;
+    return false;
+}
+
+void yf::SessionShared::Frontend::override_set(
+    BackendInstancePtr &found_backend,
+    std::string &result_set_id)
+{
+    BackendClassPtr bc = m_backend_class;
+    BackendInstanceList::const_iterator it = bc->m_backend_list.begin();
+    time_t now;
+    time(&now);
+    
+    for (; it != bc->m_backend_list.end(); it++)
+    {
+        if (!(*it)->m_in_use)
+        {
+            BackendSetList::iterator set_it = (*it)->m_sets.begin();
+            for (; set_it != (*it)->m_sets.end(); set_it++)
+            {
+                if (now >= (*set_it)->m_time_last_use &&
+                    now - (*set_it)->m_time_last_use > bc->m_backend_set_ttl)
+                {
+                    found_backend = *it;
+                    result_set_id = (*set_it)->m_result_set_id;
+                    found_backend->m_sets.erase(set_it);
+                    return;
+                }
+            }
+        }
+    }
+    size_t max_sets = bc->m_named_result_sets ? bc->m_backend_set_max : 1;
+    for (it = bc->m_backend_list.begin(); it != bc->m_backend_list.end(); it++)
+    {
+        if (!(*it)->m_in_use && (*it)->m_sets.size() < max_sets)
+        {
+            found_backend = *it;
+            if (bc->m_named_result_sets)
+            {
+                result_set_id = boost::io::str(
+                    boost::format("%1%") % 
+                    found_backend->m_result_set_sequence);
+                found_backend->m_result_set_sequence++;
+            }
+            else
+                result_set_id = "default";
+            return;
+        }
+    }
+}
+
+void yf::SessionShared::Frontend::get_set(mp::Package &package,
+                                          const Z_APDU *apdu_req,
+                                          const Databases &databases,
+                                          yazpp_1::Yaz_Z_Query &query,
+                                          BackendInstancePtr &found_backend,
+                                          BackendSetPtr &found_set)
+{
+    bool session_restarted = false;
+
+restart:
+    std::string result_set_id;
+    BackendClassPtr bc = m_backend_class;
+    {
+        boost::mutex::scoped_lock lock(bc->m_mutex_backend_class);
+     
+        // look at each backend and see if we have a similar search
+        BackendInstanceList::const_iterator it = bc->m_backend_list.begin();
+        
+        for (; it != bc->m_backend_list.end(); it++)
+        {
+            if (!(*it)->m_in_use)
+            {
+                BackendSetList::const_iterator set_it = (*it)->m_sets.begin();
+                for (; set_it != (*it)->m_sets.end(); set_it++)
+                {
+                    if ((*set_it)->m_databases == databases 
+                        && query.match(&(*set_it)->m_query))
+                    {
+                        found_set = *set_it;
+                        found_backend = *it;
+                        bc->use_backend(found_backend);
+                        found_set->timestamp();
+                        // found matching set. No need to search again
+                        return;
+                    }
+                }
+            }
+        }
+        override_set(found_backend, result_set_id);
+        if (found_backend)
+            bc->use_backend(found_backend);
+    }
+    if (!found_backend)
+    {
+        // create a new backend set (and new set)
+        found_backend = bc->create_backend(package);
+
+        if (!found_backend)
+        {
+            Z_APDU *f_apdu = 0;
+            mp::odr odr;
+            if (apdu_req->which == Z_APDU_searchRequest)
+            {
+                f_apdu = odr.create_searchResponse(
+                        apdu_req, YAZ_BIB1_TEMPORARY_SYSTEM_ERROR, 0);
+            }
+            else if (apdu_req->which == Z_APDU_presentRequest)
+            {
+                f_apdu = odr.create_presentResponse(
+                    apdu_req, YAZ_BIB1_TEMPORARY_SYSTEM_ERROR, 0);
+            }
+            else
+            {
+                f_apdu = odr.create_close(
+                    apdu_req, YAZ_BIB1_TEMPORARY_SYSTEM_ERROR, 0);
+            }
+            package.response() = f_apdu;
+            return;
+        }
+        if (bc->m_named_result_sets)
+        {
+            result_set_id = boost::io::str(
+                boost::format("%1%") % found_backend->m_result_set_sequence);
+            found_backend->m_result_set_sequence++;
+        }
+        else
+            result_set_id = "default";
+    }
+    // we must search ...
+    BackendSetPtr new_set(new BackendSet(result_set_id,
+                                         databases, query));
+    Z_Records *z_records = 0;
+    if (!new_set->search(package, apdu_req, found_backend, &z_records))
+    {
+        bc->remove_backend(found_backend);
+        return; // search error 
+    }
+
+    if (z_records)
+    {
+        int condition = 0;
+        if (z_records->which == Z_Records_NSD)
+        {
+            condition =
+                get_diagnostic(z_records->u.nonSurrogateDiagnostic);
+        }
+        else if (z_records->which == Z_Records_multipleNSD)
+        {
+            if (z_records->u.multipleNonSurDiagnostics->num_diagRecs >= 1
+                && 
+                
+                z_records->u.multipleNonSurDiagnostics->diagRecs[0]->which ==
+                Z_DiagRec_defaultFormat)
+            {
+                condition = get_diagnostic(
+                    z_records->u.multipleNonSurDiagnostics->diagRecs[0]->u.defaultFormat);
+                
+            }
+        }
+        if (!session_restarted &&
+            condition == YAZ_BIB1_TEMPORARY_SYSTEM_ERROR)
+        {
+            bc->remove_backend(found_backend);
+            session_restarted = true;
+            found_backend.reset();
+            goto restart;
+
+        }
+
+        if (condition)
+        {
+            mp::odr odr;
+            if (apdu_req->which == Z_APDU_searchRequest)
+            {
+                Z_APDU *f_apdu = odr.create_searchResponse(apdu_req, 
+                                                           0, 0);
+                Z_SearchResponse *f_resp = f_apdu->u.searchResponse;
+                *f_resp->searchStatus = Z_SearchResponse_none;
+                f_resp->records = z_records;
+                package.response() = f_apdu;
+            }
+            if (apdu_req->which == Z_APDU_presentRequest)
+            {
+                Z_APDU *f_apdu = odr.create_presentResponse(apdu_req, 
+                                                            0, 0);
+                Z_PresentResponse *f_resp = f_apdu->u.presentResponse;
+                f_resp->records = z_records;
+                package.response() = f_apdu;
+            }
+            bc->release_backend(found_backend);
+            return; // search error 
+        }
+    }
+    if (!session_restarted && new_set->m_result_set_size < 0)
+    {
+        bc->remove_backend(found_backend);
+        session_restarted = true;
+        found_backend.reset();
+        goto restart;
+    }
+
+    found_set = new_set;
+    found_set->timestamp();
+    found_backend->m_sets.push_back(found_set);
+}
+
+void yf::SessionShared::Frontend::search(mp::Package &package,
+                                         Z_APDU *apdu_req)
+{
+    Z_SearchRequest *req = apdu_req->u.searchRequest;
+    FrontendSets::iterator fset_it = 
+        m_frontend_sets.find(req->resultSetName);
+    if (fset_it != m_frontend_sets.end())
+    {
+        // result set already exist 
+        // if replace indicator is off: we return diagnostic if
+        // result set already exist.
+        if (*req->replaceIndicator == 0)
+        {
+            mp::odr odr;
+            Z_APDU *apdu = 
+                odr.create_searchResponse(
+                    apdu_req,
+                    YAZ_BIB1_RESULT_SET_EXISTS_AND_REPLACE_INDICATOR_OFF,
+                    0);
+            package.response() = apdu;
+            
+            return;
+        }
+        m_frontend_sets.erase(fset_it);
+    }
+    
+    yazpp_1::Yaz_Z_Query query;
+    query.set_Z_Query(req->query);
+    Databases databases;
+    int i;
+    for (i = 0; i<req->num_databaseNames; i++)
+        databases.push_back(req->databaseNames[i]);
+
+    BackendSetPtr found_set; // null
+    BackendInstancePtr found_backend; // null
+
+    get_set(package, apdu_req, databases, query, found_backend, found_set);
+    if (!found_set)
+        return;
+
+    mp::odr odr;
+    Z_APDU *f_apdu = odr.create_searchResponse(apdu_req, 0, 0);
+    Z_SearchResponse *f_resp = f_apdu->u.searchResponse;
+    *f_resp->resultCount = found_set->m_result_set_size;
+    package.response() = f_apdu;
+
+    FrontendSetPtr fset(new FrontendSet(databases, query));
+    m_frontend_sets[req->resultSetName] = fset;
+
+    m_backend_class->release_backend(found_backend);
+}
+
+void yf::SessionShared::Frontend::present(mp::Package &package,
+                                          Z_APDU *apdu_req)
+{
+    mp::odr odr;
+    Z_PresentRequest *req = apdu_req->u.presentRequest;
+
+    FrontendSets::iterator fset_it = 
+        m_frontend_sets.find(req->resultSetId);
+
+    if (fset_it == m_frontend_sets.end())
+    {
+        Z_APDU *apdu = 
+            odr.create_presentResponse(
+                apdu_req,
+                YAZ_BIB1_SPECIFIED_RESULT_SET_DOES_NOT_EXIST,
+                req->resultSetId);
+        package.response() = apdu;
+        return;
+    }
+    FrontendSetPtr fset = fset_it->second;
+
+    Databases databases = fset->get_databases();
+    yazpp_1::Yaz_Z_Query query = fset->get_query();
+
+    BackendClassPtr bc = m_backend_class;
+    BackendSetPtr found_set; // null
+    BackendInstancePtr found_backend;
+
+    get_set(package, apdu_req, databases, query, found_backend, found_set);
+    if (!found_set)
+        return;
+
+    Z_NamePlusRecordList *npr_res = 0;
+    if (found_set->m_record_cache.lookup(odr, &npr_res, 
+                                         *req->resultSetStartPoint,
+                                         *req->numberOfRecordsRequested,
+                                         req->preferredRecordSyntax,
+                                         req->recordComposition))
+    {
+        Z_APDU *f_apdu_res = odr.create_presentResponse(apdu_req, 0, 0);
+        Z_PresentResponse *f_resp = f_apdu_res->u.presentResponse;
+
+        yaz_log(YLOG_LOG, "Found %d+%d records in cache %p",
+                *req->resultSetStartPoint,                      
+                *req->numberOfRecordsRequested,
+                &found_set->m_record_cache);        
+
+        *f_resp->numberOfRecordsReturned = *req->numberOfRecordsRequested;
+        *f_resp->nextResultSetPosition = 
+            *req->resultSetStartPoint + *req->numberOfRecordsRequested;
+        // f_resp->presentStatus assumed OK.
+        f_resp->records = (Z_Records *) odr_malloc(odr, sizeof(Z_Records));
+        f_resp->records->which = Z_Records_DBOSD;
+        f_resp->records->u.databaseOrSurDiagnostics = npr_res;
+        package.response() = f_apdu_res;
+        bc->release_backend(found_backend);
         return;
     }
+                              
+    Z_APDU *p_apdu = zget_APDU(odr, Z_APDU_presentRequest);
+    Z_PresentRequest *p_req = p_apdu->u.presentRequest;
+    p_req->preferredRecordSyntax = req->preferredRecordSyntax;
+    p_req->resultSetId = odr_strdup(odr, found_set->m_result_set_id.c_str());
+    *p_req->resultSetStartPoint = *req->resultSetStartPoint;
+    *p_req->numberOfRecordsRequested = *req->numberOfRecordsRequested;
+    p_req->preferredRecordSyntax = req->preferredRecordSyntax;
+    p_req->recordComposition = req->recordComposition;
+
+    Package present_package(found_backend->m_session, package.origin());
+    present_package.copy_filter(package);
+
+    present_package.request() = p_apdu;
+
+    present_package.move();
+
+    Z_GDU *gdu = present_package.response().get();
+    if (!present_package.session().is_closed()
+        && gdu && gdu->which == Z_GDU_Z3950 
+        && gdu->u.z3950->which == Z_APDU_presentResponse)
+    {
+        Z_PresentResponse *b_resp = gdu->u.z3950->u.presentResponse;
+        Z_APDU *f_apdu_res = odr.create_presentResponse(apdu_req, 0, 0);
+        Z_PresentResponse *f_resp = f_apdu_res->u.presentResponse;
+
+        f_resp->numberOfRecordsReturned = b_resp->numberOfRecordsReturned;
+        f_resp->nextResultSetPosition = b_resp->nextResultSetPosition;
+        f_resp->presentStatus= b_resp->presentStatus;
+        f_resp->records = b_resp->records;
+        f_resp->otherInfo = b_resp->otherInfo;
+        package.response() = f_apdu_res;
 
+        if (b_resp->records && b_resp->records->which ==  Z_Records_DBOSD)
+        {
+            yaz_log(YLOG_LOG, "Adding %d+%d records to cache %p",
+                    *req->resultSetStartPoint,                      
+                    *f_resp->numberOfRecordsReturned,
+                    &found_set->m_record_cache);        
+            found_set->m_record_cache.add(
+                odr,
+                b_resp->records->u.databaseOrSurDiagnostics,
+                *req->resultSetStartPoint,                      
+                *f_resp->numberOfRecordsReturned);
+        }
+        bc->release_backend(found_backend);
+    }
+    else
+    {
+        bc->remove_backend(found_backend);
+        Z_APDU *f_apdu_res = 
+            odr.create_presentResponse(
+                apdu_req, YAZ_BIB1_TEMPORARY_SYSTEM_ERROR, 0);
+        package.response() = f_apdu_res;
+    }
 }
 
-yf::SessionShared::SessionShared() : m_p(new SessionShared::Rep)
+void yf::SessionShared::Frontend::scan(mp::Package &frontend_package,
+                                       Z_APDU *apdu_req)
 {
+    BackendClassPtr bc = m_backend_class;
+    BackendInstancePtr backend = bc->get_backend(frontend_package);
+    if (!backend)
+    {
+        mp::odr odr;
+        Z_APDU *apdu = odr.create_scanResponse(
+            apdu_req, YAZ_BIB1_TEMPORARY_SYSTEM_ERROR, 0);
+        frontend_package.response() = apdu;
+    }
+    else
+    {
+        Package scan_package(backend->m_session, frontend_package.origin());
+        scan_package.copy_filter(frontend_package);
+        scan_package.request() = apdu_req;
+        scan_package.move();
+        frontend_package.response() = scan_package.response();
+        if (scan_package.session().is_closed())
+        {
+            frontend_package.session().close();
+            bc->remove_backend(backend);
+        }
+        else
+            bc->release_backend(backend);
+    }
 }
 
-yf::SessionShared::~SessionShared() {
+yf::SessionShared::Worker::Worker(SessionShared::Rep *rep) : m_p(rep)
+{
 }
 
+void yf::SessionShared::Worker::operator() (void)
+{
+    m_p->expire();
+}
 
-yf::SessionShared::Frontend::Frontend(Rep *rep) : m_is_virtual(false), m_p(rep)
+void yf::SessionShared::BackendClass::expire_class()
 {
+    time_t now;
+    time(&now);
+    boost::mutex::scoped_lock lock(m_mutex_backend_class);
+    BackendInstanceList::iterator bit = m_backend_list.begin();
+    while (bit != m_backend_list.end())
+    {
+        time_t last_use = (*bit)->m_time_last_use;
+        
+        if ((*bit)->m_in_use)
+        {
+            bit++;
+        }
+        else if ((now >= last_use && now - last_use > m_backend_expiry_ttl)
+            || (now < last_use))
+        {
+            mp::odr odr;
+            (*bit)->m_close_package->response() = odr.create_close(
+                0, Z_Close_lackOfActivity, 0);
+            (*bit)->m_close_package->session().close();
+            (*bit)->m_close_package->move();
+
+            bit = m_backend_list.erase(bit);
+        }
+        else
+        {
+            bit++;
+        }
+    }
 }
 
-void yf::SessionShared::Frontend::close(mp::Package &package)
+void yf::SessionShared::Rep::expire()
 {
-#if 0
-    std::list<BackendPtr>::const_iterator b_it;
-    
-    for (b_it = m_backend_list.begin(); b_it != m_backend_list.end(); b_it++)
+    while (true)
     {
-        (*b_it)->m_backend_session.close();
-        Package close_package((*b_it)->m_backend_session, package.origin());
-        close_package.copy_filter(package);
-        close_package.move((*b_it)->m_route);
+        boost::xtime xt;
+        boost::xtime_get(&xt, boost::TIME_UTC);
+        xt.sec += 30;
+        boost::thread::sleep(xt);
+        
+        BackendClassMap::const_iterator b_it = m_backend_map.begin();
+        for (; b_it != m_backend_map.end(); b_it++)
+            b_it->second->expire_class();
     }
-    m_backend_list.clear();
-#endif
 }
 
+yf::SessionShared::Rep::Rep()
+{
+    m_resultset_ttl = 30;
+    m_resultset_max = 10;
+    m_session_ttl = 90;
+    yf::SessionShared::Worker w(this);
+    m_thrds.add_thread(new boost::thread(w));
+}
+
+yf::SessionShared::SessionShared() : m_p(new SessionShared::Rep)
+{
+}
+
+yf::SessionShared::~SessionShared() {
+}
+
+
+yf::SessionShared::Frontend::Frontend(Rep *rep) : m_is_virtual(false), m_p(rep)
+{
+}
 
 yf::SessionShared::Frontend::~Frontend()
 {
@@ -213,7 +1064,6 @@ void yf::SessionShared::Rep::release_frontend(mp::Package &package)
     {
         if (package.session().is_closed())
         {
-            it->second->close(package);
             m_clients.erase(it);
         }
         else
@@ -234,7 +1084,7 @@ void yf::SessionShared::process(mp::Package &package) const
     if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
         Z_APDU_initRequest && !f->m_is_virtual)
     {
-        f->init(package, gdu);
+        m_p->init(package, gdu, f);
     }
     else if (!f->m_is_virtual)
         package.move();
@@ -252,6 +1102,27 @@ void yf::SessionShared::process(mp::Package &package) const
             
             package.session().close();
         }
+        else if (apdu->which == Z_APDU_close)
+        {
+            mp::odr odr;
+            
+            package.response() = odr.create_close(
+                apdu,
+                Z_Close_peerAbort, "received close from client");
+            package.session().close();
+        }
+        else if (apdu->which == Z_APDU_searchRequest)
+        {
+            f->search(package, apdu);
+        }
+        else if (apdu->which == Z_APDU_presentRequest)
+        {
+            f->present(package, apdu);
+        }
+        else if (apdu->which == Z_APDU_scanRequest)
+        {
+            f->scan(package, apdu);
+        }
         else
         {
             mp::odr odr;
@@ -266,6 +1137,54 @@ void yf::SessionShared::process(mp::Package &package) const
     m_p->release_frontend(package);
 }
 
+void yf::SessionShared::configure(const xmlNode *ptr, bool test_only)
+{
+    for (ptr = ptr->children; ptr; ptr = ptr->next)
+    {
+        if (ptr->type != XML_ELEMENT_NODE)
+            continue;
+        if (!strcmp((const char *) ptr->name, "resultset"))
+        {
+            const struct _xmlAttr *attr;
+            for (attr = ptr->properties; attr; attr = attr->next)
+            {
+                if (!strcmp((const char *) attr->name, "ttl"))
+                    m_p->m_resultset_ttl = 
+                        mp::xml::get_int(attr->children, 30);
+                else if (!strcmp((const char *) attr->name, "max"))
+                {
+                    m_p->m_resultset_max = 
+                        mp::xml::get_int(attr->children, 10);
+                }
+                else
+                    throw mp::filter::FilterException(
+                        "Bad attribute " + std::string((const char *)
+                                                       attr->name));
+            }
+        }
+        else if (!strcmp((const char *) ptr->name, "session"))
+        {
+            const struct _xmlAttr *attr;
+            for (attr = ptr->properties; attr; attr = attr->next)
+            {
+                if (!strcmp((const char *) attr->name, "ttl"))
+                    m_p->m_session_ttl = 
+                        mp::xml::get_int(attr->children, 120);
+                else
+                    throw mp::filter::FilterException(
+                        "Bad attribute " + std::string((const char *)
+                                                       attr->name));
+            }
+        }
+        else
+        {
+            throw mp::filter::FilterException("Bad element " 
+                                               + std::string((const char *)
+                                                             ptr->name));
+        }
+    }
+}
+
 static mp::filter::Base* filter_creator()
 {
     return new mp::filter::SessionShared;
@@ -282,8 +1201,9 @@ extern "C" {
 /*
  * Local variables:
  * c-basic-offset: 4
+ * c-file-style: "Stroustrup"
  * indent-tabs-mode: nil
- * c-file-style: "stroustrup"
  * End:
  * vim: shiftwidth=4 tabstop=8 expandtab
  */
+