Prevent multiplexing for cookie sessions
[yazpp-moved-to-github.git] / src / yaz-proxy.cpp
index a73c95a..96054a3 100644 (file)
 /*
- * Copyright (c) 1998-2001, Index Data.
+ * Copyright (c) 1998-2003, Index Data.
  * See the file LICENSE for details.
  * 
- * $Id: yaz-proxy.cpp,v 1.28 2001-11-04 22:36:21 adam Exp $
+ * $Id: yaz-proxy.cpp,v 1.53 2003-10-08 09:49:05 adam Exp $
  */
 
 #include <assert.h>
 #include <time.h>
 
 #include <yaz/log.h>
-#include <yaz++/yaz-proxy.h>
+#include <yaz/diagbib1.h>
+#include <yaz++/proxy.h>
+
+static const char *apdu_name(Z_APDU *apdu)
+{
+    switch (apdu->which)
+    {
+    case Z_APDU_initRequest:
+        return "initRequest";
+    case Z_APDU_initResponse:
+        return "initResponse";
+    case Z_APDU_searchRequest:
+       return "searchRequest";
+    case Z_APDU_searchResponse:
+       return "searchResponse";
+    case Z_APDU_presentRequest:
+       return "presentRequest";
+    case Z_APDU_presentResponse:
+       return "presentResponse";
+    case Z_APDU_deleteResultSetRequest:
+       return "deleteResultSetRequest";
+    case Z_APDU_deleteResultSetResponse:
+       return "deleteResultSetResponse";
+    case Z_APDU_scanRequest:
+       return "scanRequest";
+    case Z_APDU_scanResponse:
+       return "scanResponse";
+    case Z_APDU_sortRequest:
+       return "sortRequest";
+    case Z_APDU_sortResponse:
+       return "sortResponse";
+    case Z_APDU_extendedServicesRequest:
+       return "extendedServicesRequest";
+    case Z_APDU_extendedServicesResponse:
+       return "extendedServicesResponse";
+    case Z_APDU_close:
+       return "close";
+    }
+    return "other";
+}
 
 Yaz_Proxy::Yaz_Proxy(IYaz_PDU_Observable *the_PDU_Observable) :
-    Yaz_Z_Assoc(the_PDU_Observable)
+    Yaz_Z_Assoc(the_PDU_Observable), m_bw_stat(60), m_pdu_stat(60)
 {
     m_PDU_Observable = the_PDU_Observable;
     m_client = 0;
     m_parent = 0;
     m_clientPool = 0;
     m_seqno = 1;
-    m_keepalive = 1;
+    m_keepalive = 0;
     m_proxyTarget = 0;
-    m_max_clients = 50;
+    m_default_target = 0;
+    m_proxy_authentication = 0;
+    m_max_clients = 150;
     m_seed = time(0);
+    m_client_idletime = 600;
+    m_target_idletime = 600;
+    m_optimize = xstrdup ("1");
+    strcpy(m_session_str, "x");
+    m_session_no=0;
+    m_bytes_sent = m_bytes_recv = 0;
+    m_bw_hold_PDU = 0;
+    m_bw_max = 0;
+    m_pdu_max = 0;
+    m_max_record_retrieve = 0;
 }
 
 Yaz_Proxy::~Yaz_Proxy()
 {
+    yaz_log(LOG_LOG, "%s Closed %d/%d sent/recv bytes total", m_session_str,
+           m_bytes_sent, m_bytes_recv);
     xfree (m_proxyTarget);
+    xfree (m_default_target);
+    xfree (m_proxy_authentication);
+    xfree (m_optimize);
 }
 
-void Yaz_Proxy::set_proxyTarget(const char *target)
+int Yaz_Proxy::set_config(const char *config)
 {
-    xfree (m_proxyTarget);
-    m_proxyTarget = 0;
+    int r = m_config.read_xml(config);
+    return r;
+}
+
+void Yaz_Proxy::set_default_target(const char *target)
+{
+    xfree (m_default_target);
+    m_default_target = 0;
     if (target)
-       m_proxyTarget = (char *) xstrdup (target);
+       m_default_target = (char *) xstrdup (target);
+}
+
+void Yaz_Proxy::set_proxy_authentication (const char *auth)
+{
+    xfree (m_proxy_authentication);
+    m_proxy_authentication = 0;
+    if (auth)
+       m_proxy_authentication = (char *) xstrdup (auth);
 }
 
 IYaz_PDU_Observer *Yaz_Proxy::sessionNotify(IYaz_PDU_Observable
@@ -43,9 +113,16 @@ IYaz_PDU_Observer *Yaz_Proxy::sessionNotify(IYaz_PDU_Observable
 {
     Yaz_Proxy *new_proxy = new Yaz_Proxy(the_PDU_Observable);
     new_proxy->m_parent = this;
-    new_proxy->timeout(500);
-    new_proxy->set_proxyTarget(m_proxyTarget);
+    new_proxy->m_config = m_config;
+    new_proxy->timeout(m_client_idletime);
+    new_proxy->m_target_idletime = m_target_idletime;
+    new_proxy->set_default_target(m_default_target);
     new_proxy->set_APDU_log(get_APDU_log());
+    new_proxy->set_proxy_authentication(m_proxy_authentication);
+    sprintf(new_proxy->m_session_str, "%ld:%d", (long) time(0), m_session_no);
+    m_session_no++;
+    yaz_log (LOG_LOG, "%s New session %s", new_proxy->m_session_str,
+            the_PDU_Observable->getpeername());
     return new_proxy;
 }
 
@@ -81,6 +158,35 @@ char *Yaz_Proxy::get_proxy(Z_OtherInformation **otherInfo)
     return 0;
 }
 
+const char *Yaz_Proxy::load_balance(const char **url)
+{
+    int zurl_in_use[MAX_ZURL_PLEX];
+    Yaz_ProxyClient *c;
+    int i;
+
+    for (i = 0; i<MAX_ZURL_PLEX; i++)
+       zurl_in_use[i] = 0;
+    for (c = m_parent->m_clientPool; c; c = c->m_next)
+    {
+       for (i = 0; url[i]; i++)
+           if (!strcmp(url[i], c->get_hostname()))
+               zurl_in_use[i]++;
+    }
+    int min = 100000;
+    const char *ret = 0;
+    for (i = 0; url[i]; i++)
+    {
+       yaz_log(LOG_DEBUG, "%s zurl=%s use=%d",
+               m_session_str, url[i], zurl_in_use[i]);
+       if (min > zurl_in_use[i])
+       {
+           ret = url[i];
+           min = zurl_in_use[i];
+       }
+    }
+    return ret;
+}
+
 Yaz_ProxyClient *Yaz_Proxy::get_client(Z_APDU *apdu)
 {
     assert (m_parent);
@@ -90,34 +196,52 @@ Yaz_ProxyClient *Yaz_Proxy::get_client(Z_APDU *apdu)
     
     get_otherInfoAPDU(apdu, &oi);
     char *cookie = get_cookie(oi);
-    yaz_log (LOG_LOG, "Yaz_Proxy::get_client cookie=%s", cookie ? cookie :
-         "null");
 
-    const char *proxy_host = get_proxy(oi);
-    if (proxy_host)
-       set_proxyTarget(proxy_host);
-    yaz_log (LOG_LOG, "proxy_host = %s", m_proxyTarget ? m_proxyTarget:"none");
-    
-    // no target specified at all?
     if (!m_proxyTarget)
-       return 0;
-
+    {
+       const char *url[MAX_ZURL_PLEX];
+       const char *proxy_host = get_proxy(oi);
+       if (proxy_host)
+       {
+           xfree(m_default_target);
+           m_default_target = xstrdup(proxy_host);
+           proxy_host = m_default_target;
+       }
+       
+       int client_idletime = -1;
+       m_config.get_target_info(proxy_host, url, &m_keepalive, &m_bw_max,
+                                &m_pdu_max, &m_max_record_retrieve,
+                                &m_target_idletime, &client_idletime,
+                                &parent->m_max_clients);
+       if (client_idletime != -1)
+       {
+           m_client_idletime = client_idletime;
+           timeout(m_client_idletime);
+       }
+       if (!url[0])
+       {
+           yaz_log(LOG_LOG, "%s No default target", m_session_str);
+           return 0;
+       }
+       // we don't handle multiplexing for cookie session, so we just
+       // pick the first one in this case (anonymous users will be able
+       // to use any backend)
+       if (cookie && *cookie)
+           m_proxyTarget = (char*) xstrdup(url[0]);
+       else
+           m_proxyTarget = (char*) xstrdup(load_balance(url));
+    }
     if (cookie && *cookie)
     {
-       yaz_log (LOG_LOG, "lookup of clients cookie=%s target=%s",
-             cookie, m_proxyTarget);
        Yaz_ProxyClient *cc = 0;
        
        for (c = parent->m_clientPool; c; c = c->m_next)
        {
-           yaz_log (LOG_LOG, " found client cookie = %s target=%s seqno=%d",
-                 c->m_cookie, c->get_hostname(), c->m_seqno);
            assert (c->m_prev);
            assert (*c->m_prev == c);
-           if (!strcmp(cookie,c->m_cookie) &&
+           if (c->m_cookie && !strcmp(cookie,c->m_cookie) &&
                !strcmp(m_proxyTarget, c->get_hostname()))
            {
-               yaz_log (LOG_LOG, "found!");
                cc = c;
            }
        }
@@ -130,25 +254,57 @@ Yaz_ProxyClient *Yaz_Proxy::get_client(Z_APDU *apdu)
            // we have an initRequest we can safely do re-open
            if (c->m_waiting && apdu->which == Z_APDU_initRequest)
            {
-               yaz_log (LOG_LOG, "reopen target=%s", c->get_hostname());
+               yaz_log (LOG_LOG, "%s REOPEN target=%s", m_session_str,
+                        c->get_hostname());
                c->close();
                c->client(m_proxyTarget);
                c->m_init_flag = 0;
-               
-               delete c->m_last_query;
-               c->m_last_query = 0;
+
+               c->m_last_ok = 0;
+               c->m_cache.clear();
                c->m_last_resultCount = 0;
                c->m_sr_transform = 0;
                c->m_waiting = 0;
-               c->timeout(600); 
+               c->m_resultSetStartPoint = 0;
+               c->timeout(m_target_idletime); 
            }
            c->m_seqno = parent->m_seqno;
            if (c->m_server && c->m_server != this)
                c->m_server->m_client = 0;
            c->m_server = this;
+           (parent->m_seqno)++;
+           yaz_log (LOG_DEBUG, "get_client 1 %p %p", this, c);
+           return c;
+       }
+    }
+    else if (!c)
+    {
+       Yaz_ProxyClient *cc = 0;
+       
+       for (c = parent->m_clientPool; c; c = c->m_next)
+       {
+           assert (c->m_prev);
+           assert (*c->m_prev == c);
+           if (c->m_server == 0 && c->m_cookie == 0 && 
+               !strcmp(m_proxyTarget, c->get_hostname()))
+           {
+               cc = c;
+           }
+       }
+       if (cc)
+       {
+           // found it in cache
+           c = cc;
+
+           yaz_log (LOG_LOG, "%s REUSE %d %d %s",
+                    m_session_str,
+                    c->m_seqno, parent->m_seqno, c->get_hostname());
+
            c->m_seqno = parent->m_seqno;
+           assert(c->m_server == 0);
+           c->m_server = this;
+           
            (parent->m_seqno)++;
-           yaz_log (LOG_LOG, "get_client 1 %p %p", this, c);
            return c;
        }
     }
@@ -159,14 +315,34 @@ Yaz_ProxyClient *Yaz_Proxy::get_client(Z_APDU *apdu)
            yaz_log (LOG_LOG, "no first INIT!");
            return 0;
        }
-       yaz_log (LOG_LOG, "got InitRequest");
-           
+        Z_InitRequest *initRequest = apdu->u.initRequest;
+
+        if (!initRequest->idAuthentication)
+        {
+            if (m_proxy_authentication)
+            {
+                initRequest->idAuthentication =
+                    (Z_IdAuthentication *)
+                    odr_malloc (odr_encode(),
+                                sizeof(*initRequest->idAuthentication));
+                initRequest->idAuthentication->which =
+                    Z_IdAuthentication_open;
+                initRequest->idAuthentication->u.open =
+                    odr_strdup (odr_encode(), m_proxy_authentication);
+            }
+        }
+
        // go through list of clients - and find the lowest/oldest one.
        Yaz_ProxyClient *c_min = 0;
        int min_seq = -1;
        int no_of_clients = 0;
+       if (parent->m_clientPool)
+           yaz_log (LOG_DEBUG, "Existing sessions");
        for (c = parent->m_clientPool; c; c = c->m_next)
        {
+           yaz_log (LOG_DEBUG, " Session %-3d wait=%d %s cookie=%s", c->m_seqno,
+                              c->m_waiting, c->get_hostname(),
+                              c->m_cookie ? c->m_cookie : "");
            no_of_clients++;
            if (min_seq < 0 || c->m_seqno < min_seq)
            {
@@ -179,21 +355,21 @@ Yaz_ProxyClient *Yaz_Proxy::get_client(Z_APDU *apdu)
            c = c_min;
            if (c->m_waiting || strcmp(m_proxyTarget, c->get_hostname()))
            {
-               yaz_log (LOG_LOG, "Yaz_Proxy::get_client re-init session %d",
-                     c->m_seqno);
+               yaz_log (LOG_LOG, "%s MAXCLIENTS Destroy %d",
+                        m_session_str, c->m_seqno);
                if (c->m_server && c->m_server != this)
                    delete c->m_server;
                c->m_server = 0;
            }
            else
            {
-               yaz_log (LOG_LOG,
-                        "Yaz_Proxy::get_client re-use session %d to %d",
-                     c->m_seqno, parent->m_seqno);
+               yaz_log (LOG_LOG, "%s MAXCLIENTS Reuse %d %d %s",
+                        m_session_str,
+                        c->m_seqno, parent->m_seqno, c->get_hostname());
+               xfree (c->m_cookie);
+               c->m_cookie = 0;
                if (cookie)
-                   strcpy (c->m_cookie, cookie);
-               else
-                   c->m_cookie[0] = '\0';
+                   c->m_cookie = xstrdup(cookie);
                c->m_seqno = parent->m_seqno;
                if (c->m_server && c->m_server != this)
                {
@@ -201,14 +377,13 @@ Yaz_ProxyClient *Yaz_Proxy::get_client(Z_APDU *apdu)
                    delete c->m_server;
                }
                (parent->m_seqno)++;
-               yaz_log (LOG_LOG, "get_client 2 %p %p", this, c);
                return c;
            }
        }
        else
        {
-           yaz_log (LOG_LOG, "Yaz_Proxy::get_client making session %d",
-                 parent->m_seqno);
+           yaz_log (LOG_LOG, "%s NEW %d %s",
+                    m_session_str, parent->m_seqno, m_proxyTarget);
            c = new Yaz_ProxyClient(m_PDU_Observable->clone());
            c->m_next = parent->m_clientPool;
            if (c->m_next)
@@ -216,108 +391,488 @@ Yaz_ProxyClient *Yaz_Proxy::get_client(Z_APDU *apdu)
            parent->m_clientPool = c;
            c->m_prev = &parent->m_clientPool;
        }
+
+       xfree (c->m_cookie);
+       c->m_cookie = 0;
        if (cookie)
-           strcpy (c->m_cookie, cookie);
-       else
-           c->m_cookie[0] = '\0';
-       yaz_log (LOG_LOG, "Yaz_Proxy::get_client connect to %s",
-                m_proxyTarget);
+           c->m_cookie = xstrdup(cookie);
+
        c->m_seqno = parent->m_seqno;
        c->client(m_proxyTarget);
        c->m_init_flag = 0;
-
-       delete c->m_last_query;
-       c->m_last_query = 0;
        c->m_last_resultCount = 0;
+        c->m_last_ok = 0;
+       c->m_cache.clear();
        c->m_sr_transform = 0;
        c->m_waiting = 0;
-       c->timeout(10);
+       c->m_resultSetStartPoint = 0;
+       c->timeout(30);
 
        (parent->m_seqno)++;
     }
-    yaz_log (LOG_LOG, "get_client 3 %p %p", this, c);
+    yaz_log (LOG_DEBUG, "get_client 3 %p %p", this, c);
     return c;
 }
 
+void Yaz_Proxy::display_diagrecs(Z_DiagRec **pp, int num)
+{
+    int i;
+    for (i = 0; i<num; i++)
+    {
+       oident *ent;
+       Z_DefaultDiagFormat *r;
+        Z_DiagRec *p = pp[i];
+        if (p->which != Z_DiagRec_defaultFormat)
+        {
+           yaz_log(LOG_LOG, "%s Error no diagnostics", m_session_str);
+            return;
+        }
+        else
+            r = p->u.defaultFormat;
+        if (!(ent = oid_getentbyoid(r->diagnosticSetId)) ||
+            ent->oclass != CLASS_DIAGSET || ent->value != VAL_BIB1)
+           yaz_log(LOG_LOG, "%s Error unknown diagnostic set", m_session_str);
+        switch (r->which)
+        {
+        case Z_DefaultDiagFormat_v2Addinfo:
+           yaz_log(LOG_LOG, "%s Error %d %s:%s",
+                   m_session_str,
+                   *r->condition, diagbib1_str(*r->condition),
+                   r->u.v2Addinfo);
+            break;
+        case Z_DefaultDiagFormat_v3Addinfo:
+           yaz_log(LOG_LOG, "%s Error %d %s:%s",
+                   m_session_str,
+                   *r->condition, diagbib1_str(*r->condition),
+                   r->u.v3Addinfo);
+            break;
+        }
+    }
+}
+
+int Yaz_Proxy::send_to_client(Z_APDU *apdu)
+{
+    int len = 0;
+    if (apdu->which == Z_APDU_searchResponse)
+    {
+       Z_SearchResponse *sr = apdu->u.searchResponse;
+       Z_Records *p = sr->records;
+       if (p && p->which == Z_Records_NSD)
+       {
+           Z_DiagRec dr, *dr_p = &dr;
+           dr.which = Z_DiagRec_defaultFormat;
+           dr.u.defaultFormat = p->u.nonSurrogateDiagnostic;
+
+           display_diagrecs(&dr_p, 1);
+       }
+       else
+       {
+           if (sr->resultCount)
+               yaz_log(LOG_LOG, "%s %d hits", m_session_str,
+                       *sr->resultCount);
+       }
+    }
+    else if (apdu->which == Z_APDU_presentResponse)
+    {
+       Z_PresentResponse *sr = apdu->u.presentResponse;
+       Z_Records *p = sr->records;
+       if (p && p->which == Z_Records_NSD)
+       {
+           Z_DiagRec dr, *dr_p = &dr;
+           dr.which = Z_DiagRec_defaultFormat;
+           dr.u.defaultFormat = p->u.nonSurrogateDiagnostic;
+
+           display_diagrecs(&dr_p, 1);
+       }
+    }
+    int r = send_Z_PDU(apdu, &len);
+    yaz_log (LOG_LOG, "%s Sending %s to client %d bytes", m_session_str,
+            apdu_name(apdu), len);
+    m_bytes_sent += len;
+    m_bw_stat.add_bytes(len);
+    return r;
+}
+
+int Yaz_ProxyClient::send_to_target(Z_APDU *apdu)
+{
+    int len = 0;
+    int r = send_Z_PDU(apdu, &len);
+    yaz_log (LOG_LOG, "%s Sending %s to %s %d bytes",
+            get_session_str(),
+            apdu_name(apdu), get_hostname(), len);
+    m_bytes_sent += len;
+    return r;
+}
+
 Z_APDU *Yaz_Proxy::result_set_optimize(Z_APDU *apdu)
 {
+    if (*m_parent->m_optimize == '0')
+        return apdu;      // don't optimize result sets..
+    if (apdu->which == Z_APDU_presentRequest)
+    {
+       Z_PresentRequest *pr = apdu->u.presentRequest;
+       Z_NamePlusRecordList *npr;
+       int toget = *pr->numberOfRecordsRequested;
+       int start = *pr->resultSetStartPoint;
+
+       if (m_client->m_last_resultSetId &&
+           !strcmp(m_client->m_last_resultSetId, pr->resultSetId))
+       {
+           if (m_client->m_cache.lookup (odr_encode(), &npr, start, toget,
+                                         pr->preferredRecordSyntax,
+                                         pr->recordComposition))
+           {
+               yaz_log (LOG_LOG, "%s Returned cache records for present request", 
+                        m_session_str);
+               Z_APDU *new_apdu = create_Z_PDU(Z_APDU_presentResponse);
+               new_apdu->u.presentResponse->referenceId = pr->referenceId;
+               
+               new_apdu->u.presentResponse->numberOfRecordsReturned
+                   = odr_intdup(odr_encode(), toget);
+                                                                
+               new_apdu->u.presentResponse->records = (Z_Records*)
+                   odr_malloc(odr_encode(), sizeof(Z_Records));
+               new_apdu->u.presentResponse->records->which = Z_Records_DBOSD;
+               new_apdu->u.presentResponse->records->u.databaseOrSurDiagnostics = npr;
+               new_apdu->u.presentResponse->nextResultSetPosition =
+                   odr_intdup(odr_encode(), start+toget);
+
+               send_to_client(new_apdu);
+               return 0;
+           }
+       }
+    }
+
     if (apdu->which != Z_APDU_searchRequest)
        return apdu;
     Z_SearchRequest *sr = apdu->u.searchRequest;
     Yaz_Z_Query *this_query = new Yaz_Z_Query;
+    Yaz_Z_Databases this_databases;
+
+    this_databases.set(sr->num_databaseNames, (const char **)
+                       sr->databaseNames);
     
     this_query->set_Z_Query(sr->query);
-    
-    if (m_client->m_last_query &&
-       m_client->m_last_query->match(this_query))
+
+    char query_str[80];
+    this_query->print(query_str, sizeof(query_str)-1);
+    yaz_log(LOG_LOG, "%s Query %s", m_session_str, query_str);
+
+    if (m_client->m_last_ok && m_client->m_last_query &&
+       m_client->m_last_query->match(this_query) &&
+        !strcmp(m_client->m_last_resultSetId, sr->resultSetName) &&
+        m_client->m_last_databases.match(this_databases))
     {
        delete this_query;
        if (m_client->m_last_resultCount > *sr->smallSetUpperBound &&
            m_client->m_last_resultCount < *sr->largeSetLowerBound)
        {
-           // medium Set
-           yaz_log (LOG_LOG, "Yaz_Proxy::result_set_optimize medium set");
-           Z_APDU *new_apdu = create_Z_PDU(Z_APDU_presentRequest);
-           Z_PresentRequest *pr = new_apdu->u.presentRequest;
-           pr->referenceId = sr->referenceId;
-           pr->resultSetId = sr->resultSetName;
-           pr->preferredRecordSyntax = sr->preferredRecordSyntax;
-           *pr->numberOfRecordsRequested = *sr->mediumSetPresentNumber;
+           Z_NamePlusRecordList *npr;
+           int toget = *sr->mediumSetPresentNumber;
+           Z_RecordComposition *comp = 0;
+
+           if (toget > m_client->m_last_resultCount)
+               toget = m_client->m_last_resultCount;
+           
            if (sr->mediumSetElementSetNames)
            {
-               pr->recordComposition = (Z_RecordComposition *)
+               comp = (Z_RecordComposition *)
                    odr_malloc(odr_encode(), sizeof(Z_RecordComposition));
-               pr->recordComposition->which = Z_RecordComp_simple;
-               pr->recordComposition->u.simple = sr->mediumSetElementSetNames;
+               comp->which = Z_RecordComp_simple;
+               comp->u.simple = sr->mediumSetElementSetNames;
+           }
+           if (m_client->m_cache.lookup (odr_encode(), &npr, 1, toget,
+                                         sr->preferredRecordSyntax, comp))
+           {
+               yaz_log (LOG_LOG, "%s Returned cache records for medium set",
+                        m_session_str);
+               Z_APDU *new_apdu = create_Z_PDU(Z_APDU_searchResponse);
+               new_apdu->u.searchResponse->referenceId = sr->referenceId;
+               new_apdu->u.searchResponse->resultCount =
+                   &m_client->m_last_resultCount;
+               
+               new_apdu->u.searchResponse->numberOfRecordsReturned
+                   = odr_intdup(odr_encode(), toget);
+                                                       
+               new_apdu->u.searchResponse->presentStatus =
+                   odr_intdup(odr_encode(), Z_PresentStatus_success);
+               new_apdu->u.searchResponse->records = (Z_Records*)
+                   odr_malloc(odr_encode(), sizeof(Z_Records));
+               new_apdu->u.searchResponse->records->which = Z_Records_DBOSD;
+               new_apdu->u.searchResponse->records->u.databaseOrSurDiagnostics = npr;
+               new_apdu->u.searchResponse->nextResultSetPosition =
+                   odr_intdup(odr_encode(), toget+1);
+               send_to_client(new_apdu);
+               return 0;
+           }
+           else
+           {
+               // medium Set
+               // send present request (medium size)
+               yaz_log (LOG_LOG, "%s Optimizing search for medium set",
+                        m_session_str);
+
+               Z_APDU *new_apdu = create_Z_PDU(Z_APDU_presentRequest);
+               Z_PresentRequest *pr = new_apdu->u.presentRequest;
+               pr->referenceId = sr->referenceId;
+               pr->resultSetId = sr->resultSetName;
+               pr->preferredRecordSyntax = sr->preferredRecordSyntax;
+               *pr->numberOfRecordsRequested = toget;
+               pr->recordComposition = comp;
+               m_client->m_sr_transform = 1;
+               return new_apdu;
            }
-           m_client->m_sr_transform = 1;
-           return new_apdu;
        }
        else if (m_client->m_last_resultCount >= *sr->largeSetLowerBound ||
-           m_client->m_last_resultCount == 0)
+           m_client->m_last_resultCount <= 0)
        {
-           // large set
-           yaz_log (LOG_LOG, "Yaz_Proxy::result_set_optimize large set");
+            // large set. Return pseudo-search response immediately
+           yaz_log (LOG_LOG, "%s Optimizing search for large set",
+                    m_session_str);
            Z_APDU *new_apdu = create_Z_PDU(Z_APDU_searchResponse);
            new_apdu->u.searchResponse->referenceId = sr->referenceId;
            new_apdu->u.searchResponse->resultCount =
                &m_client->m_last_resultCount;
-           send_Z_PDU(new_apdu);
+           send_to_client(new_apdu);
            return 0;
        }
        else
        {
+           Z_NamePlusRecordList *npr;
+           int toget = m_client->m_last_resultCount;
+           Z_RecordComposition *comp = 0;
            // small set
-           yaz_log (LOG_LOG, "Yaz_Proxy::result_set_optimize small set");
-           Z_APDU *new_apdu = create_Z_PDU(Z_APDU_presentRequest);
-           Z_PresentRequest *pr = new_apdu->u.presentRequest;
-           pr->referenceId = sr->referenceId;
-           pr->resultSetId = sr->resultSetName;
-           pr->preferredRecordSyntax = sr->preferredRecordSyntax;
-           *pr->numberOfRecordsRequested = m_client->m_last_resultCount;
+            // send a present request (small set)
+           
            if (sr->smallSetElementSetNames)
            {
-               pr->recordComposition = (Z_RecordComposition *)
+               comp = (Z_RecordComposition *)
                    odr_malloc(odr_encode(), sizeof(Z_RecordComposition));
-               pr->recordComposition->which = Z_RecordComp_simple;
-               pr->recordComposition->u.simple = sr->smallSetElementSetNames;
+               comp->which = Z_RecordComp_simple;
+               comp->u.simple = sr->smallSetElementSetNames;
+           }
+
+           if (m_client->m_cache.lookup (odr_encode(), &npr, 1, toget,
+                                         sr->preferredRecordSyntax, comp))
+           {
+               yaz_log (LOG_LOG, "%s Returned cache records for small set",
+                        m_session_str);
+               Z_APDU *new_apdu = create_Z_PDU(Z_APDU_searchResponse);
+               new_apdu->u.searchResponse->referenceId = sr->referenceId;
+               new_apdu->u.searchResponse->resultCount =
+                   &m_client->m_last_resultCount;
+               
+               new_apdu->u.searchResponse->numberOfRecordsReturned
+                   = odr_intdup(odr_encode(), toget);
+                                                                
+               new_apdu->u.searchResponse->presentStatus =
+                   odr_intdup(odr_encode(), Z_PresentStatus_success);
+               new_apdu->u.searchResponse->records = (Z_Records*)
+                   odr_malloc(odr_encode(), sizeof(Z_Records));
+               new_apdu->u.searchResponse->records->which = Z_Records_DBOSD;
+               new_apdu->u.searchResponse->records->u.databaseOrSurDiagnostics = npr;
+               new_apdu->u.searchResponse->nextResultSetPosition =
+                   odr_intdup(odr_encode(), toget+1);
+               send_to_client(new_apdu);
+               return 0;
+           }
+           else
+           {
+               yaz_log (LOG_LOG, "%s Optimizing search for small set",
+                        m_session_str);
+               Z_APDU *new_apdu = create_Z_PDU(Z_APDU_presentRequest);
+               Z_PresentRequest *pr = new_apdu->u.presentRequest;
+               pr->referenceId = sr->referenceId;
+               pr->resultSetId = sr->resultSetName;
+               pr->preferredRecordSyntax = sr->preferredRecordSyntax;
+               *pr->numberOfRecordsRequested = toget;
+               pr->recordComposition = comp;
+               m_client->m_sr_transform = 1;
+               return new_apdu;
            }
-           m_client->m_sr_transform = 1;
-           return new_apdu;
        }
     }
-    else
+    else  // query doesn't match
     {
-       yaz_log (LOG_LOG, "Yaz_Proxy::result_set_optimize new set");
        delete m_client->m_last_query;
        m_client->m_last_query = this_query;
+        m_client->m_last_ok = 0;
+       m_client->m_cache.clear();
+       m_client->m_resultSetStartPoint = 0;
+
+        xfree (m_client->m_last_resultSetId);
+        m_client->m_last_resultSetId = xstrdup (sr->resultSetName);
+
+        m_client->m_last_databases.set(sr->num_databaseNames,
+                                       (const char **) sr->databaseNames);
+    }
+    return apdu;
+}
+
+
+void Yaz_Proxy::recv_Z_PDU(Z_APDU *apdu, int len)
+{
+    int reduce = 0;
+    m_bytes_recv += len;
+    
+    yaz_log (LOG_LOG, "%s Receiving %s from client %d bytes", m_session_str,
+            apdu_name(apdu), len);
+
+    if (m_bw_hold_PDU)     // double incoming PDU. shutdown now.
+       shutdown();
+
+    m_bw_stat.add_bytes(len);
+    m_pdu_stat.add_bytes(1);
+
+    int bw_total = m_bw_stat.get_total();
+    int pdu_total = m_pdu_stat.get_total();
+
+    yaz_log(LOG_LOG, "%s stat bw=%d pdu=%d limit-bw=%d limit-pdu=%d",
+           m_session_str, bw_total, pdu_total, m_bw_max, m_pdu_max);
+    if (m_bw_max)
+    {
+       if (bw_total > m_bw_max)
+       {
+           reduce = (bw_total/m_bw_max);
+       }
+    }
+    if (m_pdu_max)
+    {
+       if (pdu_total > m_pdu_max)
+       {
+           int nreduce = (60/m_pdu_max);
+           reduce = (reduce > nreduce) ? reduce : nreduce;
+       }
+    }
+    if (reduce)  
+    {
+       yaz_log(LOG_LOG, "%s Limit delay=%d", m_session_str, reduce);
+       m_bw_hold_PDU = apdu;  // save PDU and signal "on hold"
+       timeout(reduce);       // call us reduce seconds later
+    }
+    else
+       recv_Z_PDU_0(apdu);    // all fine. Proceed receive PDU as usual
+}
+
+void Yaz_Proxy::handle_max_record_retrieve(Z_APDU *apdu)
+{
+    if (m_max_record_retrieve)
+    {
+       if (apdu->which == Z_APDU_presentRequest)
+       {
+           Z_PresentRequest *pr = apdu->u.presentRequest;
+           if (pr->numberOfRecordsRequested && 
+               *pr->numberOfRecordsRequested > m_max_record_retrieve)
+               *pr->numberOfRecordsRequested = m_max_record_retrieve;
+       }
+    }
+}
+
+Z_Records *Yaz_Proxy::create_nonSurrogateDiagnostics(ODR odr,
+                                                    int error,
+                                                    const char *addinfo)
+{
+    Z_Records *rec = (Z_Records *)
+        odr_malloc (odr, sizeof(*rec));
+    int *err = (int *)
+        odr_malloc (odr, sizeof(*err));
+    Z_DiagRec *drec = (Z_DiagRec *)
+        odr_malloc (odr, sizeof(*drec));
+    Z_DefaultDiagFormat *dr = (Z_DefaultDiagFormat *)
+        odr_malloc (odr, sizeof(*dr));
+    *err = error;
+    rec->which = Z_Records_NSD;
+    rec->u.nonSurrogateDiagnostic = dr;
+    dr->diagnosticSetId =
+        yaz_oidval_to_z3950oid (odr, CLASS_DIAGSET, VAL_BIB1);
+    dr->condition = err;
+    dr->which = Z_DefaultDiagFormat_v2Addinfo;
+    dr->u.v2Addinfo = odr_strdup (odr, addinfo ? addinfo : "");
+    return rec;
+}
+
+Z_APDU *Yaz_Proxy::handle_query_validation(Z_APDU *apdu)
+{
+    if (apdu->which == Z_APDU_searchRequest)
+    {
+       Z_SearchRequest *sr = apdu->u.searchRequest;
+       int err;
+       char *addinfo = 0;
+       err = m_config.check_query(odr_encode(), m_default_target, sr->query,
+                                  &addinfo);
+       if (err)
+       {
+           Z_APDU *new_apdu = create_Z_PDU(Z_APDU_searchResponse);
+
+           new_apdu->u.searchResponse->referenceId = sr->referenceId;
+           new_apdu->u.searchResponse->records =
+               create_nonSurrogateDiagnostics(odr_encode(), err, addinfo);
+           *new_apdu->u.searchResponse->searchStatus = 0;
+
+           send_to_client(new_apdu);
+
+           return 0;
+       }
+    }
+    return apdu;
+}
+
+Z_APDU *Yaz_Proxy::handle_syntax_validation(Z_APDU *apdu)
+{
+    if (apdu->which == Z_APDU_searchRequest)
+    {
+       Z_SearchRequest *sr = apdu->u.searchRequest;
+       if (*sr->smallSetUpperBound > 0 || *sr->largeSetLowerBound > 1)
+       {
+           int err;
+           char *addinfo = 0;
+           err = m_config.check_syntax(odr_encode(), m_default_target,
+                                       sr->preferredRecordSyntax,
+                                       &addinfo);
+           if (err)
+           {
+               Z_APDU *new_apdu = create_Z_PDU(Z_APDU_searchResponse);
+               
+               new_apdu->u.searchResponse->referenceId = sr->referenceId;
+               new_apdu->u.searchResponse->records =
+                   create_nonSurrogateDiagnostics(odr_encode(), err, addinfo);
+               *new_apdu->u.searchResponse->searchStatus = 0;
+               
+               send_to_client(new_apdu);
+               
+               return 0;
+           }
+       }
+    }
+    else if (apdu->which == Z_APDU_presentRequest)
+    {
+       Z_PresentRequest *pr = apdu->u.presentRequest;
+       int err;
+       char *addinfo = 0;
+       err = m_config.check_syntax(odr_encode(), m_default_target,
+                                   pr->preferredRecordSyntax,
+                                   &addinfo);
+       if (err)
+       {
+           Z_APDU *new_apdu = create_Z_PDU(Z_APDU_presentResponse);
+           
+           new_apdu->u.presentResponse->referenceId = pr->referenceId;
+           new_apdu->u.presentResponse->records =
+               create_nonSurrogateDiagnostics(odr_encode(), err, addinfo);
+           *new_apdu->u.presentResponse->presentStatus =
+               Z_PresentStatus_failure;
+           
+           send_to_client(new_apdu);
+           
+           return 0;
+       }
     }
     return apdu;
 }
 
-void Yaz_Proxy::recv_Z_PDU(Z_APDU *apdu)
+void Yaz_Proxy::recv_Z_PDU_0(Z_APDU *apdu)
 {
-    yaz_log (LOG_LOG, "Yaz_Proxy::recv_Z_PDU");
     // Determine our client.
     m_client = get_client(apdu);
     if (!m_client)
@@ -329,23 +884,43 @@ void Yaz_Proxy::recv_Z_PDU(Z_APDU *apdu)
 
     if (apdu->which == Z_APDU_initRequest)
     {
+       if (apdu->u.initRequest->implementationId)
+           yaz_log(LOG_LOG, "%s implementationId: %s",
+                   m_session_str, apdu->u.initRequest->implementationId);
+       if (apdu->u.initRequest->implementationName)
+           yaz_log(LOG_LOG, "%s implementationName: %s",
+                   m_session_str, apdu->u.initRequest->implementationName);
+       if (apdu->u.initRequest->implementationVersion)
+           yaz_log(LOG_LOG, "%s implementationVersion: %s",
+                   m_session_str, apdu->u.initRequest->implementationVersion);
        if (m_client->m_init_flag)
        {
-           Z_APDU *apdu = create_Z_PDU(Z_APDU_initResponse);
-           if (m_client->m_cookie)
+           Z_APDU *apdu = m_client->m_initResponse;
+           apdu->u.initResponse->otherInfo = 0;
+           if (m_client->m_cookie && *m_client->m_cookie)
                set_otherInformationString(apdu, VAL_COOKIE, 1,
                                           m_client->m_cookie);
-           send_Z_PDU(apdu);
+           send_to_client(apdu);
            return;
        }
        m_client->m_init_flag = 1;
     }
-    apdu = result_set_optimize(apdu);
+    handle_max_record_retrieve(apdu);
+
+    if (apdu)
+       apdu = handle_syntax_validation(apdu);
+
+    if (apdu)
+       apdu = handle_query_validation(apdu);
+
+    if (apdu)
+       apdu = result_set_optimize(apdu);
     if (!apdu)
+    {
+       m_client->timeout(m_target_idletime);  // mark it active even 
+       // though we didn't use it
        return;
-
-    yaz_log (LOG_LOG, "Yaz_ProxyClient::send_Z_PDU %s",
-            m_client->get_hostname());
+    }
 
     // delete other info part from PDU before sending to target
     Z_OtherInformation **oi;
@@ -353,7 +928,16 @@ void Yaz_Proxy::recv_Z_PDU(Z_APDU *apdu)
     if (oi)
         *oi = 0;
 
-    if (m_client->send_Z_PDU(apdu) < 0)
+    if (apdu->which == Z_APDU_presentRequest &&
+       m_client->m_resultSetStartPoint == 0)
+    {
+       Z_PresentRequest *pr = apdu->u.presentRequest;
+       m_client->m_resultSetStartPoint = *pr->resultSetStartPoint;
+       m_client->m_cache.copy_presentRequest(apdu->u.presentRequest);
+    } else {
+       m_client->m_resultSetStartPoint = 0;
+    }
+    if (m_client->send_to_target(apdu) < 0)
     {
        delete m_client;
        m_client = 0;
@@ -369,56 +953,77 @@ void Yaz_Proxy::connectNotify()
 
 void Yaz_Proxy::shutdown()
 {
-    yaz_log (LOG_LOG, "shutdown (client to proxy)");
-    // only keep if keep_alive flag and cookie is set...
-    if (m_keepalive && m_client && m_client->m_cookie[0])
+    // only keep if keep_alive flag is set...
+    if (m_keepalive && m_client && m_client->m_waiting == 0)
     {
-       yaz_log (LOG_LOG, "shutdown - keepalive this=%p, m_server=%p",
-            this, m_client->m_server);
-       if (m_client->m_waiting == 2)
-           abort();
+        yaz_log (LOG_LOG, "%s Shutdown (client to proxy) keepalive %s",
+                m_session_str,
+                 m_client->get_hostname());
+        assert (m_client->m_waiting != 2);
        // Tell client (if any) that no server connection is there..
        m_client->m_server = 0;
     }
     else if (m_client)
     {
-       yaz_log (LOG_LOG, "deleting %p %p", this, m_client);
-       if (m_client->m_waiting == 2)
-           abort();
+        yaz_log (LOG_LOG, "%s Shutdown (client to proxy) close %s",
+                m_session_str,
+                 m_client->get_hostname());
+        assert (m_client->m_waiting != 2);
        delete m_client;
     }
     else if (!m_parent)
     {
-       yaz_log (LOG_LOG, "abort %p", this);
-        abort();
+        yaz_log (LOG_LOG, "%s shutdown (client to proxy) bad state",
+                m_session_str);
+        assert (m_parent);
+    }
+    else 
+    {
+        yaz_log (LOG_LOG, "%s Shutdown (client to proxy)",
+                m_session_str);
     }
     delete this;
 }
 
+const char *Yaz_ProxyClient::get_session_str() 
+{
+    if (!m_server)
+       return "0";
+    return m_server->get_session_str();
+}
+
 void Yaz_ProxyClient::shutdown()
 {
-    yaz_log (LOG_LOG, "shutdown (proxy to server) %s", get_hostname());
+    yaz_log (LOG_LOG, "%s Shutdown (proxy to target) %s", get_session_str(),
+            get_hostname());
     delete m_server;
     delete this;
 }
 
 void Yaz_Proxy::failNotify()
 {
-    yaz_log (LOG_LOG, "connection closed by client");
+    yaz_log (LOG_LOG, "%s Connection closed by client",
+            get_session_str());
     shutdown();
 }
 
 void Yaz_ProxyClient::failNotify()
 {
-    yaz_log (LOG_LOG, "Yaz_ProxyClient connection closed by %s", get_hostname());
+    yaz_log (LOG_LOG, "%s Connection closed by target %s", 
+            get_session_str(), get_hostname());
     shutdown();
 }
 
 void Yaz_ProxyClient::connectNotify()
 {
-    yaz_log (LOG_LOG, "Yaz_ProxyClient connection accepted by %s",
-         get_hostname());
-    timeout(600);
+    yaz_log (LOG_LOG, "%s Connection accepted by %s", get_session_str(),
+            get_hostname());
+    int to;
+    if (m_server)
+       to = m_server->get_target_idletime();
+    else
+       to = 600;
+    timeout(to);
 }
 
 IYaz_PDU_Observer *Yaz_ProxyClient::sessionNotify(IYaz_PDU_Observable
@@ -434,68 +1039,144 @@ Yaz_ProxyClient::~Yaz_ProxyClient()
     if (m_next)
        m_next->m_prev = m_prev;
     m_waiting = 2;     // for debugging purposes only.
+    odr_destroy(m_init_odr);
     delete m_last_query;
+    xfree (m_last_resultSetId);
+    xfree (m_cookie);
 }
 
 void Yaz_Proxy::timeoutNotify()
 {
-    yaz_log (LOG_LOG, "timeout (client to proxy)");
-    shutdown();
+    if (m_bw_hold_PDU)
+    {
+       timeout(m_client_idletime);
+       Z_APDU *apdu = m_bw_hold_PDU;
+       m_bw_hold_PDU = 0;
+       recv_Z_PDU_0(apdu);
+    }
+    else
+    {
+       yaz_log (LOG_LOG, "%s Timeout (client to proxy)", m_session_str);
+       shutdown();
+    }
 }
 
 void Yaz_ProxyClient::timeoutNotify()
 {
-    yaz_log (LOG_LOG, "timeout (proxy to target) %s", get_hostname());
+    yaz_log (LOG_LOG, "%s Timeout (proxy to target) %s", get_session_str(),
+            get_hostname());
     shutdown();
 }
 
 Yaz_ProxyClient::Yaz_ProxyClient(IYaz_PDU_Observable *the_PDU_Observable) :
     Yaz_Z_Assoc (the_PDU_Observable)
 {
-    m_cookie[0] = 0;
+    m_cookie = 0;
     m_next = 0;
     m_prev = 0;
     m_init_flag = 0;
     m_last_query = 0;
+    m_last_resultSetId = 0;
     m_last_resultCount = 0;
+    m_last_ok = 0;
     m_sr_transform = 0;
     m_waiting = 0;
+    m_init_odr = odr_createmem (ODR_DECODE);
+    m_initResponse = 0;
+    m_resultSetStartPoint = 0;
+    m_bytes_sent = m_bytes_recv = 0;
 }
 
-void Yaz_ProxyClient::recv_Z_PDU(Z_APDU *apdu)
+const char *Yaz_Proxy::option(const char *name, const char *value)
 {
+    if (!strcmp (name, "optimize")) {
+       if (value) {
+            xfree (m_optimize);        
+           m_optimize = xstrdup (value);
+        }
+       return m_optimize;
+    }
+    return 0;
+}
+
+void Yaz_ProxyClient::recv_Z_PDU(Z_APDU *apdu, int len)
+{
+    m_bytes_recv += len;
     m_waiting = 0;
-    yaz_log (LOG_LOG, "Yaz_ProxyClient::recv_Z_PDU %s", get_hostname());
+    yaz_log (LOG_LOG, "%s Receiving %s from %s %d bytes", get_session_str(),
+            apdu_name(apdu), get_hostname(), len);
+    if (apdu->which == Z_APDU_initResponse)
+    {
+        NMEM nmem = odr_extract_mem (odr_decode());
+       odr_reset (m_init_odr);
+        nmem_transfer (m_init_odr->mem, nmem);
+        m_initResponse = apdu;
+
+       Z_InitResponse *ir = apdu->u.initResponse;
+       char *im0 = ir->implementationName;
+       
+       char *im1 = (char*) 
+           odr_malloc(m_init_odr, 20 + (im0 ? strlen(im0) : 0));
+       *im1 = '\0';
+       if (im0)
+       {
+           strcat(im1, im0);
+           strcat(im1, " ");
+       }
+       strcat(im1, "(YAZ Proxy)");
+       ir->implementationName = im1;
+
+        nmem_destroy (nmem);
+    }
     if (apdu->which == Z_APDU_searchResponse)
     {
-       m_last_resultCount = *apdu->u.searchResponse->resultCount;
-       int status = *apdu->u.searchResponse->searchStatus;
-       if (! status || (
-               apdu->u.searchResponse->records &&
-               apdu->u.searchResponse->records->which != Z_Records_DBOSD))
+       Z_SearchResponse *sr = apdu->u.searchResponse;
+       m_last_resultCount = *sr->resultCount;
+       int status = *sr->searchStatus;
+       if (status && (!sr->records || sr->records->which == Z_Records_DBOSD))
        {
-           delete m_last_query;
-           m_last_query = 0;
+            m_last_ok = 1;
+           
+           if (sr->records && sr->records->which == Z_Records_DBOSD)
+           {
+               m_cache.add(odr_decode(),
+                           sr->records->u.databaseOrSurDiagnostics, 1,
+                           *sr->resultCount);
+           }
        }
     }
-    if (apdu->which == Z_APDU_presentResponse && m_sr_transform)
+    if (apdu->which == Z_APDU_presentResponse)
     {
-       m_sr_transform = 0;
        Z_PresentResponse *pr = apdu->u.presentResponse;
-       Z_APDU *new_apdu = create_Z_PDU(Z_APDU_searchResponse);
-       Z_SearchResponse *sr = new_apdu->u.searchResponse;
-       sr->referenceId = pr->referenceId;
-       *sr->resultCount = m_last_resultCount;
-       sr->records = pr->records;
-       sr->nextResultSetPosition = pr->nextResultSetPosition;
-       sr->numberOfRecordsReturned = pr->numberOfRecordsReturned;
-       apdu = new_apdu;
+       if (m_sr_transform)
+       {
+           m_sr_transform = 0;
+           Z_APDU *new_apdu = create_Z_PDU(Z_APDU_searchResponse);
+           Z_SearchResponse *sr = new_apdu->u.searchResponse;
+           sr->referenceId = pr->referenceId;
+           *sr->resultCount = m_last_resultCount;
+           sr->records = pr->records;
+           sr->nextResultSetPosition = pr->nextResultSetPosition;
+           sr->numberOfRecordsReturned = pr->numberOfRecordsReturned;
+           apdu = new_apdu;
+       }
+       if (pr->records && 
+           pr->records->which == Z_Records_DBOSD && m_resultSetStartPoint)
+       {
+           m_cache.add(odr_decode(),
+                       pr->records->u.databaseOrSurDiagnostics,
+                       m_resultSetStartPoint, -1);
+           m_resultSetStartPoint = 0;
+       }
     }
     if (m_cookie)
        set_otherInformationString (apdu, VAL_COOKIE, 1, m_cookie);
     if (m_server)
     {
-       yaz_log (LOG_LOG, "Yaz_Proxy::send_Z_PDU");
-       m_server->send_Z_PDU(apdu);
+       m_server->send_to_client(apdu);
+    }
+    if (apdu->which == Z_APDU_close)
+    {
+       shutdown();
     }
 }