X-Git-Url: http://jsfdemo.indexdata.com/?a=blobdiff_plain;f=src%2Flogic.c;h=2a0e9617a11cb9d1ffd08255ea2ff9b3748fe760;hb=315af5c601a268e2d0da60477c3470a6c12654c9;hp=1f61db6bd74dc2c626de6a7ad8da56b3fe6350bf;hpb=5cc5bfa026237076ecb44ae016b78069edfcc492;p=pazpar2-moved-to-github.git

diff --git a/src/logic.c b/src/logic.c
index 1f61db6..2a0e961 100644
--- a/src/logic.c
+++ b/src/logic.c
@@ -1,4 +1,4 @@
-/* $Id: logic.c,v 1.2 2007-04-16 13:22:17 marc Exp $
+/* $Id: logic.c,v 1.19 2007-04-23 08:15:22 marc Exp $
    Copyright (c) 2006-2007, Index Data.
 
 This file is part of Pazpar2.
@@ -19,6 +19,9 @@ Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 02111-1307, USA.
  */
 
+// This file contains the primary business logic. Several parts of it should
+// Eventually be factored into separate modules.
+
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
@@ -74,8 +77,6 @@ static int client_prep_connection(struct client *cl);
 static void ingest_records(struct client *cl, Z_Records *r);
 void session_alert_watch(struct session *s, int what);
 
-IOCHAN channel_list = 0;  // Master list of connections we're handling events to
-
 static struct connection *connection_freelist = 0;
 static struct client *client_freelist = 0;
 
@@ -103,7 +104,7 @@ struct parameters global_parameters =
     0,
     30,
     "81",
-    "Index Data PazPar2 (MasterKey)",
+    "Index Data PazPar2",
     VERSION,
     600, // 10 minutes
     60,
@@ -185,10 +186,9 @@ static void send_init(IOCHAN i)
         && 0 < strlen(cl->database->database->url))
     {
 #if YAZ_VERSIONL >= 0x020163
-        const int *oid_proxy = yaz_string_to_oid(yaz_oid_std(),
-                                                 CLASS_USERINFO, OID_STR_PROXY);
         yaz_oi_set_string_oid(&a->u.initRequest->otherInfo,
-                              global_parameters.odr_out, oid_proxy,
+                              global_parameters.odr_out,
+                              yaz_oid_userinfo_proxy,
                               1, cl->database->database->url);
 #else
         yaz_oi_set_string_oidval(&a->u.initRequest->otherInfo,
@@ -207,8 +207,13 @@ static void send_init(IOCHAN i)
     odr_reset(global_parameters.odr_out);
 }
 
+// Recursively traverse query structure to extract terms.
 static void pull_terms(NMEM nmem, struct ccl_rpn_node *n, char **termlist, int *num)
 {
+    char **words;
+    int numwords;
+    int i;
+
     switch (n->kind)
     {
         case CCL_RPN_AND:
@@ -219,7 +224,9 @@ static void pull_terms(NMEM nmem, struct ccl_rpn_node *n, char **termlist, int *
             pull_terms(nmem, n->u.p[1], termlist, num);
             break;
         case CCL_RPN_TERM:
-            termlist[(*num)++] = nmem_strdup(nmem, n->u.t.term);
+            nmem_strsplit(nmem, " ", n->u.t.term, &words, &numwords);
+            for (i = 0; i < numwords; i++)
+                termlist[(*num)++] = words[i];
             break;
         default: // NOOP
             break;
@@ -242,10 +249,9 @@ static void send_search(IOCHAN i)
     struct session *se = cl->session;
     struct session_database *sdb = cl->database;
     Z_APDU *a = zget_APDU(global_parameters.odr_out, Z_APDU_searchRequest);
-    int ndb, cerror, cpos;
+    int ndb;
     char **databaselist;
     Z_Query *zquery;
-    struct ccl_rpn_node *cn;
     int ssub = 0, lslb = 100000, mspn = 10;
     char *recsyn = 0;
     char *piggyback = 0;
@@ -254,25 +260,11 @@ static void send_search(IOCHAN i)
 
     yaz_log(YLOG_DEBUG, "Sending search to %s", cl->database->database->url);
 
-    cn = ccl_find_str(sdb->database->ccl_map, se->query, &cerror, &cpos);
-    if (!cn)
-        return;
-
-    if (!se->relevance)
-    {
-        // Initialize relevance structure with query terms
-        char *p[512];
-        extract_terms(se->nmem, cn, p);
-        se->relevance = relevance_create(se->nmem, (const char **) p,
-                se->expected_maxrecs);
-    }
-
     // constructing RPN query
     a->u.searchRequest->query = zquery = odr_malloc(global_parameters.odr_out,
             sizeof(Z_Query));
     zquery->which = Z_Query_type_1;
-    zquery->u.type_1 = ccl_rpn_query(global_parameters.odr_out, cn);
-    ccl_rpn_delete(cn);
+    zquery->u.type_1 = p_query_rpn(global_parameters.odr_out, cl->pquery);
 
     // converting to target encoding
     if ((queryenc = session_setting_oneval(sdb, PZ_QUERYENCODING))){
@@ -517,8 +509,9 @@ static void add_facet(struct session *s, const char *type, const char *value)
         if (i == SESSION_MAX_TERMLISTS)
         {
             yaz_log(YLOG_FATAL, "Too many termlists");
-            exit(1);
+            return;
         }
+
         s->termlists[i].name = nmem_strdup(s->nmem, type);
         s->termlists[i].termlist = termlist_create(s->nmem, s->expected_maxrecs, 15);
         s->num_termlists = i + 1;
@@ -529,36 +522,36 @@ static void add_facet(struct session *s, const char *type, const char *value)
 static xmlDoc *normalize_record(struct client *cl, Z_External *rec)
 {
     struct database_retrievalmap *m;
-    struct database *db = cl->database->database;
+    struct session_database *sdb = cl->database;
+    struct database *db = sdb->database;
     xmlNode *res;
     xmlDoc *rdoc;
 
     // First normalize to XML
-    if (db->yaz_marc)
+    if (sdb->yaz_marc)
     {
         char *buf;
         int len;
         if (rec->which != Z_External_octet)
         {
             yaz_log(YLOG_WARN, "Unexpected external branch, probably BER %s",
-                    cl->database->database->url);
+                    db->url);
             return 0;
         }
         buf = (char*) rec->u.octet_aligned->buf;
         len = rec->u.octet_aligned->len;
-        if (yaz_marc_read_iso2709(db->yaz_marc, buf, len) < 0)
+        if (yaz_marc_read_iso2709(sdb->yaz_marc, buf, len) < 0)
         {
-            yaz_log(YLOG_WARN, "Failed to decode MARC %s",
-                    cl->database->database->url);
+            yaz_log(YLOG_WARN, "Failed to decode MARC %s", db->url);
             return 0;
         }
 
-        yaz_marc_write_using_libxml2(db->yaz_marc, 1);
-        if (yaz_marc_write_xml(db->yaz_marc, &res,
+        yaz_marc_write_using_libxml2(sdb->yaz_marc, 1);
+        if (yaz_marc_write_xml(sdb->yaz_marc, &res,
                     "http://www.loc.gov/MARC21/slim", 0, 0) < 0)
         {
             yaz_log(YLOG_WARN, "Failed to encode as XML %s",
-                    cl->database->database->url);
+                    db->url);
             return 0;
         }
         rdoc = xmlNewDoc((xmlChar *) "1.0");
@@ -569,14 +562,14 @@ static xmlDoc *normalize_record(struct client *cl, Z_External *rec)
     {
         yaz_log(YLOG_FATAL, 
                 "Unknown native_syntax in normalize_record from %s",
-                cl->database->database->url);
-        exit(1);
+                db->url);
+        return 0;
     }
 
     if (global_parameters.dump_records){
         fprintf(stderr, 
                 "Input Record (normalized) from %s\n----------------\n",
-                cl->database->database->url);
+                db->url);
 #if LIBXML_VERSION >= 20600
         xmlDocFormatDump(stderr, rdoc, 1);
 #else
@@ -584,7 +577,7 @@ static xmlDoc *normalize_record(struct client *cl, Z_External *rec)
 #endif
     }
 
-    for (m = db->map; m; m = m->next){
+    for (m = sdb->map; m; m = m->next){
         xmlDoc *new = 0;
 
 #if 1
@@ -700,7 +693,9 @@ static struct record *ingest_record(struct client *cl, Z_External *rec)
     xmlFree(mergekey);
     normalize_mergekey((char *) mergekey_norm, 0);
 
-    cluster = reclist_insert(global_parameters.server->service, se->reclist, res, (char *) mergekey_norm, 
+    cluster = reclist_insert(se->reclist, 
+                             global_parameters.server->service, 
+                             res, (char *) mergekey_norm, 
                              &se->total_merged);
     if (global_parameters.dump_records)
         yaz_log(YLOG_LOG, "Cluster id %d from %s (#%d)", cluster->recid,
@@ -973,7 +968,7 @@ static void do_presentResponse(IOCHAN i, Z_APDU *a)
     }
 }
 
-static void handler(IOCHAN i, int event)
+void connection_handler(IOCHAN i, int event)
 {
     struct connection *co = iochan_getdata(i);
     struct client *cl = co->client;
@@ -1080,7 +1075,7 @@ static void handler(IOCHAN i, int event)
 
     if (cl->state == Client_Idle)
     {
-        if (cl->requestid != se->requestid && *se->query) {
+        if (cl->requestid != se->requestid && cl->pquery) {
             send_search(i);
         }
         else if (cl->hits > 0 && cl->records < global_parameters.toget &&
@@ -1106,8 +1101,12 @@ static void connection_release(struct connection *co)
 static void connection_destroy(struct connection *co)
 {
     struct host *h = co->host;
-    cs_close(co->link);
-    iochan_destroy(co->iochan);
+    
+    if (co->link)
+    {
+        cs_close(co->link);
+        iochan_destroy(co->iochan);
+    }
 
     yaz_log(YLOG_DEBUG, "Connection destroy %s", co->host->hostport);
     if (h->connections == co)
@@ -1132,54 +1131,103 @@ static void connection_destroy(struct connection *co)
     connection_freelist = co;
 }
 
-// Creates a new connection for client, associated with the host of 
-// client's database
-static struct connection *connection_create(struct client *cl)
+static int connection_connect(struct connection *con)
 {
-    struct connection *new;
-    COMSTACK link; 
-    int res;
+    COMSTACK link = 0;
+    struct client *cl = con->client;
+    struct host *host = con->host;
     void *addr;
+    int res;
 
+    assert(host->ipport);
+    assert(cl);
 
     if (!(link = cs_create(tcpip_type, 0, PROTO_Z3950)))
-        {
-            yaz_log(YLOG_FATAL|YLOG_ERRNO, "Failed to create comstack");
-            exit(1);
-        }
+    {
+        yaz_log(YLOG_FATAL|YLOG_ERRNO, "Failed to create comstack");
+        return -1;
+    }
     
     if (0 == strlen(global_parameters.zproxy_override)){
         /* no Z39.50 proxy needed - direct connect */
         yaz_log(YLOG_DEBUG, "Connection create %s", cl->database->database->url);
         
-        if (!(addr = cs_straddr(link, cl->database->database->host->ipport)))
-            {
-                yaz_log(YLOG_WARN|YLOG_ERRNO, 
-                        "Lookup of IP address %s failed", 
-                        cl->database->database->host->ipport);
-                return 0;
-            }
-    
+        if (!(addr = cs_straddr(link, host->ipport)))
+        {
+            yaz_log(YLOG_WARN|YLOG_ERRNO, 
+                    "Lookup of IP address %s failed", host->ipport);
+            return -1;
+        }
+        
     } else {
         /* Z39.50 proxy connect */
         yaz_log(YLOG_DEBUG, "Connection create %s proxy %s", 
                 cl->database->database->url, global_parameters.zproxy_override);
-
+        
         if (!(addr = cs_straddr(link, global_parameters.zproxy_override)))
-            {
-                yaz_log(YLOG_WARN|YLOG_ERRNO, 
-                        "Lookup of IP address %s failed", 
-                        global_parameters.zproxy_override);
-                return 0;
-            }
+        {
+            yaz_log(YLOG_WARN|YLOG_ERRNO, 
+                    "Lookup of IP address %s failed", 
+                    global_parameters.zproxy_override);
+            return -1;
+        }
     }
-
+    
     res = cs_connect(link, addr);
     if (res < 0)
     {
         yaz_log(YLOG_WARN|YLOG_ERRNO, "cs_connect %s", cl->database->database->url);
-        return 0;
+        return -1;
+    }
+    con->link = link;
+    con->state = Conn_Connecting;
+    con->iochan = iochan_create(cs_fileno(link), connection_handler, 0);
+    iochan_setdata(con->iochan, con);
+    pazpar2_add_channel(con->iochan);
+
+    /* this fragment is bad DRY: from client_prep_connection */
+    cl->state = Client_Connecting;
+    iochan_setflag(con->iochan, EVENT_OUTPUT);
+    return 0;
+}
+
+void connect_resolver_host(struct host *host)
+{
+    struct connection *con = host->connections;
+
+    while (con)
+    {
+        if (con->state == Conn_Resolving)
+        {
+            if (!host->ipport) /* unresolved */
+            {
+                connection_destroy(con);
+                /* start all over .. at some point it will be NULL */
+                con = host->connections;
+            }
+            else if (!con->client)
+            {
+                yaz_log(YLOG_WARN, "connect_unresolved_host : ophan client");
+                connection_destroy(con);
+                /* start all over .. at some point it will be NULL */
+                con = host->connections;
+            }
+            else
+            {
+                connection_connect(con);
+                con = con->next;
+            }
+        }
     }
+}
+
+
+// Creates a new connection for client, associated with the host of 
+// client's database
+static struct connection *connection_create(struct client *cl)
+{
+    struct connection *new;
+    struct host *host = cl->database->database->host;
 
     if ((new = connection_freelist))
         connection_freelist = new->next;
@@ -1189,18 +1237,15 @@ static struct connection *connection_create(struct client *cl)
         new->ibuf = 0;
         new->ibufsize = 0;
     }
-    new->state = Conn_Connecting;
-    new->host = cl->database->database->host;
+    new->host = host;
     new->next = new->host->connections;
     new->host->connections = new;
     new->client = cl;
     cl->connection = new;
-    new->link = link;
-
-    new->iochan = iochan_create(cs_fileno(link), handler, 0);
-    iochan_setdata(new->iochan, new);
-    new->iochan->next = channel_list;
-    channel_list = new->iochan;
+    new->link = 0;
+    new->state = Conn_Resolving;
+    if (host->ipport)
+        connection_connect(new);
     return new;
 }
 
@@ -1258,6 +1303,167 @@ static int client_prep_connection(struct client *cl)
         return 0;
 }
 
+// Initialize YAZ Map structures for MARC-based targets
+static int prepare_yazmarc(struct session_database *sdb)
+{
+    char *s;
+
+    if (!sdb->settings)
+    {
+        yaz_log(YLOG_WARN, "No settings for %s", sdb->database->url);
+        return -1;
+    }
+    if ((s = session_setting_oneval(sdb, PZ_NATIVESYNTAX)) && !strncmp(s, "iso2709", 7))
+    {
+        char *encoding = "marc-8s", *e;
+        yaz_iconv_t cm;
+
+        // See if a native encoding is specified
+        if ((e = strchr(s, ';')))
+            encoding = e + 1;
+
+        sdb->yaz_marc = yaz_marc_create();
+        yaz_marc_subfield_str(sdb->yaz_marc, "\t");
+        
+        cm = yaz_iconv_open("utf-8", encoding);
+        if (!cm)
+        {
+            yaz_log(YLOG_FATAL, 
+                    "Unable to map from %s to UTF-8 for target %s", 
+                    encoding, sdb->database->url);
+            return -1;
+        }
+        yaz_marc_iconv(sdb->yaz_marc, cm);
+    }
+    return 0;
+}
+
+// Prepare XSLT stylesheets for record normalization
+// Structures are allocated on the session_wide nmem to avoid having
+// to recompute this for every search. This would lead
+// to leaking if a single session was to repeatedly change the PZ_XSLT
+// setting. However, this is not a realistic use scenario.
+static int prepare_map(struct session *se, struct session_database *sdb)
+{
+   char *s;
+
+    if (!sdb->settings)
+    {
+        yaz_log(YLOG_WARN, "No settings on %s", sdb->database->url);
+        return -1;
+    }
+    if ((s = session_setting_oneval(sdb, PZ_XSLT)))
+    {
+        char **stylesheets;
+        struct database_retrievalmap **m = &sdb->map;
+        int num, i;
+
+        nmem_strsplit(se->session_nmem, ",", s, &stylesheets, &num);
+        for (i = 0; i < num; i++)
+        {
+            (*m) = nmem_malloc(se->session_nmem, sizeof(**m));
+            (*m)->next = 0;
+            if (!((*m)->stylesheet = conf_load_stylesheet(stylesheets[i])))
+            {
+                yaz_log(YLOG_FATAL, "Unable to load stylesheet: %s",
+                        stylesheets[i]);
+                return -1;
+            }
+            m = &(*m)->next;
+        }
+    }
+    if (!sdb->map)
+        yaz_log(YLOG_WARN, "No Normalization stylesheet for target %s",
+                sdb->database->url);
+    return 0;
+}
+
+// This analyzes settings and recomputes any supporting data structures
+// if necessary.
+static int prepare_session_database(struct session *se, struct session_database *sdb)
+{
+    if (!sdb->settings)
+    {
+        yaz_log(YLOG_WARN, "No settings associated with %s", sdb->database->url);
+        return -1;
+    }
+    if (sdb->settings[PZ_NATIVESYNTAX] && !sdb->yaz_marc)
+    {
+        if (prepare_yazmarc(sdb) < 0)
+            return -1;
+    }
+    if (sdb->settings[PZ_XSLT] && !sdb->map)
+    {
+        if (prepare_map(se, sdb) < 0)
+            return -1;
+    }
+    return 0;
+}
+
+// Initialize CCL map for a target
+static CCL_bibset prepare_cclmap(struct client *cl)
+{
+    struct session_database *sdb = cl->database;
+    struct setting *s;
+    CCL_bibset res;
+
+    if (!sdb->settings)
+        return 0;
+    res = ccl_qual_mk();
+    for (s = sdb->settings[PZ_CCLMAP]; s; s = s->next)
+    {
+        char *p = strchr(s->name + 3, ':');
+        if (!p)
+        {
+            yaz_log(YLOG_WARN, "Malformed cclmap name: %s", s->name);
+            ccl_qual_rm(&res);
+            return 0;
+        }
+        p++;
+        ccl_qual_fitem(res, s->value, p);
+    }
+    return res;
+}
+
+// Parse the query given the settings specific to this client
+static int client_parse_query(struct client *cl, const char *query)
+{
+    struct session *se = cl->session;
+    struct ccl_rpn_node *cn;
+    int cerror, cpos;
+    CCL_bibset ccl_map = prepare_cclmap(cl);
+
+    if (!ccl_map)
+        return -1;
+    cn = ccl_find_str(ccl_map, query, &cerror, &cpos);
+    ccl_qual_rm(&ccl_map);
+    if (!cn)
+    {
+        cl->state = Client_Error;
+        yaz_log(YLOG_WARN, "Failed to parse query for %s",
+                         cl->database->database->url);
+        return -1;
+    }
+    wrbuf_rewind(se->wrbuf);
+    ccl_pquery(se->wrbuf, cn);
+    wrbuf_putc(se->wrbuf, '\0');
+    if (cl->pquery)
+        xfree(cl->pquery);
+    cl->pquery = xstrdup(wrbuf_buf(se->wrbuf));
+
+    if (!se->relevance)
+    {
+        // Initialize relevance structure with query terms
+        char *p[512];
+        extract_terms(se->nmem, cn, p);
+        se->relevance = relevance_create(se->nmem, (const char **) p,
+                se->expected_maxrecs);
+    }
+
+    ccl_rpn_delete(cn);
+    return 0;
+}
+
 static struct client *client_create(void)
 {
     struct client *r;
@@ -1268,6 +1474,7 @@ static struct client *client_create(void)
     }
     else
         r = xmalloc(sizeof(struct client));
+    r->pquery = 0;
     r->database = 0;
     r->connection = 0;
     r->session = 0;
@@ -1401,59 +1608,40 @@ char *search(struct session *se, char *query, char *filter)
 
     nmem_reset(se->nmem);
     criteria = parse_filter(se->nmem, filter);
-    strcpy(se->query, query);
     se->requestid++;
-    select_targets(se, criteria);
-    for (cl = se->clients; cl; cl = cl->next)
-    {
-        if (client_prep_connection(cl))
-            live_channels++;
-    }
+    live_channels = select_targets(se, criteria);
     if (live_channels)
     {
         int maxrecs = live_channels * global_parameters.toget;
         se->num_termlists = 0;
         se->reclist = reclist_create(se->nmem, maxrecs);
         // This will be initialized in send_search()
-        se->relevance = 0;
         se->total_records = se->total_hits = se->total_merged = 0;
         se->expected_maxrecs = maxrecs;
     }
     else
         return "NOTARGETS";
 
-    return 0;
-}
+    se->relevance = 0;
 
-// Apply a session override to a database
-void session_apply_setting(struct session *se, char *dbname, char *setting, char *value)
-{
-    struct session_database *sdb;
+    for (cl = se->clients; cl; cl = cl->next)
+    {
+        if (prepare_session_database(se, cl->database) < 0)
+            return "CONFIG_ERROR";
+        if (client_parse_query(cl, query) < 0)  // Query must parse for all targets
+            return "QUERY";
+    }
 
-    for (sdb = se->databases; sdb; sdb = sdb->next)
-        if (!strcmp(dbname, sdb->database->url))
-        {
-            struct setting *new = nmem_malloc(se->session_nmem, sizeof(*new));
-            int offset = settings_offset(setting);
+    for (cl = se->clients; cl; cl = cl->next)
+    {
+        client_prep_connection(cl);
+    }
 
-            if (offset < 0)
-            {
-                yaz_log(YLOG_WARN, "Unknown setting %s", setting);
-                return;
-            }
-            new->precedence = 0;
-            new->target = dbname;
-            new->name = setting;
-            new->value = value;
-            new->next = sdb->settings[offset];
-            sdb->settings[offset] = new;
-            break;
-        }
-    if (!sdb)
-        yaz_log(YLOG_WARN, "Unknown database in setting override: %s", dbname);
+    return 0;
 }
 
-void session_init_databases_fun(void *context, struct database *db)
+// Creates a new session_database object for a database
+static void session_init_databases_fun(void *context, struct database *db)
 {
     struct session *se = (struct session *) context;
     struct session_database *new = nmem_malloc(se->session_nmem, sizeof(*new));
@@ -1461,13 +1649,30 @@ void session_init_databases_fun(void *context, struct database *db)
     int i;
 
     new->database = db;
+    new->yaz_marc = 0;
+    new->map = 0;
     new->settings = nmem_malloc(se->session_nmem, sizeof(struct settings *) * num);
-    for (i = 0; i < num; i++)
-        new->settings[i] = db->settings[i];
+    memset(new->settings, 0, sizeof(struct settings*) * num);
+    if (db->settings)
+    {
+        for (i = 0; i < num; i++)
+            new->settings[i] = db->settings[i];
+    }
     new->next = se->databases;
     se->databases = new;
 }
 
+// Doesn't free memory associated with sdb -- nmem takes care of that
+static void session_database_destroy(struct session_database *sdb)
+{
+    struct database_retrievalmap *m;
+
+    for (m = sdb->map; m; m = m->next)
+        xsltFreeStylesheet(m->stylesheet);
+    if (sdb->yaz_marc)
+        yaz_marc_destroy(sdb->yaz_marc);
+}
+
 // Initialize session_database list -- this represents this session's view
 // of the database list -- subject to modification by the settings ws command
 void session_init_databases(struct session *se)
@@ -1476,11 +1681,80 @@ void session_init_databases(struct session *se)
     grep_databases(se, 0, session_init_databases_fun);
 }
 
+// Probably session_init_databases_fun should be refactored instead of
+// called here.
+static struct session_database *load_session_database(struct session *se, char *id)
+{
+    struct database *db = find_database(id, 0);
+
+    session_init_databases_fun((void*) se, db);
+    // New sdb is head of se->databases list
+    return se->databases;
+}
+
+// Find an existing session database. If not found, load it
+static struct session_database *find_session_database(struct session *se, char *id)
+{
+    struct session_database *sdb;
+
+    for (sdb = se->databases; sdb; sdb = sdb->next)
+        if (!strcmp(sdb->database->url, id))
+            return sdb;
+    return load_session_database(se, id);
+}
+
+// Apply a session override to a database
+void session_apply_setting(struct session *se, char *dbname, char *setting, char *value)
+{
+    struct session_database *sdb = find_session_database(se, dbname);
+    struct setting *new = nmem_malloc(se->session_nmem, sizeof(*new));
+    int offset = settings_offset(setting);
+
+    if (offset < 0)
+    {
+        yaz_log(YLOG_WARN, "Unknown setting %s", setting);
+        return;
+    }
+    new->precedence = 0;
+    new->target = dbname;
+    new->name = setting;
+    new->value = value;
+    new->next = sdb->settings[offset];
+    sdb->settings[offset] = new;
+
+    // Force later recompute of settings-driven data structures
+    // (happens when a search starts and client connections are prepared)
+    switch (offset)
+    {
+        case PZ_NATIVESYNTAX:
+            if (sdb->yaz_marc)
+            {
+                yaz_marc_destroy(sdb->yaz_marc);
+                sdb->yaz_marc = 0;
+            }
+            break;
+        case PZ_XSLT:
+            if (sdb->map)
+            {
+                struct database_retrievalmap *m;
+                // We don't worry about the map structure -- it's in nmem
+                for (m = sdb->map; m; m = m->next)
+                    xsltFreeStylesheet(m->stylesheet);
+                sdb->map = 0;
+            }
+            break;
+    }
+}
+
 void destroy_session(struct session *s)
 {
+    struct session_database *sdb;
+
     yaz_log(YLOG_LOG, "Destroying session");
     while (s->clients)
         client_destroy(s->clients);
+    for (sdb = s->databases; sdb; sdb = sdb->next)
+        session_database_destroy(sdb);
     nmem_destroy(s->nmem);
     wrbuf_destroy(s->wrbuf);
 }
@@ -1499,7 +1773,6 @@ struct session *new_session(NMEM nmem)
     session->requestid = -1;
     session->clients = 0;
     session->expected_maxrecs = 0;
-    session->query[0] = '\0';
     session->session_nmem = nmem;
     session->nmem = nmem_create();
     session->wrbuf = wrbuf_alloc();
@@ -1725,7 +1998,18 @@ void start_zproxy(void)
         return;
 }
 
+// Master list of connections we're handling events to
+static IOCHAN channel_list = 0; 
+void pazpar2_add_channel(IOCHAN chan)
+{
+    chan->next = channel_list;
+    channel_list = chan;
+}
 
+void pazpar2_event_loop()
+{
+    event_loop(&channel_list);
+}
 
 /*
  * Local variables: