From: Adam Dickmeiss <adam@indexdata.dk>
Date: Wed, 2 Nov 2011 14:24:39 +0000 (+0100)
Subject: Clients cached within session
X-Git-Tag: v1.6.6~56
X-Git-Url: http://sru.miketaylor.org.uk/cgi-bin?a=commitdiff_plain;h=7e047ebfe0f7f78205a30a4474c1c33594aea1b3;p=pazpar2-moved-to-github.git

Clients cached within session

Clients are reused if query and other parameters are same for
command=search. For example, if a subset of databases are used and
query is the same, the result set from previous search is reused.
---

diff --git a/src/client.c b/src/client.c
index e17e604..ea171b9 100644
--- a/src/client.c
+++ b/src/client.c
@@ -554,6 +554,52 @@ void client_got_records(struct client *cl)
     }
 }
 
+static void client_record_ingest(struct client *cl)
+{
+    const char *msg, *addinfo;
+    ZOOM_record rec = 0;
+    ZOOM_resultset resultset = cl->resultset;
+    int offset = cl->record_offset;
+    if ((rec = ZOOM_resultset_record(resultset, offset)))
+    {
+        cl->record_offset++;
+        if (cl->session == 0)
+            ;
+        else if (ZOOM_record_error(rec, &msg, &addinfo, 0))
+        {
+            yaz_log(YLOG_WARN, "Record error %s (%s): %s (rec #%d)",
+                    msg, addinfo, client_get_id(cl),
+                    cl->record_offset);
+        }
+        else
+        {
+            struct session_database *sdb = client_get_database(cl);
+            NMEM nmem = nmem_create();
+            const char *xmlrec;
+            char type[80];
+            
+            if (nativesyntax_to_type(sdb, type, rec))
+                yaz_log(YLOG_WARN, "Failed to determine record type");
+            xmlrec = ZOOM_record_get(rec, type, NULL);
+            if (!xmlrec)
+                yaz_log(YLOG_WARN, "ZOOM_record_get failed from %s",
+                        client_get_id(cl));
+            else
+            {
+                /* OK = 0, -1 = failure, -2 = Filtered */
+                if (ingest_record(cl, xmlrec, cl->record_offset, nmem) == -1)
+                    yaz_log(YLOG_WARN, "Failed to ingest from %s", client_get_id(cl));
+            }
+            nmem_destroy(nmem);
+        }
+    }
+    else
+    {
+        yaz_log(YLOG_WARN, "Expected record, but got NULL, offset=%d",
+                offset);
+    }
+}
+
 void client_record_response(struct client *cl)
 {
     struct connection *co = cl->connection;
@@ -569,11 +615,9 @@ void client_record_response(struct client *cl)
     }
     else
     {
-        ZOOM_record rec = 0;
-        const char *msg, *addinfo;
-        
         if (cl->show_raw && cl->show_raw->active)
         {
+            ZOOM_record rec = 0;
             if ((rec = ZOOM_resultset_record(resultset,
                                              cl->show_raw->position-1)))
             {
@@ -588,49 +632,21 @@ void client_record_response(struct client *cl)
         }
         else
         {
-            int offset = cl->record_offset;
-            if ((rec = ZOOM_resultset_record(resultset, offset)))
-            {
-                cl->record_offset++;
-                if (cl->session == 0)
-                    ;
-                else if (ZOOM_record_error(rec, &msg, &addinfo, 0))
-                {
-                    yaz_log(YLOG_WARN, "Record error %s (%s): %s (rec #%d)",
-                            msg, addinfo, client_get_id(cl),
-                            cl->record_offset);
-                }
-                else
-                {
-                    struct session_database *sdb = client_get_database(cl);
-                    NMEM nmem = nmem_create();
-                    const char *xmlrec;
-                    char type[80];
-
-                    if (nativesyntax_to_type(sdb, type, rec))
-                        yaz_log(YLOG_WARN, "Failed to determine record type");
-                    xmlrec = ZOOM_record_get(rec, type, NULL);
-                    if (!xmlrec)
-                        yaz_log(YLOG_WARN, "ZOOM_record_get failed from %s",
-                                client_get_id(cl));
-                    else
-                    {
-                        /* OK = 0, -1 = failure, -2 = Filtered */
-                        if (ingest_record(cl, xmlrec, cl->record_offset, nmem) == -1)
-                            yaz_log(YLOG_WARN, "Failed to ingest from %s", client_get_id(cl));
-                    }
-                    nmem_destroy(nmem);
-                }
-            }
-            else
-            {
-                yaz_log(YLOG_WARN, "Expected record, but got NULL, offset=%d",
-                        offset);
-            }
+            client_record_ingest(cl);
         }
     }
 }
 
+void client_reingest(struct client *cl)
+{
+    int i = cl->startrecs;
+    int to = cl->record_offset;
+
+    cl->record_offset = i;
+    for (; i < to; i++)
+        client_record_ingest(cl);
+}
+
 static void client_set_facets_request(struct client *cl, ZOOM_connection link)
 {
     struct session_database *sdb = client_get_database(cl);
@@ -695,6 +711,7 @@ void client_start_search(struct client *cl, const char *sort_strategy_and_spec,
 
     assert(link);
 
+    cl->hits = 0;
     cl->record_offset = 0;
     cl->diagnostic = 0;
 
@@ -1036,7 +1053,8 @@ static void apply_limit(struct session_database *sdb,
                         
 // Parse the query given the settings specific to this client
 int client_parse_query(struct client *cl, const char *query,
-                       facet_limits_t facet_limits)
+                       facet_limits_t facet_limits,
+                       const char *startrecs, const char *maxrecs)
 {
     struct session *se = client_get_session(cl);
     struct session_database *sdb = client_get_database(cl);
@@ -1048,10 +1066,24 @@ int client_parse_query(struct client *cl, const char *query,
     const char *pqf_strftime = session_setting_oneval(sdb, PZ_PQF_STRFTIME);
     const char *query_syntax = session_setting_oneval(sdb, PZ_QUERY_SYNTAX);
     WRBUF w_ccl, w_pqf;
+    int ret_value = 1;
+
     if (!ccl_map)
         return -1;
 
-    cl->hits = -1;
+
+    if (maxrecs && atoi(maxrecs) != cl->maxrecs)
+    {
+        ret_value = 0;
+        cl->maxrecs = atoi(maxrecs);
+    }
+
+    if (startrecs && atoi(startrecs) != cl->startrecs)
+    {
+        ret_value = 0;
+        cl->startrecs = atoi(startrecs);
+    }
+
     w_ccl = wrbuf_alloc();
     wrbuf_puts(w_ccl, query);
 
@@ -1099,8 +1131,12 @@ int client_parse_query(struct client *cl, const char *query,
                 wrbuf_putc(w_pqf, cp[0]);
         }
     }
-    xfree(cl->pquery);
-    cl->pquery = xstrdup(wrbuf_cstr(w_pqf));
+    if (!cl->pquery || strcmp(cl->pquery, wrbuf_cstr(w_pqf)))
+    {
+        xfree(cl->pquery);
+        cl->pquery = xstrdup(wrbuf_cstr(w_pqf));
+        ret_value = 0;
+    }
     wrbuf_destroy(w_pqf);
 
     yaz_log(YLOG_LOG, "PQF query: %s", cl->pquery);
@@ -1133,7 +1169,7 @@ int client_parse_query(struct client *cl, const char *query,
     }
 
     ccl_rpn_delete(cn);
-    return 0;
+    return ret_value;
 }
 
 void client_set_session(struct client *cl, struct session *se)
@@ -1222,21 +1258,11 @@ const char *client_get_id(struct client *cl)
     return cl->id;
 }
 
-void client_set_maxrecs(struct client *cl, int v)
-{
-    cl->maxrecs = v;
-}
-
 int client_get_maxrecs(struct client *cl)
 {
     return cl->maxrecs;
 }
 
-void client_set_startrecs(struct client *cl, int v)
-{
-    cl->startrecs = v;
-}
-
 void client_set_preferred(struct client *cl, int v)
 {
     cl->preferred = v;
diff --git a/src/client.h b/src/client.h
index 2fb8ada..2086871 100644
--- a/src/client.h
+++ b/src/client.h
@@ -84,16 +84,15 @@ int client_is_active_preferred(struct client *cl);
 struct client *client_next_in_session(struct client *cl);
 
 int client_parse_query(struct client *cl, const char *query,
-                       facet_limits_t facet_limits);
+                       facet_limits_t facet_limits, const char *startrecs,
+                       const char *maxrecs);
 Odr_int client_get_hits(struct client *cl);
 int client_get_num_records(struct client *cl);
 int client_get_diagnostic(struct client *cl);
 void client_set_diagnostic(struct client *cl, int diagnostic);
 void client_set_database(struct client *cl, struct session_database *db);
 const char *client_get_id(struct client *cl);
-void client_set_maxrecs(struct client *cl, int v);
 int  client_get_maxrecs(struct client *cl);
-void client_set_startrecs(struct client *cl, int v);
 void client_remove_from_session(struct client *c);
 void client_incref(struct client *c);
 void client_got_records(struct client *c);
@@ -102,6 +101,8 @@ void client_unlock(struct client *c);
 
 int client_has_facet(struct client *cl, const char *name);
 void client_check_preferred_watch(struct client *cl);
+void client_reingest(struct client *cl);
+
 
 #endif
 
diff --git a/src/session.c b/src/session.c
index 439ad7b..0006652 100644
--- a/src/session.c
+++ b/src/session.c
@@ -405,12 +405,8 @@ static int prepare_map(struct session *se, struct session_database *sdb)
 {
     const char *s;
 
-    if (!sdb->settings)
-    {
-        session_log(se, YLOG_WARN, "No settings on %s", sdb->database->id);
-        return -1;
-    }
-    if ((s = session_setting_oneval(sdb, PZ_XSLT)))
+    if (sdb->settings && sdb->settings[PZ_XSLT] && !sdb->map &&
+        (s = session_setting_oneval(sdb, PZ_XSLT)))        
     {
         char auto_stylesheet[256];
 
@@ -445,25 +441,6 @@ static int prepare_map(struct session *se, struct session_database *sdb)
     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)
-    {
-        session_log(se, YLOG_WARN, 
-                "No settings associated with %s", sdb->database->id);
-        return -1;
-    }
-    if (sdb->settings[PZ_XSLT] && !sdb->map)
-    {
-        if (prepare_map(se, sdb) < 0)
-            return -1;
-    }
-    return 0;
-}
-
 // called if watch should be removed because http_channel is to be destroyed
 static void session_watch_cancel(void *data, struct http_channel *c,
                                  void *data2)
@@ -530,12 +507,26 @@ void session_alert_watch(struct session *s, int what)
 static void select_targets_callback(struct session *se,
                                     struct session_database *db)
 {
-    struct client *cl = client_create(db->database->id);
+    struct client *cl;
     struct client_list *l;
 
-    client_set_database(cl, db);
+    for (l = se->clients_cached; l; l = l->next)
+        if (client_get_database(l->client) == db)
+            break;
 
-    client_set_session(cl, se);
+    if (l)
+        cl = l->client;
+    else
+    {
+        cl = client_create(db->database->id);
+        client_set_database(cl, db);
+        client_set_session(cl, se);
+
+        l = xmalloc(sizeof(*l));
+        l->client = cl;
+        l->next = se->clients_cached;
+        se->clients_cached = l;
+    }
 
     l = xmalloc(sizeof(*l));
     l->client = cl;
@@ -555,6 +546,25 @@ static void session_remove_clients(struct session *se)
     while (l)
     {
         struct client_list *l_next = l->next;
+        xfree(l);
+        l = l_next;
+    }
+}
+
+static void session_remove_cached_clients(struct session *se)
+{
+    struct client_list *l;
+
+    session_remove_clients(se);
+
+    session_enter(se);
+    l = se->clients_cached;
+    se->clients_cached = 0;
+    session_leave(se);
+
+    while (l)
+    {
+        struct client_list *l_next = l->next;
         client_lock(l->client);
         client_set_session(l->client, 0);
         client_set_database(l->client, 0);
@@ -687,11 +697,15 @@ enum pazpar2_error_code session_search(struct session *se,
 
     *addinfo = 0;
 
-    session_remove_clients(se);
+    if (se->settings_modified)
+        session_remove_cached_clients(se);
+    else
+        session_remove_clients(se);
     
     session_enter(se);
     reclist_destroy(se->reclist);
     se->reclist = 0;
+    se->settings_modified = 0;
     relevance_destroy(&se->relevance);
     nmem_reset(se->nmem);
     se->total_records = se->total_merged = 0;
@@ -724,19 +738,20 @@ enum pazpar2_error_code session_search(struct session *se,
     }
     for (l = se->clients; l; l = l->next)
     {
+        int parse_ret;
         struct client *cl = l->client;
         const char *strategy_plus_sort = get_strategy_plus_sort(cl, sort_field);
 
-        if (maxrecs)
-            client_set_maxrecs(cl, atoi(maxrecs));
-        if (startrecs)
-            client_set_startrecs(cl, atoi(startrecs));
-        if (prepare_session_database(se, client_get_database(cl)) < 0)
-            ;
-        else if (client_parse_query(cl, query, facet_limits) < 0)
+        if (prepare_map(se, client_get_database(cl)) < 0)
+            continue;
+
+        parse_ret = client_parse_query(cl, query, facet_limits, startrecs,
+            maxrecs);
+        if (parse_ret < 0)
             no_failed++;
-        else
+        else if (parse_ret == 0)
         {
+            yaz_log(YLOG_LOG, "client NEW %s", client_get_id(cl));
             no_working++;
             if (client_prep_connection(cl, se->service->z3950_operation_timeout,
                                        se->service->z3950_session_timeout,
@@ -744,6 +759,20 @@ enum pazpar2_error_code session_search(struct session *se,
                                        &tval))
                 client_start_search(cl, strategy_plus_sort, increasing);
         }
+        else
+        {
+            yaz_log(YLOG_LOG, "client REUSE %s", client_get_id(cl));
+            no_working++;
+            if (client_prep_connection(cl, se->service->z3950_operation_timeout,
+                                       se->service->z3950_session_timeout,
+                                       se->service->server->iochan_man,
+                                       &tval))
+            {
+                session_leave(se);
+                client_reingest(cl);
+                session_enter(se);
+            }
+        }
     }
     facet_limits_destroy(facet_limits);
     session_leave(se);
@@ -757,6 +786,7 @@ enum pazpar2_error_code session_search(struct session *se,
         else
             return PAZPAR2_NO_TARGETS;
     }
+    yaz_log(YLOG_LOG, "session_start_search done");
     return PAZPAR2_NO_ERROR;
 }
 
@@ -840,6 +870,8 @@ void session_apply_setting(struct session *se, char *dbname, char *setting,
     new->next = sdb->settings[offset];
     sdb->settings[offset] = new;
 
+    se->settings_modified = 1;
+
     // Force later recompute of settings-driven data structures
     // (happens when a search starts and client connections are prepared)
     switch (offset)
@@ -853,11 +885,12 @@ void session_apply_setting(struct session *se, char *dbname, char *setting,
     }
 }
 
-void session_destroy(struct session *se) {
+void session_destroy(struct session *se)
+{
     struct session_database *sdb;
     session_log(se, YLOG_DEBUG, "Destroying");
     session_use(-1);
-    session_remove_clients(se);
+    session_remove_cached_clients(se);
 
     for (sdb = se->databases; sdb; sdb = sdb->next)
         session_database_destroy(sdb);
@@ -906,6 +939,8 @@ struct session *new_session(NMEM nmem, struct conf_service *service,
     session->num_termlists = 0;
     session->reclist = 0;
     session->clients = 0;
+    session->clients_cached = 0;
+    session->settings_modified = 0;
     session->session_nmem = nmem;
     session->nmem = nmem_create();
     session->databases = 0;
diff --git a/src/session.h b/src/session.h
index 13bc314..e58302b 100644
--- a/src/session.h
+++ b/src/session.h
@@ -100,6 +100,7 @@ struct session {
     struct conf_service *service; /* service in use for this session */
     struct session_database *databases;  // All databases, settings overriden
     struct client_list *clients;   // Clients connected for current search
+    struct client_list *clients_cached; // Clients in cache
     NMEM session_nmem;  // Nmem for session-permanent storage
     NMEM nmem;          // Nmem for each operation (i.e. search, result set, etc)
     int num_termlists;
@@ -114,6 +115,7 @@ struct session {
     normalize_cache_t normalize_cache;
     YAZ_MUTEX session_mutex;
     unsigned session_id;
+    int settings_modified;
     struct session_sorted_results *sorted_results;
 };