From 0198d9a410e2664e29f8fa526cf9bcf8f5bea89a Mon Sep 17 00:00:00 2001
From: Adam Dickmeiss <adam@indexdata.dk>
Date: Tue, 22 Jan 2013 15:44:12 +0100
Subject: [PATCH] Work on fetch more

---
 src/client.c       |   18 ++++++++++++++++++
 src/client.h       |    1 +
 src/http_command.c |   28 +++++++++++++++++++++++++++-
 src/session.c      |   32 ++++++++++++++++++++++++++++++++
 src/session.h      |    6 +++++-
 5 files changed, 83 insertions(+), 2 deletions(-)

diff --git a/src/client.c b/src/client.c
index 0cf2e07..5f05633 100644
--- a/src/client.c
+++ b/src/client.c
@@ -762,6 +762,24 @@ static const char *get_strategy_plus_sort(struct client *l, const char *field)
     return strategy_plus_sort;
 }
 
+int client_fetch_more(struct client *cl)
+{
+    int extra = cl->hits - cl->record_offset;
+    if (extra > 0)
+    {
+        ZOOM_resultset set = cl->resultset;
+        int max_extra = 10;
+
+        if (extra > max_extra)
+            extra = max_extra;
+
+        ZOOM_resultset_records(set, 0, cl->record_offset, extra);
+        client_set_state(cl, Client_Working);
+        return 1;
+    }
+    return 0;
+}
+
 int client_parse_init(struct client *cl, int same_search)
 {
     cl->same_search = same_search;
diff --git a/src/client.h b/src/client.h
index 8176db9..eeccf0f 100644
--- a/src/client.h
+++ b/src/client.h
@@ -80,6 +80,7 @@ int client_prep_connection(struct client *cl,
                            iochan_man_t iochan,
                            const struct timeval *abstime);
 int client_start_search(struct client *cl);
+int client_fetch_more(struct client *cl);
 int client_parse_init(struct client *cl, int same_search);
 int client_parse_range(struct client *cl, const char *startrecs, const char *maxrecs);
 int client_parse_sort(struct client *cl, struct reclist_sortparms *sp);
diff --git a/src/http_command.c b/src/http_command.c
index f2f9b20..ecc1275 100644
--- a/src/http_command.c
+++ b/src/http_command.c
@@ -93,6 +93,8 @@ struct http_sessions {
 static YAZ_MUTEX g_http_session_mutex = 0;
 static int g_http_sessions = 0;
 
+static void show_records_ready(void *data);
+
 int get_version(struct http_request *rq) {
     const char *version = http_argbyname(rq, "version");
     int version_no = 0;
@@ -1118,7 +1120,31 @@ static void show_records(struct http_channel *c, struct http_session *s, int act
 
     }
 
-    rl = show_range_start(s->psession, sp, startn, &numn, &total, &total_hits, &approx_hits);
+    i = numn;
+    rl = show_range_start(s->psession, sp, startn, &numn, &total,
+                          &total_hits, &approx_hits);
+    if (i > numn)
+    {
+        show_range_stop(s->psession, rl);
+        session_log(s->psession, YLOG_LOG,
+                    "Subset %d < %d retrieved for show", numn, i);
+        if (!session_fetch_more(s->psession))
+            session_log(s->psession, YLOG_LOG, "can not fetch more");
+        else
+        {
+            session_log(s->psession, YLOG_LOG, "fetching more in progress");
+            if (session_set_watch(s->psession, SESSION_WATCH_SHOW,
+                                  show_records_ready, c, c))
+                session_log(s->psession, YLOG_WARN, "Ignoring show block");
+            else
+            {
+                session_log(s->psession, YLOG_LOG, "session watch OK");
+                return;
+            }
+        }
+        rl = show_range_start(s->psession, sp, startn, &numn, &total,
+                              &total_hits, &approx_hits);
+    }
 
     response_open(c, "show");
     wrbuf_printf(c->wrbuf, "\n<activeclients>%d</activeclients>\n", active);
diff --git a/src/session.c b/src/session.c
index b7fcfec..148f462 100644
--- a/src/session.c
+++ b/src/session.c
@@ -1234,6 +1234,38 @@ void show_single_stop(struct session *se, struct record_cluster *rec)
 }
 
 
+int session_fetch_more(struct session *se)
+{
+    struct client_list *l;
+    int ret = 0;
+
+    for (l = se->clients_active; l; l = l->next)
+    {
+        struct client *cl = l->client;
+        if (client_get_state(cl) == Client_Idle)
+        {
+            if (client_fetch_more(cl))
+            {
+                session_log(se, YLOG_LOG, "%s: more to fetch",
+                            client_get_id(cl));
+                ret = 1;
+            }
+            else
+            {
+                session_log(se, YLOG_LOG, "%s: no more to fetch",
+                            client_get_id(cl));
+            }
+        }
+        else
+        {
+            session_log(se, YLOG_LOG, "%s: no fetch due to state=%s",
+                        client_get_id(cl), client_get_state_str(cl));
+        }
+
+    }
+    return ret;
+}
+
 struct record_cluster **show_range_start(struct session *se,
                                          struct reclist_sortparms *sp,
                                          int start, int *num, int *total,
diff --git a/src/session.h b/src/session.h
index 66c41ba..be8a1cf 100644
--- a/src/session.h
+++ b/src/session.h
@@ -170,7 +170,11 @@ enum pazpar2_error_code session_search(struct session *s, const char *query,
 struct record_cluster **show_range_start(struct session *s,
                                          struct reclist_sortparms *sp,
                                          int start,
-                                         int *num, int *total, Odr_int *sumhits, Odr_int *approximation);
+                                         int *num, int *total,
+                                         Odr_int *sumhits,
+                                         Odr_int *approximation);
+
+int session_fetch_more(struct session *s);
 void show_range_stop(struct session *s, struct record_cluster **recs);
 
 struct record_cluster *show_single_start(struct session *s, const char *id,
-- 
1.7.10.4