New special sort parameter value 'position'.

The 'position' sorts merged records by their original position
from the remote target. This is primarily useful for debugging and
may be used for targets that already perform some kind of relevance
ranking. Note that sort by default is decreasing; so to get records
in their original order sort=position:1 must be used.

diff --git a/doc/pazpar2_protocol.xml b/doc/pazpar2_protocol.xml
index d332a62..fd10f67 100644 (file)
--- a/doc/pazpar2_protocol.xml
+++ b/doc/pazpar2_protocol.xml
@@ -344,7 +344,8 @@ search.pz2?session=2044502273&command=stat
        increasing or decreasing order according to that field. 0==Decreasing is
        the default.
        Sort field names can be any field name designated as a sort field
-        in the pazpar2.cfg file, or the special name 'relevance'.
+        in the pazpar2.cfg file, or the special names 'relevance' and
+       'position'.
        </para>
       </listitem>
      </varlistentry>

diff --git a/src/pazpar2_config.h b/src/pazpar2_config.h
index 1906b85..c8ea60e 100644 (file)
--- a/src/pazpar2_config.h
+++ b/src/pazpar2_config.h
@@ -47,7 +47,8 @@ enum conf_sortkey_type {
     Metadata_sortkey_relevance,
     Metadata_sortkey_numeric,       // Standard numerical sorting
     Metadata_sortkey_skiparticle,   // Skip leading article when sorting
-    Metadata_sortkey_string         // Flat string
+    Metadata_sortkey_string,        // Flat string
+    Metadata_sortkey_position       // Position
 };
 
 // This controls the ability to insert 'static' values from settings into retrieval recs

diff --git a/src/reclists.c b/src/reclists.c
index 7025af1..b4e2a6d 100644 (file)
--- a/src/reclists.c
+++ b/src/reclists.c
@@ -85,6 +85,10 @@ struct reclist_sortparms *reclist_parse_sortparms(NMEM nmem, const char *parms,
         if (!strcmp(parm, "relevance"))
         {
             type = Metadata_sortkey_relevance;
+        } 
+        else if (!strcmp(parm, "position"))
+        {
+            type = Metadata_sortkey_position;
         }
         else
         {
@@ -163,6 +167,23 @@ static int reclist_cmp(const void *p1, const void *p2)
             else
                 res = 0;
             break;
+        case Metadata_sortkey_position:
+            if (r1->records && r2->records)
+            {
+                int pos1 = 0, pos2 = 0;
+                struct record *rec;
+                for (rec = r1->records; rec; rec = rec->next)
+                    if (pos1 == 0 || rec->position < pos1)
+                        pos1 = rec->position;
+                for (rec = r2->records; rec; rec = rec->next)
+                    if (pos2 == 0 || rec->position < pos2)
+                        pos2 = rec->position;
+                if (s->increasing)
+                    res = pos1 - pos2;
+                else
+                    res = pos2 - pos1;
+            }
+            break;
         default:
             yaz_log(YLOG_WARN, "Bad sort type: %d", s->type);
             res = 0;