Applied Merijn van den Kroonenberg's patch. Bug #2202.
[idzebra-moved-to-github.git] / index / zsets.c
index c4ee2ff..9054cfe 100644 (file)
@@ -1,8 +1,5 @@
-/* $Id: zsets.c,v 1.111 2006-09-20 10:51:25 adam Exp $
-   Copyright (C) 1995-2006
-   Index Data ApS
-
-This file is part of the Zebra server.
+/* This file is part of the Zebra server.
+   Copyright (C) 1995-2008 Index Data
 
 Zebra is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free
@@ -50,7 +47,7 @@ struct zebra_set {
     NMEM rset_nmem; /* for creating the rsets in */
     zint hits;
     int num_bases;
-    char **basenames;
+    const char **basenames;
     Z_RPNQuery *rpn;
     Z_SortKeySpecList *sortSpec;
     struct zset_sort_info *sort_info;
@@ -58,6 +55,7 @@ struct zebra_set {
     int term_entries_max;
     struct zebra_set *next;
     int locked;
+    int estimated_hit_count;
 
     zint cache_position;  /* last position */
     RSFD cache_rfd;       /* rfd (NULL if not existing) */
@@ -83,7 +81,7 @@ static int log_level_searchhits=0;
 static int log_level_searchterms=0;
 static int log_level_resultsets=0;
 
-static void loglevels()
+static void loglevels(void)
 {
     if (log_level_set)
         return;
@@ -94,17 +92,15 @@ static void loglevels()
     log_level_set = 1;
 }
 
-ZEBRA_RES resultSetSearch(ZebraHandle zh, NMEM nmem, NMEM rset_nmem,
-                         Z_RPNQuery *rpn, ZebraSet sset)
+
+static ZEBRA_RES resultSetSearch(ZebraHandle zh, NMEM nmem, NMEM rset_nmem,
+                                 Z_RPNQuery *rpn, ZebraSet sset)
 {
     RSET rset = 0;
-    oident *attrset;
     Z_SortKeySpecList *sort_sequence;
     int sort_status, i;
     ZEBRA_RES res = ZEBRA_OK;
 
-    zh->hits = 0;
-
     sort_sequence = (Z_SortKeySpecList *)
         nmem_malloc(nmem, sizeof(*sort_sequence));
     sort_sequence->num_specs = 10; /* FIXME - Hard-coded number */
@@ -114,8 +110,9 @@ ZEBRA_RES resultSetSearch(ZebraHandle zh, NMEM nmem, NMEM rset_nmem,
     for (i = 0; i<sort_sequence->num_specs; i++)
         sort_sequence->specs[i] = 0;
     
-    attrset = oid_getentbyoid (rpn->attributeSetId);
-    res = rpn_search_top(zh, rpn->RPNStructure, attrset->value,
+    rpn_get_top_approx_limit(zh, rpn->RPNStructure, &sset->approx_limit);
+
+    res = rpn_search_top(zh, rpn->RPNStructure, rpn->attributeSetId,
                         nmem, rset_nmem,
                         sort_sequence,
                         sset->num_bases, sset->basenames,
@@ -131,11 +128,11 @@ ZEBRA_RES resultSetSearch(ZebraHandle zh, NMEM nmem, NMEM rset_nmem,
     rset->hits_limit = sset->approx_limit;
     if (!i)
     {
-        res = resultSetRank (zh, sset, rset, rset_nmem);
+        res = resultSetRank(zh, sset, rset, rset_nmem);
     }
     else
     {
-        res = resultSetSortSingle (zh, nmem, sset, rset,
+        res = resultSetSortSingle(zh, nmem, sset, rset,
                                   sort_sequence, &sort_status);
     }
     sset->rset = rset;
@@ -143,15 +140,17 @@ ZEBRA_RES resultSetSearch(ZebraHandle zh, NMEM nmem, NMEM rset_nmem,
 }
 
 
-ZEBRA_RES resultSetAddRPN (ZebraHandle zh, NMEM m, Z_RPNQuery *rpn,
-                          int num_bases, char **basenames,
-                          const char *setname)
+ZEBRA_RES resultSetAddRPN(ZebraHandle zh, NMEM m, Z_RPNQuery *rpn,
+                          int num_bases, char **basenames,
+                          const char *setname,
+                          zint *hits, int *estimated_hit_count)
 {
     ZebraSet zebraSet;
     int i;
     ZEBRA_RES res;
 
-    zh->hits = 0;
+    *hits = 0;
+    *estimated_hit_count = 0;
 
     zebraSet = resultSetAdd(zh, setname, 1);
     if (!zebraSet)
@@ -163,13 +162,16 @@ ZEBRA_RES resultSetAddRPN (ZebraHandle zh, NMEM m, Z_RPNQuery *rpn,
 
     zebraSet->num_bases = num_bases;
     zebraSet->basenames = 
-        nmem_malloc (zebraSet->nmem, num_bases * sizeof(*zebraSet->basenames));
+        nmem_malloc(zebraSet->nmem, num_bases * sizeof(*zebraSet->basenames));
     for (i = 0; i<num_bases; i++)
         zebraSet->basenames[i] = nmem_strdup(zebraSet->nmem, basenames[i]);
 
     res = resultSetSearch(zh, zebraSet->nmem, zebraSet->rset_nmem,
                          rpn, zebraSet);
-    zh->hits = zebraSet->hits;
+    *hits = zebraSet->hits;
+    if (zebraSet->estimated_hit_count)
+        *estimated_hit_count = 1;
+
     if (zebraSet->rset)
         zebraSet->rpn = rpn;
     zebraSet->locked = 0;
@@ -184,13 +186,13 @@ void resultSetAddTerm(ZebraHandle zh, ZebraSet s, int reg_type,
 {
     assert(zh); /* compiler shut up */
     if (!s->nmem)
-        s->nmem = nmem_create ();
+        s->nmem = nmem_create();
     if (!s->term_entries)
     {
         int i;
         s->term_entries_max = 1000;
         s->term_entries =
-            nmem_malloc (s->nmem, s->term_entries_max * 
+            nmem_malloc(s->nmem, s->term_entries_max * 
                          sizeof(*s->term_entries));
         for (i = 0; i < s->term_entries_max; i++)
             s->term_entries[i].term = 0;
@@ -198,7 +200,7 @@ void resultSetAddTerm(ZebraHandle zh, ZebraSet s, int reg_type,
     if (s->hits < s->term_entries_max)
     {
         s->term_entries[s->hits].reg_type = reg_type;
-        s->term_entries[s->hits].db = nmem_strdup (s->nmem, db);
+        s->term_entries[s->hits].db = nmem_strdup(s->nmem, db);
         s->term_entries[s->hits].index_name = nmem_strdup(s->nmem, index_name);
         s->term_entries[s->hits].term = nmem_strdup(s->nmem, term);
     }
@@ -211,7 +213,7 @@ ZebraSet resultSetAdd(ZebraHandle zh, const char *name, int ov)
     int i;
 
     for (s = zh->sets; s; s = s->next)
-        if (!strcmp (s->name, name))
+        if (!strcmp(s->name, name))
             break;
     
     if (!log_level_set)
@@ -225,35 +227,34 @@ ZebraSet resultSetAdd(ZebraHandle zh, const char *name, int ov)
        {
            if (s->cache_rfd)
                rset_close(s->cache_rfd);
-            rset_delete (s->rset);
+            rset_delete(s->rset);
        }
         if (s->rset_nmem)
-            nmem_destroy (s->rset_nmem);
+            nmem_destroy(s->rset_nmem);
         if (s->nmem)
-            nmem_destroy (s->nmem);
+            nmem_destroy(s->nmem);
     }
     else
     {
         const char *sort_max_str = zebra_get_resource(zh, "sortmax", "1000");
 
         yaz_log(log_level_resultsets, "adding result set %s", name);
-        s = (ZebraSet) xmalloc (sizeof(*s));
+        s = (ZebraSet) xmalloc(sizeof(*s));
         s->next = zh->sets;
         zh->sets = s;
-        s->name = (char *) xmalloc (strlen(name)+1);
-        strcpy (s->name, name);
+        s->name = xstrdup(name);
 
         s->sort_info = (struct zset_sort_info *)
-            xmalloc (sizeof(*s->sort_info));
+            xmalloc(sizeof(*s->sort_info));
         s->sort_info->max_entries = atoi(sort_max_str);
         if (s->sort_info->max_entries < 2)
             s->sort_info->max_entries = 2;
 
         s->sort_info->entries = (struct zset_sort_entry **)
-            xmalloc (sizeof(*s->sort_info->entries) *
+            xmalloc(sizeof(*s->sort_info->entries) *
                      s->sort_info->max_entries);
         s->sort_info->all_entries = (struct zset_sort_entry *)
-            xmalloc (sizeof(*s->sort_info->all_entries) *
+            xmalloc(sizeof(*s->sort_info->all_entries) *
                      s->sort_info->max_entries);
         for (i = 0; i < s->sort_info->max_entries; i++)
             s->sort_info->entries[i] = s->sort_info->all_entries + i;
@@ -269,6 +270,7 @@ ZebraSet resultSetAdd(ZebraHandle zh, const char *name, int ov)
     s->cache_position = 0;
     s->cache_rfd = 0;
     s->approx_limit = zh->approx_limit;
+    s->estimated_hit_count = 0;
     return s;
 }
 
@@ -277,30 +279,42 @@ ZebraSet resultSetGet(ZebraHandle zh, const char *name)
     ZebraSet s;
 
     for (s = zh->sets; s; s = s->next)
-        if (!strcmp (s->name, name))
+        if (!strcmp(s->name, name))
         {
             if (!s->term_entries && !s->rset && s->rpn)
             {
-                NMEM nmem = nmem_create ();
+                NMEM nmem = nmem_create();
                 yaz_log(log_level_resultsets, "research %s", name);
                 if (!s->rset_nmem)
-                    s->rset_nmem=nmem_create();
+                    s->rset_nmem = nmem_create();
                resultSetSearch(zh, nmem, s->rset_nmem, s->rpn, s);
                if (s->rset && s->sortSpec)
                {
                    int sort_status;
                    yaz_log(log_level_resultsets, "resort %s", name);
-                   resultSetSortSingle (zh, nmem, s, s->rset, s->sortSpec,
+                   resultSetSortSingle(zh, nmem, s, s->rset, s->sortSpec,
                                         &sort_status);
                }
-                nmem_destroy (nmem);
+                nmem_destroy(nmem);
             }
             return s;
         }
     return NULL;
 }
 
-void resultSetInvalidate (ZebraHandle zh)
+ZEBRA_RES resultSetGetBaseNames(ZebraHandle zh, const char *setname,
+                                const char ***basenames, int *num_bases)
+{
+    ZebraSet sset = resultSetGet(zh, setname);
+    if (!sset)
+        return ZEBRA_FAIL;
+    *basenames = sset->basenames;
+    *num_bases = sset->num_bases;
+    return ZEBRA_OK;
+
+}
+
+void resultSetInvalidate(ZebraHandle zh)
 {
     ZebraSet s = zh->sets;
     
@@ -311,7 +325,7 @@ void resultSetInvalidate (ZebraHandle zh)
        {
            if (s->cache_rfd)
                rset_close(s->cache_rfd);
-            rset_delete (s->rset);
+            rset_delete(s->rset);
        }
         s->rset = 0;
        s->cache_rfd = 0;
@@ -337,7 +351,7 @@ void resultSetDestroy(ZebraHandle zh, int num, char **names,int *statuses)
         if (num >= 0)
         {
             for (i = 0; i<num; i++)
-                if (!strcmp (s->name, names[i]))
+                if (!strcmp(s->name, names[i]))
                 {
                     if (statuses)
                         statuses[i] = Z_DeleteStatus_success;
@@ -349,22 +363,22 @@ void resultSetDestroy(ZebraHandle zh, int num, char **names,int *statuses)
         {
             *ss = s->next;
             
-            xfree (s->sort_info->all_entries);
-            xfree (s->sort_info->entries);
-            xfree (s->sort_info);
+            xfree(s->sort_info->all_entries);
+            xfree(s->sort_info->entries);
+            xfree(s->sort_info);
             
             if (s->nmem)
-                nmem_destroy (s->nmem);
+                nmem_destroy(s->nmem);
             if (s->rset)
            {
                if (s->cache_rfd)
                    rset_close(s->cache_rfd);
-                rset_delete (s->rset);
+                rset_delete(s->rset);
            }
             if (s->rset_nmem)
                 nmem_destroy(s->rset_nmem);
-            xfree (s->name);
-            xfree (s);
+            xfree(s->name);
+            xfree(s);
         }
         else
             ss = &s->next;
@@ -411,13 +425,13 @@ ZebraMetaRecord *zebra_meta_records_create(ZebraHandle zh, const char *name,
 
     if (!log_level_set)
         loglevels();
-    if (!(sset = resultSetGet (zh, name)))
+    if (!(sset = resultSetGet(zh, name)))
         return NULL;
     if (!(rset = sset->rset))
     {
         if (!sset->term_entries)
             return 0;
-        sr = (ZebraMetaRecord *) xmalloc (sizeof(*sr) * num);
+        sr = (ZebraMetaRecord *) xmalloc(sizeof(*sr) * num);
         for (i = 0; i<num; i++)
         {
             sr[i].sysno = 0;
@@ -434,7 +448,7 @@ ZebraMetaRecord *zebra_meta_records_create(ZebraHandle zh, const char *name,
     }
     else
     {
-        sr = (ZebraMetaRecord *) xmalloc (sizeof(*sr) * num);
+        sr = (ZebraMetaRecord *) xmalloc(sizeof(*sr) * num);
         for (i = 0; i<num; i++)
         {
             sr[i].sysno = 0;
@@ -489,9 +503,9 @@ ZebraMetaRecord *zebra_meta_records_create(ZebraHandle zh, const char *name,
            {
                if (sset->cache_rfd)
                    rset_close(sset->cache_rfd);
-               rfd = rset_open (rset, RSETF_READ);
+               rfd = rset_open(rset, RSETF_READ);
            }
-            while (num_i < num && rset_read (rfd, &key, 0))
+            while (num_i < num && rset_read(rfd, &key, 0))
             {
                 zint this_sys = key.mem[sysno_mem_index];
                 if (this_sys != psysno)
@@ -507,7 +521,7 @@ ZebraMetaRecord *zebra_meta_records_create(ZebraHandle zh, const char *name,
                             continue;
                     }
                     position++;
-                    assert (num_i < num);
+                    assert(num_i < num);
                     if (position == positions[num_i])
                     {
                         sr[num_i].sysno = psysno;
@@ -525,38 +539,72 @@ ZebraMetaRecord *zebra_meta_records_create(ZebraHandle zh, const char *name,
     return sr;
 }
 
-void zebra_meta_records_destroy (ZebraHandle zh, ZebraMetaRecord *records,
+void zebra_meta_records_destroy(ZebraHandle zh, ZebraMetaRecord *records,
                                 int num)
 {
     assert(zh); /* compiler shut up about unused arg */
-    xfree (records);
+    xfree(records);
 }
 
 struct sortKeyInfo {
     int relation;
-    int ord;
-    int numerical;
-    int index_type;
+    int *ord; // array of ord for each database searched
+    int *numerical;// array of ord for each database searched
+    const char *index_type;
 };
 
 void resultSetInsertSort(ZebraHandle zh, ZebraSet sset,
                          struct sortKeyInfo *criteria, int num_criteria,
                          zint sysno,
-                         char *cmp_buf[], char *tmp_cmp_buf[])
+                         char *cmp_buf[], char *tmp_cmp_buf[], int *cached_success_db)
 {
     struct zset_sort_entry *new_entry = NULL;
     struct zset_sort_info *sort_info = sset->sort_info;
     int i, j;
+    int scan_db,scan_count;
+    int numbases = zh->num_basenames;
 
-    sortIdx_sysno (zh->reg->sortIdx, sysno);
+    zebra_sort_sysno(zh->reg->sort_index, sysno);
     for (i = 0; i<num_criteria; i++)
     {
         char *this_entry_buf = tmp_cmp_buf[i];
         memset(this_entry_buf, '\0', SORT_IDX_ENTRYSIZE);
-        if (criteria[i].ord != -1)
+        
+        // if the first database doesn't have a sort index, we assume none of them will
+        if (criteria[i].ord[0] != -1)
         {
-            sortIdx_type(zh->reg->sortIdx, criteria[i].ord);
-            sortIdx_read(zh->reg->sortIdx, this_entry_buf);
+            // now make a best guess for the database in which we think the record is located
+            // if its not in our best guess, try the other databases one by one, till we had them all
+            scan_db=*cached_success_db;
+            scan_count=0;
+            
+            while(1){
+                scan_count++;
+                if(scan_count>numbases){
+                    // well...we scanned all databases and still nothing...give up
+                    yaz_log(log_level_sort, "zebra_sort_read failed (record not found in indices)");
+                    break;
+                }
+                
+                // the criteria[i].ord is the file id of the sort index
+                yaz_log(log_level_sort, "pre zebra_sort_type ord is %d", criteria[i].ord[scan_db]);
+                zebra_sort_type(zh->reg->sort_index, criteria[i].ord[scan_db]);
+                if(zebra_sort_read(zh->reg->sort_index, this_entry_buf)){
+                    // allright, found it
+                    // cache this db so we start trying from this db for next record
+                    *cached_success_db=scan_db;
+                    break;
+                }else{
+                    yaz_log(log_level_sort, "record not found in database, trying next one");
+                    scan_db++;
+                    if(scan_db>=numbases){
+                      scan_db=0;
+                    }
+                }
+            }
+            
+        }else{
+            yaz_log(log_level_sort, "criteria[i].ord is -1 so not reading from sort index");
         }
     }
     i = sort_info->num_entries;
@@ -568,12 +616,16 @@ void resultSetInsertSort(ZebraHandle zh, ZebraSet sset,
             char *this_entry_buf = tmp_cmp_buf[j];
             char *other_entry_buf = 
                 cmp_buf[j] + i * SORT_IDX_ENTRYSIZE;
-            if (criteria[j].numerical)
+            if (criteria[j].numerical[*cached_success_db])
             {
                 char this_entry_org[1024];
                 char other_entry_org[1024];
                 double diff;
-                int index_type = criteria[j].index_type;
+                // when searching multiple databases, we use the index type of
+                // the first one. So if they differ between databases, we have a problem here
+                // we could store the index_type for each database, but if we didn't find the
+                // record in any sort index, then we still don't know to which database it belongs.
+                const char *index_type = criteria[j].index_type;
                 zebra_term_untrans(zh, index_type, this_entry_org,
                                    this_entry_buf);
                 zebra_term_untrans(zh, index_type, other_entry_org,
@@ -592,6 +644,7 @@ void resultSetInsertSort(ZebraHandle zh, ZebraSet sset,
                 rel = memcmp(this_entry_buf, other_entry_buf,
                              SORT_IDX_ENTRYSIZE);
             }
+            // when the compare is equal, continue to next criteria, else break out
             if (rel)
                 break;
         }       
@@ -609,15 +662,19 @@ void resultSetInsertSort(ZebraHandle zh, ZebraSet sset,
         }
     }
     ++i;
+    yaz_log(log_level_sort, "ok, we want to insert record at position %d",i);
     j = sort_info->max_entries;
-    if (i == j)
+    if (i == j){
+        yaz_log(log_level_sort, "sort_info->max_entries reached (%d) abort sort",j);
         return;
+    }
 
     if (sort_info->num_entries == j)
         --j;
     else
         j = (sort_info->num_entries)++;
     new_entry = sort_info->entries[j];
+    // move up all higher entries (to make room)
     while (j != i)
     {
         int k;
@@ -630,8 +687,10 @@ void resultSetInsertSort(ZebraHandle zh, ZebraSet sset,
         sort_info->entries[j] = sort_info->entries[j-1];
         --j;
     }
+    // and insert the new entry at the correct place
     sort_info->entries[i] = new_entry;
-    assert (new_entry);
+    assert(new_entry);
+    // and add this to the compare buffer
     for (i = 0; i<num_criteria; i++)
     {
         char *new_entry_buf = cmp_buf[i] + j * SORT_IDX_ENTRYSIZE;
@@ -684,7 +743,7 @@ void resultSetInsertRank(ZebraHandle zh, struct zset_sort_info *sort_info,
         --j;
     }
     sort_info->entries[i] = new_entry;
-    assert (new_entry);
+    assert(new_entry);
     new_entry->sysno = sysno;
     new_entry->score = score;
 }
@@ -749,7 +808,7 @@ ZebraSet resultSetClone(ZebraHandle zh, const char *setname,
 
     nset->num_bases = rset->num_bases;
     nset->basenames = 
-        nmem_malloc (nset->nmem, nset->num_bases * sizeof(*rset->basenames));
+        nmem_malloc(nset->nmem, nset->num_bases * sizeof(*rset->basenames));
     for (i = 0; i<rset->num_bases; i++)
         nset->basenames[i] = nmem_strdup(nset->nmem, rset->basenames[i]);
 
@@ -782,7 +841,7 @@ ZEBRA_RES resultSetSort(ZebraHandle zh, NMEM nmem,
         loglevels();
     yaz_log(log_level_sort, "result set sort input=%s output=%s",
           *input_setnames, output_setname);
-    sset = resultSetGet (zh, input_setnames[0]);
+    sset = resultSetGet(zh, input_setnames[0]);
     if (!sset)
     {
        zebra_setError(zh, YAZ_BIB1_SPECIFIED_RESULT_SET_DOES_NOT_EXIST,
@@ -795,7 +854,7 @@ ZEBRA_RES resultSetSort(ZebraHandle zh, NMEM nmem,
                       input_setnames[0]);
        return ZEBRA_FAIL;
     }
-    if (strcmp (output_setname, input_setnames[0]))
+    if (strcmp(output_setname, input_setnames[0]))
        sset = resultSetClone(zh, output_setname, sset);
     sset->sortSpec = copy_SortKeySpecList(sort_sequence, sset->nmem);
     return resultSetSortSingle (zh, nmem, sset, rset, sort_sequence,
@@ -808,6 +867,8 @@ ZEBRA_RES resultSetSortSingle(ZebraHandle zh, NMEM nmem,
                              int *sort_status)
 {
     int i;
+    int ib;
+    int cached_success_db = 0;
     int n = 0;
     zint kno = 0;
     zint psysno = 0;
@@ -821,6 +882,9 @@ ZEBRA_RES resultSetSortSingle(ZebraHandle zh, NMEM nmem,
     TERMID *terms;
     int numTerms = 0;
     size_t sysno_mem_index = 0;
+    
+    int numbases = zh->num_basenames;
+    yaz_log(log_level_sort, "searching %d databases",numbases);
 
     if (zh->m_staticrank)
        sysno_mem_index = 1;
@@ -836,14 +900,22 @@ ZEBRA_RES resultSetSortSingle(ZebraHandle zh, NMEM nmem,
     num_criteria = sort_sequence->num_specs;
     if (num_criteria > ZSET_SORT_MAX_LEVEL)
         num_criteria = ZSET_SORT_MAX_LEVEL;
+    // set up the search criteria
     for (i = 0; i < num_criteria; i++)
     {
         Z_SortKeySpec *sks = sort_sequence->specs[i];
         Z_SortKey *sk;
         ZEBRA_RES res;
-
-        sort_criteria[i].ord = -1;
-        sort_criteria[i].numerical = 0;
+        
+        sort_criteria[i].ord = (int *)xmalloc(sizeof(int)*numbases);
+        sort_criteria[i].numerical = (int *)xmalloc(sizeof(int)*numbases);
+        
+        // initialize ord and numerical for each database
+        for (ib = 0; ib < numbases; ib++)
+        {
+          sort_criteria[i].ord[ib] = -1;
+          sort_criteria[i].numerical[ib] = 0;
+        }
 
         if (sks->which == Z_SortKeySpec_missingValueData)
         {
@@ -875,17 +947,21 @@ ZEBRA_RES resultSetSortSingle(ZebraHandle zh, NMEM nmem,
         case Z_SortKey_sortField:
             yaz_log(log_level_sort, "key %d is of type sortField",
                    i+1);
-            sort_criteria[i].numerical = 0;
-            sort_criteria[i].ord = 
-                zebraExplain_lookup_attr_str(zh->reg->zei,
-                                             zinfo_index_category_sort,
-                                             -1, sk->u.sortField);
-            if (sks->which != Z_SortKeySpec_null
-                && sort_criteria[i].ord == -1)
+            for (ib = 0; ib < numbases; ib++)
             {
-                zebra_setError(zh,
-                               YAZ_BIB1_CANNOT_SORT_ACCORDING_TO_SEQUENCE, 0);
-                return ZEBRA_FAIL;
+                zebraExplain_curDatabase(zh->reg->zei, zh->basenames[ib]);
+                sort_criteria[i].numerical[ib] = 0;
+                sort_criteria[i].ord[ib] = 
+                    zebraExplain_lookup_attr_str(zh->reg->zei,
+                                                 zinfo_index_category_sort,
+                                                 0, sk->u.sortField);
+                if (sks->which != Z_SortKeySpec_null
+                    && sort_criteria[i].ord[ib] == -1)
+                {
+                    zebra_setError(zh,
+                                   YAZ_BIB1_CANNOT_SORT_ACCORDING_TO_SEQUENCE, 0);
+                    return ZEBRA_FAIL;
+                }
             }
             break;
         case Z_SortKey_elementSpec:
@@ -895,15 +971,24 @@ ZEBRA_RES resultSetSortSingle(ZebraHandle zh, NMEM nmem,
             return ZEBRA_FAIL;
         case Z_SortKey_sortAttributes:
             yaz_log(log_level_sort, "key %d is of type sortAttributes", i+1);
-            res = zebra_sort_get_ord(zh, sk->u.sortAttributes,
-
-                                     &sort_criteria[i].ord,
-                                     &sort_criteria[i].numerical);
+            // for every database we searched, get the sort index file id (ord)
+            // and its numerical indication and store them in the sort_criteria
+            for (ib = 0; ib < numbases; ib++)
+            {
+                zebraExplain_curDatabase(zh->reg->zei, zh->basenames[ib]);
+                res = zebra_sort_get_ord(zh, sk->u.sortAttributes,
+                                       &sort_criteria[i].ord[ib],
+                                       &sort_criteria[i].numerical[ib]);
+            }
+            
             if (sks->which != Z_SortKeySpec_null && res != ZEBRA_OK)
                 return ZEBRA_FAIL;
             break;
         }
-        if (zebraExplain_lookup_ord(zh->reg->zei, sort_criteria[i].ord,
+        // right now we look up the index type based on the first database
+        // if the index_type's can differ between the indexes of different databases (which i guess they can?)
+        // then we have to store the index types for each database, just like the ord and numerical
+        if (zebraExplain_lookup_ord(zh->reg->zei, sort_criteria[i].ord[0],
                                     &sort_criteria[i].index_type,
                                     0, 0))
         {
@@ -912,14 +997,18 @@ ZEBRA_RES resultSetSortSingle(ZebraHandle zh, NMEM nmem,
         }
     }
     /* allocate space for each cmpare buf + one extra for tmp comparison */
+    /* cmp_buf is an array of array, the first dimension is the criteria and the second dimension are
+       all other result entries to compare against. This is slowly filled when records are processed.
+       tmp_cmp_buf is an array with a value of the current record for each criteria
+    */
     for (i = 0; i<num_criteria; i++)
     {
         cmp_buf[i] = xmalloc(sset->sort_info->max_entries
                              * SORT_IDX_ENTRYSIZE);
         tmp_cmp_buf[i] = xmalloc(SORT_IDX_ENTRYSIZE);
     }
-    rfd = rset_open (rset, RSETF_READ);
-    while (rset_read (rfd, &key, &termid))
+    rfd = rset_open(rset, RSETF_READ);
+    while (rset_read(rfd, &key, &termid))
     {
         zint this_sys = key.mem[sysno_mem_index];
        if (log_level_searchhits)
@@ -927,19 +1016,31 @@ ZEBRA_RES resultSetSortSingle(ZebraHandle zh, NMEM nmem,
        kno++;
         if (this_sys != psysno)
         {
+            if ((sset->hits & 255) == 0 && zh->break_handler_func)
+            {
+                if (zh->break_handler_func(zh->break_handler_data))
+                {
+                    rset_set_hits_limit(rset, 0);
+                    break;
+                }
+            }
             (sset->hits)++;
             psysno = this_sys;
             resultSetInsertSort(zh, sset,
                                 sort_criteria, num_criteria, psysno, cmp_buf,
-                                tmp_cmp_buf);
+                                tmp_cmp_buf, &cached_success_db);
         }
     }
-    rset_close (rfd);
+    rset_close(rfd);
 
+    // free the compare buffers
     for (i = 0; i<num_criteria; i++)
     {
         xfree(cmp_buf[i]);
         xfree(tmp_cmp_buf[i]);
+        // and the criteria
+        xfree(sort_criteria[i].ord);
+        xfree(sort_criteria[i].numerical);
     }
 
     yaz_log(log_level_sort, ZINT_FORMAT " keys, " ZINT_FORMAT " sysnos, sort",
@@ -955,7 +1056,7 @@ RSET resultSetRef(ZebraHandle zh, const char *resultSetId)
 {
     ZebraSet s;
 
-    if ((s = resultSetGet (zh, resultSetId)))
+    if ((s = resultSetGet(zh, resultSetId)))
         return s->rset;
     return NULL;
 }
@@ -983,11 +1084,11 @@ ZEBRA_RES resultSetRank(ZebraHandle zh, ZebraSet zebraSet,
     sort_info = zebraSet->sort_info;
     sort_info->num_entries = 0;
     zebraSet->hits = 0;
+    zebraSet->estimated_hit_count = 0;
     rset_getterms(rset, 0, 0, &n);
     terms = (TERMID *) nmem_malloc(nmem, sizeof(*terms)*n);
     rset_getterms(rset, terms, n, &numTerms);
 
-
     rank_class = zebraRankLookup(zh, rank_handler_name);
     if (!rank_class)
     {
@@ -1001,10 +1102,8 @@ ZEBRA_RES resultSetRank(ZebraHandle zh, ZebraSet zebraSet,
        struct rank_control *rc = rank_class->control;
        int score;
        zint count = 0;
-       
-       void *handle =
-           (*rc->begin) (zh->reg, rank_class->class_handle, rset, nmem,
-                         terms, numTerms);
+        void *handle = (*rc->begin) (zh->reg, rank_class->class_handle, rset,
+                                     nmem, terms, numTerms);
        zint psysno = 0;  /* previous doc id / sys no */
        zint pstaticrank = 0; /* previous static rank */
        int stop_flag = 0;
@@ -1018,23 +1117,35 @@ ZEBRA_RES resultSetRank(ZebraHandle zh, ZebraSet zebraSet,
                key_logdump_txt(log_level_searchhits, &key, termid->name);
            if (this_sys != psysno) 
            {   /* new record .. */
+                if (!(rfd->counted_items & 255) && zh->break_handler_func)
+                {
+                    if (zh->break_handler_func(zh->break_handler_data))
+                    {
+                        yaz_log(YLOG_LOG, "Aborted search");
+                        stop_flag = 1;
+                    }
+                }
                if (rfd->counted_items > rset->hits_limit)
-                   break;
+                    stop_flag = 1;
                if (psysno)
                {   /* only if we did have a previous record */
-                   score = (*rc->calc) (handle, psysno, pstaticrank,
+                   score = (*rc->calc)(handle, psysno, pstaticrank,
                                         &stop_flag);
                    /* insert the hit. A=Ascending */
-                   resultSetInsertRank (zh, sort_info, psysno, score, 'A');
+                   resultSetInsertRank(zh, sort_info, psysno, score, 'A');
                    count++;
-                   if (stop_flag)
-                       break;
                }
+                if (stop_flag)
+                {
+                    zebraSet->estimated_hit_count = 1;
+                    rset_set_hits_limit(rset, 0);
+                    break;
+                }
                psysno = this_sys;
                if (zh->m_staticrank)
                    pstaticrank = key.mem[0];
            }
-           (*rc->add) (handle, CAST_ZINT_TO_INT(seqno), termid);
+           (*rc->add)(handle, CAST_ZINT_TO_INT(seqno), termid);
        }
        /* no more items */
        if (psysno)
@@ -1044,8 +1155,8 @@ ZEBRA_RES resultSetRank(ZebraHandle zh, ZebraSet zebraSet,
            resultSetInsertRank(zh, sort_info, psysno, score, 'A');
            count++;
        }
-       (*rc->end) (zh->reg, handle);
-       rset_close (rfd);
+       (*rc->end)(zh->reg, handle);
+       rset_close(rfd);
     }
     zebraSet->hits = rset->hits_count;
 
@@ -1063,7 +1174,7 @@ ZEBRA_RES resultSetRank(ZebraHandle zh, ZebraSet zebraSet,
 ZebraRankClass zebraRankLookup(ZebraHandle zh, const char *name)
 {
     ZebraRankClass p = zh->reg->rank_classes;
-    while (p && strcmp (p->control->name, name))
+    while (p && strcmp(p->control->name, name))
         p = p->next;
     if (p && !p->init_flag)
     {
@@ -1076,10 +1187,10 @@ ZebraRankClass zebraRankLookup(ZebraHandle zh, const char *name)
 
 void zebraRankInstall(struct zebra_register *reg, struct rank_control *ctrl)
 {
-    ZebraRankClass p = (ZebraRankClass) xmalloc (sizeof(*p));
-    p->control = (struct rank_control *) xmalloc (sizeof(*p->control));
-    memcpy (p->control, ctrl, sizeof(*p->control));
-    p->control->name = xstrdup (ctrl->name);
+    ZebraRankClass p = (ZebraRankClass) xmalloc(sizeof(*p));
+    p->control = (struct rank_control *) xmalloc(sizeof(*p->control));
+    memcpy(p->control, ctrl, sizeof(*p->control));
+    p->control->name = xstrdup(ctrl->name);
     p->init_flag = 0;
     p->next = reg->rank_classes;
     reg->rank_classes = p;
@@ -1180,7 +1291,11 @@ ZEBRA_RES zebra_result_set_term_info(ZebraHandle zh, const char *setname,
                    if (ret == (size_t)(-1))
                        *termlen = 0;
                    else
+                    {
+                       yaz_iconv(zh->iconv_from_utf8, 0, 0, 
+                                  &outbuf, &outleft);
                        *termlen = outbuf - termbuf;
+                    }
                }
                else
                {
@@ -1218,7 +1333,7 @@ ZEBRA_RES zebra_snippets_hit_vector(ZebraHandle zh, const char *setname,
        struct it_key key;
        RSET rsets[2], rset_comb;
        RSET rset_temp = rset_create_temp(nmem, kc, kc->scope, 
-                                          res_get (zh->res, "setTmpDir"),0 );
+                                          res_get(zh->res, "setTmpDir"),0 );
        
        TERMID termid;
        RSFD rsfd = rset_open(rset_temp, RSETF_WRITE);
@@ -1228,8 +1343,8 @@ ZEBRA_RES zebra_snippets_hit_vector(ZebraHandle zh, const char *setname,
        key.mem[2] = 0;
        key.mem[3] = 0;
        key.len = 2;
-       rset_write (rsfd, &key);
-       rset_close (rsfd);
+       rset_write(rsfd, &key);
+       rset_close(rsfd);
 
        rsets[0] = rset_temp;
        rsets[1] = rset_dup(sset->rset);
@@ -1245,7 +1360,7 @@ ZEBRA_RES zebra_snippets_hit_vector(ZebraHandle zh, const char *setname,
                struct ord_list *ol;
                for (ol = termid->ol; ol; ol = ol->next)
                {
-                   zebra_snippets_append(snippets, key.mem[key.len-1],
+                   zebra_snippets_append(snippets, key.mem[key.len-1], 0,
                                          ol->ord, termid->name);
                }
            }
@@ -1259,6 +1374,135 @@ ZEBRA_RES zebra_snippets_hit_vector(ZebraHandle zh, const char *setname,
     return ZEBRA_OK;
 }
 
+static ZEBRA_RES zebra_recid_to_sysno(ZebraHandle zh, 
+                                      const char **basenames, int num_bases,
+                                      zint recid,
+                                      zint *sysnos, int *no_sysnos)
+{
+    ZEBRA_RES res = ZEBRA_OK;
+    int sysnos_offset = 0;
+    int i;
+    
+    if (!zh->reg->isamb || !zh->m_segment_indexing)
+    {
+        if (sysnos_offset < *no_sysnos)
+            *sysnos = recid;
+        sysnos_offset++;
+    }
+    else
+    {
+        for (i = 0; res == ZEBRA_OK && i < num_bases; i++)
+        {
+            const char *database = basenames[i];
+            if (zebraExplain_curDatabase(zh->reg->zei, database) == 0)
+            {
+                const char *index_type = "w";
+                const char *use_string = "_ALLRECORDS";
+                int ord;
+                zinfo_index_category_t cat = zinfo_index_category_alwaysmatches;
+                ord = zebraExplain_lookup_attr_str(zh->reg->zei, cat,
+                                                   index_type, use_string);
+                if (ord != -1)
+                {
+                    char ord_buf[32];
+                    int ord_len = key_SU_encode(ord, ord_buf);
+                    char *info;
+                
+                    ord_buf[ord_len] = '\0';
+                
+                    info = dict_lookup(zh->reg->dict, ord_buf);
+                    if (info)
+                    {
+                        if (*info != sizeof(ISAM_P))
+                        {
+                            res = ZEBRA_FAIL;
+                        }
+                        else
+                        {
+                            ISAM_P isam_p;
+                            ISAMB_PP pt;
+                            struct it_key key_until, key_found;
+                            int i = 0;
+                            int r;
+                        
+                            memcpy(&isam_p, info+1, sizeof(ISAM_P));
+                        
+                            pt = isamb_pp_open(zh->reg->isamb, isam_p, 2);
+                            if (!pt)
+                                res = ZEBRA_FAIL;
+                            else
+                            {
+                                key_until.mem[i++] = recid;
+                                key_until.mem[i++] = 0;  /* section_id */
+                                if (zh->m_segment_indexing)
+                                    key_until.mem[i++] = 0; /* segment */
+                                key_until.mem[i++] = 0;
+                                key_until.len = i;
+                            
+                                r = isamb_pp_forward(pt, &key_found, &key_until);
+                                while (r && key_found.mem[0] == recid)
+                                {
+                                    if (sysnos_offset < *no_sysnos)
+                                        sysnos[sysnos_offset++] = 
+                                            key_found.mem[key_found.len-1];
+                                    r = isamb_pp_read(pt, &key_found);
+                                }
+                                isamb_pp_close(pt);
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+    *no_sysnos = sysnos_offset;
+    return res;
+}
+
+ZEBRA_RES zebra_result_recid_to_sysno(ZebraHandle zh, 
+                                      const char *setname,
+                                      zint recid,
+                                      zint *sysnos, int *no_sysnos)
+{
+    const char **basenames;
+    int num_bases;
+    ZEBRA_RES res;
+
+    res = resultSetGetBaseNames(zh, setname, &basenames, &num_bases);
+    if (res != ZEBRA_OK)
+        return ZEBRA_FAIL;
+
+    return zebra_recid_to_sysno(zh, basenames, num_bases,
+                                recid, sysnos, no_sysnos);
+}
+
+void zebra_count_set(ZebraHandle zh, RSET rset, zint *count,
+                     zint approx_limit)
+{
+    zint psysno = 0;
+    struct it_key key;
+    RSFD rfd;
+
+    yaz_log(YLOG_DEBUG, "count_set");
+
+    rset->hits_limit = approx_limit;
+
+    *count = 0;
+    rfd = rset_open(rset, RSETF_READ);
+    while (rset_read(rfd, &key,0 /* never mind terms */))
+    {
+        if (key.mem[0] != psysno)
+        {
+            psysno = key.mem[0];
+           if (rfd->counted_items >= rset->hits_limit)
+               break;
+        }
+    }
+    rset_close(rfd);
+    *count = rset->hits_count;
+}
+                   
+
 /*
  * Local variables:
  * c-basic-offset: 4