Split zrpn.c
[idzebra-moved-to-github.git] / index / scan.c
diff --git a/index/scan.c b/index/scan.c
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+/* $Id: scan.c,v 1.1 2006-09-21 08:39:14 adam Exp $
+   Copyright (C) 1995-2006
+   Index Data ApS
+
+This file is part of the Zebra server.
+
+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
+Software Foundation; either version 2, or (at your option) any later
+version.
+
+Zebra is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+*/
+
+#include <stdio.h>
+#include <assert.h>
+#ifdef WIN32
+#include <io.h>
+#endif
+#if HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#include <ctype.h>
+
+#include <yaz/diagbib1.h>
+#include "index.h"
+#include <zebra_xpath.h>
+#include <attrfind.h>
+#include <charmap.h>
+#include <rset.h>
+
+struct scan_info_entry {
+    char *term;
+    ISAM_P isam_p;
+};
+
+struct scan_info {
+    struct scan_info_entry *list;
+    ODR odr;
+    int before, after;
+    char prefix[20];
+};
+
+/* convert APT SCAN term to internal cmap */
+static ZEBRA_RES trans_scan_term(ZebraHandle zh, Z_AttributesPlusTerm *zapt,
+                                char *termz, int reg_type)
+{
+    char termz0[IT_MAX_WORD];
+
+    if (zapt_term_to_utf8(zh, zapt, termz0) == ZEBRA_FAIL)
+        return ZEBRA_FAIL;    /* error */
+    else
+    {
+        const char **map;
+        const char *cp = (const char *) termz0;
+        const char *cp_end = cp + strlen(cp);
+        const char *src;
+        int i = 0;
+        const char *space_map = NULL;
+        int len;
+            
+        while ((len = (cp_end - cp)) > 0)
+        {
+            map = zebra_maps_input(zh->reg->zebra_maps, reg_type, &cp, len, 0);
+            if (**map == *CHR_SPACE)
+                space_map = *map;
+            else
+            {
+                if (i && space_map)
+                    for (src = space_map; *src; src++)
+                        termz[i++] = *src;
+                space_map = NULL;
+                for (src = *map; *src; src++)
+                    termz[i++] = *src;
+            }
+        }
+        termz[i] = '\0';
+    }
+    return ZEBRA_OK;
+}
+
+static void count_set(ZebraHandle zh, RSET rset, zint *count)
+{
+    zint psysno = 0;
+    struct it_key key;
+    RSFD rfd;
+
+    yaz_log(YLOG_DEBUG, "count_set");
+
+    rset->hits_limit = zh->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;
+}
+
+static int scan_handle (char *name, const char *info, int pos, void *client)
+{
+    int len_prefix, idx;
+    struct scan_info *scan_info = (struct scan_info *) client;
+
+    len_prefix = strlen(scan_info->prefix);
+    if (memcmp (name, scan_info->prefix, len_prefix))
+        return 1;
+    if (pos > 0)
+       idx = scan_info->after - pos + scan_info->before;
+    else
+        idx = - pos - 1;
+
+    /* skip special terms.. of no interest */
+    if (name[len_prefix] < 4)
+        return 1;
+
+    if (idx < 0)
+       return 0;
+    scan_info->list[idx].term = (char *)
+        odr_malloc(scan_info->odr, strlen(name + len_prefix)+1);
+    strcpy(scan_info->list[idx].term, name + len_prefix);
+    assert (*info == sizeof(ISAM_P));
+    memcpy (&scan_info->list[idx].isam_p, info+1, sizeof(ISAM_P));
+    return 0;
+}
+
+
+#define RPN_MAX_ORDS 32
+
+ZEBRA_RES rpn_scan(ZebraHandle zh, ODR stream, Z_AttributesPlusTerm *zapt,
+                  oid_value attributeset,
+                  int num_bases, char **basenames,
+                  int *position, int *num_entries, ZebraScanEntry **list,
+                  int *is_partial, RSET limit_set, int return_zero)
+{
+    int i;
+    int pos = *position;
+    int num = *num_entries;
+    int before;
+    int after;
+    int base_no;
+    char termz[IT_MAX_WORD+20];
+    struct scan_info *scan_info_array;
+    ZebraScanEntry *glist;
+    int ords[RPN_MAX_ORDS], ord_no = 0;
+    int ptr[RPN_MAX_ORDS];
+
+    unsigned index_type;
+    char *search_type = NULL;
+    char rank_type[128];
+    int complete_flag;
+    int sort_flag;
+    NMEM rset_nmem = NULL; 
+    struct rset_key_control *kc = 0;
+
+    *list = 0;
+    *is_partial = 0;
+
+    if (attributeset == VAL_NONE)
+        attributeset = VAL_BIB1;
+
+    if (!limit_set)
+    {
+        AttrType termset;
+        int termset_value_numeric;
+        const char *termset_value_string;
+        attr_init_APT(&termset, zapt, 8);
+        termset_value_numeric =
+            attr_find_ex(&termset, NULL, &termset_value_string);
+        if (termset_value_numeric != -1)
+        {
+            char resname[32];
+            const char *termset_name = 0;
+            
+            if (termset_value_numeric != -2)
+            {
+                
+                sprintf(resname, "%d", termset_value_numeric);
+                termset_name = resname;
+            }
+            else
+                termset_name = termset_value_string;
+            
+            limit_set = resultSetRef (zh, termset_name);
+        }
+    }
+        
+    yaz_log(YLOG_DEBUG, "position = %d, num = %d set=%d",
+           pos, num, attributeset);
+        
+    if (zebra_maps_attr(zh->reg->zebra_maps, zapt, &index_type, &search_type,
+                       rank_type, &complete_flag, &sort_flag))
+    {
+        *num_entries = 0;
+       zebra_setError(zh, YAZ_BIB1_UNSUPP_ATTRIBUTE_TYPE, 0);
+        return ZEBRA_FAIL;
+    }
+    for (base_no = 0; base_no < num_bases && ord_no < RPN_MAX_ORDS; base_no++)
+    {
+       int ord;
+
+       if (zebraExplain_curDatabase (zh->reg->zei, basenames[base_no]))
+       {
+           zebra_setError(zh, YAZ_BIB1_DATABASE_UNAVAILABLE,
+                          basenames[base_no]);
+           *num_entries = 0;
+           return ZEBRA_FAIL;
+       }
+        if (zebra_apt_get_ord(zh, zapt, index_type, 0, attributeset, &ord) 
+            != ZEBRA_OK)
+            continue;
+        ords[ord_no++] = ord;
+    }
+    if (ord_no == 0)
+    {
+        *num_entries = 0;
+        return ZEBRA_FAIL;
+    }
+    /* prepare dictionary scanning */
+    if (num < 1)
+    {
+       *num_entries = 0;
+       return ZEBRA_OK;
+    }
+    before = pos-1;
+    if (before < 0)
+       before = 0;
+    after = 1+num-pos;
+    if (after < 0)
+       after = 0;
+    yaz_log(YLOG_DEBUG, "rpn_scan pos=%d num=%d before=%d "
+           "after=%d before+after=%d",
+           pos, num, before, after, before+after);
+    scan_info_array = (struct scan_info *)
+        odr_malloc(stream, ord_no * sizeof(*scan_info_array));
+    for (i = 0; i < ord_no; i++)
+    {
+        int j, prefix_len = 0;
+        int before_tmp = before, after_tmp = after;
+        struct scan_info *scan_info = scan_info_array + i;
+        struct rpn_char_map_info rcmi;
+
+        rpn_char_map_prepare (zh->reg, index_type, &rcmi);
+
+        scan_info->before = before;
+        scan_info->after = after;
+        scan_info->odr = stream;
+
+        scan_info->list = (struct scan_info_entry *)
+            odr_malloc(stream, (before+after) * sizeof(*scan_info->list));
+        for (j = 0; j<before+after; j++)
+            scan_info->list[j].term = NULL;
+
+        prefix_len += key_SU_encode (ords[i], termz + prefix_len);
+        termz[prefix_len] = 0;
+        strcpy(scan_info->prefix, termz);
+
+        if (trans_scan_term(zh, zapt, termz+prefix_len, index_type) == 
+            ZEBRA_FAIL)
+            return ZEBRA_FAIL;
+       
+        dict_scan(zh->reg->dict, termz, &before_tmp, &after_tmp,
+                 scan_info, scan_handle);
+    }
+    glist = (ZebraScanEntry *)
+        odr_malloc(stream, (before+after)*sizeof(*glist));
+
+    rset_nmem = nmem_create();
+    kc = zebra_key_control_create(zh);
+
+    /* consider terms after main term */
+    for (i = 0; i < ord_no; i++)
+        ptr[i] = before;
+    
+    *is_partial = 0;
+    for (i = 0; i<after; i++)
+    {
+        int j, j0 = -1;
+        const char *mterm = NULL;
+        const char *tst;
+        RSET rset = 0;
+       int lo = i + pos-1; /* offset in result list */
+
+       /* find: j0 is the first of the minimal values */
+        for (j = 0; j < ord_no; j++)
+        {
+            if (ptr[j] < before+after && ptr[j] >= 0 &&
+                (tst = scan_info_array[j].list[ptr[j]].term) &&
+                (!mterm || strcmp (tst, mterm) < 0))
+            {
+                j0 = j;
+                mterm = tst;
+            }
+        }
+        if (j0 == -1)
+            break;  /* no value found, stop */
+
+       /* get result set for first one , but only if it's within bounds */
+       if (lo >= 0)
+       {
+           /* get result set for first term */
+           zebra_term_untrans_iconv(zh, stream->mem, index_type,
+                                    &glist[lo].term, mterm);
+           rset = rset_trunc(zh, &scan_info_array[j0].list[ptr[j0]].isam_p, 1,
+                             glist[lo].term, strlen(glist[lo].term),
+                             NULL, 0, zapt->term->which, rset_nmem, 
+                             kc, kc->scope, 0, index_type, 0 /* hits_limit */,
+                             0 /* term_ref_id_str */);
+       }
+       ptr[j0]++; /* move index for this set .. */
+       /* get result set for remaining scan terms */
+        for (j = j0+1; j<ord_no; j++)
+        {
+            if (ptr[j] < before+after && ptr[j] >= 0 &&
+                (tst = scan_info_array[j].list[ptr[j]].term) &&
+                !strcmp (tst, mterm))
+            {
+               if (lo >= 0)
+               {
+                   RSET rsets[2];
+                   
+                   rsets[0] = rset;
+                   rsets[1] =
+                       rset_trunc(
+                           zh, &scan_info_array[j].list[ptr[j]].isam_p, 1,
+                           glist[lo].term,
+                           strlen(glist[lo].term), NULL, 0,
+                           zapt->term->which,rset_nmem,
+                           kc, kc->scope, 0, index_type, 0 /* hits_limit */,
+                           0 /* term_ref_id_str */ );
+                   rset = rset_create_or(rset_nmem, kc,
+                                          kc->scope, 0 /* termid */,
+                                          2, rsets);
+               }
+                ptr[j]++;
+            }
+        }
+       if (lo >= 0)
+       {
+           zint count;
+           /* merge with limit_set if given */
+           if (limit_set)
+           {
+               RSET rsets[2];
+               rsets[0] = rset;
+               rsets[1] = rset_dup(limit_set);
+               
+               rset = rset_create_and(rset_nmem, kc, kc->scope, 2, rsets);
+           }
+           /* count it */
+           count_set(zh, rset, &count);
+           glist[lo].occurrences = count;
+           rset_delete(rset);
+       }
+    }
+    if (i < after)
+    {
+       *num_entries -= (after-i);
+       *is_partial = 1;
+       if (*num_entries < 0)
+       {
+           (*kc->dec)(kc);
+           nmem_destroy(rset_nmem);
+           *num_entries = 0;
+           return ZEBRA_OK;
+       }
+    }
+    /* consider terms before main term */
+    for (i = 0; i<ord_no; i++)
+       ptr[i] = 0;
+    
+    for (i = 0; i<before; i++)
+    {
+       int j, j0 = -1;
+       const char *mterm = NULL;
+       const char *tst;
+       RSET rset;
+       int lo = before-1-i; /* offset in result list */
+       zint count;
+       
+       for (j = 0; j <ord_no; j++)
+       {
+           if (ptr[j] < before && ptr[j] >= 0 &&
+               (tst = scan_info_array[j].list[before-1-ptr[j]].term) &&
+               (!mterm || strcmp (tst, mterm) > 0))
+           {
+               j0 = j;
+                   mterm = tst;
+           }
+       }
+       if (j0 == -1)
+           break;
+       
+       zebra_term_untrans_iconv(zh, stream->mem, index_type,
+                                &glist[lo].term, mterm);
+       
+       rset = rset_trunc
+           (zh, &scan_info_array[j0].list[before-1-ptr[j0]].isam_p, 1,
+            glist[lo].term, strlen(glist[lo].term),
+            NULL, 0, zapt->term->which, rset_nmem,
+            kc, kc->scope, 0, index_type, 0 /* hits_limit */,
+            0 /* term_ref_id_str */);
+       
+       ptr[j0]++;
+       
+       for (j = j0+1; j<ord_no; j++)
+       {
+           if (ptr[j] < before && ptr[j] >= 0 &&
+               (tst = scan_info_array[j].list[before-1-ptr[j]].term) &&
+               !strcmp (tst, mterm))
+           {
+               RSET rsets[2];
+               
+               rsets[0] = rset;
+               rsets[1] = rset_trunc(
+                   zh,
+                   &scan_info_array[j].list[before-1-ptr[j]].isam_p, 1,
+                   glist[lo].term,
+                   strlen(glist[lo].term), NULL, 0,
+                   zapt->term->which, rset_nmem,
+                   kc, kc->scope, 0, index_type, 0 /* hits_limit */,
+                   0 /* term_ref_id_str */);
+               rset = rset_create_or(rset_nmem, kc,
+                                      kc->scope, 0 /* termid */, 2, rsets);
+               
+               ptr[j]++;
+           }
+       }
+        if (limit_set)
+       {
+           RSET rsets[2];
+           rsets[0] = rset;
+           rsets[1] = rset_dup(limit_set);
+           
+           rset = rset_create_and(rset_nmem, kc, kc->scope, 2, rsets);
+       }
+       count_set(zh, rset, &count);
+       glist[lo].occurrences = count;
+       rset_delete (rset);
+    }
+    (*kc->dec)(kc);
+    nmem_destroy(rset_nmem);
+    i = before-i;
+    if (i)
+    {
+        *is_partial = 1;
+        *position -= i;
+        *num_entries -= i;
+       if (*num_entries <= 0)
+       {
+           *num_entries = 0;
+           return ZEBRA_OK;
+       }
+    }
+    
+    *list = glist + i;               /* list is set to first 'real' entry */
+    
+    yaz_log(YLOG_DEBUG, "position = %d, num_entries = %d",
+           *position, *num_entries);
+    return ZEBRA_OK;
+}
+
+/*
+ * Local variables:
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ * vim: shiftwidth=4 tabstop=8 expandtab
+ */
+