## modules/rx/rx_search.c

/* [<][>][^][v][top][bottom][index][help] */

## FUNCTIONS

This source file includes following functions.

1. rx_build_stack
2. rx_nod_append
3. rx_walk_hook_addnode
4. rx_walk_hook_adddoubles
5. rx_nod_search
6. RX_bin_search

       1 /***************************************
       2   $Revision: 1.33 $
       3
       4   Radix tree (rx).  rx_search.c - functions to search nodes of the tree
       5
       6   Status: NOT REVUED, TESTED, COMPLETE
       7
       8   Design and implementation by: Marek Bukowy
       9
      10   ******************/ /******************
      11   Copyright (c) 1999                              RIPE NCC
      12
      13   All Rights Reserved
      14
      15   Permission to use, copy, modify, and distribute this software and its
      16   documentation for any purpose and without fee is hereby granted,
      17   provided that the above copyright notice appear in all copies and that
      18   both that copyright notice and this permission notice appear in
      19   supporting documentation, and that the name of the author not be
      20   used in advertising or publicity pertaining to distribution of the
      21   software without specific, written prior permission.
      22
      23   THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
      24   ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS; IN NO EVENT SHALL
      25   AUTHOR BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY
      26   DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
      27   AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
      28   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
      29   ***************************************/
      30
      31
      32 #include <erroutines.h>
      33 #include <rxroutines.h>
      34 #include <stubs.h>
      35
      36 #include "iproutines.h"
      37
      38 /***************************************************************************/
      39
      40 /*++++++++++++++
      41 Descends the given tree following the last prefix bit to get [past]
      42 the node with the given prefix.
      43 It fills up a stack of COPIES of nodes, including glue nodes.
      44
      45 Then it also sets the number of elements on the stack:
      46 set maxdepth to the position where a next one would be written
      47 ( = last + 1, or number of nodes pushed)
      48
      49    The dmodes:
      50
      51    RX_STK_QUERY_NOGLUE = (search exact/less spec) stop when
      52                          * the current prefix length >= newprefix length
      53                          * the current prefix does not match anymore
      54                          * do not add glue nodes
      55
      56    RX_STK_QUERY_ALLNOD = as above, except that the glue and data nodes are
      57                          treated equally (i.e. glue nodes are not skipped)
      58
      59    RX_STK_CREAT        = descend until the next non-glue node past the one found
      60                          in exact mode (for creation)
      61
      62 ++++++++++++++*/
      63
      64 er_ret_t
      65 rx_build_stack(rx_nodcpy_t    stack[],
         /* [<][>][^][v][top][bottom][index][help] */
      66                int            *maxdepth,
      67                rx_tree_t      *tree,
      68                ip_prefix_t    *newpref,
      69                rx_stk_mt      dmode
      70                )
      71 {
      72   register rx_node_t *curnode;
      73   register int link, quit_now=0;
      74   register int tracedet = ER_is_traced( FAC_RX, ASP_RX_STKBLD_DET);
      75   char bbf[IP_PREFSTR_MAX];
      76
      77   if( ER_is_traced( FAC_RX, ASP_RX_STKBLD_GEN)) {
      78     IP_pref_b2a( newpref , bbf, IP_PREFSTR_MAX);
      79     ER_dbg_va(FAC_RX, ASP_RX_STKBLD_GEN,
      80             "rx_build_stack: searching for %s in mode %d", bbf, dmode);
      81   }
      82
      83   *maxdepth = 0;
      84
      85   if ( tree -> num_nodes == 0) {
      86     /* The tree was empty. */
      87     return RX_OK;
      88   }
      89
      90   curnode = tree->top_ptr;
      91   /* this works for RAM, for SQL one would have to call a 'getsqlnode' here*/
      92
      93   /* OK, there is at least one node. Descend the tree */
      94   /* as long as the correct bit length is not exceeded*/
      95   /* or a glue is being found (take the last non-glue node then) */
      96   /* or you run out of nodes in the direction of descending*/
      97
      98   do {
      99     /* check at the current node, where the one we look for would fit*/
     100     /* (the second argument of IP_addr_bit_get starts with 0,*/
     101     /* so this effectively looks at the bit next to the last significant bit*/
     102     /* of the current node*/
     103
     104     link = IP_addr_bit_get( & newpref->ip, curnode->prefix.bits );
     105
     106     /* check conditions for leaving the loop    */
     107     if(curnode->child_ptr[link] == NULL) {
     108       /* end of branch. quit after adding the current node to the stack*/
     109       /* (or before - subject to bit test in QUERY mode)*/
     110       quit_now = 1;
     111     }
     112     else {
     113     /* check the node.
     114        BIG DIFFERENCE between the modes:
     115        in CREAT we don't mind the stack to go too deep,
     116        in QUERY it can lead to false answers
     117        (e.g. a /24 is found for a /23 query).
     118
     119        So this must be "peeled off the stack" later in the search routine,
     120        if both types of stack are to work properly with query searches.
     121     */
     122
     123
     124       if( curnode->prefix.bits > newpref->bits ) {
     125         /* deep enough.*/
     126         quit_now = 2;
     127       }
     128
     129       if(dmode == RX_STK_CREAT && curnode->glue) {
     130         /* mode: creation. */
     131         /* Cancel quitting if glue -- in CREAT mode the stack building */
     132         /* should stop at the next real (non-glue) node.*/
     133         /* ("next" meaning following link #0)*/
     134         quit_now = 0;
     135       }
     136     }
     137
     138     /* now that the conditions for leaving the loop after the node is
     139        added on the stack, see if we shouldn't leave the loop BEFOREHAND */
     140
     141     /* In query mode, we should quit as soon as we see a mismatch */
     142
     143     if(dmode != RX_STK_CREAT
     144        && 0 != IP_addr_cmp(&curnode->prefix.ip, &newpref->ip,
     145                            curnode->prefix.bits) ) {
     146         /*QUIT NOW! (but add this node)*/
     147       quit_now = 4;
     148     }
     149
     150     /* push the current node on the stack. RAM only.*/
     151     /* */
     152     /* (unless quit_now is 64 which means do NOT copy the current node.*/
     153     /**/
     154     /* In CREAT and QUERY_ALLNOD modes, push everything. */
     155     /* In QUERY_NOGLUE mode, only non-glues.*/
     156
     157     if( /* quit_now < 64 &&           disabled as 64 is not in use right now */
     158        (dmode != RX_STK_QUERY_NOGLUE || curnode->glue == 0 )) {
     159         memcpy( & stack[*maxdepth].cpy, curnode, sizeof(rx_node_t));
     160         stack[*maxdepth].srcptr = curnode;
     161         stack[*maxdepth].srckey = SQ_NOKEY;
     162         stack[*maxdepth].tree = tree;
     163         (*maxdepth)++;
     164     }
     165
     166     /* make debug info.*/
     167
     168     if( tracedet ) {
     169       IP_pref_b2a( & curnode->prefix , bbf, IP_PREFSTR_MAX );
     170       ER_dbg_va(FAC_RX, ASP_RX_STKBLD_DET,
     171                 "rx_build_stack: %s%d at %s%s (stk len: %d)",
     172                 quit_now ? "stop/" : "link ",
     173                 quit_now ? quit_now : link,
     174                 bbf, ( curnode->glue ) ? " ++glue++" : "",
     175                 *maxdepth  );
     176     }
     177
     178     curnode = curnode -> child_ptr[link];
     179
     180   } while( !quit_now );
     181
     182   return RX_OK;
     183 }
     184
     185 /***************************************************************************/
     186 /*+++++++++
     187    helper for the nod_search routine:
     188
     189    allocate a new node copy struct, copy the struct and add to nodlist
     190 ++++++++++*/
     191
     192 static
     193 er_ret_t
     194 rx_nod_append( GList **nodlist, rx_nodcpy_t *element)
         /* [<][>][^][v][top][bottom][index][help] */
     195 {
     196   rx_nodcpy_t *newcpy;
     197   er_ret_t err;
     198
     199   if( (err=wr_calloc( (void **) & newcpy, 1, sizeof(rx_nodcpy_t))) != UT_OK) {
     200     return err; /*    die;*/
     201   }
     202   memcpy(newcpy, element, sizeof(rx_nodcpy_t));
     203   (*nodlist) = g_list_prepend( *nodlist, newcpy );
     204
     205   return RX_OK;
     206 }
     207
     208
     209
     210
     211 /***************************************************************************/
     212
     213 /*+++++++++++
     214   helper for MORE specific lookup in rx_nod_search
     215
     216   adds a node to the list of answers.
     217 +++++++++++*/
     218
     219 static
     220 er_ret_t
     221 rx_walk_hook_addnode(rx_node_t *node, int level, int nodecounter,
         /* [<][>][^][v][top][bottom][index][help] */
     222                      void *userptr)
     223 {
     224   rx_nodcpy_t nodcpy;
     225   hook_addnode_userdat_t *userdat = userptr;
     226
     227
     228   /* do not append glue nodes*/
     229   if( node->glue == 1 ) return RX_OK;
     230
     231   /* in RAM mode, do not copy the node.*/
     232   /*  memcpy( &nodcpy.cpy, node, sizeof(rx_node_t));*/
     233
     234   /* XXX reset to 0 to avoid warnings from workshop: but it
     235      slows things down! */
     236   memset( &nodcpy.cpy, 0, sizeof(rx_node_t));
     237
     238   nodcpy.srcptr = node;
     239   nodcpy.srckey = SQ_NOKEY;
     240   nodcpy.tree = userdat->tree;
     241
     242   return rx_nod_append( userdat->nodlist, &nodcpy);
     243 }
     244
     245
     246 /***************************************************************************/
     247
     248 /*+++++++++++
     249   helper for DBLS lookup in rx_nod_search
     250
     251   adds a node to the list of answers.
     252 +++++++++++*/
     253
     254 static
     255 er_ret_t
     256 rx_walk_hook_adddoubles(rx_node_t *node, int level, int nodecounter,
         /* [<][>][^][v][top][bottom][index][help] */
     257                         void *userptr)
     258 {
     259   rx_nodcpy_t nodcpy;
     260   hook_addnode_userdat_t  *userdat = userptr;
     261   int leaves = g_list_length(node->leaves_ptr);
     262   char buf[1024];
     263
     264   /* do not append glue nodes*/
     265   if( node->glue == 1 ) return RX_OK;
     266
     267
     268   /* add only nodes with more than 1 dataleaf*/
     269   if( leaves < 2 ) return RX_OK;
     270
     271   if( ER_is_traced( FAC_RX, ASP_RX_SRCH_DET)) {
     272     rx_nod_print(node, buf, 1024);
     273     ER_dbg_va(FAC_RX, ASP_RX_SRCH_DET,
     274               "rx_walk_hook_adddoubles: %30s, %d leaves", buf, leaves);
     275   }
     276
     277   /*  memcpy( &nodcpy.cpy, node, sizeof(rx_node_t));*/
     278   nodcpy.srcptr = node;
     279   nodcpy.srckey = SQ_NOKEY;
     280   nodcpy.tree = userdat->tree;
     281
     282   return rx_nod_append( userdat->nodlist, &nodcpy);
     283 }
     284
     285
     286 /***************************************************************************/
     287 er_ret_t
     288 rx_nod_search (
         /* [<][>][^][v][top][bottom][index][help] */
     289                rx_srch_mt  search_mode,
     290                int         par_a,
     291                int         par_b,
     292                /* see rx_asc_search() for explanation */
     293                rx_tree_t  *tree,           /* tree ptr*/
     294                ip_prefix_t  *prefix,          /* binary prefix*/
     295
     296                rx_nodcpy_t stack[],         /* stack==array of node_copies*/
     297                int         stackcount,      /* number of element on the stack,*/
     298                                             /* can come from a creat stack!*/
     299
     300                GList       **nodlist,       /* answers go here*/
     301                int         max_count        /* max # of answers*/
     302                )
     303      /*
     304         searches the stack for a given prefix, finds *nodes* in the stack
     305         and appends *copies of the nodes* to the nodlist;
     306
     307         finds
     308         0 or 1 nodes for exact search
     309         0 or 1 nodes for exless (0 if no less specific node found)
     310         any number (incl. 0) for {more|less}^n-m specific
     311
     312        returns errcode.
     313
     314
     315      */
     316 {
     317   char buf[1024];
     318   int sps = stackcount-1;       /* stack position.*/
     319   int depthcounter=0;
     320   er_ret_t err=RX_OK;
     321   int i;
     322   hook_addnode_userdat_t datstr;
     323   er_ret_t (*hook_function)();  /* pointer to the walk_hook function*/
     324                                 /* (see MORE spec lookup)*/
     325
     326   /* structure for carrying data to walk_tree hook functions, used only
     327      in MORE, DBLS and RANG search modes
     328   */
     329   datstr.nodlist = nodlist;
     330   datstr.tree    = tree;
     331   datstr.prefix  = prefix;
     332
     333
     334   if( ER_is_traced( FAC_RX, ASP_RX_SRCH_BOT)) {
     335     IP_pref_b2a( prefix , buf, IP_PREFSTR_MAX);
     336     ER_dbg_va(FAC_RX, ASP_RX_SRCH_BOT,
     337               "rx_nod_search: searching for %s in mode %d (%s)",
     338               buf, search_mode, RX_text_srch_mode(search_mode) );
     339   }
     340
     341   /* in non-CREAT modes, glue nodes are skipped anyway.
     342      (they should normally not be there if the stack was created in
     343      the STK_QUERY mode, but it's possible to use a CREAT stack too).
     344
     345      It's also possible that the stack is too deep.
     346      So, truncate the stack to the last non-glue node
     347      of the length <= search term.
     348      otherwise a /24 would be returned for a /23 query.
     349
     350      For LESS SPECIFIC searches one has to peel off entries
     351      whose prefixes do not contain the search term,
     352   */
     353
     354   if( search_mode != RX_SRCH_CREAT ) {
     355
     356     while( sps >= 0 ) {
     357       char *reason = NULL;
     358
     359       if( stack[sps].cpy.prefix.bits > prefix->bits ) {            /* too deep*/
     360         reason = "2deep";
     361       }
     362       else if( 0 != IP_addr_cmp(& stack[sps].cpy.prefix.ip, &prefix->ip,
     363                                 stack[sps].cpy.prefix.bits) ) {   /* mismatch */
     364         reason = "mismatch";
     365       }
     366       else if ( search_mode != RX_SRCH_MORE && search_mode != RX_SRCH_DBLS
     367                 && search_mode != RX_SRCH_RANG && stack[sps].cpy.glue == 1 ) {                    /* is glue*/
     368         reason = "glue";
     369       }
     370 #if 0
     371       /* mhm. it can't be limited here, must be done in RP */
     372       else if ( search_mode == RX_SRCH_LESS && par_a == 1
     373                 && stack[sps].cpy.prefix.bits == prefix->bits ) {  /* too deep*/
     374         reason = "2deep4less";
     375       }
     376 #endif
     377
     378       else {
     379
     380         break;  /* stop peeling off */
     381       }
     382
     383       if( ER_is_traced( FAC_RX, ASP_RX_SRCH_DET)) {
     384         rx_nod_print( & stack[sps].cpy , buf, IP_PREFSTR_MAX);
     385         ER_dbg_va(FAC_RX, ASP_RX_SRCH_DET,
     386                   "rx_nod_search: peeling off %d: %s (%s)", sps, buf, reason);
     387       }
     388       sps--;
     389     }
     390   }
     391
     392   /* nothing left on the stack. Sorry.*/
     393   /* we allow that for more spec search -- this means*/
     394   /* that the search term is a shorter prefix than the one*/
     395   /* in the top node. Possibly it's 0/0 which is valid for more spec search.*/
     396
     397   if( search_mode != RX_SRCH_MORE && search_mode != RX_SRCH_DBLS
     398       && sps < 0 ) {
     399     return RX_OK;
     400   }
     401
     402   switch(search_mode) {
     403   case RX_SRCH_EXACT:
     404   case RX_SRCH_CREAT:
     405     /* go up the tree (stack) and exit when the proper prefix is found.*/
     406     /* For RX_SRCH_EXACT skip glue nodes, for RX_SRCH_CREAT take all.*/
     407     /* They may contain a valid prefix, so watch out.*/
     408
     409     while(sps >= 0) {
     410
     411       if( ER_is_traced( FAC_RX, ASP_RX_SRCH_DET)) {
     412         rx_nod_print(& stack[sps].cpy, buf, 1024);
     413         ER_dbg_va(FAC_RX, ASP_RX_SRCH_DET,
     414                   "rx_nod_search: position %d: %s", sps, buf);
     415       }
     416
     417       if ( search_mode == RX_SRCH_EXACT
     418            && stack[sps].cpy.glue ) {
     419         die;
     420       }
     421
     422       if ( memcmp( & stack[sps].cpy.prefix,
     423                    prefix,
     424                    sizeof(ip_prefix_t)) == 0 ) {
     425         /* FOUND!!*/
     426         /* add to the nodlist.*/
     427
     428         if( (err=rx_nod_append( nodlist, & stack[sps])) != RX_OK ) {
     429           return err;
     430         }
     431
     432         ER_dbg_va(FAC_RX, ASP_RX_SRCH_BOT, "rx_nod_search: found!");
     433         break;
     434       }
     435       sps--;
     436     }
     437     break;
     438
     439   case RX_SRCH_EXLESS:
     440     /* just fetch the last element off the stack (if any). */
     441     /* Must be non-glue for EXLESS.*/
     442
     443     if( sps >= 0 ) {
     444       rx_nod_append( nodlist, & stack[sps]);
     445     }
     446
     447     /* else : nothing found.*/
     448     /* For EXLESS: check if the stack contains only non-glue nodes.*/
     449     /* If it contains a glue, it means it was created in the CREAT mode,*/
     450     /* which renders the above algorithm absolutely useless. Then crash,*/
     451     /* this is a programmer's error.*/
     452
     453     while( sps >= 0 ) {
     454       if( stack[sps].cpy.glue ) {
     455         die;
     456       }
     457       sps--;
     458     }
     459
     460     break;
     461
     462   case RX_SRCH_LESS:
     463     while( sps >= 0 && depthcounter < par_a ) {
     464       if( stack[sps].cpy.glue == 0 ) {
     465         rx_nod_append( nodlist, & stack[sps]);
     466         depthcounter++;
     467       }
     468       sps--;
     469     }
     470     break;
     471
     472   case RX_SRCH_MORE:
     473   case RX_SRCH_DBLS:   /* special (debug?) mode : find nodes with multiple*/
     474                        /* data leaves. Much like more specific, except that*/
     475                        /* most nodes will be skipped.*/
     476                        /* The difference is in calling another hook function*/
     477     hook_function = ( search_mode == RX_SRCH_MORE )
     478       ? rx_walk_hook_addnode
     479       : rx_walk_hook_adddoubles;
     480
     481     /* the result of a more spec search should NOT contain the object exactly*/
     482     /* matching the query, even if it exists in the database. So two walks are */
     483     /* performed, one for each child (if it exists). */
     484     /* MEMORY IMPLEMENTATION ONLY FOR THE MOMENT*/
     485
     486     /* start from the top node if the searched prefix is between the
     487        top node and the first node on the stack (i.e. the first node is
     488        contained within the search term) */
     489
     490     /* COVERS THE CASE 0.0.0.0/0 */
     491     /* or any other prefix that the tree might be set to represent,*/
     492     /* but there is no actual object for it (not even glue)*/
     493
     494     if( sps < 0 ) {
     495       if( tree->num_nodes > 0         /* there is any node in the tree */
     496           && 0 == IP_addr_cmp( & prefix->ip,
     497                                & stack[0].cpy.prefix.ip,
     498                                prefix->bits) ) {     /* addr match */
     499         rx_walk_tree( tree->top_ptr, hook_function,
     500                       /* RX_WALK_REVERS | */ RX_WALK_SKPGLU, /* skip glue nodes while counting*/
     501                       par_a, /* display this many levels */
     502                       0, 0, &datstr, &err);
     503         if( err != RX_OK ) {
     504           return err;
     505         }
     506       }
     507     } /* if nothing on stack */
     508     else {
     509
     510       /* walk from this node if it matches the query prefix and is
     511        long enough (if it is shorter, then it will harvest too many
     512        results
     513       */
     514       if(  prefix->bits <= stack[sps].srcptr->prefix.bits
     515            && 0 == IP_addr_cmp( & stack[sps].srcptr->prefix.ip,
     516                                 & prefix->ip,
     517                                 prefix->bits) ) {
     518         rx_walk_tree( stack[sps].srcptr,  hook_function,
     519                       /* RX_WALK_REVERS | */ RX_WALK_SKPGLU, /* skip glue nodes while counting*/
     520                       par_a, /* display up to this max length*/
     521                       0, 0, &datstr, &err);
     522         if( err != RX_OK ) {
     523           return err;
     524         }
     525       }
     526       else {
     527         /* or walk the child nodes otherwise (still check the address) */
     528
     529         for( i = 1; i >= 0; i--) {
     530           if( stack[sps].cpy.child_ptr[i] != NULL ) {
     531             if( ER_is_traced( FAC_RX, ASP_RX_SRCH_DET)) {
     532               IP_pref_b2a(& stack[sps].cpy.child_ptr[i]->prefix, buf, 1023);
     533             }
     534
     535             if( 0 == IP_addr_cmp( & stack[sps].cpy.child_ptr[i]->prefix.ip,
     536                                   & prefix->ip,
     537                                   prefix->bits) ) {
     538
     539               ER_dbg_va(FAC_RX, ASP_RX_SRCH_DET,
     540                         "rx_nod_search: digging child %d: %s", i, buf);
     541
     542               rx_walk_tree( stack[sps].cpy.child_ptr[i],  hook_function,
     543                             /* RX_WALK_REVERS | */ RX_WALK_SKPGLU, /* skip glue nodes while counting*/
     544                             par_a, /* display this many levels */
     545                             0, 0, &datstr, &err);
     546               if( err != RX_OK ) {
     547                 return err;
     548               }
     549           }
     550             else {
     551               ER_dbg_va(FAC_RX, ASP_RX_SRCH_DET,
     552                         "rx_nod_search: prefix mismatch with child %d: %s",
     553                         i, buf);
     554             }
     555           }
     556         }
     557       } /* if node does not match, dig child nodes */
     558
     559     }
     560     break;
     561
     562   case RX_SRCH_RANG:
     563     /* OK, start from the node at the end of the stack (exless match including
     564        glue nodes) then
     565
     566
     567        if its prefix length is
     568          OK -> found! descend from here as long as the prefixes are in range
     569          shorter -> apparently there is even no such glue node. come back down
     570                     one step
     571
     572     */
     573
     574     i = sps;               /* go up the tree (down the stack) */
     575                            /* until too far (one node too much, after >= )*/
     576     while( i >= 0 && stack[i].cpy.prefix.bits >= prefix->bits ) {
     577       i--;
     578     }
     579
     580     /* look where you are:*/
     581
     582     if( i < 0 )          /* it was the top object, but its prefix was too long*/
     583       i=0;               /* take the top object as the base*/
     584     else
     585       i++;               /* went one too much, now come back one step*/
     586
     587
     588     rx_walk_tree( stack[i].srcptr,  rx_walk_hook_addnode,
     589                   RX_WALK_PRFLEN, /* skip glue nodes while counting*/
     590                   par_a, /* display up to this max length*/
     591                   0, 0, &datstr, &err);
     592     if( err != RX_OK ) {
     593       return err;
     594     }
     595
     596     break;
     597
     598     /* return RX_NOYETI;*/
     599     /*not implemented*/
     600     /*    die; */
     601   default:
     602     die; /* are you nuts??*/
     603   }
     604
     605   return err;
     606
     607 }
     608
     609
     610
     611 /*****************************************************************************/
     612
     613 /*+++++++++++++
     614   builds a stack for this prefix, finds *nodes* in the stack
     615   and appends *copies of the data leaves* to the LL of answers;
     616
     617   sorts by SQL object keys and uniq's the data
     618
     619   finds:
     620   0 or 1 nodes for exact search
     621   0 or 1 nodes for exless (0 if no less specific node found)
     622   any number (incl. 0) for {more|less}-n specific
     623
     624   then copies the nodes/dataleaves to the answer structs and appends them
     625   to the given LL. So, effectively, the number of answers can be
     626   anything from 0 to infinity, because objects may be duplicate
     627   even at the same node.
     628
     629   returns errcode.
     630
     631   algorithm:
     632
     633   builds stack[MAXBIT (==128)];
     634
     635   if( more/less-depth && par_a == 0)
     636
     637   run rx_nod_search, then
     638
     639   if(more spec) rx_nod_walk(maxdepth=n, append_to_LL() );
     640   if(less spec) do { append(LL, stack[i]) } while(i-- && n--);
     641   otherwise just set LL
     642
     643
     644   The routine provides _at_least_ max_count answers.
     645   It will *try* to stop after max_count as soon as possible
     646   - but it's the higher level routine that should do the final cut.
     647 +++++++++++++++*/
     648
     649 er_ret_t
     650 RX_bin_search (
         /* [<][>][^][v][top][bottom][index][help] */
     651                rx_srch_mt  search_mode,
     652                int         par_a,
     653                int         par_b,
     654                rx_tree_t  *tree,           /* tree ptr*/
     655                ip_prefix_t *prefix,         /* binary prefix*/
     656                GList       **datleaves,    /* data leaves go here*/
     657                int         max_count
     658                )
     659
     660 {
     661   rx_nodcpy_t  stack[128];
     662   int k;
     663   int stkcnt, resnum = 0, maxleaves;
     664   GList  *nodlist = NULL, *nitem;
     665   rx_node_t *curnode;
     666   rx_nodcpy_t *curcpy;
     667   rx_datref_t *datref;
     668   rx_stk_mt     dmode;
     669
     670   /* more specific node search may start from a glue node, */
     671   /* for all others the stack should not contain glues.*/
     672
     673   dmode = ( search_mode == RX_SRCH_MORE
     674             || search_mode == RX_SRCH_DBLS
     675             || search_mode == RX_SRCH_RANG )
     676     ? RX_STK_QUERY_ALLNOD
     677     : RX_STK_QUERY_NOGLUE;
     678
     679   rx_build_stack(stack, &stkcnt, tree, prefix, dmode);
     680
     681   rx_nod_search( search_mode, par_a, par_b, tree, prefix,
     682                  stack, stkcnt, &nodlist, 1000);
     683
     684   ER_dbg_va(FAC_RX, ASP_RX_SRCH_BOT, "RX_bin_search: processing nodes");
     685
     686   for( nitem = g_list_first(nodlist);
     687        nitem != NULL;
     688        nitem = g_list_next(nitem)) {
     689
     690     resnum++;
     691     curcpy = nitem->data;
     692
     693     /*
     694       if memory mode includes RAM:
     695       * do not expect copies of nodes in the list received from bin_search.
     696       * iterate through data leaves with g_list_nth_data.
     697       */
     698
     699     curnode = curcpy->srcptr;
     700
     701     /*    rx_nod_print( curnode, buf, 1024 );*/
     702
     703     maxleaves = g_list_length(curnode->leaves_ptr);
     704     /*    fprintf(stderr,"###node %d, %d dataleaves attached:", i, maxleaves);*/
     705
     706     /* iterate through dataleafs attached to this node*/
     707     for(k=0; k<maxleaves; k++) {
     708       rx_dataleaf_t *leafptr = g_list_nth_data(curnode->leaves_ptr, k);
     709
     710       /*
     711          check the conditions to add the leaf:
     712
     713          XXX never add composed inetnum for exact prefix search
     714          (but do for exact range search...) - must be solved in upper layer.
     715
     716       */
     717
     718
     719       /* add*/
     720
     721       dieif( wr_calloc( (void **) &datref,
     722                         sizeof(rx_datref_t), 1) != UT_OK);
     723       datref->leafptr = leafptr;
     724       /* srckey and excluded fields are initialised to 0 by calloc */
     725
     726       *datleaves = g_list_prepend(*datleaves, datref);
     727     }
     728   }
     729
     730   wr_clear_list( &nodlist );
     731
     732   ER_dbg_va(FAC_RX, ASP_RX_SRCH_BOT,
     733             "RX_bin_search: found %d nodes", resnum);
     734
     735
     736   /* the LL of answers (*datleaves) contains pointers to answer structs,
     737      that SHOULD BE NORMALIZED HERE (==with no redundant entries)
     738   */
     739
     740 return RX_OK;
     741 }
     742

/* [<][>][^][v][top][bottom][index][help] */