Source File modules/rx/rx_tree.c

    1    | /***************************************
    2    |   $Revision: 1.19 $
    3    |
    4    |   Radix tree (rx).  rx_tree.c - functions to operate on trees
    5    |   (creation/deletion/finding).
    6    |
    7    |   Status: NOT REVUED, TESTED, INCOMPLETE
    8    |
    9    |   Design and implementation by: Marek Bukowy
    10   |
    11   |   ******************/ /******************
    12   |   Copyright (c) 1999                              RIPE NCC
    13   |
    14   |   All Rights Reserved
    15   |
    16   |   Permission to use, copy, modify, and distribute this software and its
    17   |   documentation for any purpose and without fee is hereby granted,
    18   |   provided that the above copyright notice appear in all copies and that
    19   |   both that copyright notice and this permission notice appear in
    20   |   supporting documentation, and that the name of the author not be
    21   |   used in advertising or publicity pertaining to distribution of the
    22   |   software without specific, written prior permission.
    23   |
    24   |   THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
    25   |   ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS; IN NO EVENT SHALL
    26   |   AUTHOR BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY
    27   |   DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
    28   |   AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
    29   |   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
    30   |   ***************************************/
    31   |
    32   | #include <erroutines.h>
    33   | #include <iproutines.h>
    34   | #include <memwrap.h>
    35   | #include <stubs.h>
    36   |
    37   | /***************************************************************************/
    38   |
    39   | #define RX_IMPL
    40   |
    41   | #include <rxroutines.h>
    42   | /***************************************************************************/
    43   |
    44   |
    45   | /*+++++++++
    46   |   go down the tree calling func on every node.
    47   |   (func takes the node pointer and the current level)
    48   |
    49   |   the function is called recursively with level increased
    50   |   it stops recursing when no child nodes are found or maxlevel is reached.
    51   |
    52   |   therefore the initial call must set level to 0.
    53   |
    54   |   the nodecounter increments at every node, and is the return value
    55   |   of the function. So start with 0 to get the number of nodes traversed.
    56   |
    57   |   ERROR HANDLING IS DIFFERENT HERE!
    58   |   Unlike other functions it is not the return value:
    59   |   The error code from the func function IF DEFINED (== not NULL ) goes
    60   |   to the variable pointed to by the last parameter.
    61   |
    62   |   XXX: nodecounter is ALWAYS passed as 0, so should probably be removed from
    63   |        calling parameter list, shane 2001-02-01
    64   | ++++++++++++*/
    65   | int
    66   | rx_walk_tree(rx_node_t *node,
    67   | 	     er_ret_t (*func)(rx_node_t *node, int level, int nodecounter,
    68   | 			  void *userptr),
    69   | 	     rx_walk_mt walk_mode,
    70   | 	                     /* controls if glue nodes are counted*/
    71   | 	                     /* and if levels or prefix lenghts are checked*/
    72   | 	     int maxlevel,
    73   | 	     int level,
    74   | 	     int nodecounter,
    75   | 	     void *userptr,
    76   | 	     er_ret_t *err)
    77   | {
    78   | int i, link;
    79   |
    80   |  if( node == NULL ) die; /* program error. we expect a valid, checked, node.*/
    81   |
    82   |  /* check the limits and maybe quit here: prefix length for RX_WALK_PRFLEN, */
    83   |  /* level otherwise */
    84   |
    85   |  if(walk_mode & RX_WALK_PRFLEN) {
    86   |    if(node->prefix.bits > maxlevel) {
    87   |      return nodecounter;
    88   |    }
    89   |  }
    90   |  else if( level > maxlevel ) {
    91   |    return nodecounter;
    92   |  }
    93   |
    94   |
    95   |  /* process the node appropriately: */
    96   |  /* if (not node glue) or (process glue nodes) */
    97   |
    98   |  if( node->glue == 0 || (walk_mode & RX_WALK_SKPGLU) == 0 ) {
    99   |
    100  |    /* increase our depth counter */
    101  |    level++;
    102  |
    103  |    /* increase the count of visited nodes */
    104  |    nodecounter++;
    105  |
    106  |    /* call supplied function, if any */
    107  |    if( func != NULL ) {
    108  |      *err = func(node, level, nodecounter, userptr);
    109  |
    110  |      /* abort the walk on error*/
    111  |      if( *err != RX_OK ) {
    112  |        ER_dbg_va(FAC_RX, ASP_RX_TREE_WALK,
    113  |   	         "walk_tree: func returned error %d, aborting", *err);
    114  |        return nodecounter;
    115  |      }
    116  |    }
    117  |  }
    118  |
    119  |  /* process left and right children */
    120  |  for(i=0; i<=1; i++) {
    121  |
    122  |    /* reverse the sense of the walk*/
    123  |    link = ( walk_mode & RX_WALK_REVERS ) ? ! i : i;
    124  |
    125  |    if( node->child_ptr[link] != NULL ) {
    126  |      nodecounter += rx_walk_tree(node->child_ptr[link], func, walk_mode,
    127  | 				 maxlevel, level, 0, userptr, err);
    128  |      /* abort the walk on error*/
    129  |      if( func != NULL && *err != RX_OK ) {
    130  |        break;
    131  |      }
    132  |    }
    133  |  }
    134  |
    135  |  /* return count of nodes visited */
    136  |  return nodecounter;
    137  | }
    138  |
    139  | /*+++++++++
    140  |   go down the tree and delete all nodes of the tree.
    141  |
    142  |   the function is called recursively with level increased
    143  |   it stops recursing when no child nodes are found or maxlevel is reached.
    144  |
    145  |   therefore the initial call must set level to 0.
    146  |
    147  |   the nodecounter increments at every node, and is the return value
    148  |   of the function. So start with 0 to get the number of nodes traversed.
    149  |
    150  |   ERROR HANDLING IS DIFFERENT HERE!
    151  |   Unlike other functions it is not the return value:
    152  |   The error code from the func function IF DEFINED (== not NULL ) goes
    153  |   to the variable pointed to by the last parameter.
    154  |
    155  |   XXX: nodecounter is ALWAYS passed as 0, so should probably be removed from
    156  |        calling parameter list, shane 2001-02-01
    157  | ++++++++++++*/
    158  | void rx_delete_dataleaves(void *element_data, void *result_ptr)
    159  | {
    160  | 	rx_dataleaf_t *leafptr = element_data;
    161  | 	rx_tree_t *tree = result_ptr;
    162  |
    163  | 	if(tree->family == RX_FAM_IP ) {
    164  |         /* do not look at the leaf if  RX_FAM_IP */
    165  |         /* Just free the payload, there must be one and just one. */
    166  |            wr_free(leafptr);
    167  |         }
    168  |         else { /* other families */
    169  |           /* if not >composed< then delete dataleaf */
    170  |           if( leafptr->composed == 0 ) {
    171  |              if( leafptr->data_ptr )
    172  | 	         wr_free(leafptr->data_ptr);
    173  |              wr_free(leafptr);
    174  |
    175  |              ER_dbg_va(FAC_RX, ASP_RX_NODCRE_DET, "dataleaf refcount = 0, removed");
    176  |
    177  |           }
    178  |           /* else decrement the reference number ( == number of prefixes
    179  |              composing the range minus 1 == the >composed< flag */
    180  |           else {
    181  |              leafptr->composed--;
    182  |
    183  |              ER_dbg_va(FAC_RX, ASP_RX_NODCRE_DET, "dataleaf refcount -- to %d ",
    184  | 		           leafptr->composed );
    185  |           }
    186  |         } /* if family != RX_FAM_IP */
    187  | }
    188  |
    189  | void rx_delete_treenode(rx_tree_t *tree, rx_node_t *curnode)
    190  | {
    191  |      if(curnode->leaves_ptr) {
    192  | 	 ER_dbg_va(FAC_RX, ASP_RX_NODCRE_DET, "deleting dataleaves of node at %08x", curnode);
    193  |          g_list_foreach( curnode->leaves_ptr, rx_delete_dataleaves, tree);
    194  | 	 /* delete the GList */
    195  | 	 g_list_free(curnode->leaves_ptr);
    196  |      }
    197  |      ER_dbg_va(FAC_RX, ASP_RX_NODCRE_DET, "node at %08x removed", curnode);
    198  |      wr_free(curnode);
    199  |
    200  | }
    201  |
    202  | /* The fuction itself */
    203  | int
    204  | rx_delete_tree(rx_tree_t *tree, rx_node_t *node,
    205  |              int maxlevel,
    206  | 	     int level,
    207  | 	     int nodecounter,
    208  | 	     void *userptr)
    209  | {
    210  | int i, link;
    211  |
    212  |  if( node == NULL ) die; /* program error. we expect a valid, checked, node.*/
    213  |
    214  |  /* check if the level is reached */
    215  |
    216  |  if( level > maxlevel ) {
    217  |    return nodecounter;
    218  |  }
    219  |
    220  |
    221  |  /* process the node appropriately: */
    222  |  /* increase our depth counter */
    223  |  level++;
    224  |
    225  |  /* increase the count of visited nodes */
    226  |  nodecounter++;
    227  |
    228  |
    229  |  /* process left and right children */
    230  |  for(i=0; i<=1; i++) {
    231  |
    232  |    link = i;
    233  |
    234  |    if( node->child_ptr[link] != NULL ) {
    235  |      nodecounter += rx_delete_tree(tree, node->child_ptr[link], maxlevel, level, 0, userptr);
    236  |      /* delete the processed child node */
    237  |      rx_delete_treenode(tree, node->child_ptr[link]);
    238  |    }
    239  |  }
    240  |
    241  |  /* if this is the top level - delete the top node and the tree*/
    242  |  if(node == tree->top_ptr){
    243  | 	 rx_delete_treenode(tree, node);
    244  | 	 tree->top_ptr=NULL;
    245  |  }
    246  |
    247  |  /* return count of nodes deleted */
    248  |  return nodecounter;
    249  | }
    250  |
    251  |
    252  | /***************************************************************************/
    253  | /*++++++
    254  |   creates a (top) tree for the space, fills out sql table of trees
    255  |   generates a tablename for a tree (if NONE)
    256  |   updates LL of trees
    257  |
    258  |   MT-note: locks/unlocks the forest (still to be done)
    259  |
    260  | ++++++++*/
    261  | er_ret_t
    262  | RX_tree_cre (
    263  | 	      char      *prefixstr, /*+ prefix the tree will cover (string) +*/
    264  | 	      rx_fam_t   fam_id,
    265  | 	      rx_mem_mt   mem_mode, /* memory only, memory+sql, sql only +*/
    266  | 	      rx_subtree_mt subtrees,	/*+ one of NONE, AUTO, HAND +*/
    267  | 	      rx_tree_t **treestore /* store the tree pointer here */
    268  | 	     )
    269  |
    270  | {
    271  |   er_ret_t     err;
    272  |   rx_tree_t    *newtree;
    273  |   ip_prefix_t  newpref;
    274  |   ip_space_t   spc_id;
    275  |
    276  |   if( IP_pref_e2b(&newpref, prefixstr) != IP_OK ) {
    277  |     die;
    278  |   }
    279  |
    280  |   spc_id = IP_pref_b2_space( &newpref );
    281  |
    282  |   if ( (err=wr_malloc( (void **) & newtree, sizeof(rx_tree_t))) != UT_OK ) {
    283  |     return err;  /* die*/
    284  |   }
    285  |
    286  |   ER_dbg_va(FAC_RX, ASP_RX_TREE_GEN, "creating a tree at %08x", newtree);
    287  |
    288  |   /* copy tree settings */
    289  |   newtree -> space  = spc_id;
    290  |   newtree -> family = fam_id;
    291  |
    292  |   newtree -> subtrees = subtrees;
    293  |   newtree -> mem_mode = mem_mode;
    294  |
    295  |   /* set other tree values */
    296  |
    297  |   /* parent set to NULL because it's not a subtree */
    298  |   newtree -> parent_tree = NULL;
    299  |   /* PR_zeroprefix(& newtree -> prefix);*/
    300  |   newtree -> maxbits = IP_sizebits(spc_id);
    301  |
    302  |   strcpy(newtree->data_table.val,"");
    303  |   strcpy(newtree->radix_table.val,"");
    304  |   strcpy(newtree->leaves_table.val,"");
    305  |
    306  |   newtree->num_nodes = 0;
    307  |
    308  |   newtree->top_ptr = NULL;
    309  |   newtree->top_key = SQ_NOKEY;
    310  |
    311  |   newtree->prefix = newpref;
    312  |
    313  |   TH_init_read_write_lockw( &(newtree->rwlock));
    314  |
    315  |   *treestore = newtree;
    316  |
    317  |   return RX_OK;
    318  | }
    319  |
    320  |
    321  | /* ************************************
    322  |    special walk function for use in consistency checks - it checks the parent
    323  |    pointer too.
    324  | ************************************/
    325  | int rx_check_walk_tree( rx_node_t *node,
    326  | 			rx_node_t *parent_node,
    327  | 			int nodecounter,
    328  | 			rx_treecheck_t *checkstruct )
    329  | {
    330  | int i;
    331  |
    332  |  /* checks*/
    333  |  if( node == NULL ) {
    334  |    checkstruct->code |= 1;
    335  |  }
    336  |  if( node->parent_ptr != parent_node ) {
    337  |    checkstruct->code |= 2;
    338  |  }
    339  |  if( node->glue && node->leaves_ptr ) {
    340  |    checkstruct->code |= 4;
    341  |  }
    342  |  if( node->glue && (node->child_ptr[0] == NULL || node->child_ptr[1] == NULL ) ) {
    343  |    checkstruct->code |= 8;
    344  |  }
    345  |
    346  |
    347  |  if( node->leaves_ptr && checkstruct->datatoo ) {
    348  |    switch( checkstruct->tree->family ) {
    349  |    case  RX_FAM_IP:
    350  |      /* the simplest (?) case: only one leaf attached to any node
    351  | 	(except for glues) */
    352  |      if( g_list_length(node->leaves_ptr) != 1 ) {
    353  |        checkstruct->code |= 16;
    354  |      }
    355  |      break;
    356  |    case RX_FAM_RT:
    357  |      /* many dataleaves attached to nodes. */
    358  |      break;
    359  |    case RX_FAM_IN:
    360  |      /* many dataleaves attached to nodes.
    361  | 	Some leaves pointed to from many nodes => from as many as the number
    362  | 	of composing prefixes
    363  |      */
    364  |      break;
    365  |    default:
    366  |      /* ignore */
    367  |      break;
    368  |    }
    369  |  }
    370  |
    371  |
    372  |  if( checkstruct->code != 0 ) {
    373  |    checkstruct->node = node;
    374  |
    375  |    return nodecounter;          /* abort the walk on error*/
    376  |  }
    377  |
    378  |
    379  |   nodecounter++;
    380  |
    381  |   for(i=0; i<=1; i++) {
    382  |     if( node->child_ptr[i] != NULL ) {
    383  |       nodecounter += rx_check_walk_tree( node->child_ptr[i],
    384  | 					 node,
    385  | 					 0, checkstruct );
    386  |       /* abort the walk on error*/
    387  |       if ( checkstruct->code != 0 ) {
    388  | 	die; break;
    389  |       }
    390  |     }
    391  |   }
    392  |   return nodecounter;
    393  | }
    394  |
    395  | /* **************************************************************************
    396  | tree consistency check.
    397  |
    398  | if datatoo = 0, then only parent/child links are checked.
    399  |
    400  | if datatoo = 1, then a check on the contents of the nodes is done too.
    401  |
    402  | **************************************************************************/
    403  |
    404  | er_ret_t
    405  | RX_treecheck( rx_tree_t *tree, int datatoo, rx_treecheck_t *errorfound)
    406  | {
    407  |   er_ret_t err = RX_OK;
    408  |   int nodnum;
    409  |
    410  |   errorfound->tree = tree;
    411  |   errorfound->datatoo = datatoo;
    412  |
    413  |   /* errorfound.node will be set by hook if it finds an error*/
    414  |   errorfound->code = 0;
    415  |
    416  |   nodnum = rx_check_walk_tree( tree->top_ptr,
    417  | 			       NULL,
    418  | 			       0,
    419  | 			       errorfound );
    420  |
    421  |   if( nodnum != tree->num_nodes ) {
    422  |     errorfound->code |= 1024;
    423  |   }
    424  |   if( tree->num_nodes == 0 && tree->top_ptr != NULL ) {
    425  |     errorfound->code |= 2048;
    426  |   }
    427  |   if( tree->num_nodes != 0 && tree->top_ptr == NULL ) {
    428  |     errorfound->code |= 4096;
    429  |   }
    430  |
    431  |   if( errorfound->code != 0) {
    432  |     err = RX_DATNOF;
    433  |   }
    434  |   return err;
    435  | }