/**
* If current is set set its link to point to the next node, then clear it
* @param st the suffixtree in question
* @param v the link to point current to
*/
void update_current_link( suffixtree *st, node *v )
{
if ( st->current != NULL )
{
node_set_link( st->current, v );
#ifdef DEBUG
verify_link( current );
#endif
st->current = NULL;
}
}
/**
* If current is set set its link to point to the next node, then clear it
* @param v the link to point current to
*/
static void update_current_link( node *v )
{
if ( current != NULL )
{
node_set_link( current, v );
#ifdef DEBUG
verify_link( current );
#endif
current = NULL;
}
}
/**
* Extend the implicit suffix tree by adding one suffix of the current prefix
* @param st the current suffixtree
* @param j the offset into str of the suffix's start
* @param i the offset into str at the end of the current prefix
* @param log the log to record errors in
* @return 1 if the phase continues else 0
*/
static int extension( suffixtree *st, int j, int i, plugin_log *log )
{
int res = 1;
pos *p = find_beta( st, j, i-1, log );
// rule 1 (once a leaf always a leaf)
if ( node_is_leaf(p->v) && pos_at_edge_end(st,p) )
res = 1;
// rule 2
else if ( !continues(st,p,st->str[i]) )
{
//printf("applying rule 2 at j=%d for phase %d\n",j,i);
node *leaf = node_create_leaf( i, log );
if ( p->v==st->root || pos_at_edge_end(st,p) )
{
node_add_child( p->v, leaf, st->str, log );
update_current_link( st, p->v );
}
else
{
node *u = node_split( p->v, p->loc, st->str, log );
update_current_link( st, u );
if ( i-j==1 )
{
node_set_link( u, st->root );
#ifdef DEBUG
verify_link( current );
#endif
}
else
st->current = u;
node_add_child( u, leaf, st->str, log );
}
update_old_beta( st, p, i );
}
// rule 3
else
{
//printf("applying rule 3 at j=%d for phase %d\n",j,i);
update_current_link( st, p->v );
update_old_beta( st, p, i );
res = 0;
}
free( p );
return res;
}
/**
* Extend the implicit suffix tree by adding one suffix of the current prefix
* @param j the offset into str of the suffix's start
* @param i the offset into str at the end of the current prefix
* @return 1 if the phase continues else 0
*/
static int extension( int j, int i )
{
int res = 1;
pos *p = find_beta( j, i-1 );
// rule 1 (once a leaf always a leaf)
if ( node_is_leaf(p->v) && pos_at_edge_end(p) )
res = 1;
// rule 2
else if ( !continues(p,str[i]) )
{
//printf("applying rule 2 at j=%d for phase %d\n",j,i);
node *leaf = node_create_leaf( i );
if ( p->v==root || pos_at_edge_end(p) )
{
node_add_child( p->v, leaf );
update_current_link( p->v );
}
else
{
node *u = node_split( p->v, p->loc );
update_current_link( u );
if ( i-j==1 )
{
node_set_link( u, root );
#ifdef DEBUG
verify_link( current );
#endif
}
else
current = u;
node_add_child( u, leaf );
}
update_old_beta( p, i );
}
// rule 3
else
{
//printf("applying rule 3 at j=%d for phase %d\n",j,i);
update_current_link( p->v );
update_old_beta( p, i );
res = 0;
}
free( p );
return res;
}