/*
* Append a string representation of the entire node to orig and return it.
* This is used to produce debugging information if check_redblack_tree() finds
* a problem with a red-black binary tree.
*/
static char *append_node(char * orig, BtRbNode *pNode, int indent)
{
char buf[128];
int i;
for( i=0; i<indent; i++ ){
orig = append_val(orig, " ");
}
sprintf(buf, "%p", pNode);
orig = append_val(orig, buf);
if( pNode ){
indent += 3;
if( pNode->isBlack ){
orig = append_val(orig, " B \n");
}else{
orig = append_val(orig, " R \n");
}
orig = append_node( orig, pNode->pLeft, indent );
orig = append_node( orig, pNode->pRight, indent );
}else{
orig = append_val(orig, "\n");
}
return orig;
}
void Pds_add_numval(pds_t *pds, const uint64_t value)
{
uint64_t i = value;
if ((i & 0x8000000000000000LL) && (~i < 0x100000000LL)) {
// Signed number.
i = ~i;
if (i <= 0x3) {
// Shortcase for -1 to -4
append_val(pds, 0xFC | i);
return;
} else {
append_val(pds, 0xF8);
}
}
if (i < 0x80) {
// Need top bit clear
append_val(pds, i);
} else if (i < 0x4000) {
// Need top two bits clear
append_val(pds, (i >> 8) | 0x80);
append_val(pds, i & 0xFF);
} else if (i < 0x200000) {
LFUNC bool get_next_dfs_val(tval_list *l, tnode *y,tvalue *v)
{
tvalue child,x ;
tval_list newl ;
newl.head=0 ;
do {
if(!pop_val(l,v)) return(FALSE) ;
x= *v ;
duel_get_struct_ptr_val(&x,"x-->y");
} while(x.u.lvalue==0) ; /* ignore null pointers */
while(eval_dot(y,&child,"-->",v,&x)) {
set_search_symb_val("-->",&x,&child); /* makes x-->y[n] neatly */
append_val(&newl,&child); /* append to childs list */
}
push_val_list(l,&newl); /* append new childs to stack */
return(TRUE); /* returns the popped value in v */
}
/*
* Check the following properties of the red-black tree:
* (1) - If a node is red, both of it's children are black
* (2) - Each path from a given node to a leaf (NULL) node passes thru the
* same number of black nodes
*
* If there is a problem, append a description (using append_val() ) to *msg.
*/
static void check_redblack_tree(BtRbTree * tree, char ** msg)
{
BtRbNode *pNode;
/* 0 -> came from parent
* 1 -> came from left
* 2 -> came from right */
int prev_step = 0;
pNode = tree->pHead;
while( pNode ){
switch( prev_step ){
case 0:
if( pNode->pLeft ){
pNode = pNode->pLeft;
}else{
prev_step = 1;
}
break;
case 1:
if( pNode->pRight ){
pNode = pNode->pRight;
prev_step = 0;
}else{
prev_step = 2;
}
break;
case 2:
/* Check red-black property (1) */
if( !pNode->isBlack &&
( (pNode->pLeft && !pNode->pLeft->isBlack) ||
(pNode->pRight && !pNode->pRight->isBlack) )
){
char buf[128];
sprintf(buf, "Red node with red child at %p\n", pNode);
*msg = append_val(*msg, buf);
*msg = append_node(*msg, tree->pHead, 0);
*msg = append_val(*msg, "\n");
}
/* Check red-black property (2) */
{
int leftHeight = 0;
int rightHeight = 0;
if( pNode->pLeft ){
leftHeight += pNode->pLeft->nBlackHeight;
leftHeight += (pNode->pLeft->isBlack?1:0);
}
if( pNode->pRight ){
rightHeight += pNode->pRight->nBlackHeight;
rightHeight += (pNode->pRight->isBlack?1:0);
}
if( leftHeight != rightHeight ){
char buf[128];
sprintf(buf, "Different black-heights at %p\n", pNode);
*msg = append_val(*msg, buf);
*msg = append_node(*msg, tree->pHead, 0);
*msg = append_val(*msg, "\n");
}
pNode->nBlackHeight = leftHeight;
}
if( pNode->pParent ){
if( pNode == pNode->pParent->pLeft ) prev_step = 1;
else prev_step = 2;
}
pNode = pNode->pParent;
break;
default: assert(0);
}
}
}
