/*
* Clean query tree from values which is always in
* text (stopword)
*/
static NODE *
clean_fakeval_intree(NODE *node, char *result)
{
char lresult = V_UNKNOWN,
rresult = V_UNKNOWN;
/* since this function recurses, it could be driven to stack overflow. */
check_stack_depth();
if (node->valnode->type == QI_VAL)
return node;
else if (node->valnode->type == QI_VALSTOP)
{
pfree(node);
*result = V_STOP;
return NULL;
}
Assert(node->valnode->type == QI_OPR);
if (node->valnode->qoperator.oper == OP_NOT)
{
node->right = clean_fakeval_intree(node->right, &rresult);
if (!node->right)
{
*result = V_STOP;
freetree(node);
return NULL;
}
}
else
{
NODE *res = node;
node->left = clean_fakeval_intree(node->left, &lresult);
node->right = clean_fakeval_intree(node->right, &rresult);
if (lresult == V_STOP && rresult == V_STOP)
{
freetree(node);
*result = V_STOP;
return NULL;
}
else if (lresult == V_STOP)
{
res = node->right;
pfree(node);
}
else if (rresult == V_STOP)
{
res = node->left;
pfree(node);
}
return res;
}
return node;
}
ITEM *
clean_fakeval(ITEM * ptr, int4 *len)
{
NODE *root = maketree(ptr);
char result = V_UNKNOWN;
NODE *resroot;
resroot = clean_fakeval_intree(root, &result);
if (result != V_UNKNOWN)
{
elog(NOTICE, "query contains only stopword(s) or doesn't contain lexeme(s), ignored");
*len = 0;
return NULL;
}
return plaintree(resroot, len);
}
QueryItem *
clean_fakeval(QueryItem *ptr, int *len)
{
NODE *root = maketree(ptr);
char result = V_UNKNOWN;
NODE *resroot;
resroot = clean_fakeval_intree(root, &result);
if (result != V_UNKNOWN)
{
ereport(NOTICE,
(errmsg("text-search query contains only stop words or doesn't contain lexemes, ignored")));
*len = 0;
return NULL;
}
return plaintree(resroot, len);
}
/*
* Clean query tree from values which is always in
* text (stopword)
*/
static NODE *
clean_fakeval_intree(NODE * node, char *result)
{
char lresult = V_UNKNOWN,
rresult = V_UNKNOWN;
if (node->valnode->type == VAL)
return node;
else if (node->valnode->type == VALTRUE)
{
pfree(node);
*result = V_TRUE;
return NULL;
}
if (node->valnode->val == (int4) '!')
{
node->right = clean_fakeval_intree(node->right, &rresult);
if (!node->right)
{
*result = (rresult == V_TRUE) ? V_FALSE : V_TRUE;
freetree(node);
return NULL;
}
}
else if (node->valnode->val == (int4) '|')
{
NODE *res = node;
node->left = clean_fakeval_intree(node->left, &lresult);
node->right = clean_fakeval_intree(node->right, &rresult);
if (lresult == V_TRUE || rresult == V_TRUE)
{
freetree(node);
*result = V_TRUE;
return NULL;
}
else if (lresult == V_FALSE && rresult == V_FALSE)
{
freetree(node);
*result = V_FALSE;
return NULL;
}
else if (lresult == V_FALSE)
{
res = node->right;
pfree(node);
}
else if (rresult == V_FALSE)
{
res = node->left;
pfree(node);
}
return res;
}
else
{
NODE *res = node;
node->left = clean_fakeval_intree(node->left, &lresult);
node->right = clean_fakeval_intree(node->right, &rresult);
if (lresult == V_FALSE || rresult == V_FALSE)
{
freetree(node);
*result = V_FALSE;
return NULL;
}
else if (lresult == V_TRUE && rresult == V_TRUE)
{
freetree(node);
*result = V_TRUE;
return NULL;
}
else if (lresult == V_TRUE)
{
res = node->right;
pfree(node);
}
else if (rresult == V_TRUE)
{
res = node->left;
pfree(node);
}
return res;
}
return node;
}
