/*
* Evaluate tsquery boolean expression using ternary logic.
*
* chkcond is a callback function used to evaluate each VAL node in the query.
* checkval can be used to pass information to the callback. TS_execute doesn't
* do anything with it.
*/
static GinTernaryValue
TS_execute_ternary(QueryItem *curitem, void *checkval,
GinTernaryValue (*chkcond) (void *checkval, QueryOperand *val))
{
GinTernaryValue val1,
val2,
result;
/* since this function recurses, it could be driven to stack overflow */
check_stack_depth();
if (curitem->type == QI_VAL)
return chkcond(checkval, (QueryOperand *) curitem);
switch (curitem->qoperator.oper)
{
case OP_NOT:
result = TS_execute_ternary(curitem + 1, checkval, chkcond);
if (result == GIN_MAYBE)
return result;
return !result;
case OP_AND:
val1 = TS_execute_ternary(curitem + curitem->qoperator.left,
checkval, chkcond);
if (val1 == GIN_FALSE)
return GIN_FALSE;
val2 = TS_execute_ternary(curitem + 1, checkval, chkcond);
if (val2 == GIN_FALSE)
return GIN_FALSE;
if (val1 == GIN_TRUE && val2 == GIN_TRUE)
return GIN_TRUE;
else
return GIN_MAYBE;
case OP_OR:
val1 = TS_execute_ternary(curitem + curitem->qoperator.left,
checkval, chkcond);
if (val1 == GIN_TRUE)
return GIN_TRUE;
val2 = TS_execute_ternary(curitem + 1, checkval, chkcond);
if (val2 == GIN_TRUE)
return GIN_TRUE;
if (val1 == GIN_FALSE && val2 == GIN_FALSE)
return GIN_FALSE;
else
return GIN_MAYBE;
default:
elog(ERROR, "unrecognized operator___: %d", curitem->qoperator.oper);
}
/* not reachable, but keep compiler quiet */
return false;
}
Datum
gin_tsquery_triconsistent(PG_FUNCTION_ARGS)
{
GinTernaryValue *check = (GinTernaryValue *) PG_GETARG_POINTER(0);
/* StrategyNumber strategy = PG_GETARG_UINT16(1); */
TSQuery query = PG_GETARG_TSQUERY(2);
/* int32 nkeys = PG_GETARG_INT32(3); */
Pointer *extra_data = (Pointer *) PG_GETARG_POINTER(4);
GinTernaryValue res = GIN_FALSE;
bool recheck;
/* The query requires recheck only if it involves weights */
recheck = false;
if (query->size > 0)
{
QueryItem *item;
GinChkVal gcv;
/*
* check-parameter array has one entry for each value (operand) in the
* query.
*/
gcv.first_item = item = GETQUERY(query);
gcv.check = check;
gcv.map_item_operand = (int *) (extra_data[0]);
gcv.need_recheck = &recheck;
res = TS_execute_ternary(GETQUERY(query),
&gcv,
checkcondition_gin);
if (res == GIN_TRUE && recheck)
res = GIN_MAYBE;
}
PG_RETURN_GIN_TERNARY_VALUE(res);
}
/*
* Evaluate tsquery boolean expression using ternary logic.
*/
static GinTernaryValue
TS_execute_ternary(GinChkVal *gcv, QueryItem *curitem, bool in_phrase)
{
GinTernaryValue val1,
val2,
result;
/* since this function recurses, it could be driven to stack overflow */
check_stack_depth();
if (curitem->type == QI_VAL)
return
checkcondition_gin_internal(gcv,
(QueryOperand *) curitem,
NULL /* don't have position info */ );
switch (curitem->qoperator.oper)
{
case OP_NOT:
/* In phrase search, always return MAYBE since we lack positions */
if (in_phrase)
return GIN_MAYBE;
result = TS_execute_ternary(gcv, curitem + 1, in_phrase);
if (result == GIN_MAYBE)
return result;
return !result;
case OP_PHRASE:
/*
* GIN doesn't contain any information about positions, so treat
* OP_PHRASE as OP_AND with recheck requirement
*/
*(gcv->need_recheck) = true;
/* Pass down in_phrase == true in case there's a NOT below */
in_phrase = true;
/* FALL THRU */
case OP_AND:
val1 = TS_execute_ternary(gcv, curitem + curitem->qoperator.left,
in_phrase);
if (val1 == GIN_FALSE)
return GIN_FALSE;
val2 = TS_execute_ternary(gcv, curitem + 1, in_phrase);
if (val2 == GIN_FALSE)
return GIN_FALSE;
if (val1 == GIN_TRUE && val2 == GIN_TRUE)
return GIN_TRUE;
else
return GIN_MAYBE;
case OP_OR:
val1 = TS_execute_ternary(gcv, curitem + curitem->qoperator.left,
in_phrase);
if (val1 == GIN_TRUE)
return GIN_TRUE;
val2 = TS_execute_ternary(gcv, curitem + 1, in_phrase);
if (val2 == GIN_TRUE)
return GIN_TRUE;
if (val1 == GIN_FALSE && val2 == GIN_FALSE)
return GIN_FALSE;
else
return GIN_MAYBE;
default:
elog(ERROR, "unrecognized operator: %d", curitem->qoperator.oper);
}
/* not reachable, but keep compiler quiet */
return false;
}
