private FunctionDescProto findFunction(
String signature,
FunctionType type,
List<TajoDataTypes.DataType> params,
boolean strictTypeCheck) {
List<FunctionDescProto> candidates = Lists.newArrayList();
if (functions.containsKey(signature)) {
if (strictTypeCheck) {
for (FunctionDescProto func : functions.get(signature)) {
if (func.getSignature().getType() == type
&& func.getSignature().getParameterTypesList().equals(params)) {
candidates.add(func);
}
}
} else {
for (FunctionDescProto func : functions.get(signature)) {
if (func.getSignature().getParameterTypesList() != null
&& CatalogUtil.isMatchedFunction(
func.getSignature().getParameterTypesList(), params)) {
candidates.add(func);
}
}
}
}
// if there are more than one function candidates, we choose the nearest matched function.
if (candidates.size() > 0) {
return findNearestMatchedFunction(candidates);
} else {
return null;
}
}
private FunctionDescProto findFunction(String signature, List<TajoDataTypes.DataType> params) {
List<FunctionDescProto> candidates = Lists.newArrayList();
if (functions.containsKey(signature)) {
for (FunctionDescProto func : functions.get(signature)) {
if (func.getSignature().getParameterTypesList() != null
&& func.getSignature().getParameterTypesList().equals(params)) {
candidates.add(func);
}
}
}
/*
*
* FALL BACK to look for nearest match
* WORKING BUT BAD WAY TO IMPLEMENT.I WOULD RATHER implement compareTo in FunctionDesc to keep them
* in sorted order of param types LIKE INT1 SHOULD BE BEFORE INT2 should be before INT3 so on.
* Due to possibility of multiple parameters and types the permutation and combinations are endless
* to implement compareTo so decided to take the shortcut.
*
* */
if (functions.containsKey(signature)) {
for (FunctionDescProto func : functions.get(signature)) {
if (func.getSignature().getParameterTypesList() != null
&& CatalogUtil.isMatchedFunction(
func.getSignature().getParameterTypesList(), params)) {
candidates.add(func);
}
}
// if there are more than one function candidates, we choose the nearest matched function.
if (candidates.size() > 0) {
return findNearestMatchedFunction(candidates);
} else {
return null;
}
}
return null;
}