@Override
public Statistics visitFunctionHolderExpression(FunctionHolderExpression holderExpr, Void value)
throws RuntimeException {
FuncHolder funcHolder = holderExpr.getHolder();
if (!(funcHolder instanceof DrillSimpleFuncHolder)) {
// Only Drill function is allowed.
return null;
}
final String funcName = ((DrillSimpleFuncHolder) funcHolder).getRegisteredNames()[0];
if (CastFunctions.isCastFunction(funcName)) {
Statistics stat = holderExpr.args.get(0).accept(this, null);
if (stat != null && !stat.isEmpty()) {
return evalCastFunc(holderExpr, stat);
}
}
return null;
}
private Statistics evalCastFunc(FunctionHolderExpression holderExpr, Statistics input) {
try {
DrillSimpleFuncHolder funcHolder = (DrillSimpleFuncHolder) holderExpr.getHolder();
DrillSimpleFunc interpreter = funcHolder.createInterpreter();
final ValueHolder minHolder, maxHolder;
TypeProtos.MinorType srcType = holderExpr.args.get(0).getMajorType().getMinorType();
TypeProtos.MinorType destType = holderExpr.getMajorType().getMinorType();
if (srcType.equals(destType)) {
// same type cast ==> NoOp.
return input;
} else if (!CAST_FUNC.containsKey(srcType) || !CAST_FUNC.get(srcType).contains(destType)) {
return null; // cast func between srcType and destType is NOT allowed.
}
switch (srcType) {
case INT:
minHolder = ValueHolderHelper.getIntHolder(((IntStatistics) input).getMin());
maxHolder = ValueHolderHelper.getIntHolder(((IntStatistics) input).getMax());
break;
case BIGINT:
minHolder = ValueHolderHelper.getBigIntHolder(((LongStatistics) input).getMin());
maxHolder = ValueHolderHelper.getBigIntHolder(((LongStatistics) input).getMax());
break;
case FLOAT4:
minHolder = ValueHolderHelper.getFloat4Holder(((FloatStatistics) input).getMin());
maxHolder = ValueHolderHelper.getFloat4Holder(((FloatStatistics) input).getMax());
break;
case FLOAT8:
minHolder = ValueHolderHelper.getFloat8Holder(((DoubleStatistics) input).getMin());
maxHolder = ValueHolderHelper.getFloat8Holder(((DoubleStatistics) input).getMax());
break;
default:
return null;
}
final ValueHolder[] args1 = {minHolder};
final ValueHolder[] args2 = {maxHolder};
final ValueHolder minFuncHolder =
InterpreterEvaluator.evaluateFunction(interpreter, args1, holderExpr.getName());
final ValueHolder maxFuncHolder =
InterpreterEvaluator.evaluateFunction(interpreter, args2, holderExpr.getName());
switch (destType) {
// TODO : need handle # of nulls.
case INT:
return getStatistics(
((IntHolder) minFuncHolder).value, ((IntHolder) maxFuncHolder).value);
case BIGINT:
return getStatistics(
((BigIntHolder) minFuncHolder).value, ((BigIntHolder) maxFuncHolder).value);
case FLOAT4:
return getStatistics(
((Float4Holder) minFuncHolder).value, ((Float4Holder) maxFuncHolder).value);
case FLOAT8:
return getStatistics(
((Float8Holder) minFuncHolder).value, ((Float8Holder) maxFuncHolder).value);
default:
return null;
}
} catch (Exception e) {
throw new DrillRuntimeException("Error in evaluating function of " + holderExpr.getName());
}
}