Examples with BoundVariables com.facebook.presto.metadata.BoundVariables used on opensource projects

Example 6 with BoundVariables

use of com.facebook.presto.metadata.BoundVariables in project presto by prestodb.

the class JsonToRowCast method specialize.

@Override
public BuiltInScalarFunctionImplementation specialize(BoundVariables boundVariables, int arity, FunctionAndTypeManager functionAndTypeManager) {
    checkArgument(arity == 1, "Expected arity to be 1");
    RowType rowType = (RowType) boundVariables.getTypeVariable("T");
    checkCondition(canCastFromJson(rowType), INVALID_CAST_ARGUMENT, "Cannot cast JSON to %s", rowType);
    List<Field> rowFields = rowType.getFields();
    BlockBuilderAppender[] fieldAppenders = rowFields.stream().map(rowField -> createBlockBuilderAppender(rowField.getType())).toArray(BlockBuilderAppender[]::new);
    MethodHandle methodHandle = METHOD_HANDLE.bindTo(rowType).bindTo(fieldAppenders).bindTo(getFieldNameToIndex(rowFields));
    return new BuiltInScalarFunctionImplementation(true, ImmutableList.of(valueTypeArgumentProperty(RETURN_NULL_ON_NULL)), methodHandle);
}