@Override
public Expression optimize(Session session) {
userConnection = session.createConnection(false);
int len = args.length;
argTypes = new int[len];
for (int i = 0; i < len; i++) {
Expression expr = args[i];
args[i] = expr.optimize(session);
int type = expr.getType();
argTypes[i] = type;
}
try {
Aggregate aggregate = getInstance();
dataType = aggregate.getInternalType(argTypes);
} catch (SQLException e) {
throw DbException.convert(e);
}
return this;
}
/**
* Call the user-defined function and return the value.
*
* @param session the session
* @param args the argument list
* @param columnList true if the function should only return the column list
* @return the value
*/
public Value getValue(Session session, Expression[] args, boolean columnList)
throws SQLException {
Class<?>[] paramClasses = method.getParameterTypes();
Object[] params = new Object[paramClasses.length];
int p = 0;
if (hasConnectionParam && params.length > 0) {
params[p++] = session.createConnection(columnList);
}
// allocate array for varArgs parameters
Object varArg = null;
if (varArgs) {
int len = args.length - params.length + 1 + (hasConnectionParam ? 1 : 0);
varArg = Array.newInstance(varArgClass, len);
params[params.length - 1] = varArg;
}
for (int a = 0; a < args.length; a++, p++) {
boolean currentIsVarArg = varArgs && p >= paramClasses.length - 1;
Class<?> paramClass;
if (currentIsVarArg) {
paramClass = varArgClass;
} else {
paramClass = paramClasses[p];
}
int type = DataType.getTypeFromClass(paramClass);
Value v = args[a].getValue(session);
v = v.convertTo(type);
Object o = v.getObject();
if (o == null) {
if (paramClass.isPrimitive()) {
if (columnList) {
// if the column list is requested, the parameters may
// be null
// need to set to default value otherwise the function
// can't be called at all
o = DataType.getDefaultForPrimitiveType(paramClass);
} else {
// NULL for a java primitive: return NULL
return ValueNull.INSTANCE;
}
}
} else {
if (!paramClass.isAssignableFrom(o.getClass()) && !paramClass.isPrimitive()) {
o = DataType.convertTo(session, session.createConnection(false), v, paramClass);
}
}
if (currentIsVarArg) {
Array.set(varArg, p - params.length + 1, o);
} else {
params[p] = o;
}
}
boolean old = session.getAutoCommit();
Value identity = session.getScopeIdentity();
try {
session.setAutoCommit(false);
try {
Object returnValue;
returnValue = method.invoke(null, params);
if (returnValue == null) {
return ValueNull.INSTANCE;
}
Value ret = DataType.convertToValue(session, returnValue, dataType);
return ret.convertTo(dataType);
} catch (Exception e) {
throw Message.convert(e);
}
} finally {
session.setScopeIdentity(identity);
session.setAutoCommit(old);
}
}