/**
* The caller will have pushed a DataValueFactory and value of that can be converted to the
* correct type, e.g. int for a SQL INTEGER.
*
* <p>Thus upon entry the stack looks like: ...,dvf,value
*
* <p>If field is not null then it is used as the holder of the generated DataValueDescriptor to
* avoid object creations on multiple passes through this code. The field may contain null or a
* valid value.
*
* <p>This method then sets up to call the required method on DataValueFactory using the
* dataValueMethodName(). The value left on the stack will be a DataValueDescriptor of the correct
* type:
*
* <p>If the field contained a valid value then generated code will return that value rather than
* a newly created object. If field was not-null then the generated code will set the value of
* field to be the return from the DataValueFactory method call. Thus if the field was empty (set
* to null) when this code is executed it will contain the newly generated value, otherwise it
* will be reset to the same value.
*
* <p>...,dvd
*
* @see TypeCompiler#generateDataValue(MethodBuilder, int, LocalField)
*/
public void generateDataValue(MethodBuilder mb, int collationType, LocalField field) {
String interfaceName = interfaceName();
// push the second argument
/* If fieldName is null, then there is no
* reusable wrapper (null), else we
* reuse the field.
*/
if (field == null) {
mb.pushNull(interfaceName);
} else {
mb.getField(field);
}
int argCount;
if (pushCollationForDataValue(collationType)) {
mb.push(collationType);
argCount = 3;
} else argCount = 2;
mb.callMethod(
VMOpcode.INVOKEINTERFACE, (String) null, dataValueMethodName(), interfaceName, argCount);
if (field != null) {
/* Store the result of the method call in the field,
* so we can re-use the wrapper.
*/
mb.putField(field);
}
}
/**
* The caller will have pushed a DataValueFactory and a null or a value of the correct type
* (interfaceName()). Thus upon entry the stack looks like on of: ...,dvf,ref ...,dvf,null
*
* <p>This method then sets up to call the required method on DataValueFactory using the
* nullMethodName(). The value left on the stack will be a DataValueDescriptor of the correct
* type:
*
* <p>...,dvd
*
* @see TypeCompiler#generateNull(MethodBuilder, int)
*/
public void generateNull(MethodBuilder mb, int collationType) {
int argCount;
if (pushCollationForDataValue(collationType)) {
mb.push(collationType);
argCount = 2;
} else argCount = 1;
mb.callMethod(
VMOpcode.INVOKEINTERFACE, (String) null, nullMethodName(), interfaceName(), argCount);
}