package jnr.ffi.provider.jffi;
import com.kenai.jffi.MemoryIO;
import com.kenai.jffi.ObjectParameterType;
import java.nio.Buffer;
import java.util.EnumSet;
/**
*
*/
final class DirectBufferParameterStrategy extends PointerParameterStrategy {
private final int shift;
public DirectBufferParameterStrategy(ObjectParameterType.ComponentType componentType) {
super(DIRECT, ObjectParameterType.create(ObjectParameterType.ObjectType.BUFFER, componentType));
this.shift = calculateShift(componentType);
}
@Override
public long address(Object o) {
Buffer buffer = (Buffer) o;
return MemoryIO.getInstance().getDirectBufferAddress(buffer) + (buffer.position() << shift);
}
@Override
public Object object(Object o) {
return o;
}
@Override
public int offset(Object o) {
return ((Buffer) o).position() << shift;
}
@Override
public int length(Object o) {
return ((Buffer) o).remaining() << shift;
}
private static int calculateShift(ObjectParameterType.ComponentType componentType) {
switch (componentType) {
case BYTE:
return 0;
case SHORT:
case CHAR:
return 1;
case INT:
case BOOLEAN:
case FLOAT:
return 2;
case LONG:
case DOUBLE:
return 3;
default:
throw new IllegalArgumentException("unsupported component type: " + componentType);
}
}
private static final DirectBufferParameterStrategy[] directBufferStrategies;
static {
EnumSet<ObjectParameterType.ComponentType> componentTypes = EnumSet.allOf(ObjectParameterType.ComponentType.class);
directBufferStrategies = new DirectBufferParameterStrategy[componentTypes.size()];
for (ObjectParameterType.ComponentType componentType : componentTypes) {
directBufferStrategies[componentType.ordinal()] = new DirectBufferParameterStrategy(componentType);
}
}
static PointerParameterStrategy get(ObjectParameterType.ComponentType componentType) {
return directBufferStrategies[componentType.ordinal()];
}
}