org.yamcs.xtce.ParameterInstanceRef Maven / Gradle / Ivy
package org.yamcs.xtce;
/**
* A reference to an instance of a Parameter.
*
* Used when the value of a parameter is required for a calculation or as an index value.
*
* Starting with Yamcs 5.10.4 the {@link #relativeTo} field has been introduced to better qualify what the instance
* refers to exactly.
*
* If the parameter is an aggregate or an array, the reference can be made to a member of the aggregate/array or more
* generally to a path inside the aggregate (if a hierarchy of aggregates/arrays)
*
* Thus the reference can be something like: g1/g2/a[1]/g4[a3]/p7
*
*/
public class ParameterInstanceRef extends ParameterOrArgumentRef {
private static final long serialVersionUID = 4;
private Parameter parameter;
private int instance = 0;
public static enum InstanceRelativeTo {
/**
* The instance field counts positively from the beginning of the packet.
*
* Negative values are not allowed.
*/
PACKET_START_WITHIN_PACKET,
/**
* The instance field counts positively from the beginning of the packet.
*
* Negative values means previously received data (with the possibility of missing packets, which may result in
* retrieving older values than intended)
*
*/
PACKET_START_ACROSS_PACKETS,
/**
* The instance field counts negatively from the current entry. 0 means the last instance. Strictly positive
* values are not allowed.
*
* The lookup stops in the current packet, values from previous packets are not considered.
*/
CURRENT_ENTRY_WITHIN_PACKET,
/**
* This is the same as CURRENT_ENTRY_WITHIN_PACKET but not restricted to the current packet.
*
* The lookup continues to the previous packets (with the possibility of missing packets, which may result in
* retrieving older values than intended).
*/
CURRENT_ENTRY_ACROSS_PACKETS,
}
InstanceRelativeTo relativeTo = InstanceRelativeTo.CURRENT_ENTRY_WITHIN_PACKET;
/**
* Constructor to be used when the parameter is not yet known. The parameter will have to be set later with
* setParameter()
*/
public ParameterInstanceRef() {
super();
}
public ParameterInstanceRef(Parameter para) {
this.parameter = para;
}
public ParameterInstanceRef(Parameter para, PathElement[] path) {
this.parameter = para;
this.path = path;
}
public ParameterInstanceRef(Parameter para, boolean useCalibratedValue) {
this.parameter = para;
this.useCalibratedValue = useCalibratedValue;
}
public ParameterInstanceRef(boolean useCalibratedValue) {
this.useCalibratedValue = useCalibratedValue;
}
public void setParameter(Parameter para) {
this.parameter = para;
}
public Parameter getParameter() {
return parameter;
}
public void setInstance(int instance) {
this.instance = instance;
}
/**
* The interpretation of instance depends on the {@link #relativeTo}
*/
public int getInstance() {
return instance;
}
/**
*
* @return true if the instance can reference values from older packets
*/
public boolean requireOldValues() {
return instance <= 0 && (relativeTo == InstanceRelativeTo.CURRENT_ENTRY_ACROSS_PACKETS
|| relativeTo == InstanceRelativeTo.PACKET_START_ACROSS_PACKETS);
}
public InstanceRelativeTo getRelativeTo() {
return relativeTo;
}
public void setRelativeTo(InstanceRelativeTo relativeTo) {
this.relativeTo = relativeTo;
}
public DataType getDataType() {
return parameter == null ? null : parameter.getParameterType();
}
@Override
public String getName() {
return parameter == null ? null : parameter.getQualifiedName();
}
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
if (parameter != null) {
sb.append(parameter.getQualifiedName());
}
if (path != null) {
sb.append("/");
sb.append(PathElement.pathToString(path));
}
if (instance != 0) {
sb.append("[" + instance + "]");
}
return sb.toString();
}
}