org.coweb.oe.DeleteOperation Maven / Gradle / Ivy
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package org.coweb.oe;
import java.util.Map;
public class DeleteOperation extends Operation {
protected DeleteOperation(Map args) throws OperationEngineException {
super(args);
this.type = "delete";
}
/**
* Transforms this delete to include the effect of a delete.
*
* @param op Delete to include in this op
* @return This instance or null if this op has no
* further effect on other operations
*/
public Operation transformWithDelete(Operation op) {
if(!this.key.equals(op.key)) {
return this;
}
if(this.position > op.position) {
--this.position;
} else if(this.position == op.position) {
return null;
}
return this;
}
/**
* No-op. Update has no effect on a delete.
*
* @param op Update to include in this op
* @return This instance
*/
public Operation transformWithUpdate(Operation op) {
return this;
}
/**
* Transforms this delete to include the effect of an insert.
*
* @param op Insert to include in this op
* @return This instance
*/
public Operation transformWithInsert(Operation op) {
if(!this.key.equals(op.key)) {
return this;
}
if(this.position >= op.position) {
++this.position;
}
return this;
}
}