package org.nustaq.offheap.structs;
import org.nustaq.offheap.bytez.Bytez;
import java.io.Serializable;
/**
* Created with IntelliJ IDEA.
* User: ruedi
* Date: 01.11.13
* Time: 14:17
* To change this template use File | Settings | File Templates.
*/
// FIXME: move to long indizies
public class FSTStructChange implements Serializable {
int changeOffsets[];
int changeLength[];
String changedFields[];
int curIndex;
transient public String _parentField;
transient public FSTStructChange _parent;
byte snapshot[]; // created by snapshotChanges, contains new byte values
public FSTStructChange(FSTStructChange par, String parField) {
_parentField = parField;
_parent = par;
}
public FSTStructChange() {
changeLength = new int[2];
changeOffsets = new int[2];
changedFields = new String[2];
}
public void addChange(int offset, int len, String field) {
addChange((long)offset,(long)len,field);
}
public void addChange(long offset, int len, String field) {
addChange((long)offset,(long)len,field);
}
public void addChange(long offset, long len, String field) {
if ( _parent != null ) {
_parent.addChange(offset,len,_parentField);
return;
}
if ( curIndex > 0 && changeOffsets[curIndex-1]+changeLength[curIndex-1] == offset ) {
changeLength[curIndex-1]+=len;
return;
}
if ( curIndex >= changeOffsets.length ) {
int newOff[] = new int[changeOffsets.length*2];
System.arraycopy(changeOffsets,0,newOff,0,changeOffsets.length);
int newLen[] = new int[changeOffsets.length*2];
System.arraycopy(changeLength,0,newLen,0,changeLength.length);
String newCF[] = new String[changeOffsets.length*2];
System.arraycopy(changedFields,0,newCF,0,changedFields.length);
changeOffsets = newOff;
changeLength = newLen;
changedFields = newCF;
}
changeOffsets[curIndex] = (int) (offset);
changeLength[curIndex] = (int) len;
changedFields[curIndex] = field;
curIndex++;
}
public void rebase(int toSubtract) {
for (int i = 0; i < curIndex; i++) {
changeOffsets[i]-=toSubtract;
}
}
/**
* collects all changes and rebases.
* @param originBase
* @param origin
*/
public void snapshotChanges(int originBase, Bytez origin) {
int sumLen = 0;
for (int i = 0; i < curIndex; i++) {
sumLen += changeLength[i];
}
snapshot = new byte[sumLen];
int targetIdx = 0;
for (int i = 0; i < curIndex; i++) {
int changeOffset = changeOffsets[i];
int len = changeLength[i];
for ( int ii = 0; ii < len; ii++) {
snapshot[targetIdx++] = origin.get(changeOffset+ii);
}
}
rebase(originBase);
}
public void applySnapshot(FSTStruct target) {
Bytez arr = target.getBase();
int baseIdx = (int) target.getOffset();
int snapIdx = 0;
for (int i = 0; i < curIndex; i++) {
int changeOffset = changeOffsets[i];
int len = changeLength[i];
for ( int ii = 0; ii < len; ii++) {
arr.put(baseIdx+changeOffset+ii,snapshot[snapIdx++]);
}
}
}
public String[] getChangedFields() {
return changedFields;
}
public byte[] getSnapshot() {
return snapshot;
}
}