/**
* the binary protocol see {@linkplain #toBytes()}
*
* @param b
*/
public void fill(byte[] b) {
int coordinate = 0;
storagePointer = NumberUtils.byteArrayToInt(Arrays.copyOfRange(b, coordinate, coordinate + 4));
coordinate += 4;
int parent_storagePointer =
NumberUtils.byteArrayToInt(Arrays.copyOfRange(b, coordinate, coordinate + 4));
coordinate += 4;
if (parent_storagePointer > 0) {
parent = new Node(storage);
parent.storagePointer = parent_storagePointer;
}
count = b[coordinate];
coordinate += 1;
isLeaf = b[coordinate] == 1 ? true : false;
coordinate += 1;
for (int i = 0; i < DATAITEMS_COUNT; i++) {
if (i < count) {
if (dataItems[i] == null) dataItems[i] = new DataItem();
dataItems[i].fill(Arrays.copyOfRange(b, coordinate, coordinate + DataItem.BYTE_LENGTH));
}
coordinate += DataItem.BYTE_LENGTH;
}
for (int i = 0; i <= DATAITEMS_COUNT; i++) {
if (!isLeaf && i <= count) {
if (child[i] == null) child[i] = new Node(this.storage);
child[i].storagePointer =
NumberUtils.byteArrayToInt(Arrays.copyOfRange(b, coordinate, coordinate + 4));
}
coordinate += 4;
}
}
/**
* the binary protocol is below:
*
* <p>
*
* <pre>
* -----------------------------------------------------------------------------------------------------------
* currentPointer(4) | parentPointer(4) | count(1) | isLeaf(1) | dataItems | childPoints |
* -----------------------------------------------------------------------------------------------------------
* </pre>
*
* @return
*/
public byte[] toBytes() {
byte[] b = new byte[NODE_BYTES_LEN];
int coordinate = 0;
System.arraycopy(NumberUtils.intToByteArray((int) storagePointer), 0, b, coordinate, 4);
coordinate += 4;
if (parent != null)
System.arraycopy(
NumberUtils.intToByteArray((int) parent.getStoragePointer()), 0, b, coordinate, 4);
else System.arraycopy(new byte[4], 0, b, coordinate, 4);
coordinate += 4;
b[coordinate] = (byte) count;
coordinate += 1;
b[coordinate] = isLeaf ? (byte) 1 : (byte) 0;
coordinate += 1;
for (int i = 0; i < DATAITEMS_COUNT; i++) {
if (i < count) {
System.arraycopy(dataItems[i].toBytes(), 0, b, coordinate, DataItem.BYTE_LENGTH);
} else {
System.arraycopy(new byte[DataItem.BYTE_LENGTH], 0, b, coordinate, DataItem.BYTE_LENGTH);
}
coordinate += DataItem.BYTE_LENGTH;
}
for (int i = 0; i <= DATAITEMS_COUNT; i++) {
if (!isLeaf && i <= count) {
System.arraycopy(
NumberUtils.intToByteArray((int) child[i].storagePointer), 0, b, coordinate, 4);
} else {
System.arraycopy(new byte[4], 0, b, coordinate, 4);
}
coordinate += 4;
}
return b;
}
protected void addDataItem(DataItem item, Node... insertedChild) {
if (count >= DATAITEMS_COUNT)
throw new RuntimeException("the node couldn't contains dataitems over the pre-set counts");
int i = 0;
/*
* insert data item
*/
for (; i < count; i++) {
if (item.compareTo(dataItems[i]) < 0) {
for (int j = count; j > i; j--) {
dataItems[j] = dataItems[j - 1];
}
break;
}
}
dataItems[i] = item;
/*
* insert the child reference
*/
for (int j = count + 1; j > i + 1; j--) {
child[j] = child[j - 1];
}
if (insertedChild != null) {
if (insertedChild.length == 1) child[i + 1] = insertedChild[0];
else if (insertedChild.length == 2) {
child[0] = insertedChild[0];
child[1] = insertedChild[1];
}
}
for (Node cn : insertedChild) {
if (cn != null) {
cn = StorageUtils.loadNode(this.storage, cn.getStoragePointer());
cn.setParent(this);
StorageUtils.flushToStorage(cn, this.storage);
}
}
// count increment
count++;
}