DatanodeDescriptor getDatanode(int index) {
assert this.triplets != null : "BlockInfo is not initialized";
assert index >= 0 && index * 3 < triplets.length : "Index is out of bound";
DatanodeDescriptor node = (DatanodeDescriptor) triplets[index * 3];
assert node == null || DatanodeDescriptor.class.getName().equals(node.getClass().getName())
: "DatanodeDescriptor is expected at " + index * 3;
return node;
}
/**
* Remove the block from the block map; remove it from all data-node lists it belongs to; and
* remove all data-node locations associated with the block.
*/
void removeBlock(BlockInfo blockInfo) {
if (blockInfo == null) return;
blockInfo.inode = null;
for (int idx = blockInfo.numNodes() - 1; idx >= 0; idx--) {
DatanodeDescriptor dn = blockInfo.getDatanode(idx);
dn.removeBlock(blockInfo); // remove from the list and wipe the location
}
map.remove(blockInfo); // remove block from the map
System.out.println("BLOCKSMAP removes block : " + blockInfo);
}
/**
* Remove data-node reference from the block. Remove the block from the block map only if it does
* not belong to any file and data-nodes.
*/
boolean removeNode(Block b, DatanodeDescriptor node) {
BlockInfo info = map.get(b);
if (info == null) return false;
// remove block from the data-node list and the node from the block info
boolean removed = node.removeBlock(info);
if (info.getDatanode(0) == null // no datanodes left
&& info.inode == null) { // does not belong to a file
map.remove(b); // remove block from the map
System.out.println("BLOCKSMAP removes block : " + b);
}
return removed;
}
/**
* returns true if the node does not already exists and is added. false if the node already
* exists.
*/
boolean addNode(Block b, DatanodeDescriptor node, int replication) {
// insert into the map if not there yet
BlockInfo info = checkBlockInfo(b, replication);
// add block to the data-node list and the node to the block info
return node.addBlock(info);
}
/** @return index of free triplet */
private int ensureSpace(DatanodeDescriptor newNode) {
assert this.triplets != null : "BlockInfo is not initialized";
int index = 0;
int last = numNodes();
DatanodeDescriptor node = (DatanodeDescriptor) triplets[index * 3];
// System.out.println("ensureSpace 1");
while (node != null && node.compareTo(newNode) < 0 && index < (triplets.length / 3) - 1) {
index++;
node = (DatanodeDescriptor) triplets[index * 3];
}
// System.out.println("ensureSpace 2");
if (node == null) {
return index;
} else {
assert node.compareTo(newNode) != 0;
}
// System.out.println("ensureSpace 3");
// --------
int j = 1;
if (triplets.length >= (last + 1) * 3) {
j += last + 1 * 4;
for (int i = last * 3 + 2; i >= (index + 1) * 3; i--) {
triplets[i] = triplets[i - 3];
}
// System.out.println("ensureSpace 4");
// System.out.println("ensureSpace 5");
} else {
j += 24 * last;
// System.out.println("ensureSpace 6");
// Not enough space. create a larger array
Object[] old = triplets;
triplets = new Object[3 * (last + 1)];
// copy datanode that precedes the new node
for (int i = 0; i < index * 3; i++) {
triplets[i] = old[i];
}
// System.out.println("ensureSpace 7");
for (int i = index * 3; i < old.length; i++) {
j = j - 2;
triplets[i + 3] = old[i];
}
// System.out.println("ensureSpace 8");
}
triplets[index * 3] = null;
triplets[index * 3 + 1] = null;
triplets[index * 3 + 2] = null;
// --------
/*
if((triplets.length/3) > last ){
// we already have enough space
for(int i=last; i>index; i--){
triplets[3*i] = triplets[3*(i-1)];
triplets[3*i +1] = triplets[3*(i-1) +1];
triplets[3*i +2] = triplets[3*(i-1) +2];
}
triplets[index*3] = null;
triplets[index*3+1] = null;
triplets[index*3+2] = null;
} else {
// Not enough space. create a larger array
Object[] old = triplets;
triplets = new Object[3*(last+1)];
// copy datanode that precedes the new node
for(int i=0; i < index*3; i++){
triplets[i] = old[i];
}
for(int i=index*3; i < old.length; i++){
triplets[i+3] = old[i];
}
}
*/
// System.out.println("ensureSpace 9");
return index;
}
