protected static void writeToINode(INode node) {
int blockID = node.getIndex() / (Constants.BLOCK_SIZE / Constants.INODE_SIZE);
int inodeOffset = node.getIndex() % (Constants.BLOCK_SIZE / Constants.INODE_SIZE);
byte[] dataToWrite = new byte[Constants.BLOCK_SIZE];
byte[] fileMetadata = node.getMetadata();
DBuffer buffer = _cache.getBlock(blockID);
buffer.read(dataToWrite, 0, Constants.BLOCK_SIZE);
for (int k = 0; k < fileMetadata.length; k++)
dataToWrite[inodeOffset * Constants.INODE_SIZE + k] = fileMetadata[k];
buffer.write(dataToWrite, 0, Constants.BLOCK_SIZE);
_cache.releaseBlock(buffer);
}
private void init() {
for (int i = 0; i < _inodes.length; i++) {
int blockID = i / (Constants.BLOCK_SIZE / Constants.INODE_SIZE);
int offset = i % (Constants.BLOCK_SIZE / Constants.INODE_SIZE);
byte[] buffer = new byte[Constants.BLOCK_SIZE];
DBuffer dbuf = _cache.getBlock(blockID);
dbuf.read(buffer, 0, Constants.BLOCK_SIZE);
_cache.releaseBlock(dbuf);
_inodes[i].initialize(buffer, offset * Constants.INODE_SIZE, Constants.INODE_SIZE);
if (_inodes[i].isUsed()) {
int actualNumBlocks = _inodes[i].getBlockList().size();
int predictedNumBlocks =
(int) Math.ceil((double) _inodes[i].getSize() / Constants.BLOCK_SIZE);
// ensure that the # blocks in your list is correct
if (actualNumBlocks == predictedNumBlocks) {
for (int dfid : _inodes[i].getBlockList()) {
if (_usedBlocks[dfid])
System.err.println("Block " + dfid + " is in use by multiple INodes");
// block # is either - or greater than allowed # blocks
// signifies corruption of block list
if (dfid < 0 || dfid >= Constants.NUM_OF_BLOCKS) {
try {
_inodes[i].clearContent(); // delete the block data
System.err.println(
"INode " + i + " has a # blocks outside of the acceptable range");
} catch (Exception e) {
System.err.println("Error in clearing dfiles");
}
break;
}
// we can initialize & use block
else _usedBlocks[dfid] = true;
}
} else {
// File size doesn't compute, given operations
try {
_inodes[i].clearContent(); // delete the block data
System.err.println("File " + i + " doesn't have the correct size");
} catch (Exception e) {
System.err.println("Error in clearing dfiles");
}
}
}
}
}
public AbstractDFS(String volName, boolean format) {
_volName = volName;
_format = format;
_cache = DBufferCache.getInstance(_volName, format, Constants.NUM_OF_CACHE_BLOCKS);
_inodes = new INode[Constants.MAX_DFILES];
_usedBlocks = new boolean[Constants.NUM_OF_BLOCKS];
for (int i = 0; i < _inodes.length; i++) {
_inodes[i] = new INode(i);
}
if (format) format();
else init();
}