/* write a chunk data to the region file at specified sector number */
private void write(int sectorNumber, byte[] data, int length) throws IOException {
debugln(" " + sectorNumber);
file.seek(sectorNumber * SECTOR_BYTES);
file.writeInt(length + 1); // chunk length
file.writeByte(VERSION_DEFLATE); // chunk version number
file.write(data, 0, length); // chunk data
}
public RegionFile(File path) {
offsets = new int[SECTOR_INTS];
chunkTimestamps = new int[SECTOR_INTS];
fileName = path;
debugln("REGION LOAD " + fileName);
sizeDelta = 0;
try {
if (path.exists()) {
lastModified = path.lastModified();
}
file = new RandomAccessFile(path, "rw");
if (file.length() < SECTOR_BYTES) {
/* we need to write the chunk offset table */
for (int i = 0; i < SECTOR_INTS; ++i) {
file.writeInt(0);
}
// write another sector for the timestamp info
for (int i = 0; i < SECTOR_INTS; ++i) {
file.writeInt(0);
}
sizeDelta += SECTOR_BYTES * 2;
}
if ((file.length() & 0xfff) != 0) {
/* the file size is not a multiple of 4KB, grow it */
for (int i = 0; i < (file.length() & 0xfff); ++i) {
file.write((byte) 0);
}
}
/* set up the available sector map */
int nSectors = (int) file.length() / SECTOR_BYTES;
sectorFree = new ArrayList<Boolean>(nSectors);
for (int i = 0; i < nSectors; ++i) {
sectorFree.add(true);
}
sectorFree.set(0, false); // chunk offset table
sectorFree.set(1, false); // for the last modified info
file.seek(0);
for (int i = 0; i < SECTOR_INTS; ++i) {
int offset = file.readInt();
offsets[i] = offset;
if (offset != 0 && (offset >> 8) + (offset & 0xFF) <= sectorFree.size()) {
for (int sectorNum = 0; sectorNum < (offset & 0xFF); ++sectorNum) {
sectorFree.set((offset >> 8) + sectorNum, false);
}
}
}
for (int i = 0; i < SECTOR_INTS; ++i) {
int lastModValue = file.readInt();
chunkTimestamps[i] = lastModValue;
}
} catch (IOException e) {
e.printStackTrace();
}
}
private void setTimestamp(int x, int z, int value) throws IOException {
chunkTimestamps[x + z * 32] = value;
file.seek(SECTOR_BYTES + (x + z * 32) * 4);
file.writeInt(value);
}
private void setOffset(int x, int z, int offset) throws IOException {
offsets[x + z * 32] = offset;
file.seek((x + z * 32) * 4);
file.writeInt(offset);
}