Try fixing region issues, and other tweaks/optimizations (fixes Glows…

…toneMC#995)

src/main/java/net/glowstone/io/anvil/RegionFile.java

@@ -98,10 +98,8 @@ public class RegionFile {
 
  private static final byte[] emptySector = new byte[SECTOR_BYTES];
  private final int[] offsets;
- private final int[] chunkTimestamps;
  private RandomAccessFile file;
  private BitSet sectorsUsed;
- private int totalSectors;
  private final AtomicInteger sizeDelta = new AtomicInteger();
  /**
  * Returns the modification timestamp of the region file when it was first opened by this
@@ -121,7 +119,6 @@ public class RegionFile {
  */
  public RegionFile(File path) throws IOException {
  offsets = new int[SECTOR_INTS];
- chunkTimestamps = new int[SECTOR_INTS];
 
  sizeDelta.set(0);
 
@@ -167,24 +164,24 @@ public RegionFile(File path) throws IOException {
  }
 
  // set up the available sector map
- totalSectors = (int) file.length() / SECTOR_BYTES;
+ int totalSectors = (int) Math.ceil(file.length() / (double) SECTOR_BYTES);
  sectorsUsed = new BitSet(totalSectors);
 
- sectorsUsed.set(0);
- sectorsUsed.set(1);
+ // reserve the first two sectors
+ sectorsUsed.set(0, 2);
 
  // read offset table and timestamp tables
  file.seek(0);
 
- ByteBuffer header = ByteBuffer.allocate(2 * SECTOR_BYTES);
+ ByteBuffer header = ByteBuffer.allocate(SECTOR_BYTES);
  while (header.hasRemaining()) {
  if (file.getChannel().read(header) == -1) {
  throw new EOFException();
  }
  }
- header.clear();
+ header.flip();
 
- // populate the tables
+ // populate the offset table
  IntBuffer headerAsInts = header.asIntBuffer();
  for (int i = 0; i < SECTOR_INTS; ++i) {
  int offset = headerAsInts.get();
@@ -194,20 +191,14 @@ public RegionFile(File path) throws IOException {
  int numSectors = offset & 255;
 
  if (offset != 0 && startSector >= 0 && startSector + numSectors <= totalSectors) {
- for (int sectorNum = 0; sectorNum < numSectors; ++sectorNum) {
- sectorsUsed.set(startSector + sectorNum);
- }
+ sectorsUsed.set(startSector, startSector + numSectors + 1);
  } else if (offset != 0) {
  GlowServer.logger.warning(
  "Region \"" + path + "\": offsets[" + i + "] = " + offset + " -> "
  + startSector
  + "," + numSectors + " does not fit");
  }
  }
- // read timestamps from timestamp table
- for (int i = 0; i < SECTOR_INTS; ++i) {
- chunkTimestamps[i] = headerAsInts.get();
- }
  }
 
  /**
@@ -237,6 +228,7 @@ public DataInputStream getChunkDataInputStream(int x, int z) throws IOException
  return null;
  }
 
+ int totalSectors = sectorsUsed.length();
  int sectorNumber = offset >> 8;
  int numSectors = offset & 0xFF;
  if (sectorNumber + numSectors > totalSectors) {
@@ -320,56 +312,52 @@ protected void write(int x, int z, byte[] data, int length) throws IOException {
  /* we can simply overwrite the old sectors */
  write(sectorNumber, data, length);
  } else {
- /* we need to allocate new sectors */
-
  /* mark the sectors previously used for this chunk as free */
- for (int i = 0; i < sectorsAllocated; ++i) {
- sectorsUsed.clear(sectorNumber + i);
+ if (sectorNumber != 0) {
+ sectorsUsed.clear(sectorNumber, sectorNumber + sectorsAllocated + 1);
  }
 
  /* scan for a free space large enough to store this chunk */
- int runStart = 2;
- int runLength = 0;
- int currentSector = 2;
- while (runLength < sectorsNeeded) {
- int nextSector = sectorsUsed.nextClearBit(currentSector + 1);
- if (currentSector + 1 == nextSector) {
- runLength++;
- } else {
- runStart = nextSector;
- runLength = 1;
- }
- currentSector = nextSector;
- }
-
- if (runLength >= sectorsNeeded) {
- /* we found a free space large enough */
- sectorNumber = runStart;
- setOffset(x, z, sectorNumber << 8 | sectorsNeeded);
- for (int i = 0; i < sectorsNeeded; ++i) {
- sectorsUsed.set(sectorNumber + i);
- }
- write(sectorNumber, data, length);
- } else {
+ sectorNumber = findNewSectorStart(sectorsNeeded);
+ if (sectorNumber == -1) {
  /*
  * no free space large enough found -- we need to grow the
  * file
  */
  file.seek(file.length());
- sectorNumber = totalSectors;
  for (int i = 0; i < sectorsNeeded; ++i) {
  file.write(emptySector);
- sectorsUsed.set(totalSectors + i);
  }
- totalSectors += sectorsNeeded;
  sizeDelta.addAndGet(SECTOR_BYTES * sectorsNeeded);
+ sectorNumber = sectorsUsed.length();
+ }
+
+ sectorsUsed.set(sectorNumber, sectorNumber + sectorsNeeded + 1);
+ write(sectorNumber, data, length);
+ setOffset(x, z, sectorNumber << 8 | sectorsNeeded);
+ }
+ }
 
- write(sectorNumber, data, length);
- setOffset(x, z, sectorNumber << 8 | sectorsNeeded);
+ private int findNewSectorStart(int sectorsNeeded) {
+ int start = -1;
+ int runLength = 0;
+ for (int i = sectorsUsed.nextClearBit(0); i < sectorsUsed.length(); i++) {
+ if (sectorsUsed.get(i)) {
+ // must reset
+ start = -1;
+ runLength = 0;
+ } else {
+ if (start == -1) {
+ start = i;
+ }
+ runLength++;
+ if (runLength >= sectorsNeeded) {
+ return start;
+ }
  }
  }
- setTimestamp(x, z, (int) (System.currentTimeMillis() / 1000L));
- //file.getChannel().force(true);
+ // reached the end, append to the end of the region instead
+ return -1;
  }
 
  /* write a chunk data to the region file at specified sector number */
@@ -401,12 +389,6 @@ private void setOffset(int x, int z, int offset) throws IOException {
  file.writeInt(offset);
  }
 
- private void setTimestamp(int x, int z, int value) throws IOException {
- chunkTimestamps[x + (z << 5)] = value;
- file.seek(SECTOR_BYTES + ((x + (z << 5)) << 2));
- file.writeInt(value);
- }
-
  public void close() throws IOException {
  file.getChannel().force(true);
  file.close();