Introducing external chunklets

src/main/java/com/gmail/nossr50/util/blockmeta/ChunkletStore.java

@@ -1,8 +1,9 @@
 package com.gmail.nossr50.util.blockmeta;
 
+import java.io.Externalizable;
 import java.io.Serializable;
 
-public interface ChunkletStore extends Serializable {
+public interface ChunkletStore extends Serializable, Externalizable {
     /**
      * Checks the value at the given coordinates
      *

src/main/java/com/gmail/nossr50/util/blockmeta/PrimitiveChunkletStore.java

@@ -1,5 +1,9 @@
 package com.gmail.nossr50.util.blockmeta;
 
+import java.io.IOException;
+import java.io.ObjectInput;
+import java.io.ObjectOutput;
+
 public class PrimitiveChunkletStore implements ChunkletStore {
     private static final long serialVersionUID = -3453078050608607478L;
 
@@ -32,4 +36,87 @@ public class PrimitiveChunkletStore implements ChunkletStore {
         }
         return true;
     }
+
+    @Override
+    public void writeExternal(ObjectOutput out) throws IOException {
+        byte[] buffer = new byte[2304]; // 2304 is 16*16*9
+        int bufferIndex = 0;
+
+        for(int x = 0; x < 16; x++) {
+            for(int z = 0; z < 16; z++) {
+                for(int y = 0; y < 64; y++) {
+                    if(store[x][z][y]) {
+                        byte[] temp = constructColumn(x, z);
+
+                        for(int i = 0; i < 9; i++) {
+                            buffer[bufferIndex] = temp[i];
+                            bufferIndex++;
+                        }
+
+                        break;
+                    }
+                }
+            }
+        }
+
+        out.write(buffer, 0, bufferIndex);
+        out.flush();
+    }
+
+    private byte[] constructColumn(int x, int z) {
+        byte[] column = new byte[9];
+        int index = 1;
+
+        column[0] = makeAddressByte(x, z);
+
+        for (int i = 0; i < 8; i++){
+            byte yCompressed = 0x0;
+            int subColumnIndex = 8 * i;
+            int subColumnEnd = subColumnIndex + 8;
+
+            for(int y = subColumnIndex; y < subColumnEnd; y++) {
+                if(store[x][z][y]) {
+                    yCompressed |= 1 << y % 8; 
+                }
+            }
+
+            column[index] = yCompressed;
+            index++;
+        }
+
+        return column;
+    }
+
+    private static byte makeAddressByte(int x, int z) {
+        return (byte) ((x << 4) + z);
+    }
+
+    // For this we assume that store has been initialized to be all false by now
+    @Override
+    public void readExternal(ObjectInput in) throws IOException {
+        byte[] temp = new byte[9];
+
+        // Could probably reorganize this loop to print nasty things if it does not equal 9 or -1
+        while(in.read(temp, 0, 9) == 9) {
+            int x = addressByteX(temp[0]);
+            int z = addressByteZ(temp[0]);
+            boolean[] yColumn = new boolean[64];
+
+            for(int i = 0; i < 8; i++) {
+                for(int j = 0; j < 8; j++) {
+                    yColumn[j + (i * 8)] = (temp[++i] & 1 << j) != 0;
+                }
+            }
+
+            store[x][z] = yColumn;
+        }
+    }
+
+    private static int addressByteX(byte address) {
+        return (address & 0xF0) >>> 4;
+    }
+
+    private static int addressByteZ(byte address) {
+        return address & 0x0F;
+    }
 }