Improve handling of /reload, clean up dead code

src/main/java/org/dynmap/utils/DynmapBufferedImage.java

@@ -0,0 +1,88 @@
+package org.dynmap.utils;
+
+import java.awt.image.BufferedImage;
+import java.awt.image.ColorModel;
+import java.awt.image.DataBuffer;
+import java.awt.image.DataBufferInt;
+import java.awt.image.Raster;
+import java.awt.image.WritableRaster;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.LinkedList;
+
+public class DynmapBufferedImage {
+    public BufferedImage buf_img;
+    public int[] argb_buf;
+    public int width;
+    public int height;
+    
+    /* BufferedImage cache - we use the same things a lot... */
+    private static Object lock = new Object();
+    private static HashMap<Long, LinkedList<DynmapBufferedImage>> imgcache = 
+        new HashMap<Long, LinkedList<DynmapBufferedImage>>(); /* Indexed by resolution - X<<32+Y */
+    private static final int CACHE_LIMIT = 10;
+
+    /**
+     * Allocate buffered image from pool, if possible
+     * @param x - x dimension
+     * @param y - y dimension
+     */
+    public static DynmapBufferedImage allocateBufferedImage(int x, int y) {
+        DynmapBufferedImage img = null;
+        synchronized(lock) {
+            long k = (x<<16) + y;
+            LinkedList<DynmapBufferedImage> ll = imgcache.get(k);
+            if(ll != null) {
+                img = ll.poll();
+            }
+        }
+        if(img != null) {   /* Got it - reset it for use */
+            Arrays.fill(img.argb_buf, 0);
+        }
+        else {
+            img = new DynmapBufferedImage();
+            img.width = x;
+            img.height = y;
+            img.argb_buf = new int[x*y];
+        }
+        img.buf_img = createBufferedImage(img.argb_buf, img.width, img.height);
+        return img;
+    }
+    
+    /**
+     * Return buffered image to pool
+     */
+    public static void freeBufferedImage(DynmapBufferedImage img) {
+        img.buf_img.flush();
+        img.buf_img = null; /* Toss bufferedimage - seems to hold on to other memory */
+        synchronized(lock) {
+            long k = (img.width<<16) + img.height;
+            LinkedList<DynmapBufferedImage> ll = imgcache.get(k);
+            if(ll == null) {
+                ll = new LinkedList<DynmapBufferedImage>();
+                imgcache.put(k, ll);
+            }
+            if(ll.size() < CACHE_LIMIT) {
+                ll.add(img);
+                img = null;
+            }
+        }
+    }    
+    
+    /* ARGB band masks */
+    private static final int [] band_masks = {0xFF0000, 0xFF00, 0xff, 0xff000000};
+
+    /**
+     * Build BufferedImage from provided ARGB array and dimensions
+     */
+    public static BufferedImage createBufferedImage(int[] argb_buf, int w, int h) {
+        /* Create integer-base data buffer */
+        DataBuffer db = new DataBufferInt (argb_buf, w*h);
+        /* Create writable raster */
+        WritableRaster raster = Raster.createPackedRaster(db, w, h, w, band_masks, null);
+        /* RGB color model */
+        ColorModel color_model = ColorModel.getRGBdefault ();
+        /* Return buffered image */
+        return new BufferedImage (color_model, raster, false, null);
+    }
+}