--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dwt/internal/image/TIFFRandomFileAccess.d	Sun Jan 06 22:54:14 2008 +0100
@@ -0,0 +1,98 @@
+/*******************************************************************************
+ * Copyright (c) 2000, 2003 IBM Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+module dwt.internal.image.TIFFRandomFileAccess;
+
+import dwt.internal.image.LEDataInputStream;
+import Math = tango.math.Math;
+import tango.core.Exception;
+
+final class TIFFRandomFileAccess {
+
+	LEDataInputStream inputStream;
+	int start, current, next;
+	byte[][] buffers;
+
+	static final int CHUNK_SIZE = 8192;
+	static final int LIST_SIZE = 128;
+
+public this(LEDataInputStream stream) {
+	inputStream = stream;
+	start = current = next = inputStream.getPosition();
+	buffers = new byte[][](LIST_SIZE);
+}
+
+void seek(int pos) {
+	if (pos == current) return;
+	if (pos < start) throw new IOException( "pos < start" );
+	current = pos;
+	if (current > next) {
+		int n = current - next;
+		/* store required bytes */
+		int index = next / CHUNK_SIZE;
+		int offset = next % CHUNK_SIZE;
+		while (n > 0) {
+			if (index >= buffers.length) {
+				byte[][] oldBuffers = buffers;
+				buffers = new byte[][]( Math.max(index + 1, oldBuffers.length + LIST_SIZE) );
+                buffers[ 0 .. oldBuffers.length ] = oldBuffers[];
+			}
+			if (buffers[index] == null) buffers[index] = new byte[CHUNK_SIZE];
+			int cnt = inputStream.read(buffers[index], offset, Math.min(n, CHUNK_SIZE - offset));
+			n -= cnt;
+			next += cnt;
+			index++;
+			offset = 0;
+		}
+	}
+}
+
+void read(byte b[]) {
+	int size = b.length;
+	int nCached = Math.min(size, next - current);
+	int nMissing = size - next + current;
+	int destNext = 0;
+	if (nCached > 0) {
+		/* Get cached bytes */
+		int index = current / CHUNK_SIZE;
+		int offset = current % CHUNK_SIZE;
+		while (nCached > 0) {
+			int cnt = Math.min(nCached, CHUNK_SIZE - offset);
+            b[ destNext .. destNext+cnt ] = buffers[index][ offset .. offset+cnt ];
+			nCached -= cnt;
+			destNext += cnt;
+			index++;
+			offset = 0;
+		}
+	}
+	if (nMissing > 0) {
+		/* Read required bytes */
+		int index = next / CHUNK_SIZE;
+		int offset = next % CHUNK_SIZE;
+		while (nMissing > 0) {
+			if (index >= buffers.length) {
+				byte[][] oldBuffers = buffers;
+				buffers = new byte[][](Math.max(index, oldBuffers.length + LIST_SIZE));
+                buffers[ 0 .. oldBuffers.length ] = oldBuffers[];
+			}
+			if (buffers[index] == null) buffers[index] = new byte[CHUNK_SIZE];
+			int cnt = inputStream.read(buffers[index], offset, Math.min(nMissing, CHUNK_SIZE - offset));
+            b[ destNext .. destNext+cnt ] = buffers[index][ offset .. offset+cnt ];
+			nMissing -= cnt;
+			next += cnt;
+			destNext += cnt;
+			index++;
+			offset = 0;
+		}
+	}
+	current += size;
+}
+
+}