Related issue: NETTY-175 Large Data Transfer

* Added ChunkedStream
* Moved ChunkedFile.DEFAULT_CHUNK_SIZE to ChunkedStream

src/main/java/org/jboss/netty/handler/stream/ChunkedFile.java

@@ -35,8 +35,6 @@ import java.io.RandomAccessFile;
  */
 public class ChunkedFile implements ChunkedInput {
 
-    private static final int DEFAULT_CHUNK_SIZE = 8192;
-
     private final RandomAccessFile file;
     private final long startOffset;
     private final long endOffset;
@@ -44,7 +42,7 @@ public class ChunkedFile implements ChunkedInput {
     private volatile long offset;
 
     public ChunkedFile(File file) throws IOException {
-        this(file, DEFAULT_CHUNK_SIZE);
+        this(file, ChunkedStream.DEFAULT_CHUNK_SIZE);
     }
 
     public ChunkedFile(File file, int chunkSize) throws IOException {

src/main/java/org/jboss/netty/handler/stream/ChunkedStream.java

@@ -0,0 +1,102 @@
+/*
+ * JBoss, Home of Professional Open Source
+ *
+ * Copyright 2009, Red Hat Middleware LLC, and individual contributors
+ * by the @author tags. See the COPYRIGHT.txt in the distribution for a
+ * full listing of individual contributors.
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this software; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
+ */
+package org.jboss.netty.handler.stream;
+
+import static org.jboss.netty.buffer.ChannelBuffers.*;
+
+import java.io.InputStream;
+import java.io.PushbackInputStream;
+
+/**
+ * @author The Netty Project (netty-dev@lists.jboss.org)
+ * @author Trustin Lee (tlee@redhat.com)
+ * @version $Rev$, $Date$
+ */
+public class ChunkedStream implements ChunkedInput {
+
+    static final int DEFAULT_CHUNK_SIZE = 8192;
+
+    private final PushbackInputStream in;
+    private final int chunkSize;
+    private volatile long offset;
+
+    public ChunkedStream(InputStream in) {
+        this(in, DEFAULT_CHUNK_SIZE);
+    }
+
+    public ChunkedStream(InputStream in, int chunkSize) {
+        if (in == null) {
+            throw new NullPointerException("in");
+        }
+        if (chunkSize <= 0) {
+            throw new IllegalArgumentException(
+                    "chunkSize: " + chunkSize +
+                    " (expected: a positive integer)");
+        }
+
+        if (in instanceof PushbackInputStream) {
+            this.in = (PushbackInputStream) in;
+        } else {
+            this.in = new PushbackInputStream(in);
+        }
+        this.chunkSize = chunkSize;
+    }
+
+    public long getCurrentRelativeOffset() {
+        return offset;
+    }
+
+    public boolean available() throws Exception {
+        int b = in.read();
+        if (b < 0) {
+            return false;
+        } else {
+            in.unread(b);
+            return true;
+        }
+    }
+
+    public void close() throws Exception {
+        in.close();
+    }
+
+    public Object readChunk() throws Exception {
+        if (!available()) {
+            return null;
+        }
+
+        int chunkSize = Math.min(this.chunkSize, in.available());
+        byte[] chunk = new byte[chunkSize];
+        int readBytes = 0;
+        for (;;) {
+            int localReadBytes = in.read(chunk, readBytes, chunkSize - readBytes);
+            if (localReadBytes < 0) {
+                break;
+            }
+            readBytes += localReadBytes;
+        }
+
+        offset += readBytes;
+        return wrappedBuffer(chunk, 0, readBytes);
+    }
+}