[Cronet] Initial implementation of HttpURLConnection

components/cronet/android/java/src/org/chromium/net/urlconnection/ByteBufferInputStream.java

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.net.urlconnection;
+
+import java.io.InputStream;
+import java.nio.ByteBuffer;
+
+/**
+ * Wrapper class to construct an InputSteam based on a ByteBuffer.
+ */
+class ByteBufferInputStream extends InputStream {
+

[mmenke, 2014/11/18 15:53:52]

nit:  Remove blank line, to be consistent with other cronet files (Goes for the
other Java files, too).

[xunjieli, 2014/11/18 18:13:35]

Done.

+    private final ByteBuffer mBuf;

[mmenke, 2014/11/18 15:53:51]

optional nit:  Suggest just writing out buffer for readability.  It is a common
enough abbreviation that the C++ style guide does allow for it, though.

[xunjieli, 2014/11/18 18:13:35]

Done.

+
+    public ByteBufferInputStream(ByteBuffer buf) {
+        // Makes a read-only copy of the buffer passed in.

[mmenke, 2014/11/18 15:53:51]

This is not actually a copy, but a read only reference to the data pointed at by
the old buffer.

[xunjieli, 2014/11/18 18:13:35]

The java docs says it is a new instance
http://developer.android.com/reference/java/nio/ByteBuffer.html#asReadOnlyBuf....
I thought a new instance means it is a new object. hmm.. but the method is
abstract. maybe that depends on the implementation. What's an alternative?

[mmenke, 2014/11/18 18:40:59]

It's a new Java object, but it shares the buffer.  Read the full text at that
link:

...The new buffer shares its content with this buffer, which means this buffer's
change of content will be visible to the new buffer. The two buffer's position,
limit and mark are independent.

I'm not sure if clone() would duplicate the buffer contents or not.  You can
always allocate a new one and copy.

+        mBuf = buf.asReadOnlyBuffer();
+    }
+
+    @Override
+    public int read() {
+        if (!mBuf.hasRemaining()) {
+            return -1;
+        }
+        return mBuf.get() & 0xFF;
+    }
+
+    @Override
+    public int read(byte[] bytes, int off, int len) {
+        if (!mBuf.hasRemaining()) {
+            return -1;
+        }
+
+        len = Math.min(len, mBuf.remaining());
+        mBuf.get(bytes, off, len);
+        return len;
+    }
+}