From 469bbcf0701e1eb8a6670c23145b0da87357e178 Mon Sep 17 00:00:00 2001
From: Mike Buland <eichlan@xagasoft.com>
Date: Sun, 25 Mar 2012 20:00:08 +0000
Subject: Code is all reorganized.  We're about ready to release.  I should
 write up a little explenation of the arrangement.

---
 src/stable/substream.h | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)
 create mode 100644 src/stable/substream.h

(limited to 'src/stable/substream.h')

diff --git a/src/stable/substream.h b/src/stable/substream.h
new file mode 100644
index 0000000..1db4d6c
--- /dev/null
+++ b/src/stable/substream.h
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2007-2011 Xagasoft, All rights reserved.
+ *
+ * This file is part of the libbu++ library and is released under the
+ * terms of the license contained in the file LICENSE.
+ */
+
+#ifndef BU_SUB_STREAM_H
+#define BU_SUB_STREAM_H
+
+#include "bu/filter.h"
+
+namespace Bu
+{
+	/**
+	 * Creates a sub-stream of a given stream.  This allows you to read and
+	 * write safely to a section of another stream, keeping all data within
+	 * the given bounds.  The substream acts exactly like a top level stream
+	 * when you reach the bounds of either the containing stream or the
+	 * artificial bounds of the substream, except that unlike many stream types,
+	 * when writing you cannot move beyond the bounds of the substream.  Reads,
+	 * on the other hand, work exactly the same way, returning less data than
+	 * requested when the end of the stream is reached.
+	 *
+	 * The substream always begins at the current position in the base stream,
+	 * if you would like to skip some data first, simply seek.
+	 *
+	 * The substream class is safe to use with all blocking and non-blocking
+	 * base streams, including sockets, however it can have unpredictable
+	 * results when used on a buffering stream that may read more data than
+	 * requested in order to complete a request such as the buffer or bzip2
+	 * filters.
+	 */
+	class SubStream : public Bu::Filter
+	{
+	public:
+		SubStream( Bu::Stream &rNext, Bu::size iSize );
+		virtual ~SubStream();
+
+		virtual Bu::size read( void *pBuf, Bu::size nBytes );
+		virtual Bu::size write( const void *pBuf, Bu::size nBytes );
+		using Bu::Stream::write;
+
+		virtual void start();
+		virtual Bu::size stop();
+		virtual void close();
+		virtual Bu::size tell();
+		virtual void seek( Bu::size offset );
+		virtual void setPos( Bu::size pos );
+		virtual void setPosEnd( Bu::size pos );
+		virtual bool isEos();
+
+		virtual bool canRead();
+		virtual bool canWrite();
+
+	protected:
+		Bu::size iStart;
+		Bu::size iPos;
+		Bu::size iSize;
+	};
+};
+
+#endif
-- 
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