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.cpp | 109 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 109 insertions(+)
 create mode 100644 src/stable/substream.cpp

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

diff --git a/src/stable/substream.cpp b/src/stable/substream.cpp
new file mode 100644
index 0000000..c201752
--- /dev/null
+++ b/src/stable/substream.cpp
@@ -0,0 +1,109 @@
+/*
+ * 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.
+ */
+
+#include "bu/substream.h"
+
+Bu::SubStream::SubStream( Bu::Stream &rNext, Bu::size iSize ) :
+	Bu::Filter( rNext ),
+	iStart( 0 ),
+	iPos( 0 ),
+	iSize( iSize )
+{
+	iStart = rNext.tell();
+}
+
+Bu::SubStream::~SubStream()
+{
+}
+
+Bu::size Bu::SubStream::read( void *pBuf, Bu::size nBytes )
+{
+	if( (Bu::size)nBytes > iSize-iPos )
+		nBytes = iSize-iPos;
+	nBytes = rNext.read( pBuf, nBytes );
+	iPos += nBytes;
+	return nBytes;
+}
+
+Bu::size Bu::SubStream::write( const void *pBuf, Bu::size nBytes )
+{
+	if( (Bu::size)nBytes > iSize-iPos )
+		nBytes = iSize-iPos;
+	nBytes = rNext.write( pBuf, nBytes );
+	iPos += nBytes;
+	return nBytes;
+}
+
+void Bu::SubStream::start()
+{
+	// doesn't mean anything...
+}
+
+Bu::size Bu::SubStream::stop()
+{
+	// doesn't mean anything...
+	return 0;
+}
+
+void Bu::SubStream::close()
+{
+	// don't do anything?  maybe...
+}
+
+Bu::size Bu::SubStream::tell()
+{
+	return iPos;
+}
+
+void Bu::SubStream::seek( Bu::size offset )
+{
+	if( iPos+offset < 0 )
+		offset = -iPos;
+	else if( iPos+offset > iSize )
+		offset = iSize-iPos;
+	rNext.seek( offset );
+	iPos += offset;
+}
+
+void Bu::SubStream::setPos( Bu::size pos )
+{
+	if( pos < 0 )
+		pos = 0;
+	else if( pos > iSize )
+		pos = iSize;
+	iPos = pos;
+	pos += iStart;
+	rNext.setPos( pos );
+}
+
+void Bu::SubStream::setPosEnd( Bu::size pos )
+{
+	if( iSize-pos < 0 )
+		pos = 0;
+	else if( iSize-pos > iSize )
+		pos = iSize;
+	else
+		pos = iSize-pos;
+	iPos = pos;
+	rNext.setPos( iStart+pos );
+}
+
+bool Bu::SubStream::isEos()
+{
+	return rNext.isEos() || iPos == iSize;
+}
+
+bool Bu::SubStream::canRead()
+{
+	return rNext.canRead() && (iPos < iSize);
+}
+
+bool Bu::SubStream::canWrite()
+{
+	return rNext.canWrite() && (iPos < iSize);
+}
+
-- 
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