From 8baf7e1e75a185c742dc6d5b27e50058635e5522 Mon Sep 17 00:00:00 2001
From: Mike Buland <eichlan@xagasoft.com>
Date: Mon, 10 May 2010 03:31:08 +0000
Subject: Added the new QueueBuf.  It's brilliant, and I've wanted it for a
 long time.

...I mean brilliant as in cool.
---
 src/queuebuf.cpp | 233 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 233 insertions(+)
 create mode 100644 src/queuebuf.cpp

(limited to 'src/queuebuf.cpp')

diff --git a/src/queuebuf.cpp b/src/queuebuf.cpp
new file mode 100644
index 0000000..9404164
--- /dev/null
+++ b/src/queuebuf.cpp
@@ -0,0 +1,233 @@
+/*
+ * Copyright (C) 2007-2010 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/queuebuf.h"
+
+#include "bu/sio.h"
+using Bu::sio;
+
+Bu::QueueBuf::QueueBuf( int iBlockSize /*=256*/ ) :
+	iBlockSize( iBlockSize ),
+	iReadOffset( 0 ),
+	iWriteOffset( 0 ),
+	iTotalSize( 0 )
+{
+}
+
+Bu::QueueBuf::~QueueBuf()
+{
+	for( BlockList::iterator i = lBlocks.begin(); i; i++ )
+		delete[] *i;
+}
+
+int Bu::QueueBuf::getSize()
+{
+	return iTotalSize;
+}
+
+void Bu::QueueBuf::close()
+{
+	for( BlockList::iterator i = lBlocks.begin(); i; i++ )
+		delete[] *i;
+	lBlocks.clear();
+	iReadOffset = iWriteOffset = iTotalSize = 0;
+}
+
+size_t Bu::QueueBuf::read( void *pRawBuf, size_t nBytes )
+{
+	if( nBytes <= 0 )
+		return 0;
+
+	if( lBlocks.isEmpty() )
+		return 0;
+
+	size_t iLeft = nBytes;
+	char *pBuf = (char *)pRawBuf;
+
+	while( iLeft > 0 && iTotalSize > 0 )
+	{
+		if( iReadOffset == iBlockSize )
+		{
+			removeBlock();
+			if( lBlocks.isEmpty() )
+			{
+				return nBytes-iLeft;
+			}
+			iReadOffset = 0;
+		}
+		char *pBlock = lBlocks.first();
+		size_t iCopy = iBlockSize-iReadOffset;
+		if( iLeft < iCopy )
+			iCopy = iLeft;
+		if( iTotalSize < iCopy )
+			iCopy = iTotalSize;
+		memcpy( pBuf, pBlock+iReadOffset, iCopy );
+		iReadOffset += iCopy;
+		iLeft -= iCopy;
+		pBuf += iCopy;
+		iTotalSize -= iCopy;
+		sio << "Read " << iCopy << " bytes, new size: " << iTotalSize << sio.nl;
+	}
+
+	return nBytes - iLeft;
+}
+
+size_t QueueBuf::peek( void *pBuf, size_t nBytes )
+{
+	if( nBytes <= 0 )
+		return 0;
+
+	if( lBlocks.isEmpty() )
+		return 0;
+
+	size_t iLeft = nBytes;
+	char *pBuf = (char *)pRawBuf;
+
+	int iTmpReadOffset = iReadOffset;
+	int iTmpRemSize = iTotalSize;
+	while( iLeft > 0 && iTmpRemSize > 0 )
+	{
+
+		// Switching to use temp variables instead of iReadOffset and iTotalSize
+		if( iReadOffset == iBlockSize )
+		{
+			if( lBlocks.isEmpty() )
+			{
+				return nBytes-iLeft;
+			}
+			iReadOffset = 0;
+		}
+		char *pBlock = lBlocks.first();
+		size_t iCopy = iBlockSize-iReadOffset;
+		if( iLeft < iCopy )
+			iCopy = iLeft;
+		if( iTotalSize < iCopy )
+			iCopy = iTotalSize;
+		memcpy( pBuf, pBlock+iReadOffset, iCopy );
+		iReadOffset += iCopy;
+		iLeft -= iCopy;
+		pBuf += iCopy;
+		iTotalSize -= iCopy;
+		sio << "Read " << iCopy << " bytes, new size: " << iTotalSize << sio.nl;
+	}
+
+	return nBytes - iLeft;
+}
+
+size_t Bu::QueueBuf::write( const void *pRawBuf, size_t nBytes )
+{
+	if( nBytes <= 0 )
+		return 0;
+
+	if( lBlocks.isEmpty() )
+	{
+		addBlock();
+		iWriteOffset = 0;
+	}
+	size_t iLeft = nBytes;
+	const char *pBuf = (const char *)pRawBuf;
+
+	while( iLeft > 0 )
+	{
+		if( iWriteOffset == iBlockSize )
+		{
+			addBlock();
+			iWriteOffset = 0;
+		}
+		char *pBlock = lBlocks.last();
+		size_t iCopy = iBlockSize-iWriteOffset;
+		if( iLeft < iCopy )
+			iCopy = iLeft;
+		memcpy( pBlock+iWriteOffset, pBuf, iCopy );
+		iWriteOffset += iCopy;
+		iLeft -= iCopy;
+		pBuf += iCopy;
+		iTotalSize += iCopy;
+		sio << "Wrote " << iCopy << " bytes, new size: " << iTotalSize << sio.nl;
+	}
+
+	return nBytes;
+}
+
+long Bu::QueueBuf::tell()
+{
+	return -1;
+}
+
+void Bu::QueueBuf::seek( long )
+{
+}
+
+void Bu::QueueBuf::setPos( long )
+{
+}
+
+void Bu::QueueBuf::setPosEnd( long )
+{
+}
+
+bool Bu::QueueBuf::isEos()
+{
+	return iTotalSize == 0;
+}
+
+bool Bu::QueueBuf::isOpen()
+{
+	return true;
+}
+
+void Bu::QueueBuf::flush()
+{
+}
+
+bool Bu::QueueBuf::canRead()
+{
+	return iTotalSize > 0;
+}
+
+bool Bu::QueueBuf::canWrite()
+{
+	return true;
+}
+
+bool Bu::QueueBuf::isReadable()
+{
+	return true;
+}
+
+bool Bu::QueueBuf::isWritable()
+{
+	return true;
+}
+
+bool Bu::QueueBuf::isSeekable()
+{
+	return false;
+}
+
+bool Bu::QueueBuf::isBlocking()
+{
+	return false;
+}
+
+void Bu::QueueBuf::setBlocking( bool )
+{
+}
+
+void Bu::QueueBuf::addBlock()
+{
+	lBlocks.append( new char[iBlockSize] );
+	sio << "Added new block." << sio.nl;
+}
+
+void Bu::QueueBuf::removeBlock()
+{
+	delete[] lBlocks.first();
+	lBlocks.erase( lBlocks.begin() );
+	sio << "Removed block." << sio.nl;
+}
+
-- 
cgit v1.2.3