Added the new QueueBuf. It's brilliant, and I've wanted it for a long time.

...I mean brilliant as in cool.

1 files changed, 233 insertions, 0 deletions

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;
+}
+