--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/videoeditorengine/vedengine/videoprocessor/inc/activequeue.h	Fri Jan 29 14:08:33 2010 +0200
@@ -0,0 +1,139 @@
+/*
+* Copyright (c) 2010 Ixonos Plc.
+* All rights reserved.
+* This component and the accompanying materials are made available
+* under the terms of the "Eclipse Public License v1.0"
+* which accompanies this distribution, and is available
+* at the URL "http://www.eclipse.org/legal/epl-v10.html".
+*
+* Initial Contributors:
+* Nokia Corporation - Initial contribution
+*
+* Contributors:
+* Ixonos Plc
+*
+* Description: 
+* Data buffering and queuing support definitions, class CActiveQueue.
+*
+*/
+
+
+#ifndef     __ACTIVEQUEUE_H__
+#define     __ACTIVEQUEUE_H__
+
+
+//  INCLUDES
+
+#ifndef __E32BASE_H__
+#include <e32base.h>
+#endif
+
+
+//  FORWARD DECLARATIONS
+
+class CDataProcessor;
+class CActiveQueue;
+
+
+//#define BLOCK_GUARD_AREA
+
+
+//  CLASS DEFINITIONS
+
+// Queue block class
+class TActiveQueueBlock : public TPtr8
+{
+    TActiveQueueBlock(TUint8 *aBuf, TInt aMaxLength) : TPtr8(aBuf, aMaxLength) {};
+protected:
+    friend class CActiveQueue;
+    TActiveQueueBlock *iNextBlock; // next block in the allocated block list
+    TActiveQueueBlock *iPrevBlock; // prev. block in the allocated block list
+    TActiveQueueBlock *iNextList; // next block in the data queue / free list
+};
+
+// The queue class
+class CActiveQueue : public CBase
+{
+public: // constants
+    enum TErrorCode
+    {
+        EInternalAssertionFailure = -1000,
+        ENoWriter = -1001, 
+        ENoReader = -1002,
+        EWriteAfterStreamEnd = -1003
+    };
+
+public: // interface functions
+    // Constructors and destructor
+    CActiveQueue(TUint aNumberOfBlocks, TUint aBlockLength);
+    ~CActiveQueue();
+    void ConstructL();
+
+    // Set/remove reader
+    void SetReader(CDataProcessor *aReader, TAny *aUserPointer);
+    void RemoveReader();
+
+    // Set/remove writer
+    void SetWriter(CDataProcessor *aWriter, TAny *aUserPointer);
+    void RemoveWriter();
+
+    void ResetStreamEnd();
+    
+    // Get the number of free blocks available for new data
+    TUint NumFreeBlocks();
+
+    // Get the number of blocks with data queued
+    TUint NumDataBlocks();
+
+    // Get a free block for writing data into the queue (writer)
+    TPtr8 *GetFreeBlockL(TUint aBlockLength);
+
+    // Add a data block to the queue (writer)
+    void WriteBlock(TPtr8 *aBlock);
+
+    // Read a data block from the queue (reader)
+    TPtr8 *ReadBlock();
+
+    // Return a read block back to the empty block list (reader)
+    void ReturnBlock(TPtr8 *aBlock);
+
+    // Notify that the stream has ended (writer)
+    void WriteStreamEnd();
+
+    // Check if the writer has notified that the stream has ended (reader)
+    TBool StreamEnded();
+
+    // Testing aid: get total number of blocks
+    TUint NumBlocks() { return iNumBlocks; };
+
+
+private: // Internal methods
+    TActiveQueueBlock *AllocateBlockL();
+    void FreeBlockL(TActiveQueueBlock *aBlock);
+    
+private: // Data
+    TUint iNewBlockLength; // length of new blocks that are allocated
+    TUint iInitialBlocks; // initial number of blocks to allocate
+    
+    CDataProcessor *iReader; // the reader
+    TAny *iReaderUserPointer;
+    CDataProcessor *iWriter; // the writer
+    TAny *iWriterUserPointer;
+
+    TActiveQueueBlock *iBlocks; // the list of all allocated blocks
+    TUint iNumBlocks; // total number of blocks
+    TActiveQueueBlock *iFreeList; // the free block list
+    TUint iNumFreeBlocks; // number of free blocks
+    TActiveQueueBlock *iDataQueueHead; // the data queue head (where blocks are
+                                       // read from)
+    TActiveQueueBlock *iDataQueueTail; // the data queue tail (where blocks are
+                                       // written to
+    TUint iNumDataBlocks; // number of data blocks
+
+    TBool iStreamEnd; // has the stream ended?
+};
+
+
+#endif      //  __ACTIVEQUEUE_H__
+            
+// End of File