Imported existing code

indra/llmessage/lliobuffer.h

@@ -0,0 +1,141 @@
+/** 
+ * @file lliobuffer.h
+ * @author Phoenix
+ * @date 2005-05-04
+ * @brief Declaration of buffers for use in IO Pipes.
+ *
+ * $LicenseInfo:firstyear=2005&license=viewergpl$
+ * 
+ * Copyright (c) 2005-2009, Linden Research, Inc.
+ * 
+ * Second Life Viewer Source Code
+ * The source code in this file ("Source Code") is provided by Linden Lab
+ * to you under the terms of the GNU General Public License, version 2.0
+ * ("GPL"), unless you have obtained a separate licensing agreement
+ * ("Other License"), formally executed by you and Linden Lab.  Terms of
+ * the GPL can be found in doc/GPL-license.txt in this distribution, or
+ * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
+ * 
+ * There are special exceptions to the terms and conditions of the GPL as
+ * it is applied to this Source Code. View the full text of the exception
+ * in the file doc/FLOSS-exception.txt in this software distribution, or
+ * online at
+ * http://secondlifegrid.net/programs/open_source/licensing/flossexception
+ * 
+ * By copying, modifying or distributing this software, you acknowledge
+ * that you have read and understood your obligations described above,
+ * and agree to abide by those obligations.
+ * 
+ * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
+ * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
+ * COMPLETENESS OR PERFORMANCE.
+ * $/LicenseInfo$
+ */
+
+#ifndef LL_LLIOBUFFER_H
+#define LL_LLIOBUFFER_H
+
+#include "lliopipe.h"
+
+/** 
+ * @class LLIOBuffer
+ * @brief This class is an io class that represents an automtically
+ * resizing io buffer.
+ * @see LLIOPipe
+ *
+ * This class is currently impelemented quick and dirty, but should be
+ * correct. This class should be extended to have a more flexible
+ * (and capped) memory allocation and usage scheme. Eventually, I
+ * would like to have the ability to share this buffer between
+ * different objects.
+ */
+class LLIOBuffer : public LLIOPipe
+{
+public:
+	LLIOBuffer();
+	virtual ~LLIOBuffer();
+
+	/** 
+	 * @brief Return a raw pointer to the current data set.
+	 *
+	 * The pointer returned can be used for reading or even adjustment
+	 * if you are a bit crazy up to size() bytes into memory.
+	 * @return A potentially NULL pointer to the raw buffer data
+	 */
+	U8* data() const;
+
+	/** 
+	 * @brief Return the size of the buffer
+	 */
+	S64 size() const;
+
+	/** 
+	 * @brief Return a raw pointer to the current read position in the data.
+	 *
+	 * The pointer returned can be used for reading or even adjustment
+	 * if you are a bit crazy up to bytesLeft() bytes into memory.
+	 * @return A potentially NULL pointer to the buffer data starting
+	 * at the read point
+	 */
+	U8* current() const;
+
+	/** 
+	 * @brief Return the number of unprocessed bytes in buffer.
+	 */
+	S64 bytesLeft() const;
+
+	/** 
+	 * @brief Move the buffer offsets back to the beginning.
+	 *
+	 * This method effectively clears what has been stored here,
+	 * without mucking around with memory allocation.
+	 */
+	void clear();
+
+	/** 
+	 * @brief Enumeration passed into the seek function
+	 *
+	 * The READ head is used for where to start processing data for
+	 * the next link in the chain, while the WRITE head specifies
+	 * where new data processed from the previous link in the chain
+	 * will be written.
+	 */
+	enum EHead
+	{
+		READ,
+		WRITE
+	};
+
+	/** 
+	 * @brief Seek to a place in the buffer
+	 *
+	 * @param head The READ or WRITE head.
+	 * @param delta The offset from the current position to seek.
+	 * @return The status of the operation. status >= if head moved.
+	 */
+	EStatus seek(EHead head, S64 delta);
+
+public:
+	/* @name LLIOPipe virtual implementations
+	 */
+	//@{
+protected:
+	/** 
+	 * @brief Process the data in buffer
+	 */
+	virtual EStatus process_impl(
+		const LLChannelDescriptors& channels,
+		buffer_ptr_t& buffer,
+		bool& eos,
+		LLSD& context,
+		LLPumpIO* pump);
+	//@}
+
+protected:
+	U8* mBuffer;
+	S64 mBufferSize;
+	U8* mReadHead;
+	U8* mWriteHead;
+};
+
+#endif // LL_LLIOBUFFER_H