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diff --git a/public/tier1/lzmaDecoder.h b/public/tier1/lzmaDecoder.h
new file mode 100644
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+++ b/public/tier1/lzmaDecoder.h
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+//========= Copyright Valve Corporation, All rights reserved. ============//
+//
+//  LZMA Codec interface for engine.
+//
+//  LZMA SDK 9.38 beta
+//  2015-01-03 : Igor Pavlov : Public domain
+//  http://www.7-zip.org/
+//
+//========================================================================//
+
+#ifndef _LZMADECODER_H
+#define _LZMADECODER_H
+#pragma once
+
+// Thanks for the useful define namespacing, LZMA
+#include "../../utils/lzma/C/7zVersion.h"
+#define LZMA_SDK_VERSION_MAJOR MY_VER_MAJOR
+#define LZMA_SDK_VERSION_MINOR MY_VER_MINOR
+
+#if !defined( _X360 )
+#define LZMA_ID				(('A'<<24)|('M'<<16)|('Z'<<8)|('L'))
+#else
+#define LZMA_ID				(('L'<<24)|('Z'<<16)|('M'<<8)|('A'))
+#endif
+
+// bind the buffer for correct identification
+#pragma pack(1)
+struct lzma_header_t
+{
+	unsigned int	id;
+	unsigned int	actualSize;		// always little endian
+	unsigned int	lzmaSize;		// always little endian
+	unsigned char	properties[5];
+};
+#pragma pack()
+
+class CLZMAStream;
+
+class CLZMA
+{
+public:
+	static unsigned int	Uncompress( unsigned char *pInput, unsigned char *pOutput );
+	static bool			IsCompressed( unsigned char *pInput );
+	static unsigned int	GetActualSize( unsigned char *pInput );
+};
+
+// For files besides the implementation, we forward declare a dummy struct. We can't unconditionally forward declare
+// this because LzmaEnc.h typedefs this directly to an unnamed struct :-/
+#ifndef CLzmaDec_t
+struct _CLzmaDec_t;
+#define CLzmaDec_t struct _CLzmaDec_t
+#endif
+
+class CLZMAStream
+{
+public:
+	CLZMAStream();
+	~CLZMAStream();
+
+	// Initialize a stream to read data from a LZMA style zip file, passing the original size from the zip headers.
+	// Streams with a source-engine style header (lzma_header_t) do not need an init call.
+	void InitZIPHeader( unsigned int nCompressedSize, unsigned int nOriginalSize );
+
+	// Attempt to read up to nMaxInputBytes from the compressed stream, writing up to nMaxOutputBytes to pOutput.
+	// Makes progress until blocked on input or output.
+	// Returns false if read stops due to an error or if called at EOF (GetExpectedBytesRemaining == 0)
+	bool Read( unsigned char *pInput, unsigned int nMaxInputBytes,
+	           unsigned char *pOutput, unsigned int nMaxOutputBytes,
+	           /* out */ unsigned int &nCompressedBytesRead, /* out */ unsigned int &nOutputBytesWritten );
+
+	// Get the expected uncompressed bytes yet to be read from this stream. Returns false if not yet known, such as
+	// before being fed the header.
+	bool GetExpectedBytesRemaining( /* out */ unsigned int &nBytesRemaining );
+
+private:
+	enum eHeaderParse
+	{
+		eHeaderParse_OK,
+		eHeaderParse_Fail,
+		eHeaderParse_NeedMoreBytes
+	};
+
+	eHeaderParse TryParseHeader( unsigned char *pInput, unsigned int nBytesAvailable, /* out */ unsigned int &nBytesConsumed );
+
+	void FreeDecoderState();
+	bool CreateDecoderState( const unsigned char *pProperties );
+
+	// Init from a zip-embedded LZMA stream. Requires the original size be passed from zip headers.
+	CLzmaDec_t *m_pDecoderState;
+
+	unsigned int m_nActualSize;
+	unsigned int m_nActualBytesRead;
+	unsigned int m_nCompressedSize;
+	unsigned int m_nCompressedBytesRead;
+
+	// If we have read past the header
+	bool m_bParsedHeader   : 1;
+	// If InitZIPHeader() was called. We're expecting a zip-style header and have size information.
+	bool m_bZIPStyleHeader : 1;
+};
+
+#endif